ATA5279

ATA5279_10 ATMEL | Alldatasheet

Document overview

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Technical content

Features

• Six Connections for Series-resonant LF Coil Antennas  Drives up to 1A Peak Current on the First Three Channels and up to 700mA Peak on the Second Three, Largely Independent of the Battery Voltage  On-off-keyed Data Modulation with up to 5.7kbit/s (Manchester Coded)  Sinusoidal-like Output Signal for Superior EMC Behavior  20 Selectable Steps for Current Regulation for Field Strength Measurement (RSSI)  Output Driver Stages are Protected Against Electrical and Thermal Overload  Very Low Power-down Current Consumption  SPI Interface for Easy Microcontroller Bus Connection  LF Data Buffer to Minimize Microcontroller’s CPU Load During a Data Transmission  Small Outline Package: QFN48, 7mm × 7mm 1. Description The Atmel® ATA5279 is an LF coil driver IC intended for passive entry/-go (PEG) sys- tems. It can drive up to six low-frequency-antennas (i.e., coils) to provide a wake-up and initialization channel to the key fob. Figure 1-1. Block Diagram Oscillator Internal Supply POR, BG, UV/OV Control Logic Communication Protocol Handling DC DC Boost Controller LF Data BufferSPI PGND VD S A4P A6P A5P A1P A3P A2P A1N A3N A2N VLVCC IRQ BCNT MACT NRES VIF MISO MOSI S_CLK S_CS OSCO OSCI VS RGND V SHSCINTAGND Reference Sine Wave Generator Driver Stage Control Zero Cross Detector Return Line Driver HP 1-3 Integrator Sample and Hold LP 1-3 A4N A6N VSHF A5N Antenna Driver for Multiple Antennas Atmel ATA5279 9125I–RKE–09/10

9125I–RKE–09/10 Atmel ATA5279 2. Pin Configuration Figure 2-1. Pinning QFN48 A3N2 A2N1 A2N2 VDS1 A1N1 A4N2 A4N1 A5N1 VSHF2 A5N2 A6N2 A3N1 Atmel ATA5279 VL3 PGND3 VL2 PGND2 VL1 PGND1 VDS3 IRQ NRES S_CLK S_CS MOSI VS RGND CINT VCC VSHS VIF OSCI BCNT VSHF1 A6N1 MACT OSCO VDS2 A4P A2P AGND2 A6P AGND3 MISO A3P A5P AGND1 A1P A1N2 13 14 15 16 191817 20 21 22 23 24 42434445464748 41 40 39 38 37 Table 2-1. Pin Description Pin Symbol Function Pin Group Heat Slug PGND Backside ground connection -

1 VS Battery supply pin -

2 RGND Reference ground -

3 CINT Integration capacitor connection -

4 VCC Analog 5V stabilization capacitor connection -

5 VSHS Shunt resistor voltage sense input -

6 VIF Digital supply voltage input -

7 OSCI Oscillator input pin CSP

8 OSCO Oscillator output pin CSP

9 MACT Modulator active indicator output pin DO

10 BCNT LF-bit counter output pin DO

11 VSHF1 Shunt resistor driving pin 1 RLO

12 A6N1 Coil 6 negative connection line pin 1 LRL

13 A6N2 Coil 6 negative connection line pin 2 LRL

14 A3N1 Coil 3 negative connection line pin 1 HRL

15 A3N2 Coil 3 negative connection line pin 2 HRL

16 A5N1 Coil 5 negative connection line pin 1 LRL

17 A5N2 Coil 5 negative connection line pin 2 LRL

18 VSHF2 Shunt resistor driving pin 2 RLO

19 A2N1 Coil 2 negative connection line pin 1 HRL

20 A2N2 Coil 2 negative connection line pin 2 HRL

9125I–RKE–09/10 Atmel ATA5279

21 VDS1 Driver supply pin 1 DS

22 A4N1 Coil 4 negative connection line pin 1 LRL

23 A4N2 Coil 4 negative connection line pin 2 LRL

24 A1N1 Coil 1 negative connection line pin 1 HRL

25 A1N2 Coil 1 negative connection line pin 2 HRL

26 A1P Coil 1 positive connection line pin HDL

27 VDS2 Driver supply pin 2 DS

28 AGND1 Driver ground pin 1 -

29 A4P Coil 4 positive connection line pin LDL

30 A2P Coil 2 positive connection line pin HDL

31 AGND2 Driver ground pin 2 -

32 A5P Coil 5 positive connection line pin LDL

33 A3P Coil 3 positive connection line pin HDL

34 A6P Coil 6 positive connection line pin LDL

35 AGND3 Driver ground pin 3 -

36 MISO Master-In-Slave-Out SPI output pin DO

37 MOSI Master-Out-Slave-In SPI input pin DI

38 S_CS SPI chip select pin DI

39 S_CLK SPI clock input pin DI

40 NRES Chip reset input pin DI

41 IRQ Interrupt request output pin DO

42 VDS3 Driver supply pin 3 DS

43 PGND1 Boost converter low-side switch output 1 -

44 VL1 Boost converter low-side switch input 1 BLS

45 PGND2 Boost converter low-side switch output 2 -

46 VL2 Boost converter low-side switch input 2 BLS

47 PGND3 Boost converter low-side switch output 3 -

48 VL3 Boost converter low-side switch input 3 BLS

Table 2-1. Pin Description (Continued) Pin Symbol Function Pin Group

9125I–RKE–09/10 Atmel ATA5279 3. Functional Description

3.1 Operation Modes

Atmel® ATA5279 features five operation modes. They are:  Power-down mode (reset state)  Idle mode  Operating mode  Shutdown mode  Diagnosis mode Power-down mode is active after supply voltages have been applied to the chip. No internal circuitry is active in this mode and as such power consumption is minimal. If no operation of the chip is demanded, it should be kept in this state. To enter power-down mode, a negative pulse on the NRES pin for at least t NRES,min is required. After wake-up from power-down mode by a logic high signal at the S_CS pin, the chip is in idle mode. That is, the osc illator is running and th e control logic waits for commands coming from the serial interface. Furthermore, the selected output driver stage is ready for operation (the voltage on the corresponding output pin AxP is approximately half the battery supply voltage). The current consumption of the chip is now mainly defined by the cross current through the active driver stage (please refer also to Section 3.2 “Coil Driver Stage” on page 5). When processing coil driving commands, the chip is in operation mode. From the interface point of view, there is no difference from the idle mode; however, current consumption is now higher as the output driver stages are operating and, depending on the selected output cur- rent, the DC-DC converter is also operating. If a connection failure (short circuit on any of the coil connection lines) is detected, the ATA5279 enters the shutdown mode to protect itself from damage. In this mode, the interface operates in idle mode but with all power stages shutdown and no LF transmission command processing. This mode should be exited using the Reset Fault Status command (see below), however, it can also be exited by resetting the chip. In diagnosis mode, the output driver stages are also disabled. In their place, high-ohmic cur- rent sources are activated that can be programm ed via the serial interface in order to check the coil connection lines for failures. This mode can be exited by an appropriate SPI command or by resetting the chip.

9125I–RKE–09/10 Atmel ATA5279

3.2 Coil Driver Stage

The driver stage for each coil consists of two N-channel DMOS transistors. The low-side tran- sistor is in Darlington configuration to maintain a source-follower characteristic. Figure 3-1. Principle Driver Stage Setup In the graphic above, the names of internal pins have a grey shaded background, and the hatched area is not part of the driver stage itself but only used in diagnostic mode (please refer to the Diagnosis Block description for further information on this topic). The driver stages are supplied by the three VDS pins, which are tied together inside the chip. A quiescence current regulation ensures low cross current while in idle state. The output tran- sistors are monitored for current and temperature to protect them from damage caused by irregular load conditions or too high ambient temperatures. The driving stage is optimized for signal quality to ensure low harmonic distortions. Two groups of driver stages are integrated: the first group is intended for high-current coils, whereas the second group drives low-current coils. Note that there are certain coil impedance ranges for each driver group. If the connected load exceeds this range, proper current regula- tion and/or data modulation is not guaranteed. While in idle mode and especially during a transmiss ion, the driver stages of the five inactive (i.e., not selected) coils are switched to high-side outputs, i.e., the positive coil connection lines are tied to the VDS potential. The same applies to the return line inputs AxN. These mea- sures ensure minimum parasitic currents in th e disabled coils while the selected coil is operating. VSin_pre Internal nodes AxP Ax_State Diag Enable VDS IHSDiag Diag Enable IHS Nmirr ILS ILS ILSDiag Pmirr2 Pmirr1 Npwr GND

