AS8846

AS8846 AMSCO | Alldatasheet

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Technical content

Revision 1.8, Date 2005-03-17 Page 1 of 35 Vbat M Rmeas AS8446 TP Wake-up Vbat VSS Iref VDDctrl VDD CP2 CP1 Vpump OUT CS CMP DATAout CMN FAIL PWM CLK DATAin Test1 Test2 RESET Cbat Tr1 CP12 CP0 VDD = 5 V CVDD Rref RNTC RT1 GND_P Power partControl part WakeUp VMO ADC WD µP OSC1 OSC2 PWMout VDD GND (optional) Test3 n.c. CLK CS INR ANA Port1 Port2 SPIout SPIin RESET Tout GND_P VSS Key Features - Programmable PWM DC Motor Driver / Controller with µP Interface (Three Wire Interface) - Programmable Functions and Parameters for Motor Current, Voltage and Speed Regulation - Single Voltage Supply in the range Vbat = 6.0 V to 18 V (Vbat,max = 30 V) 1 - Total Power Efficiency up to 96 % - Low RF Emission within the whole frequency range due to an integrated special EMC optimized driver - Dynamically self-adjusting slew rate regulated switching technology - Fully protected by programmable failure handling procedures via µP - Fast Over Current and Over / Under Voltage Detection and Protection, Battery Voltage Monitoring - External and On Chip Temperature Detection and Protection - Motor Current and Speed Measurement with a shunt resistor and capability of trimming the chip for an external shunt value - Programmable Parameters:

• EMC compliant Driver Functions
• Over Current, Over / Under Voltage Threshold Values
• Motor Failure Threshold Levels
• Motor Current Measurement Range
• Trimming for the current measurement shunt
• PWM Frequency, Charge Pump Monitor - Charge Pump to control high side drivers - Integrated 5 V Power Supply for external components (µP, etc.) - Standby and Wake-up capability - Sleep / Wake-up Mode system controlled by the µP and the Wake-up Pin - SOIC 28 Package General Description The AS8446 is a complete and fully protected PWM DC motor driver/controller, which can be implemented by interfacing a low cost 8-bit µP and a high-side N-channel power FET switch. 1 Low-Batttery-mode between 6.0 V and 6.5 V It is an advanced PWM DC motor controller subsystem with an excellent EMC behavior targeted especially for high current automotive applications. The optimization of the EMC behavior of the entire module only by software changes makes it easier to implement it in harsh environments. The programmability of parameters and functions allows the adaptation of the AS8446 to a wide range of applications. So the system can act either as a motor current or motor speed or motor voltage regulator. Also a full diagnosis of motor failures and power FET failures, over temperature and over/under voltage can be formed by programmable failure handling procedures using the motor characteristic and the real time measured motor current, motor speed and battery voltage.

Applications

• Fan cooler - Air conditioning - Fuel pumps - Water and oil pumps - General purpose DC Motor Regulators Typical Application Diagram AS 8446 Programmable PWM DC Motor Driver / Controller DATA SHEET

Revision 1.8, Date 2005-03-17 Page 2 of 35 Functional Description Overview The AS8446 is a complex integrated circuit, which contains both low and high voltage circuitry to regulate PWM brush DC motors with an external n-channel power FET and an 8-bit µP. The regulation loop is a closed loop environment where a µP is connected to the device with a Three-Wire Interface. The AS8446 measures and delivers the motor current as an analog value to the µP. The µP uses a special algorithm to calculate the motor speed by considering the motor current as a function of time. This technique allows the system to act either as a motor current or a motor speed regulator . The AS8446 also monitors and delivers the battery voltage to the µP as an analog value and by leveraging this voltage-monitoring feature a motor voltage regulator could be implemented also. A full diagnosis of motor and power FET failures is performed automatically by the programmable failure handling functions after carefully analyzing the motor characteristics, real-time motor current, motor speed and battery voltage. The dynamically self-adjusting slew rate regulated switching technology (patented) is one of the most important features of this ASSP in automotive app lications. This technology enables two features of the PWM DC motor regulator, which were up till now impossible to realize:

• Excellent EMC behavior (very low RF emission in the whole frequency range)
• High power efficiency up to 96 % @ f PWM = 20 kHz (fall / rise time down up to < 150 ns) Most of the parameters (e.g. PWM frequency, slew rate, over current threshold, current measurement range, etc.) of the AS8446 can be programmed (setting up the internal registers) through the Three-Wire Interface, which makes the regulator a versatile and easily adaptable device to a wide range of regulation modes and motors. The field programmability option of the slew rate regulation parameters makes it easier to comply with the system level EMC behavior (regulator board, motor, power cables, etc.) A bandgap is used as a reference for a Low Drop Voltage Regulator with a nominal output voltage of 5 V. This regulator is capable to deliver a supply current of up to 40 mA. Higher current is possible with an external bipolar transistor. The device is bundled with a set of software to handle the regulation loop, motor speed measurement and failure detection. A sleep/wake up system is integrated to bring the AS8446 into a power save mode. It is controlled via the specified wake-up pin. A short overview of the main features follows.
• programmable PWM DC motor current, speed or voltage regulator
• single voltage supply in the range Vbat = 6.0V to 18V (Vbat,max = 30 V)
• Low-Battery-Mode guarantees operation also when battery voltage is between 6.0V and 6.5V; In this mode the output driver is constantly on (100% PWM), Vpump-Vbat ≥ 4.0V.
• applicable directly to the automotive battery supply (burst, surge, load dump)
• closed loop regulation of the motor speed, motor current or motor voltage with a µP.
• high power efficiency of the whole regulator module (up to 96 % @ f PWM = 20 kHz)
• low RF emission within the whole frequency range
• fully protected by programmable failure handling procedures (see below: Security Functions)
• fast over current and over / under voltage detection and protection
• motor current and motor speed measurement with only one shunt resistor (typ. measurement voltage at nominal motor current: 50 mV)
• on chip trimming capability of the external shunt resistor
• Sleep/wake up mode system controlled by the µP and the wake-up pin
• Three Wire Interface
• programming possibilities of the following regulator parameters inside of the AS8446: - PWM frequency (generated by µP, e.g. 20 kHz) - charge pump voltage monitoring and protection - slew rate control parameters (EMC behavior) - power FET Gate driver currents up to 500 mA - over current threshold level - over / under voltage threshold level - motor current measurement range and trimming of the external current measurement resistor
• programming possibilities of the following regulator parameters / functions via the µP - motor failure threshold levels (motor currents and voltages) for all motor failures: blocked motor, open wire, no load, shorted motor segments, etc. - failure handling procedures for all motor failures, over / under voltage and for over temperature (type of reaction and timing) - sleep mode criteria and sleep mode signal to the AS8446

Revision 1.8, Date 2005-03-17 Page 3 of 35 - closed loop regulation timing with µP for speed, current and voltage control - special features e.g. suppression of particular motor speeds, dynamical change of the over current threshold level, etc. Security Functions Extensive diagnosis of the DC motor and the power FET as well as failure handling procedures are programmable via a µP.

• over current detection and protection
• no load detection of the motor
• open wire detection (motor or power switch)
• short circuit of the power switch detection
• blocked motor detection and protection
• short circuited motor segments detection and protection
• protection of the power FET and the AS8446, if the motor works in generator mode
• battery voltage monitoring and over / under voltage detection and protection
• two over temperature detection and protection modes - external temperature sensor - on chip temperature sensor Item (Start up values) AS 8446 Over Voltage Threshold 40.0 V Under Voltage Threshold 2.5 V Minimum Charge Pump Voltage 4.0 V Over Current Threshold (Shunt Measurement Voltage) 125 mV Mode after Start up sleep mode Table 1 Start up values of the AS 8446

Revision 1.8, Date 2005-03-17 Page 4 of 35 Pin Description The AS8446 Motor Driver/Controller contains the driver/controller chip in a SOIC28 package The complete PWM DC Motor Regulator board needs an additional µP to close the regulation loop and control the whole regulator (dual package solution, free choice of the controlling µP). Pinout AS8446 Figure 1 Pinout AS 8446 Pin Description AS8446, Pin Types S power supply AI analog in AO analog out AIO analog in/out DI digital in DIPU digital in with pull-up DIPD digital in with pull-down DO digital out DIO digital in/out DO_T digital out, tristate LV low voltage HV high voltage Pin Name Type Note

1 CMN HV AI Current Measurement Input

(negative side)

2 CMP HV AI Current Measurement Input

(positive side)

3 VMO HV AI Motor Voltage Input

4 Vbat S Battery Voltage, Main Supply

5 TP HV AI Temperature Sensor Input

6 FAIL LV DO Error Status Output of

7 CS LV DIPU Chip Select, Enable Pin of

8 ADC HV AO Analog Measurement Output

(multiplexed)

9 Wake-up HV AIO Wake-up Pin

10 n.c.

11 Tst 1 LV DIPU Test Pin 1 (1)

12 Tst 2 LV DO Test Pin 2 (2)

13 DATAin LV DIPD Data Input of the Three-Wire

14 DATAout LV DO_T Data Output of the Three-

15 Clk LV DIPD Clock of the Three-Wire

16 PWM LV DIPU PWM Input (Control of the

Power FET Driver)

17 Tst 3 LV DO Test Pin 3 (2)

18 WD LV DIPU Watch Dog Input

19 RESET LV DO Reset Output (controlled by

Watch Dog)

20 Iref LV AIO Reference Current Pin

21 VDD AI VDD feedback input

22 VDDctrl HV AO VDD supply (5 V generated

regulator)

23 CP1 HV AIO Charge Pump Capacitor (Vbat

side)

24 CP2 HV AIO Charge Pump Capacitor

(Vpump side)

25 Vpump AO Charge Pump Buffer

26 OUT HV AO Power FET Driver Output

27 GND_P S Power Ground

28 VSS S Digital/Analog Ground

Table 2 PIN description of AS 8446 Note (1) Must be connected to VDD Note (2) Must be left open AS8446 TP Wake-Up Vbat VSS Iref VDDctrl VDD CP2 CP1 Vpump OUT GND_P CS CMP DATAout CMN FAIL PWM Clk DATAin Tst 1 Tst 2 RESET VMO ADC WD Tst 3 n.c.