9125I–RKE–09/10 Atmel ATA5279

3.3 Sine Wave Generator

The sinusoidal coil-driving signal is inter nally generated. Its amplitude is dependant on the measured coil current, and the frequency is deriv ed from the oscillator stage. In conjunction with the output driver stages, the generated signal is optimized for low harmonic distortions. The peak-to-peak amplitude of the sinusoidal signal is directly def ined by the voltage on the external integration capacitor connected to the CINT pin. This voltage, with an offset sub- tracted, is internally used to generate a low-voltage sine wave signal, which is in turn amplified and level-shifted up to the desired output level. The output signal itself has a DC offset close to the half of the supply voltage, and the maxi- mum possible amplitude has about 3V distance to each of the supplies. Figure 3-2 illustrates this. Figure 3-2. Maximum Possible Coil Driving Signal for a Given Supply Voltage VDS Table 3-1. States of Driver Outputs within Operation Modes Mode Operation/ Transmission Mode Entering by SPI cmd Shutdown Mode Fault has detected Idle Mode Entering by S_CS Power Down/Reset Entering by NRES or POC Diagnosis Mode Entering by SPIOutput AxP Selected driver active others are on High Level (VDS) All high impedance Selected driver stays on Vbatt /2 ready for Operation Others are on High Level High impedance High impedance (Diagnosis current sources programmable) AxN Selected driver stays on l o w l eve l Others are on High Level All high impedance Selected driver stays on l o w l eve l Others are on High Level High impedance High impedance (Diagnosis current sources programmable) VOUT,min VOUT,max 0.5 × VDS GND VDS

9125I–RKE–09/10 Atmel ATA5279 In application, the output coil current is the fixed valued (selectable via SPI). Hence, the required output voltage is calculated as follows: Here, Z Coil is the complex impedance of the coil, R DSon,HRS/LRS is the on-resistance of the appropriate return line current selector (see also Section 8. “Functional Parameters” on page 32) and RShunt is the resistance of the externally applied current sense shunt resistor (typ. 1 Ω, see also Section 4. “Application” on page 27).

3.4 Boost Converter

The coil driver stage can be supplied by a DC-DC converter in boost configuration. Together with an externally applied choke, freewheeling diode and capacitor, the battery voltage can be brought up to the required value, which is dependant on the coil's impedance and the selected current. The converter is only enabled during an active transmission. The peak current through the low-side switch I VL and the output voltage V VDS are measured to shut down the converter operation in case one of the values exceeds its upper limit. Note: There is no dedicated temperature monitoring for the boost converter low-side switch. For fur- ther details, please refer to Section 4.1 “Application Hints” on page 28. The switching frequency is, like the coil driving signal, derived from the oscillator stage and 125kHz in value when using an 8MHz input clock. The least possible time the boost converter takes to generate the maximum possible output voltage from the minimum possible input volt- age is dependant on several parameters. The values of the external components (choke inductance, charge capacitance and CINT integration capacitance) greatly effects this time.

3.5 Coil Current Sensing (Zero Cross , Sample and Hold, Integrator)

The coil current flows through an external shunt resistor, causing a current-dependant voltage, which is fed into the IC via the VSHS pin. By monitoring the zero crossing events of this signal, the phase of the coil current is known and hence the positive peak value can be sampled. The peak coil current is then subtracted from an internal reference voltage that is dependant on the selected coil current, which results in the regulation difference. An amplifier stage converts this difference into a current, which is then fed into an externally applied integration capacitor connected to the CINT pin. The resulting voltage on this capaci- tor directly influences the amplitude of the sine wave signal. It also determines the supply voltage generated by the boost converter, if t he necessary coil supply voltage exceeds the actual supply voltage level. Note that during an active transmission, this voltage is internally limited to V CINT,max. Note that in idle mode, the voltage on the integration capacitor is kept at a value that corre- sponds to the battery supply voltage. This ensures that the boost converter, if needed, always performs a soft start from the battery voltage level on. The desired current can be selected via the SPI. A total of 20 predefined steps are available, divided into the following sections:  The lower four steps (50mA to 200mA) are intended for the low-current coils only  The next ten steps (250mA to 700mA) are intended for both types of coils  The upper six steps (750mA to 1A) are intended only for the high-current coils VOut,p ICoil,p ZCoil RDSon,HRS/LRS RShunt++()×=

9125I–RKE–09/10 Atmel ATA5279 The IC allows the use of a current step not intended for a particular driver group; however, in this case, full functionality, especially a stabilized coil current, cannot be guaranteed. See also the Control Logic block description for an overview over the commands.

3.6 Diagnosis

The diagnosis stage monitors both the positive (AxP) and negative (AxN) connection lines of the six coils. If one of these li nes is shorted to battery supply or to ground, the following mea- sures are taken for protection and diagnostic reasons:  All coil driver stages are shut down, i.e., put into high impedance state  The shunt resistor is disconnected from the coil return lines  The reason for the fault shutdown is stored in the fault register  An interrupt request is triggered (see also control logic block) In addition to short circuits, a disconnected coil (i.e., open load) or an excessive junction tem- perature can also lead to such a fault shutdown. Note that this type of diagnosis is carried out continuously during normal operation of the IC to protect both the IC and the peripherals from damage. It must be avoided to design the system's load profile in such a way that the protection fea- tures of the chip are triggered under normal operating conditions. Consecutive triggering of the overtemperature shutdown may lead to a reduced lifetime. In the event of such a fault shutdown, the IC can be brought back to operation by resetting its fault register with the appropriate SPI command (please refer also to the Section 3.9.2 “Gen- eral Command Description” on page 21 later in this document). As a result, transmission on non- faulty coils is still possible even if there is a failure of one coil. Beyond this, the diagnosis of all connected coil lines is a very useful tool for maintenance rea- sons. The Atmel ® ATA5279 has implemented test structures that can be activated and read out via SPI commands, so that the microcontroller can be programmed to detect most of the possible faults, for example, shorts between different coil connection lines and multiple shorts in one pair of lines.

9125I–RKE–09/10 Atmel ATA5279

3.6.1 Functional Description of Diagnosis Mode

In this diagnosis mode, the coil-line driv ers themselves are switched to high impedance. Hence, only the test structure at every coil connection (both at the positive outputs AxP of the drivers and at the negative outputs AxN) is present and can directly test the status of the line. Figure 3-3 illustrates this: Figure 3-3. Base Structure of the Diagnosis Module of One Output Channel The structure above can be found in each of the six channels of the Atmel ® ATA5279. As soon as the diagnosis mode is engaged, all channels are operated in this way. On the channel that is actually selected, the setting of the switches can be changed with the Set Coil Current com- mand and the status of the two connection lines can be checked with the Get Driver Setup command. The two switches in the P line driver are c ontrolled with one bit. That means, either the high-side (S_HxP) or the low-side (S_LxP) switch is closed. The same is true for the N line driver (S_HxN, S_LxN). The controlling bits c 0 and c1 are taken from the coil current selection register (see Section 3.9.2 “General Command Description” on page 21 in this document). Note that the setting of the switches is latched. That means, if the setting on the switches of the selected driver is changed, the setting on the five other channels remains unchanged. By a combination of test structures, many di fferent faults, even between the coils, can be detected. As described in the principle schematic of a driver stage above, a test structure consists of two switchable current sources (one to VDS and one to GND) and a comparator that converts the voltage level on the line into a digital signal. The switches for the current sources can only be controlled in diagnosis mode, with the corresponding coil being selected (see also Driver Command description). Note that one switch is always closed, either the high-side or the low-side switch of one test structure. These structures are independent, i.e., they can be set up for each line individually and at the same time. The status of the connection lines of the selected coil can be read out with a SPI command. VDS AGND Driver x select Latch c0 bit c0, 1 bits c1 bit VDS AGND S_HxN c1 = '1' S_LxN c1 = '0' AxNAxP S_HxP c0 = '1' S_LxP c0 = '0'

9125I–RKE–09/10 Atmel ATA5279 In the following example, there is a short circuit between the positive coil connections of coil 1 and 2. Figure 3-4. Example 1, Using the Diagnosis Mode Taking the circuit situation shown above, t he test run starts with both S_L1P and S_L2P switches closed (default state when entering the diagnosis mode for the first time). The read-back of the line state result in both times 0, which is not unexpected. However, the result does not change when either altering the channel 1 or the channel 2 switch setting. That can be caused both by the failure shown above and by short-circuits of both lines to ground. The final diagnosis can be identified by changing bo th channels to the high-side switches (S_H1P and S_H2P). In this case, the two status lines both return 1s – which eliminates the possibility of two short-circuits to ground. Table 3-2 summarizes this test sequence. GND VDS S_L1P S_H1P RShort Status_1 S_L2P S_H2P Status_2 A1P A2P

9125I–RKE–09/10 Atmel ATA5279 The suggested waiting time is calculated as follows: The sequence above is an example of how the failure illustrated in Figure 3-4 on page 10 could be detected. Depending on the grade of detection detail that is required, a matrix for the test sequence should be set up to find the most effective way of programming and testing. For more details on the commands, please refer also to Section 3.9.2 “General Command Description” on page 21. Table 3-2. Sequence for Example 1, Using the Diagnosis Mode Step Command I/O Codi ng Actions/Remarks

1 Select Driver I 00101001 – 29h Selects driver 1 with Diagnosis Mode enabled

2G e t D r i v e r S e t u p I O 01101000 – 68h 00000001 – 01h Reads back active driver info: Channel 1 active, both lines return a 0

3 Select Driver I 00101010 – 2Ah Selects driver 2 with Diagnosis Mode enabled

4G e t D r i v e r S e t u p I O 01101000 – 68h 00000010 – 02h Reads back active driver info: Channel 2 active, both lines return a 0

5 Set Coil Current I 10100001 – A1h Closes test switches S_H2P and S_L2N

Note: S_L2P and S_H2N are then open 6 - no command - Wait for the test structures to stabilize in the new setting, see below 7G e t D r i v e r S e t u p I O 01101000 – 68h 00000010 – 02h Reads back active driver info: Channel 2 active, but both lines return a 0

8 Select Driver I 00101001 – 29h Selects driver 1 with Diagnosis Mode enabled

9 Set Coil Current I 10100001 – A1h Closes test switches S_H1P and S_L1N (Note: S_L1P and

S_H1N are then open) 10 - no command - Wait for the test structures to stabilize in the new setting, see below

11 Get Driver Setup I

O 01101000 – 68h 00001001 – 09h Reads back active driver info: Channel 1 active and A1P returns a 1

12 Select Driver I 00101010 – 2Ah Selects driver 2 with Diagnosis Mode enabled

13 Set Coil Current I 10100000 – A0h Closes test switches S_L2P and S_L2N

Note: S_H2P and S_H2N are then open 14 - no command - Wait for the test structures to stabilize in the new setting, see below

15 Get Driver Setup I

O 01101000 – 68h 00000010 – 02h Reads back active driver info: Channel 2 active and A2P returns a 1 Note: Steps 6, 10 and 14 are wait states, as the test structures need some time to stabilize in their new setting. This depends mainly on the externally applied capacitors on the AxP and the AxN pins. tdiag,wait 2V S× Ce Cant+()×

9125I–RKE–09/10 Atmel ATA5279 The second example circuit has two faults in the circuitry. Figure 3-5. Example 2, Using the Diagnosis Mode If channel four is activated in normal operation, a fault shutdown will occur. The reason for this shutdown (i.e., the entry in the fault register) could either be an overload on the A4P line (here a short circuit to VS) or a short-circuit on the A4N line to VS. In any case, the IC protects itself and the external components from damage; however, the fact that there is more than one fail- ure in the wiring cannot be discovered. In diagnosis mode, by testing the A4P line with S_H4P and S_L4P, the short circuit to VS could be found first. The same result would be found when testing the return line switch 4 accordingly, so the presence of more than one fault on coil 4 is determined. The precise fault cannot be found though. The diagnosis result would be the same both for the above shown cir- cuit and for the A4N line being directly shorted to VS (without the failure in the coil module, here R Shunt2) and for the combination of the two. A4NA4P VDS GND S_L4N S_H4N S_L4P S_H4P RShort1 RShort2 Status_4NStatus_4

9125I–RKE–09/10 Atmel ATA5279 Again, this is only an example of how the diagnosis system can be used. Generally, a more systematic approach is suggested in order to efficiently test all connection lines used. Note: To exit the diagnosis mode correctly, two SPI comm ands have to be sent: the first is the Select Driver command with the DM bit set to 0 and the second is a Reset Fault Status command. See also SPI Command Description.

3.7 SPI

The SPI is used to select the required coil and its current, to provide LF data to the IC, to select and start an LF transmission, and to read out status information. It is equipped with a chip select input to enable or disable communication. When disabled, the data output of the IC is in high impedance mode, so other devices may communicate on the same bus. The interface is configured as a slave device, always requiring a master (e.g., a microcon- troller) for operation. The maximum input clock frequency is 1/4 of the system clock present at the OSCI pin, resulting, for example, in a maximum signal speed of 2 Mbit/s when using a typ- ical 8MHz input clock. The SPI features four different operation modes, which only differ in the relationship between the clock signal (S_CLK) and the data I/Os. Both the SPI itself and the corresponding I/O lines are supplied by the application-provided logic supply voltage connected to the VIF pin. This ensures that the controller (master) and the IC (slave) operate with the same voltage levels. In total, four modes of operations are possible, each differing in clock polarity and phase. Figure 3-7 and Figure 3-8 illustrate this. Table 3-3. Sequence for Example 2, Using the Diagnosis Mode Step Command I/O Coding Actions / Remarks

1 Select Driver I 00101101 – 2Dh Selects driver 4 with Diagnosis Mode enabled

2G e t D r i v e r S e t u p I O 01101000 – 68h 00011101 – 15h Reads back active driver info: Channel 4 active, A4N returns a 1

3 Set Coil Current I 10100010 – A2h Closes test switches S_L4P and S_H4N

Note: S_H4P and S_L4N are open then 4 - no command - Wait for the test structures to stabilize in the new setting, see first example 5G e t D r i v e r S e t u p I O 01101000 – 68h 00011101 – 1Dh Reads back active driver info: Channel 4 active, both lines return a 1

6 Set Coil Current I 10100000 – A0h Closes test switches S_L4P and S_L4N

Note: S_H4P and S_H4N are open then 7 - no command - Wait for the test structures to stabilize in the new setting, see first example 8G e t D r i v e r S e t u p I O 01101000 – 68h 00010101 – 15h Reads back active driver info: Channel 4 active and A4N returns a 1

9125I–RKE–09/10 Atmel ATA5279 Figure 3-9. SPI Operation in POL = 0 and PHA = 1 Mode The configuration mode can be selected with the appropriate SPI command (see Section 3.9.2 “General Command Description” on page 21 ). Note that after power-up or a reset, the IC is always in its default configuration (POL = 1, PHA = 1), which must be used to alter the config- uration. At the end of the SPI configuration-changing command, the new configuration is activated with the falling edge of the S_CS signal.

3.7.1 Timing

Figure 3-10 illustrates the timing parameters of the SPI communication. Figure 3-10. Timing Parameters of the SPI Communication Note: The diagram above is using POL = 0 and PHA = 0 as a setup for the SPI. The values are also valid for the other three configurations. The limits for the timing values shown above can be found in Section 8. “Functional Parameters” on page 32. Sample Setup XX LSB MSB12345 X 6X Z ZX S_CS MOSI MISO S_CLK LSB 1 6 MSB Z S_CS tIo thi tsetup thold tCS,set tSPIoff tSPI tout,valid tCShold MOSI MISO S_CLK XX X XX tMISOoff tMISOon

9125I–RKE–09/10 Atmel ATA5279

3.8 Command Buffer

This buffer is a First-In-First-Out (FIFO)-type buffer, located between the SPI and the modula- tor stage. The microcontroller can write coil-driving related commands and data with full SPI speed to keep the CPU and bus load low.

3.8.1 Structure

The buffer can store up to 128bits, organized in 16 words, each eight bit in size. Hence, each data word from the SPI that contains a control command for the driver stages (i.e., select a certain driver, select a certain current, transmit LF-data bits and transmit a constant wave) is stored in a buffer word. Figure 3-11 outlines this. Table 3-4. States of Control I/Os Name Pin # Direction Operation/ Transmission Mode Entering by SPI cmd Shutdown Mode Fault has detected Idle Mode Entering by S_CS Power Down/Reset Entering by NRES or POC S P I S_CS 38 Input Weak-pull-down Weak-pull-down Weak-pull-down Weak-pull-down S_CLK 39 Input High impedance High impedance High impedance High impedance MOSI 37 Input High impedance High impedance High impedance High impedance MISO 36 Push-pull output Tristate (S_CS = low) Low/High (S_CS = high) Tristate (S_CS = low) Low/High (S_CS = high) Tristate (S_CS = low) Low/high (S_CS = high) Tristate (S_CS = low) Low/high (S_CS = high) C o n t r VIF 6 Input Supply current Supply current Supply current Supply current NRES 40 Input Weak-pull-up Weak-pul l-up Weak-pull-up Weak-pull-up IRQ 41 Push-pull output Low/high(1) Low/high(1) Low/high(1) High BCNT 10 Push-pull output Low/high(1) Low Low Low MACT 9 Push-pull output High Low Low Low Note: 1. State dependant on modulat ion, chip state or SPI data

9125I–RKE–09/10 Atmel ATA5279 Figure 3-11. Structure of 128-bit FIFO Command Buffer The read pointer indicates the next word to be processed by the Modulator Stage, whereas the write pointer indicates the next free location for data from the SPI. These pointers are con- trolled by the internal logic to enable the first-in-first-out functionality.