Revision 1.8, Date 2005-03-17 Page 5 of 35 Block Diagram Figure 2 Block Diagram of AS8446 10 V Ch ar ge pump GND M oto rc ur re n ta n ds p e ed mea su rement / over c u rr ent slew rate (high) programming M otor - a nd P ower FE T p r ot ec tion Clk VDDH = Vbat M OUT Ser ia l In terface DATAin R/W Control S hi ft Reg is ter AS 8 444 uP ba se dD CM o to r R egula tor Bi t_0 Bit _n R CO sc illator 50 k Hz CP1 CP2 Vpump PWM VDDH 21 2 RmeasV A _cu r re nt =k x *Imo tor A_curren t CMp C M n W a k e-u p In ter fa ce Tst 1 Regi sters SET_0 a)s etting s b)c ontrol SE T_ k PWM TP VDDH1 Poverc sleep CLKpump VDDH pro gra mm ing an d t rimmi ng (o ver cu rr ent, Rmeas) GND_P DATAout CS ADC A_ o ve rc k6, k7 P To ve r2 FAIL Tst 2 prog ram m a ble:

12 V, 24 V, 42 V

Vin = Vbat programming (analog ) VS SA 5V - regul a tor (b an dg a pr ef. ) VDD VDDctrl VDD VDDH ba nd g a p re fe re nc e Vre f/Ire f ge n era tor Vref Iref Vre f= 1.0V Vbat_mon pa ckag e: SO IC 28VDDctrl au stri a mi cr o systems Vref T2 On c hip Ov er Temperature detection VrefT1 Exter nal Over Temperat ure detection PWM H V- IN / LV-O U T VDDH = Vbat POR POR t S leep /wake u ps ys te m V DD p d VrefV P Vover PVun der PTo ver1 Poverc OR RESET CP12 CP 0 CV DD Rref VDD R T1 RNTC Rx sleep WD V A _o ver c =k y * I m o t o r Self Adjusting Slew Rate Regulation Interface / Control Hi g h Si de Dr ive Low S id e D ri ve slew rate (low) programming Imotor low voltage high volt a ge Wat c h d og Iref Vmo VDD OR VSS a ctive/ de activ e Cl k_wd wd Analog MUX TP A_ cu rrent A_ov erc Vbat_ mon Wake-up Tst 3

Revision 1.8, Date 2005-03-17 Page 6 of 35 General Application Diagram Vbat M Rmeas AS8446 TP Wake-up Vbat VSS Iref VDDctrl VDD CP2 CP1 Vpump OUT CS CMP DATAout CMN FAIL PWM CLK DATAin Tst1 Tst2 RESET Cbat Tr1 CP12 CP0 VDD = 5 V CVDD Rref RNTC RT1 GND_P Power partControl part WakeUp VMO ADC WD µP OSC1 OSC2 PWMout VDD GND (optional) Tst3 n.c. CLK CS INR ANA Port1 Port2 SPIout SPIin RESET Tout GND_P VSS Figure 3 General Board Diagram of a complete PWM DC Motor Regulator Remarks: a) The communication between the AS8446 and the controlling µP is realized via the Three-Wire Interface b) The communication of the whole motor regulator module with the environment can be realized in different ways: 1. low voltage 5 V digital input using a digital µP port 2. low voltage 5 V analog output using an analog ADC input of the µP c) The EMC parameters to optimize the EMC behavior of the whole regulator system can be stored in the program of the µP and transmitted to the AS8446 via Three-Wire Interface during start up of the system. d) The customer has free choice of the µP.

Revision 1.8, Date 2005-03-17 Page 7 of 35 Absolute Maximum Ratings (NON OPERATING) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only. Functional operation of the device at these or any other conditions beyond those indicated under Operating Conditions is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameter Symbol Min Max Unit Note Battery voltage Vbat -0.3 30 V (1) Pumped voltage Vpump -0.3 44 V Low Power Supply Voltage VDD -0.3 7 V Input Pin Voltage (Low voltage pins) Vin -0.3 VDD+0.3 V Input Current (latchup immunity) Iscr -100 100 mA 125°C ESD -0,9 0,9 kV Norm: MIL 883 E method 3015 (2) Total Power dissipation Pvtot 500 mW Junction temperature Tj 150 °C Storage temperature Tstg -55 150 °C Humidity 5 85 % Non condensing Body temperature TBody 240 °C Norm: IPC/JEDEC J-STD 020 C Note (1): Load Dump, 500ms, according to DIN40839 Note (2): Except for Pin 1 (CMN) and Pin 25 (Vpump): ESD = +/- 0,5 kV Table 3 Absolute Maximum Ratings Operating Conditions Parameter Symbol Min Typ Max Unit Note Battery voltage (normal operating-mode) Vbat 6.5 18 V (1) Battery voltage (Low-Battery- mode) Vbat 6.0 6.5 V Vpump-Vbat ≥ 4.0V; Vout = const. high; (2) Pumped voltage Vpump Vbat + 4V Vbat + 10V Vbat + 14V V (2) Low Voltage Power Supply VDD 4.8 5.15 V (2);(3) Standby Current (power down) I_pd1 Vbat (50) µA Tamb < 27 °C; (4) Standby Current (power down) I_pd2 Vbat 90 µA Tamb < 125 °C; Vbat = 13.5V Ambient temperature Tamb -40 125 °C Note (1): Jump Start: Vbat < 28V, 1 min, 1 pulse/h Note (2): Low Battery mode guarantees operation when the battery voltage is below 6.5V; In this mode the output driver is constantly on (100% PWM), Vpump-Vbat ≥ 4.0V at 250µA load on Pin OUT; the load current of VDD is limited to 2.5mA Note (3): Low Drop voltage regulator; 40 mA max. external load at VDD; higher current with external transistor possible Note (4): only as information. Will not be tested Table 4 Operating Conditions Thermal Characteristics Parameter Symbol Min Max Unit Note Thermal resistance from junction to ambient Rth,ja 76.2 °C/W free air, single layer PCB Table 5 Thermal Characteristic