3.8.2 Usage

After wake-up from power-down, the buffer is empty and ready to receive commands and LF data. Any LF command and data is fed into the buffer via the SPI. The buffer can be filled even during an active data modulation, i.e., when some LF data and/or commands remain in the buffer while waiting to be processed. This increases the independency of the coil driver from the microcontroller. An interrupt request (IRQ) is triggered when the fill state of the buffer drops below 25% or if too many words are sent and a FIFO overflow occurs. Seamless data processing is an important feature of the command buffer. LF data intended for the same coil and the same current step can be distributed to several commands without the risk of having unwanted gaps in the LF telegram. This allows protocols to have any length and is usable both with the Send LF-data and the Send Carrier command. Refer also to the Sec- tion 3.9.1 “Modulator Stage” on page 18 for further details. 128 bit FIFO buffer From SPI Modulator Stage Read Pointer General Command Processing Write Pointer Data Selector

9125I–RKE–09/10 Atmel ATA5279

3.9 Control Logic

The internal control logic handles all informat ion coming from the SPI and controls the power stages. Diagnostic information is also collected and evaluated here.

3.9.1 Modulator Stage

The modulator stage controls the coil drivers. It gets all necessary information from the com- mand buffer. That is:  Which coil to drive  Which current to maintain in this coil/which diagnosis switch to close (in diagnosis mode)  Which baud rate to use for LF data transmission  What kind of transmission (i.e., data or carrier)  LF data itself (respectively the on-time when a carrier is to be transmitted) When a modulator operation is started by an SPI command, the data in the buffer is processed in the order it arrives via SPI, command by command. The time for this data processing depends on the command itself and, if LF transmissions are involved, the amount and length of the data bits. Table 3-5 lists the timings for the driver-related commands. Note: Table 3-5 lists the duration of command execution for the different commands and not the decoding or processing time. This is done simultaneous, so that two commands can be exe- cuted seamlessly. Table 3-5. Execution Durations of Driver-related Commands Command Dur. [LF per.] Comment Select Driver 64 During the first 32 periods, the actual driver is stopped in order to decay any oscillation in the coil. Then the switching itself is performed and another 32 periods waiting time is started in order to wait for the new driver to reach its operation point Select Coil Curr. < 1 The switching time of internal references takes less than 1LF period. Note that there will always be an interruption in a telegram if the coil current is changed between two transmission commands Send LF Data N × 2 × {32 / 22} The duration of this command depends on the selected data 22 periods/LF bit) and the amount of nibbles N (2LF data bits) to be transmitted Send LF Carrier T × (32 / 22) The duration of this command depends on the selected data rate (see also above) and the carrier duration T

9125I–RKE–09/10 Atmel ATA5279 LF data is transmitted on-off-keyed (OOK). “1” enables the field, whereas “0” disables it. Note that the field generation strongly depends on the bandwidth (the Q factor) of the coil. If it is too narrow, the receiver might not be able to decode the data correctly. Figure 3-12 shows the sig- nal path from the modulator stage to the receiver. Figure 3-12. Example for OOK-data Modulation with Atmel ATA5279 Coils with high Q values need more periods to reach the desired field strength and hence appropriate detection level thresholds in the receiver. So the Q factor must be adapted in order to ensure proper data communication. For example, the thresholds here are chosen at 70% of the required output current for a 0 to 1 and at 30% for a 1 to 0 detection. The IC supports two data rates: standard, which is 3.9kbit/s (or 32LF periods), and high speed, rated with 5.7kbit/s (or 22LF periods). Note that this refers to the encoded (net) data rate. The minimum length of an active field (e.g., the time for the first 1 in Figure 3-12), is 16LF periods in standard and 11LF periods in high speed mode (i.e., gross data rate). Another aspect of the LF data transmission is that current regulation can only be done roughly, as the measurement must be interrupted over and over again. At a 0 to 1 transition, the cur- rent measurem ent will not start until the 5th period, and there will not be any measurement during a 0-transmission. The regulation precision that is achieved duri ng carrier transmission is not valid here. As described in Section 3.8 “Command Buffer” on page 16, data is processed seamlessly to avoid gaps in longer LF telegrams. The following example illustrates this feature. Assume that following data words have been written into the command buffer via the SPI: 1. Send 2LF bits (SPI data 00h 05h) 2. Send carrier with a length of 24 data bits (SPI data 98h) 11 110 0off Receiver Threshold sDetection 11 110 Current Envelope off Transmitter Coil Current Receiver Data Modulator Data

9125I–RKE–09/10 Atmel ATA5279

3.9.2 General Command Description

The following commands are directly processed by the control logic, i.e., they are not fed into the data buffer: Refer to Section 3.7 “SPI” on page 13 for bit direction definitions.  Get Status Info: This command delivers the general IC status information back to the microcontroller (via the SPI bus). One part of the return word is the interrupt request source. If such a request is active (i.e., the IRQ line is high), the source for it is coded here.  Possible sources include the diagnosis block to indicate a driver stage fault (bit F), a general reset (either triggered externally by the NRES pin or internally by the power-on reset structure, bit R), an overtemperature of the chip (bit T), or the FIFO buffer indicating that the fill state has dropped to 25% or below (i.e., only four words are left, bit BU), or the fill state exceeds the upper limit of 16 bytes (bit BO). The IRQ signal is reset with this command. Additionally, the operability flag of the IC (bit Op) is returned in the word. Note that only if no fault is stored in the fault register and all operation voltages are present and valid, the operability is given (indicated by a 1 in the Op bit). Otherwise, Atmel ® ATA5279 will not process any driver-related command. Finally, the LF speed mode bit returned here indicates the current speed state of the modulator stage (bit S, 0 for normal speed, 1 for high speed). bit R: Chip reset - either triggered extern ally by the NRES pin or internally by the power on reset structure bit F: Indicator for a driver stage fault bit BO: The FIFO buffer fill state e xceeds the upper limit of 16 bytes bit BU: The FIFO buffer fill state drops to 25% or below, i.e., only 4 words are left bit T: Chip overtemperature indicator bit S: LF modulator speed mode indicator bit Op LF driver stage operability indicator Table 3-6. Bit Definitions of the General SPI Commands Command Input Word (MOSI Data) Output Word (MISO Data) MSB654321 LSB MSB654321 LSB Get status info 0 X X X X X X X X X R X F X BO X BU X T X S X Op X X Get driver setup 0 X X X X X X X X X X X X X X DG X X Get fault info 0 X X X X X X X X X DG X X X T X F03 X F02 X F01 X F00 R e s e t f a u l t s t a t u s 01000000XX XXXXXX S e t S P I c o n f i g 010010 P O P H XXXXXXXX H a l t o p e r a t i o n 01010000XX XXXXXX

9125I–RKE–09/10 Atmel ATA5279  Get Driver Setup: This command returns the actual setup of the driver stage, i.e., the selected coil, encoded in the bits DG,D1..0, and the selected current, which can be found in the bits C4..0 (see also “Select Driver” and “Set Coil Current” command description below for details on bit coding). This command is also used in diagnosis mode to fetch the state of the coil connection lines.  Get Fault Info: This command returns the content of the driver stage fault register back to the microcontroller via the SPI bus. The register contains both the code for the detected fault and the number of the driver stage that was active when the fault occurred. Refer also to the Section 3.9.4 “Status Monitor” on page 25 for further details.  Reset Fault Status: This command clears the content of the driver stage fault register and sets the operability bit in the general state register if all supply voltages are present and valid. This command is necessary to resume normal operation following the occurrence and subsequent removal of a fault. Please note that prior to this command, the active channel should be switched to a line that is not faulty. Otherwise, the internal logic might get corrupted and must then be reset with a negative pulse on the NRES line. Note that this command is also required to bring the Atmel ATA5279 back into operation mode once the diagnosis mode was active and was then cleared by a Select Driver command.  Set SPI Config: This command changes the two configuration bits PO(L) and PH(A). These bits are responsible for the serial data processing of the SPI. Default: PO = 1, PH = 1  Halt Operation: As this command is processed immediately, it is not written to the FIFO buffer even if it is a driver-related command. The effect of this command is that the content of the FIFO buffer is cleared, hence no new LF data is available, and if any driver is active it will be stopped. Note that such stops are only carried out at the end of an LF period (i.e., when the sinusoidal output signal reaches half of the supply voltage).