Revision 1.8, Date 2005-03-17 Page 8 of 35 Characteristics for Analog and Digital Inputs and Outputs CMOS LV Digital Input Pins: Clk, DATAin, CS, PWM, WD Parameter Symbol Min Max Unit Note High Level Input Voltage VIH 0.7 * VDD V Low Level Input Voltage VIL 0.3 * VDD V Input Leakage Current ILEAK -1 1 µA pull-up/down current for inputs with pull-up/down typ. 60µA Table 6 CMOS Input parameters CMOS LV Digital Output Pins: RESET, DATAout, FAIL Parameter Symbol Min Max Unit Note High Level Output Voltage VOH VDD -0.5 V C LOAD = 50 pF Low Level Output Voltage VOL VSS +0.4 V C LOAD = 50 pF Table 7 CMOS Output parameters Analog Signals Input / Output Pins: Vpump, CP1, CP2, OUT, CMP, CMN, VMO, ADC, TP, Iref Parameter, Pin Name Pin type Symbol Min Typ Max Unit Note Charge Pump Voltage, pin: Vpump HV S Vpump Vbat + 6 Vbat + 4 Vbat + 10 Vbat + 14 V (1) Charge pump switched capacitor voltage, pin: CP1 HV AIO V CP1 VSS Vbat V Charge pump switched capacitor voltage, pin: CP2 HV AIO V CP2 VSS Vbat + 14 V HS driver source current, pin: OUT HV AO Iout_p -500 mA (2) HS driver sink current, pin: OUT HV AO Iout_n 500 mA (2) Motor current measurement inputs, Common mode range, pins: CMP, CMN HV AI V CMP, VCMN -1.5 Vbat V Motor voltage input, pin: VMO HV AI V VMO -1.5 Vbat V Analog measurement output voltage, pin: ADC LV AO V A_current 0 VDD V Multiplexed analog output (3) External temperature sensor input, threshold voltage, pin: TP LV AI V TP_th 00 . 5 VDD VDD V Threshold voltage: VDD / 2 Reference current generation voltage, pin: Iref LV AI Vref 1.0 V (4) Note (1): external capacitors CP1/2 = 100 nF, CP0 = 400 nF recommended; on chip Vpump monitoring and protection: Vpump_min = (Vbat + 6 V) or (Vbat + 4 V), programmable Note (2): typical rise/ fall time at the external Power MOSFET source: 0.2 µs to 0.5 µs, independently programmable rise and fall times, voltage range of the voltage V OUT = 0 Vpump Note (3): Multiplexed output (controlled by register R15<3:0> = ADC_CH, see section Summary of all programmable registers (parameters, functions) Full motor current measurement range corresponds to V ADC = 4.0 V. Multiplexed output must not be switched during operation! Note (4): regulated voltage Vref = 1.0 V, external resistor Rref = 22 k Ω must be connected to generate the 45 µA reference current. Use Pin Iref to connect Rref only. Table 8 Analog signal parameters

Revision 1.8, Date 2005-03-17 Page 9 of 35 Wake-up system Parameter Pin type Symbol Min Max Unit Note Low Level Input Voltage V IL -8 0.4 * Vbat V High Level Input Voltage V IH 0.6 * Vbat Vbat V Input Hysteresis HV AIO VHYS 0.05 * Vbat 0.1 * Vbat V V IH - V IL Table 9 Wake-up system signal parameter Start up Behavior Figure 4 Start up and sleep mode behavior of AS8446 (simplified timing) Vbat nPORraw nPOR VPok Mcalib Wake-up (VDDraw) (VDD) (Charge pump enable) (calibration ready) 14 V 4.3 V 5.0 V 100 us … 500 us time is user defined by LIN wake up 200 us Charge pump start up measurement unit calibration system enable (normal work) SPI sends 1 to R17 (sleep) sleep mode 300 us wake up t=t 1 t t2 t3 t4 t5 SPI communication possible 300 us Sleep R17 not defined Failure R18 14 V not defined 5.0 V not defined Registers R1 to R16 defined (start-up) defined by SPI and/or failure detection units not defined wake up sleep mode new system start-up t=t 1+T defined by SPI first system start-up (connection of Vbat to the system) defined (start-up) sleep mode driver enable RESET 5.0 V4.3 V 4.3 V 20 us possible RESET by watch dog redefined (start-up) RESET by nPOR RESET by nPOR