3.9.3 Driver-related Command Description

Following commands are processed via the LF data buffer: Table 3-7. Bit Definitions of the Driver-Related SPI Commands Command Input Word Output Word MSB654321 LSB MSB654321 LSB Select driver 0 0 1 BR DM D G D1 D0 XXXXXXXX Select coil current 1 0 1 C 4 C3 C2 C1 C0 XXXXXXXX Send LF data L 7 L 6 L 5 L 4 X L 7 X L 6 X L 5 X L 4 X N 3 X N 2 X N 1 X N 0 Send LF carrier 1 0 0 T 4 T3 T2 T1 T0 XXXXXXXX

9125I–RKE–09/10 Atmel ATA5279  Select Driver: This command selects the coil that is to be driven or tested next. The BR-bit indicates the T h e D G,1..0 bits indicate the channel number to be activated. DG selects the driver group (0 group (01 for driver 1 / 4, 11 for driver 3 / 6). For connection line diagnosis, the diagnosis mode can be enabled by setting the DM-bit to 1. bit BR: LF modulator speed (0 for 3.9kbit/s, i.e., 32LF periods and 1 for 5.7kbit/s, i.e., 22 LF periods, referred to Manchester coding) bit DM: Diagnosis mode selector (0: Normal LF operation mode, 1: Coil connection diagnosis mode) LF transmission). The same works for the opposite way: once a Select Driver command is received with the DM-bit at 0, all connection lines are switched back to normal operation mode. 2. For a proper operation after a diagnosis run, a Reset Fault Status command also needs to be sent. bits DG,1..0: Active channel indicator bit DG: Driver group selector (0 for high-current driver 1..3, 1 for low-current driver 4..6) bits D1..0: Driver selector, i.e. 01 is driver 1 (D G =0 ) / 4 ( DG = 1), 11 is driver 3 Default: DG,1..0 = [001], DM = 0, BR = 0 --> Channel 1, diagnosis mode off and normal LF speed selected.  Select Coil Current This command defines the current to be established for the next LF transmissions. bits C4..0: Contain the step number in the range of 0 to 19 (00hex to 13hex) bits C1..C0: Are used in diagnosis mode, to control the test switches of the activated connection line whereas … bit C 0: The low/high-side switch of the AxP line bit C1: The low/high-side switch of the AxN line) Default: C4..0 = [00000] --> 50 mA coil current selected.  Send LF Data: This command must be used to start an LF data telegram on the selected coil. The bits N3..0 contain the amount of nibbles to be transferred into the LF data buffer of the Atmel ATA5279. This amount has to be coded as follows: N3..0 = (nNibbles – 1) Hence, a maximum of 16 nibbles or eight words and a minimum of one nibble can be written into the buffer using one command. Note also that this command uses one more word of space in the buffer, as the header word is also stored. So for example, if the LF telegram consists of four words, the required space in the LF data buffer is five words (four words of pure data and one word for the command header).

9125I–RKE–09/10 Atmel ATA5279 It is important that the amount of nibbles passed in the header word matches the number of words transferred afterwards to the IC, as no data consistency checking can be carried out here. If an odd number of nibbles is to be transferred, the data word on the SPI has to be completed with dummy data in the upper nibble, as the SPI always requires complete data words on the bus. The FIFO buffer is also only filled with complete words. For an example, if seven nibbles of LF data (i.e., 14LF data bits) are to be sent by the Atmel ® ATA5279 via the LF channel, the Send LF Data command consists of five words, the header word (here 06h) and four LF data words, whereas the last word contains only four bits (the four least significant) of the LF data. For an additional example, see Figure 3-15, which illustrates how LF transmission data is processed in ATA5279. Figure 3-15. LF Data Processing  Send LF Carrier: This command should be used when a carrier shall be transmitted on the LF channel via the selected coil. The current will be regulated by ATA5279 to the value selected with the last Select Coil Current command (resp. the default value of 50mA). See also Section 3.5 “Coil Current Sensing (Zero Cross, Sample and Hold, Integrator)” on page 7 for further details. The duration of this carrier can be defined by the T 4..0 bits. Note that the time unit here is one LF data bit, i.e., 32LF periods in normal- and 22LF periods in high-speed mode. That leads to a maximum definable carrier time per command of 31× 0.256ms = 7.936ms when using an 8MHz system clock. However, when the T 4..0-value is set to 0, an endless carrier transmission with the actually selected current on the actually active coil is started. This can be used for long-term measurements or for energy-coupling purposes. Be aware that long-term transmissions can produce a huge amount of heat in the driver, dependant on the selected coil current and the properties of the coil itself. It is therefore strongly recommended to use this feature only with a maximum current settings of 100mA; otherwise, the chip temperature might reach excessive values. LF Telegram MACT Signal BCNT Signal SPi Data String (bin) SPi Data String (hex) 0000 0010 02h 35h 04h 01 1 010 101 00 0

9125I–RKE–09/10 Atmel ATA5279

3.9.4 Status Monitor

The status monitor holds all information from the diagnosis stage. In case of an existing fault, all power stages are disabled. As soon as a faul t is stored, an interrupt request (IRQ) to the microcontroller is generated. This signal is persistent until the status info is polled by the microcontroller. The entry in the fault regist er can only be cleared by the Reset Fault com- mand or a global reset. There are two different status registers:  A general IC status register (requestable by the Get Status Info command)  A coil-driver related fault register (requestable by the Get Fault Info command) The fault register is encoded as follows: The meaning of the bits is described below: G, D1..0: The driver group and number that was active when the fault occurred. Only a selected driver can be affected by external faults. Therefore, it is sufficient to store the type of failure and the corresponding driver number. Refer to Section 3.9.3 “Driver-related Command Description” on page 22 for further details on the coding of these bits.  T: A temperature shutdown has occurred. Note that there is not necessarily a link between the driver number and this fault, as all sensor signals of the chip are OR’ed together. However, in general, it can be assumed that the last active driver also caused the overtemperature condition. 03: This bit indicates a missing return line signal during modulation. That means that the current detection unit was not able to find a sinusoidal signal on the VSHS pin although the LF coil was driven. The reason for this can either be an open load condition or a short-circuit on the AxN pin towards ground. 02: This bit indicates an excessive positive voltage on the VSHS pin. In normal applications, this is only the case if there is a high current flowing through the shunt resistor. The typical reason for this is a short-circuit on the AxN line towards battery. Another possible reason could be a shorted LF coil. 01: This bit indicates an excessive current through the high-side transistor that drives the AxP line. The most typical reason for this is a short-circuit towards ground. F 00: This bit indicates an excessive current through the low-side transistor that drives the AxP line. The most typical reason for this is a short-circuit towards battery. Table 3-8. Fault Assignment between Driver Stages and the Fault Registers MSB LSB Fault Register D G D1 D0 TF 03 F02 F01 F00

9125I–RKE–09/10 Atmel ATA5279

3.10 Oscillator

This block provides the clock signals internally needed for control logic, the LF driver stage, and the boost converter. The osc illator requires an external clock source, which can either be an active signal from a microcontroller for exam ple, or a passive oscillation device like a crys- tal or a ceramic resonator. As the LF carrier fr equency is directly derived from this clock, the (resonance) frequency of the clock source must be chosen to match the desired LF frequency. Possible values range from 6.4MHz to 9.6MHz, where 8MHz is the typical value resulting in an LF frequency of 125kHz. Note that during start-up (i.e., as long as no stable oscillation can be detected), the driving cur- rent for the crystal is increased to shorten the start-up delay. Furthermore, the IC is only functional if the oscillator is working properly. That means, during start-up after a power-down phase, no communication and no operation of the IC is possible until the oscillator reaches its operation point. If an external clock source such as a microcontroller is to be used, the logic-level clock signal must be applied at the OSCI pin, and the OSCO pin must be left open. Note that the chip pro- tection features, need a clock signal present at the OSCI pin; without this, the chip is not fully protected. Therefore, if the chip is in any mode but in power-down (reset), a clock signal is needed. The oscillator block is, like the control logic and the SP I, supplied by the application-provided logic supply voltage connected to the pin VIF.

3.11 Internal Supply

The internal power supply stage provides all internally needed BIAS currents and reference voltages. An integrated one-time-programming (OTP) structure is used to adjust internal set- tings. This ensures parameter stability over the production process. The internal supply block performs monitoring functions to reset or shut down the IC in case of supply shortages or during power-up. A power-management minimizes current consumption during power-down mode of the IC. Another part of this block is the internal 5V voltage regulator. It is supplied by the VS pin, i.e., the battery supply connection. This voltage is used for all internal analog functions and driving processes. It is active as long as the IC is not in power-do wn mode. To increase stability and quality of this supply line, it is externally available (pin VCC) fo r connection to a ceramic capacitor for filtering and buffering. Note that no loads must be connected to this pin. As with the oscillator, this supply voltage must settle in its operation point prior to any opera- tion. The control logic checks the status of this voltage and inhibits operation until it reaches the required level. Furthermore, the driver su pply voltage present on th e VDSx pins is also monitored. If the level falls below V VDS,min, the operability flag of the chip is cleared (bit Op in the Status Register) and driver-related commands cannot be processed. Once the voltage level is valid again, the Op bit is set again, and operability is restored.