Revision 1.8, Date 2005-03-17 Page 10 of 35 Programming Capabilities There are in total 18 registers to program the behavior of the AS8446 via the Three Wire Interface Register No Register Name Meaning R1<4:0> SRon EMC parameter 1, rising edge R2<4:0> SRon_stat EMC parameter 2, rising edge R3<2:0> SRon_min EMC parameter 3, rising edge R4<4:0> SRoff EMC parameter 1, falling edge R5<3:0> Sroff_stat EMC parameter 2, falling edge R6<1:0> Acu_on/off EMC parameter, rising and falling edge, multiplying factor 1 or 2 R7<4:0> AV_TRIMM Motor current measurement amplification (steps of 1.25%) R8<1:0> AV_RANG_norm Motor current measurement amplification, normal measurement channel (large steps) R9<2:0> OVERC_level Over current threshold value R10<1:0> AV_RANG_over Motor current measurement amplification, over current measurement channel (large steps) R11<2:0> VBAT_RANG Range of supply voltage (max. battery voltage to measure) R12<2:0> OVER_VOLT Over voltage threshold value R13<2:0> UNDER_VOLT Under voltage threshold value R14<0:0> VPUMP_MIN Min. pumped voltage (Vpump – Vbat) R15<3:0> ADC_CH Selection of one of the analog channel to be connected to pin ADC (Analog- MUX) R16<0:0> WATCH_D Switch on or off of watch dog function R17<1:0> SLEEP Switch on or off of sleep mode R18<7:0> FAILURE_STAT Failure status register Full descriptions of all registers see below. Table 10 Meaning of the AS 8446 registers. Driver Programming (Slew Rate Regulation Parameters) The Power FET driver is controlled in two different ways: 1. By the digital input PWM (output of the PWM generator of the µP) to realize the PWM duty cycle of the motor drive for regulating the motor current, speed or voltage in the closed loop. 2. By the dynamically self-adjus ting slew rate regulated switching technology during the rising and falling edges of the motor voltage. There are 6 registers to program the driving parameters in different time intervals of the rising and the falling edge of the m otor voltage independently (definition of the time functions of the power FET driver gate currents in wide ranges): Rising edge: registers R1<4:0>, R2<4:0>, R3<2:0> and R6<0> Falling edge: registers R4<4:0>, R5<3:0> and R6<1> These registers can be programmed via the Three-Wire Inte rface and thus the EMC behavior of the system (motor, power switches, cables) can be adapted and optimized to a particular application. Although the total rising and falling times are ver y short ( t RISE or t FALL < 150 ns with driver currents to the power FET gate up to 500 mA), the RF emission (EMC) is very low. See also section Summary of all programmable registers (parameters, functions) . A detailed description of these programming and EMC optimization will be given in the application manual of the AS8446.

Revision 1.8, Date 2005-03-17 Page 11 of 35 Rising edge (switch on): Programmable Gate Drive Source Currents (13 bit) Register / timing part of rising edge Programmable range Programmable range Unit Note R6<0> = 1, Acu_on/off R6<0> = 0, Acu_on/off min max step min max step R1<4:0> = SRon (Vmotor = 12.7 V) 0 496 16 0 248 8 mA R1<4:0> = SRon (Vmotor = 30.7 V) 0 (1240) 1 40 0 (620) 1 20 mA R1 = 0, 1, 2, R2<3:0> = SRon_stat 1.0 32 1.0 0.5 16 0.5 mA R2 = 0, 1, 2, R3<2:0> = SRon_min (Vmotor = -0.5 V) 20 160 20 10 80 10 mA R3 = 0, 1, 2, Note (1): The total driver current I out_on must be limited to 500 mA (I out_on < 500 mA ) in the real application with the given Vmotor_max = V bat by appropriate programming. Table 11 Programming of the slew rate parameters (rising edge) Figure 5 Rising edge of the motor voltage before and after the EMC optimization

Revision 1.8, Date 2005-03-17 Page 12 of 35 Falling edge (switch off): Programmable Gate Drive Sink Currents (10 bit) Register / timing part of falling edge Programmable range Programmable range Unit Note R6<1> = 1, Acu_on/off R6<1> = 0, Acu_on/off min max step min max step R4<4:0> = SRoff (Vmotor = 12.7 V) 0 496 16 0 248 8 mA R4<4:0>, SRoff (Vmotor = 30.7 V) 0 (1240) 1 40 0 (620) 1 20 mA R4 = 0, 1, 2, R5<3:0>, SRoff_stat 1.0 32 1.0 5 80 5 mA R2 = 0, 1, 2, Note (1): The total driver current I out_on must be limited to 500 mA (I out_on < 500 mA ) in the real application with the given Vmotor_max = V bat by appropriate programming. Table 12 Programming of the slew rate parameters (falling edge) Figure 6 Falling edge of the motor voltage before and after the EMC optimization -10 0.1 1 10 100 1000 [MHz] [dBµV] DUT: Demo board AS8444_TC Conditions: V BAT =1 3 . 5V Load : Ri = 0.4 Ohm, Li = 0.063 mH EMC parameter set 1 (not EMC optimized) EMC parameter set 2 (EMC optimized) Conducted Emission power supply lines according CISPR 25 Detector: Peak EMC parameter set 1 (not EMC optimized) EMC parameter set 2 (EMC optimized)Figure 7 Comparison of the EMC measurement results of the same application with two different EMC parameter sets

Revision 1.8, Date 2005-03-17 Page 14 of 35 Programming of the motor current measurement and over current detection unit The motor current measurement unit transforms the differential voltage over the measurement resistor at the high side motor line (V CMP - V CMN ) = Imotor * Rmeas to the ground related voltage V A_current (channel1) and to the ground related voltage V A_overc (channel2) with a programmable amplification. Definition and programming of the voltage amplifications AV meas_norm and AV meas_overc of the motor current measurement unit: a) channel 1: AV meas_norm = V A_current / (V CMP - V CMN ) = AV_TRIMM * AV_RANGE_norm b) channel 2: AV meas_overc = V A_overc / (V CMP - V CMN ) = AV_TRIMM * AV_RANGE_over Register No Register Name Meaning R7<4:0> AV_TRIMM Voltage amplification factor1 of the current measurement unit in small steps (trimming of the external current measurement resistor) for the normal and over current analog measurement output R7 = 0 /Ge0 AV_TRIMM = 70 R7 = 1 /Ge0 AV_TRIMM = 71 R7 = 2 /Ge0 AV_TRIMM = 72 R7 = 10 /Ge0 AV_TRIMM = 80 (default value) R7 = 11 /Ge0 AV_TRIMM = 81 R7 = 19 /Ge0 AV_TRIMM = 89 R7 = 20 /Ge0 AV_TRIMM = 90 R7 > 20 /Ge0 AV_TRIMM = 90 R8<1:0> AV_RANGE Voltage amplification factor2 of the normal analog measurement output (A_current) R8 = 0 /Ge0 AV_RANGE = 1 (default value) R8 = 1 /Ge0 AV_RANGE = 2 R8 = 2 /Ge0 AV_RANGE = 3 R8 = 3 /Ge0 AV_RANGE = 4 R9<2:0> OVERC_level Threshold value of the internal over current detection Def.: Vocmax = 4/5 * VDD (typ. 4.0 V) Vocstep = (4/5 * VDD) / 8 (typ. 0.5 V) R9 = 0 /Ge0 OVERC_level = Vocmax (typ. 4.0 V) R9 = 1 /Ge0 OVERC_level = Vocmax – Vocstep (typ. 3.5 V) R9 = 2 /Ge0 OVERC_level = Vocmax - 2*Vocstep (typ. 3.0 V) R9 = 3 /Ge0 OVERC_level = Vocmax - 3*Vocstep (typ. 2.5 V) R9 = 7 /Ge0 OVERC_level = Vocmax - 7*Vocstep (typ. 0.5 V) R10<1:0> AV_RANGE_over Voltage amplification factor2 of the over current analog measurement output (A_overc) R10 = 0 /Ge0 AV_RANGE_over = 1 * 1/4 (default value) R10 = 1 /Ge0 AV_RANGE_over = 2 * 1/4 R10 = 2 /Ge0 AV_RANGE_over = 3 * 1/4 R10 = 3 /Ge0 AV_RANGE_over = 4 * 1/4 Remark 1: The maximum of the valid analog output voltage of the outputs A_current and A_overc must be 4.0 V. Remark 2: The total voltage amplification of the current measurement unit is determined by normal current analog output A_current: AV meas_norm = V A_current / (V CMP - V CMN ) = AV_TRIMM * AV_RANGE (default value: 80) over current analog output A_overc: AV meas_overc = V A_overc / (V CMP - V CMN ) = AV_TRIMM * AV_RANGE_over (default value: 20)

Revision 1.8, Date 2005-03-17 Page 15 of 35 Remark 3: The external current measurement voltage over the measurement resistor Rmeas (V CMP - V CMN ) = Imotor * Rmeas where the internal over current detection is switched on can be determined by: (V CMP - V CMN )overc * AV_TRIMM * AV_RANGE_over = OVERC_level (VCMP - V CMN )overc = OVERC_level / (AV_TRIMM * AV_RANGE_over) example: OVERC_level = 4 V, AV_TRIMM = 80, AV_RANGE_over = 1/4 /Ge0 (V CMP - V CMN )overc = 200 mV Remark 4: Example of the programming of the current measurement / over current detection unit: Step1: Definition of the nominal voltage drop over the external current measurement resistor Rmeas (V CMP - V CMN )nom = Imotor nom * Rmeas e.g. (V CMP - V CMN )nom = 50 A * 1 m Ω = 50 mV Step2: Definition of the over current threshold value of (V CMP - V CMN ) e.g. (V CMP - V CMN )overc = 100 mV Step3: Determination of the voltage amplification of the normal current measurement channel so that the nominal output voltage V A_current_nom = 4.0 V e.g. AV_TRIMM * AV_RANGE = 80 * 1 /Ge0 VA_current-nom = 50 mV * 80 = 4.0 V Step4: Determination of the voltage amplification of the over current measurement e.g. AV_TRIMM * AV_RANGE_over = 80 * 1/4 /Ge0 V A_overc_max = 100mV * 20 = 2.0 V < 4.0 V Step5: Determination of the programming of the internal over current threshold value (OVERC_level) With the formula: (V CMP - V CMN )overc = OVERC_level / (AV_TRIMM * AV_RANGE_over) and all values above: OVERC_level = (V CMP - V CMN )overc * (AV_TRIMM * AV_RANGE_over) = 100 mV * 80 *1/4 = 2.0 V /Ge0 R9 = 4 Remark 5: The amplifications AV meas_norm and AV meas_overc of the current measurement unit can be adapted to the external measurement resistor R meas by the programming word AV_TRIMM in steps of 1.25 % in the range of + 12.5% (trimming of R meas ). Table 13 Programming of the motor current measurement an over current detection unit