9125I–RKE–09/10 Atmel ATA5279 4. Application Find below a typical application schematic for the Atmel® ATA5279. Figure 4-1. Application Schematic for the Atmel ATA5279 Notes: 1. A negative current on pin MI SO that causes the voltage to drop below –0.6V with respect to ground might lead to a chip reset, comparable to a logic low on the NRES pin. 2. For applications with > 6 antennas please re fer to the application note “Atmel ATA5279 Antenna Driver Extension”. 3. R1 ≥ 1Ω for proper operation. 4. No pull-up resistance (by means of resi stor or microcontroller pull-up) allowed. VBATT Oscillator Internal Supply POR, BG, UV/OV Control Logic Communication Protocol Handling DC DC Boost Controller LF Data BufferSPI µC voltage supply line (VDD) µC connection PGND VD S A4P A6P A5P A1P A3P A2P A1N A3N A2N VLVCC IRQ BCNT MACT NRES VIF MISO(4) MOSI S_CLK S_CS OSCO OSCI VS RGND V SHSCINTAGND R1(3)C6 Reference Sine Wave Generator Driver Stage Control Ant1 Zero Cross Detector Return Line Driver HP 1-3 Integrator Sample and Hold LP 1-3 Ant2 Ant3 Ant4 Ant5 PCB c ar Ant6 A4N A6N VSHF A5N

9125I–RKE–09/10 Atmel ATA5279

4.1 Application Hints

An important application aspect is the the rmal budget. Under certain conditions, high power dissipations can occur during operation of the chip. The Atmel ® ATA5279's power dissipation mainly depends on the supply voltage and the selected antenna output current. Under worst case conditions (e.g., low supply voltage and maximum antenna power) the power dissipation increases exponentially and may rise to values exceeding 10W. It must be avoided under all circumstances to exceed the specified maximum average junction temperature. Therefore, the thermal aspects of the entire application, along with the electrical design, are essential. The thermal resistance between the IC and the ambient has to be designed according to the specific application requirements. It is manda tory to solder the exposed die pad to the PCB. As many vias as possible must be provided between the top and the bottom layer (soldering side to the PCB's backside). This copper plane is able to store and dissipate the heat. It must be electrically connected to ground, and an appropriate heat transfer away from the chip must be ensured. In addition, multi-layer-PCBs (more than two layers) are recommended. The ATA5279's power dissipation depends on the supply voltage, the selected antenna current, the antenna's impedance and further parameters such as the external components used for the DC-DC converter. Background information, design hints and an example are given in the application note “LF Antenna Driver ATA5279 – Thermal Considerations and PCB Design Hints”. It is strongly recommended to measure the power dissipation in the target application during the design phase to verify the system's thermal budget. One option is to calculate the differ- ence between input and output power. Table 4-1. Bill of Materials (BOM) for Typical Application Circuit Part Value Description R1 1 Ω Shunt resistor, ±1% tolerance C1 220µF/50V Supply line input filter and stabilizing cap C2 100nF cer. Supply line input filter cap C3 4.7µF/50V tant. Boost converter storage cap, low ESR C4 100nF cer. Boost converter filter cap (+ESD clamp) C5 100nF cer. Internal 5V supply line stabilizing cap C6 33nF cer. Integration cap for current regulation loop C7 100nF cer. Filter cap for µC supply line D1 50V/3A Rectifying diode D2 50V/3A/50ns High-speed freewheeling diode L1 150µH Supply line input filter choke, I sat > 3A L2 82µH Boost converter charging choke, I sat > 3A X1 8MHz Crystal or resonator

9125I–RKE–09/10 Atmel ATA5279 Note: To define the operation limits, the static ther mal resistance of the PCB must be known (see the measurement hints in the application note). The Atmel® ATAB5279 application board features a total thermal resistance of 42K/W. Under worst case conditions, e.g., low supply voltage and high antenna impedance, the maxi- mum antenna current might not be reached. A “static” operation of ATA5279 is not allowed for typical transmit currents of several hundreds of mAs. Typical applications are operated with a temporary LF field, resulting in an on/off oper- ation mode of the chip. A suitable on/off duty cycle n duty reduces the average power dissipation and keeps the thermal budget of the system. Therefore, following equation needs to be fulfilled: with Tamb the application’s maximum ambient temperature Pdiss,tot the total power dissipation of the chip nduty Operation duty cycle‚On-time during period, t1/tper Note: It must be avoided to design the system's load profile in such a way that the protection features of the chip are triggered under normal operating conditions. If the output voltage reaches the upper shutdown limit, the power dissipation of the DC-DC converter increases significantly. Consecutive triggering of the overtemperature shutdown may lead to a reduced lifetime. In addition to the average junction temperature T j,max, the maximum peak temperature during a transmission must not be exceeded. The equation to be met is as follows: with: Tpeak maximum peak temperature = 200°C Rthca Thermal resistance case-to-ambient (PCB) t1 Transmission on-time, 10 ms ≤ t 1 ≤ 1s e c tauPCB Thermal time constant of PCB (Rthca × Cthca) nduty Operation duty cycle Note: Application Note “LF Antenna Driver ATA5279 – Thermal Considerations and PCB Design Hints” available Tamb RthJA Pdiss,tot nduty Tj,max<××+ Tpeak Pdiss Rthjc Rthca 1e τ PCB ×+ n duty Pdiss Rthjc Rthca+() Tamb+××+×≥

9125I–RKE–09/10 Atmel ATA5279 5. Absolute Maximum Ratings Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameters Symbol Min. Max. Unit Voltage range on pin VS V VS –0.3 40 V Voltage range on pins VDSx, VLx V VDS,max –0.3 46 V Voltage range on pins AxP V AxP ,max –0.3 V VDS + 0.3 V Voltage range on pins VSHFx, VSHS V VSHF ,max –3 V VCC + 0.3 V Voltage range on pins AxNx V AxNx,max V VSHF – 0.3 46 V Voltage range on pins VCC, VIF V DIGSUP ,max –0.3 +5.5 V Voltage on pins RGND, PGNDx V GND,max –0.3 +0.3 V Voltage range on pins NRES, S_CS, S_CLK, MOSI, OSCI, MACT, BCNT, IRQ, MISO, OSCO VIO,max –0.3 V VIF + 0.3 V Voltage range on pin CINT V CINT,max –0.3 V VCC + 0.3 V ESD Voltage Ratings - HBM (MIL-STD-883F , M. 3015.7) VESD 2k V Count of peaks over lifetime: Number of events Peak junction temperature T j.max 500,000 at 200 °C Note: All voltages refer to the AGND pins. 6. Thermal Resistance Parameters Symbol Value Unit Thermal resistance junction to case R thJC 10 K/W Thermal resistance junction to ambient(1) RthJA 35 K/W Note: 1. Value that can be achieved when providi ng sufficient thermal vias and heat dissipation area 7. Operating Range Parameters Symbol Min. Max. Unit Junction temperature range(1)(2)(3) Tj –40 +145 °C Note: 1. For details see Section 5. “Absolute Maximum Ratings” on page 31 2. Triggering the overtemperature switch of f mode as described in item 6.5 in Section 8. “Functional Parameters” on page 32 is not recommended for standard application. Note: The permanent use of overtemperature switch off will reduce the life time of the IC. 3. For more details in terms of thermal considerations please refer to the application note “Thermal Considerations and PCB Design Hints”.