Revision 1.8, Date 2005-03-17 Page 16 of 35 Summary of all programmable registers (parameters, functions) Register / address Internal name Meaning Note Ra<b1:b0> means: address = a, most significant data bit = b1, least significant data bit = b0 All registers can be write and read by the Three-Wire Interface (write priority has the Three-Wire Interface). 1. The start up reset of all registers unless the R17 and the R18 is done by the signal nPOR (controlled by the VDD). 2. The start up reset of the register R17 is done by the nPORraw (controlled by the voltage VDDraw) only. 3. The start up reset of the register R18 (failure register) is done with a delay after the nPOR, this delay is generated by the enable signal of the charge pump VPok. Programming of the driver output currents (independent for switch on and switch off) R0<7:0> Not used Slew rate regulation programming, on switch, voltage V Vmo dependent driver output current for positive V VMO voltage SRon = 0, 1, 2, ISRon = V Vmo * Acu_on * SRon * K1 V VMO > 0 Register write by: Three Wire Interface Register read by: Three Wire Interface and FET driver unit - - - d4 d3 d2 d1 d0 R1<4:0> SRon - - -11111 start up values Slew rate regulation programming, on switch, constant driver output current SRon_stat = 0, 1, 2, ISRon_stat = 2.0 µA * (SRon_stat + 1) * Acu_on Register write by: Three Wire Interface Register read by: Three Wire Interface and FET driver unit - - - d4 d3 d2 d1 d0 R2<4:0> SRon_stat - - -11111 start up values Slew rate regulation programming, on switch, voltage V VMO dependent driver output current for negative V VMO voltage SRon_min = 0, 1, 2, ISRon_min = V Vmo * (SRon_min + 1) *Acu_on * K2 V VMO < 0 Register write by: Three Wire Interface Register read by: Three Wire Interface and FET driver unit - - - - - d2 d1 d0 R3<2:0> SRon_min -----1 1 1 start up values

Revision 1.8, Date 2005-03-17 Page 17 of 35 Slew rate regulation programming, off switch, voltage V VMO dependent driver input current for positive V VMO voltage SRoff = 0, 1, 2, ISRoff = V Vmo * Acu_off * SRoff * K3 Register write by: Three Wire Interface Register read by: Three Wire Interface and FET driver unit - - - d4 d3 d2 d1 d0 R4<4:0> SRoff - - -11111 start up values Slew rate regulation programming, off switch, constant driver input current SRoff_stat = 0, 1, 2, ISRoff_stat = 20 µA * (SRoff_stat + 1) * Acu_off Register write by: Three Wire Interface Register read by: Three Wire Interface and FET driver unit - - - - d 3d 2d 1d 0 R5<3:0> SRoff_stat ----1 1 1 1 start up values Current amplification of the driver for on and off switch R6<0> = 0 /Ge0 Acu_on = (Iout / Iin) on = 256 R6<0> = 1 /Ge0 Acu_on = (Iout / Iin) on = 512 R6<1> = 0 /Ge0 Acu_off = (Iout / Iin) off = 256 R6<1> = 1 /Ge0 Acu_off = (Iout / Iin) off = 512 Register write by: Three Wire Interface Register read by: Three Wire Interface and FET driver unit R6<1:0> Acu_on Acu_off Programming of the motor current measurement and over current detection unit The motor current measurement unit transforms the differential voltage over the measurement resistor (VCMP - V CMN ) = Imotor * Rmeas to the ground related voltages V A_current (channel1: normal current measurement channel) and VA_overc (channel2: over current measurement channel) with a programmable amplification. Def. of the voltage amplification of the motor current measurement unit: Voltage amplification of the normal current measurement channel: 1. AV meas_norm = V A_current / (V CMP - V CMN ) = AV_TRIMM * AV_RANGE_norm Voltage amplification of the normal current measurement channel 2. AVmeas_overc = V A_overc / (V CMP - V CMN ) = AV_TRIMM * AV_RANGE_over