9125I–RKE–09/10 Atmel ATA5279 8. Functional Parameters All parameters valid for 7.0V ≤ VS ≤ 16.5V and –40°C ≤ Ta ≤ 105°C unless otherwise noted. No. Parameters Test Conditions Pi n Symbol Min. Typ. Max. Unit Type* 1P o w e r S u p p l y

1.1 VS-pin power-down

mode supply current VVS ≤ 14V 1 I VSpd 5.5 10 µA A

1.2 VS-pin idle mode

supply current VVS = 16.5V 1 I VS,idle 3.5 5 mA A 1.3 Internal VCC voltage - idle - load 7V ≤ VS ≤ 28V IVCC = 0 IVCC = 5mA 4V VCC,0 VVCC,1 4.8 5.05 5.3 V A

1.4 VS voltage clamp VS = 28V

VS = 40V 1 IVS,C28 IVS,C40 1.5 180 400 4.5 µA mA A

1.5 VCC power-on reset

threshold 4V PORVCC 4.1 4.8 V A

1.6 VDS operation

threshold VS = 16.5V DS V VDS,min 5.1 5.15 6 V A

1.7 Battery supply range for

normal operation Idle mode 1 V VS 7 16.5 V D

1.8 VDS power-down mode

supply current VVDS = 28V DS I VDS,0 0 0.12 1.4 µA A

1.9 VDS fault-shutdown

mode supply current VVDS = 16.5V DS I VDS,FS 0.85 2.45 mA A

1.10 Battery supply range for

Jump start operation Idle mode 1 V VS 7 26.5 V D

1.11 VCC power-up time 4 t VCC 200 µs D

1.12 Minimum VS voltage

level for VCC operation 1V VS,min 6V D 2B o o s t C o n v e r t e r

2.1 Overvoltage shut-down

level DS V VDSmax 40 42 44 V A

2.2 Switch overcurrent

shutdown level BLS I VLmax 2.9 3.2 4 A A

2.3 Switch on-state

resistance IVL = 500mA BLS R DSon,VL 0.5 Ω A 2.4 Max duty cycle (t on / T) BLS D Boost 0.875 - A

2.5 Switch leakage current V VL = 38V BLS I VL,leak 500 nA A

2.6 Switch fall time I VL = 200mA BLS t VL,f 50 200 ns A

2.7 Switch rise time I VL = 200mA BLS t VL,r 50 200 ns A

3 Oscillator

3.1 External clock source

frequency range CSP f OSC 6.4 8 9.6 MHz D 3.2 Driver output sink resistance during startup IOSCO = 100µA CSP R OSC,L1 0.9 2.2 k Ω A *) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter Notes: 1. In this column, pin group names are given. Please refer to Section 2. “Pin Configuration” on page 2 in this document for more details. 2. Operation of coils with higher impedance than the given value is possible but functional limitations might occur (inability to reach to configured coil current). Coils with lower impedance should not be used as they might be detected as faulty.

9125I–RKE–09/10 Atmel ATA5279 3.3 Driver output sink resistance during operation IOSCO = 100µA CSP R OSC,L1 1.8 4.4 k Ω A 3.4 Driver output source resistance during startup IOSCO = –100µA CSP R OSC,L1 0.9 2.2 k Ω A 3.5 Driver output source resistance during operation IOSCO = –100µA CSP R OSC,L1 1.8 4.4 k Ω A

3.6 Feedback resistance V OSCI, OSCO = 5V CSP R FB,OSC 220 360 k Ω A

3.7 Clock input low-to-high

detection threshold CSP V LH,OSC 0.45 × VIF 0.55 × VIF A

3.8 Power-down input

VOSCI = 5V VVIF = 5V 7R OSCI,0 36 k Ω A

4 High-current Driver Stage (A1P, A2P, A3P)

4.1 Sourcing current limit

(RMS) Idle mode, DC ramping HDL I HP ,HSCL –1.7 –0.88 A B

4.2 Sinking current limit

(RMS) Idle mode, DC ramping HDL I HP ,LSCL 1.1 2 A B

4.3 Signal difference carrier

to harmonics 2, 3, 4, 5 VAxP ,pp = 30V Icoil,p = 200mA fOSCI = 8MHZ HDL D Sig –34 dB A 4.4 Load imped. range (amount of complex impedance)(2) Icoil,pp = 2App HDL HRL ZCoil,HP 21 2 Ω D 4.5 Min. output voltage IAxP = 200mA Tj ≅ 30°C HDL V OHP ,min 2.5 4.3 V A 4.6 Max. output voltage IAxP = –200mA Tj ≅ 30°C HDL V OHP ,max VDS – 4.5 VDS – 2.5 VA 4.7 Idle mode cross current V VDS = 16.5V DS I AxPH,CC 35 50 68 mA A

4.8 Idle mode output

VVDS = 20V IAxP = 0 IAxP = ±200mA Tj ≅ 30°C HDL V AxPH,dile 91 1 V A

4.9 Inactive pull-up current VVDS = 20V

IAxP = –100µA HDL R AxPH,PU 11.5 27 k Ω B

4.10 Diagnosis mode pull-up

VVDS = 16.5V VAxP = 0V IPU,Diag –150 –100 µA A

4.11 Diagnosis mode

VVDS = 16.5V VAxP = 16.5V IPD,Diag 170 260 µA A

5 Low Current Driver Stage (A4P, A5P, A6P)

5.1 Sourcing current limit

(RMS) Idle mode, DC ramping LDL I LP ,HSCL –1.2 –0.55 A B 8. Functional Parameters (Continued) All parameters valid for 7.0V ≤ VS ≤ 16.5V and –40°C ≤ Ta ≤ 105°C unless otherwise noted. No. Parameters Test Conditions Pi n Symbol Min. Typ. Max. Unit Type* *) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter Notes: 1. In this column, pin group names are given. Please refer to Section 2. “Pin Configuration” on page 2 in this document for more details. 2. Operation of coils with higher impedance than the given value is possible but functional limitations might occur (inability to reach to configured coil current). Coils with lower impedance should not be used as they might be detected as faulty.

9125I–RKE–09/10 Atmel ATA5279

5.2 Sinking current limit

(RMS) Idle mode, DC ramping LDL I LP ,LSCL 0.9 1.7 A B

5.3 Signal difference carrier

to harmonics 2, 3, 4, 5 VAxP ,pp = 30V Icoil,p = 200mA fOSCI = 8MHZ LDL D Sig –34 dB A 5.4 Load imped. range (amount of complex impedance)(2) LDL LRL ZCoil,LP 10 25 Ω D 5.5 Min. output voltage IAxP = 200mA Tj ≅ 30°C LDL V OLP ,min 2.5 4.3 V A 5.6 Max. output voltage IAxP = –200mA Tj ≅ 30°C LDL V OLP ,max VDS – 4.5 VDS – 2.5 VA 5.7 Idle mode cross current V VDS = 16.5V DS I AxPL,CC 28 40 53 mA A

5.8 Idle mode output

VVDS = 20V IAxP = 0 IAxP = ±200mA Tj ≅ 30°C HDL V AxPL,dile 91 1 V A

5.9 Inactive pull-up current VVDS = 20V

IAxP = –100µA HDL R AxPL,PU 11.5 27 k Ω B

5.10 Diagnosis mode pull-up

VVDS = 16.5V VAxP = 0V HDL LDL IPU,Diag –150 –100 µA A

5.11 Diagnosis mode

VVDS = 16.5V VAxP = 16.5V HDL LDL IPD,Diag 170 260 µA A

6 Coil Return Line and Diagnosis Stage (A1N … A6N)

6.1 Return line switch

IHPS = 0.3A ILPS = 0.22A HRL LRL RDS,onHPS RDS,onLPS 1.05 1.2 Ω Ω A 6.2 Return line switch overcurrent shutdown threshold RShunt = 1Ω Ch. 1-3 selected Ch. 4-6 selected RLO I Shunt,max 1.25 0.875 1.75 1.225 A A A

6.3 Diagnosis mode pull-up

VVDS = 16.5V VAxP/N = 0V HRL LRL IPU,Diag –150 –100 µA A

6.4 Diagnosis mode

VVDS = 16.5V VAxP/N = 16.5V HRL LRL IPD,Diag 170 260 µA A

6.5 Overtemperature

shutdown threshold TOTsdwn 145 170 °C B

6.6 Open load detection

LRL tOLdet 115 215 µs A

7 Zero Crossing Detector

7.1 Pos. slope detection threshold 5V ZC –10 +10 mV A

7.2 Switching propagation

VVSHS – 20mV to VVSHS + 20mV 5t ZCdel 150 290 ns A 8. Functional Parameters (Continued) All parameters valid for 7.0V ≤ VS ≤ 16.5V and –40°C ≤ Ta ≤ 105°C unless otherwise noted. No. Parameters Test Conditions Pi n Symbol Min. Typ. Max. Unit Type* *) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter Notes: 1. In this column, pin group names are given. Please refer to Section 2. “Pin Configuration” on page 2 in this document for more details. 2. Operation of coils with higher impedance than the given value is possible but functional limitations might occur (inability to reach to configured coil current). Coils with lower impedance should not be used as they might be detected as faulty.

9125I–RKE–09/10 Atmel ATA5279

8 Sample and Hold Stage

8.1 Sampled differential

V VSHS = 200 mVpp VVSHS = 1 Vpp Vsmpl,1 Vsmpl,2 830 440 970 560 mV mV A

9 Integrator Stage

9.1 Input offset voltage 5 V ofs,Integ –2.5 +2.5 mV B

9.2 Positive output linearity

VVSHS = 1.1Vpp Current step 20 selected 3I INT,POS –20 –8 µA A

9.3 Negative output

VVSHS = 0.9Vpp Current step 20 selected 3I INT,NEG 82 0 µ A A

9.6 Upper output voltage

ICINT = 30µA VSHS = 100mVp Current step 20 selected CINT,max 3.15 3.45 V A

10 References

10.1 Current step 1 level - V REF ,S1 49.5 54.5 mV A

10.2 Current step 2 level - V REF ,S2 97 105 mV A

10.3 Current step 3 level - V REF ,S3 145 157 mV A

10.4 Current step 4 level - V REF ,S4 192 208 mV A

10.5 Current step 5 level - V REF ,S5 245 255 mV A

10.6 Current step 6 level - V REF ,S6 294 306 mV A

10.7 Current step 7 level - V REF ,S7 343 357 mV A

10.8 Current step 8 level - V REF ,S8 392 408 mV A

10.9 Current step 9 level - V REF ,S9 441 459 mV A

10.10 Current step 10 level - V REF ,S10 490 510 mV A

10.11 Current step 11 level - V REF ,S11 539 561 mV A

10.12 Current step 12 level - V REF ,S12 588 612 mV A

10.13 Current step 13 level - V REF ,S13 637 663 mV A

10.14 Current step 14 level - V REF ,S14 686 714 mV A

10.15 Current step 15 level - V REF ,S15 735 765 mV A

10.16 Current step 16 level - V REF ,S16 784 816 mV A

10.17 Current step 17 level - V REF ,S17 833 867 mV A

10.18 Current step 18 level - V REF ,S18 882 918 mV A

10.19 Current step 19 level - V REF ,S19 931 969 mV A

10.20 Current step 20 level - V REF ,S20 980 1020 mV A

1. Functional Parameters (Continued) All parameters valid for 7.0V ≤ VS ≤ 16.5V and –40°C ≤ Ta ≤ 105°C unless otherwise noted. No. Parameters Test Conditions Pi n Symbol Min. Typ. Max. Unit Type* *) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter Notes: 1. In this column, pin group names are given. Please refer to Section 2. “Pin Configuration” on page 2 in this document for more details. 2. Operation of coils with higher impedance than the given value is possible but functional limitations might occur (inability to reach to configured coil current). Coils with lower impedance should not be used as they might be detected as faulty.

9125I–RKE–09/10 Atmel ATA5279

11 Digital Interface (SPI, Control Logic)

11.1 Supply current in

operation mode VVIF ≤ 5.5V 6 I supVIF 0.6 1.9 3 mA A

11.2 Supply current in

power-down mode VVIF = 5.0V 6 2 30 µA A

11.3 SPI clock period Chip in operation 39 T SPI 4 × 1/fOSCI sD

11.4 SPI clock low-phase

timing Chip in operation 39 t Lo,min 2 × 1/fOSCI sD

11.5 SPI clock high-phase

timing Chip in operation 39 t hi,min 2 × 1/fOSCI sD

11.6 SPI output enabling

time Chip in operation t MISOon,max 100 ns D

11.7 SPI output disabling

time Chip in operation t MISOoff,max 100 ns D

11.8 Minimum SPI disable

time Chip in operation t SPIoff,min 4 × 1/fOSCI sD

11.9 Minimum chip select

setup time Chip in operation t CSset,min 2 × 1/fOSCI sD

11.10 Minimum chip select

hold time Chip in operation t CShold,min 2 × 1/fOSCI sD

11.11 Minimum data input

setup time Chip in operation t setup,min 100 ns D

11.12 Minimum data input

hold time Chip in operation t hold,min 100 ns D

11.13 Output source

VVIF = 5V ISource = –1mA DO V dig,H 4.75 V A

11.14 Output sink capability VVIF = 5 V

Isink = 1mA DO V dig,L 0.25 V A

11.15 Input current

Vin = 0V VVIF = 5.5V Vin = 5.5V VVIF = 5.5V I in,L Iin,H –0.2 –0.2 –0.2 –60 –20 0.2 0.2 0.2 µA A

11.16 Input high level

VIF = 3.1V DI V LH 0.48 0.64 V VIF A 11.17 Input low level threshold V VIF = 3.1V DI V HL 0.32 0.48 V VIF A

11.18 External reset input

timing tNRES,min 100 ns D

11.19 Tristate output leakage

current VMISO = 2.5V I L,max 500 nA A 8. Functional Parameters (Continued) All parameters valid for 7.0V ≤ VS ≤ 16.5V and –40°C ≤ Ta ≤ 105°C unless otherwise noted. No. Parameters Test Conditions Pi n Symbol Min. Typ. Max. Unit Type* *) Type means: A = 100% tested, B = 100% correlation tested, C = Characterized on samples, D = Design parameter Notes: 1. In this column, pin group names are given. Please refer to Section 2. “Pin Configuration” on page 2 in this document for more details. 2. Operation of coils with higher impedance than the given value is possible but functional limitations might occur (inability to reach to configured coil current). Coils with lower impedance should not be used as they might be detected as faulty.

9125I–RKE–09/10 Atmel ATA5279 10. Package Information 9. Ordering Information Extended Type Number Package Remarks ATA5279P-PLQW VQFN48, 7mm × 7mm Taped and reeled, MOQ 4000 ATA5279P-PLPW VQFN48, 7mm × 7mm Taped and reeled, MOQ 1000 specifications according to DIN technical drawings Issue: 1; 19.10.06 Drawing-No.: 6.543-5137.01-4 0.5 nom. 5.5 24 13 37 48 Z 4.5±0.15 Bottom Pin 1 identification Top Package: VQFN_7 x 7_48L Exposed pad 4.5 x 4.5 Dimensions in mm Not indicated tolerances ±0.05 0.2 0.9 ±0.1 0.4±0.1Z 10:1 0.23±0.07

9125I–RKE–09/10 Atmel ATA5279 11. Revision History Please note that the following page numbers referred to in this section refer to the specific revision mentioned, not to this document. Revision No. History 9125I-RKE-09/10

• Figure 1-1 “Block Diagram” on page 1 changed
• Table 2-1 “Pin Description” on page 3 changed
• Order of Figures 3-6 to 3-9 on pages 14 to 15 changed
• Figure 4-1 “Application Schematic for ATA5279” on page 27 changed
• Table 4-1 “Bill of Materials (BOM) for Typical Application Circuit” on page 28 changed
• Section 7 “Operating Range” on page 31 changed
• Section 8 “Functional Parameters” numbers 1.11 and 1.12 on page 32 added
• Section 8 “Functional Parameters” numbers 11.1 to 11.12 on page 36 changed 9125H-RKE-05/10
• Datasheet ATA5279P renamed in datasheet ATA5279
• Ordering number for small taped & reeled unit introduced as following: ATA5279P-PLPW 9125G-RKE-01/10
• Features item 3 “On-off-keyed Data Modulation ... “ on page 1 changed
• Table 3-1 “States of Driver Outputs within Operation Modes” on page 6 added
• Table 3-4 “States of Control I/Os” on page 16 added
• Note 2 “For applications with 6 antennas ... “ on page 27 added
• Note “Application Note - LF Antenna Driver ATA5279P ... “ on page 30 added
• Section 5 “Absolute Maximum Ratings” part “Count of peaks over lifetime ... “ on page 31 changed
• Section 7 “Operating Range” Note 2 “Triggering the overtemperature ... “ and Note 3 “For more details in terms ... “ on page 31 changed
• Data rate from 4.0kbit/s to 3.9kbit/s on pages 18, 19 and 23 changed 9125F-RKE-09/09
• Features changed
• Table 2-1 (page 2) changed
• Page 23: last paragraph changed
• Text under heading 3.4 “Boost Converter” changed
• Text under heading 3.6 “Diagnosis” changed
• New section “4.1 Application Hints” added
• Table Abs. Max. Ratings changed
• Table Th. Resistance added
• Table El. Characteristics changed 9125E-RKE-04/09 • Table “Functional Parameters” item 1.10 added and item 1.3 changed 9125D-RKE-02/09
• Section 3.9.2 “General Command Description” on pages 20 to 21 changed
• Section 3.9.3 “Driver-related Command Description” on pages 21 to 22 changed 9125C-RKE-01/09 • ATA5279 renamed in ATA5279N 9125B-RKE-12/08
• Table 3-1 “Sequence for Example 1, Using the Diagnosis Mode” on page 11 changed
• Table 3-2 “Sequence for Example 2, Using the Diagnosis Mode” on page 13 changed
• Section 4 “Application” on page 26 changed
• Section 6 “Functional Parameters” on pages 28 to 32 changed

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