Revision 1.8, Date 2005-03-17 Page 18 of 35 R7 = 0 /Ge0 AV_TRIMM = 70 R7 = 1 /Ge0 AV_TRIMM = 71 R7 = 2 /Ge0 AV_TRIMM = 72 R7 = 10 /Ge0 AV_TRIMM = 80 (default value) R7 = 11 /Ge0 AV_TRIMM = 81 R7 = 19 /Ge0 AV_TRIMM = 89 R7 = 20 /Ge0 AV_TRIMM = 90 R7 > 20 /Ge0 AV_TRIMM = 90 Register write by: Three-Wire Interface Register read by: Three-Wire Interface and current measurement unit - - - d4 d3 d2 d1 d0 R7<4:0> AV_TRIMM - - -01010 start up values R8 = 0 /Ge0 AV_RANGE-norm = 1 (default value) R8 = 1 /Ge0 AV_RANGE-norm = 2 R8 = 2 /Ge0 AV_RANGE-norm = 3 R8 = 3 /Ge0 AV_RANGE-norm = 4 Register write by: Three-Wire Interface Register read by: Three-Wire Interface and current measurement unit R8<1:0> AV_RANGE_norm Threshold value of the internal over current detection Def.: Vocmax = 4/5 * VDD (typ. 4.0 V) Vocstep = (4/5 * VDD) / 8 (typ. 0.5 V) R9 = 0 /Ge0 OVERC_level = Vocmax (typ. 4.0 V) R9 = 1 /Ge0 OVERC_level = Vocmax – Vocstep (typ. 3.5 V) R9 = 2 /Ge0 OVERC_level = Vocmax - 2*Vocstep (typ. 3.0 V) R9 = 3 /Ge0 OVERC_level = Vocmax - 3*Vocstep (typ. 2.5 V) R9 = 7 /Ge0 OVERC_level = Vocmax - 7*Vocstep (typ. 0.5 V) Register write by: Three-Wire Interface Register read by: Three-Wire Interface and current measurement unit - - - - - d2 d1 d0 R9<2:0> OVERC_level -----0 1 1 start up values Voltage amplification factor2 of the over current analogue measurement output (A_overc) R10 = 0 /Ge0 AV_RANGE_over = 1 * 1/4 (default value) R10 = 1 /Ge0 AV_RANGE_over = 2 * 1/4 R10 = 2 /Ge0 AV_RANGE_over = 3 * 1/4 R10 = 3 /Ge0 AV_RANGE_over = 4 * 1/4 Register write by: Three-Wire Interface Register read by: Three-Wire Interface and current measurement unit R10<1:0> AV_RANGE_over

Revision 1.8, Date 2005-03-17 Page 19 of 35 Programming of the battery voltage monitor and over / under voltage detection R11= 0 /Ge0 VBAT_RANGE = 5 /Ge0 Vbat-max = 20 V R11= 1 /Ge0 VBAT_RANGE = 8 /Ge0 Vbat-max = 32 V R11= 2 /Ge0 VBAT_RANGE = 10 /Ge0 Vbat-max = 40 V R11= 3 /Ge0 VBAT_RANGE = 15 /Ge0 Vbat-max = 60 V R11= 4 /Ge0 VBAT_RANGE = 20 /Ge0 Vbat-max = 80 V Register write by: Three-Wire Interface Register read by: Three-Wire Interface and voltage monitor - - - - - d2 d1 d0 R11<2:0> VBAT_RANGE -----0 1 0 start up values R11= 0 /Ge0 VBAT_RANGE = 5 /Ge0 Vbat-max = 20 V R11= 1 /Ge0 VBAT_RANGE = 8 /Ge0 Vbat-max = 32 V R11= 2 /Ge0 VBAT_RANGE = 10 /Ge0 Vbat-max = 40 V R11= 3 /Ge0 VBAT_RANGE = 15 /Ge0 Vbat-max = 60 V R11= 4 /Ge0 VBAT_RANGE = 20 /Ge0 Vbat-max = 80 V Register write by: Three-Wire Interface Register read by: Three-Wire Interface and voltage monitor - - - - - d2 d1 d0 R12<2:0> OVER_VOLT -----1 1 1 start up values Step of UNDER_VOLT = 0.25 V * VBAT_RANGE UNDER_VOLT = 0.25 V * VBAT_RANGE * (R13 + 1) Start up value: UNDER_VOLT = 7.5 V Register write by: Three-Wire Interface Register read by: Three-Wire Interface and voltage monitor - - - - - d2 d1 d0 R13<2:0> UNDER_VOLT -----0 0 0 start up values Programming of the charge pump voltages R14 = 0 /Ge0 VPUMP_MIN = 4.0 V R14 = 1 /Ge0 VPUMP_MIN = 6.0 V Register write by: Three-Wire Interface Register read by: Three-Wire Interface and charge pump R14<0:0> VPUMP_MIN

Revision 1.8, Date 2005-03-17 Page 20 of 35 Programming of the analog MUX R15 = 0 /Ge0 A_current (normal current measurement channel) R15 = 1 /Ge0 A_overc (over current measurement channel) R15 = 2 /Ge0 Vbat_mon (Vbat measurement channel) R15 = 3 /Ge0 TP (temperature measurement channel) The following signals can be given at the ADC output for chip test purposes: R15 = 4 /Ge0 Vtemp (temperature voltage of the internal sensor) R15 = 5 /Ge0 PVover (Over voltage Vbat signal) R15 = 6 /Ge0 PVunder (Under voltage Vbat signal) R15 = 7 /Ge0 PTover_in (Over temperature signal, internal) R15 = 8 /Ge0 PTover_ex (Over temperature signal, external) Register write by: Three-Wire Interface Register read by: Three-Wire Interface and analog MUX ---- d 3 d 2 d1 d0 R15<3:0> ADC_CH ----0 0 00 start up values Note: Do not switch the analog MUX during operation! Programming of the watch dog R16 = 0 /Ge0 watch dog is off (watch dog not used) R16 =1 /Ge0 watch dog is on (watch dog used) Register write by: Three-Wire Interface Register read by: Three-Wire Interface and watch dog R16<0:0> WATCH_D Programming of the sleep mode R17 = 0 /Ge0 no sleep mode (normal operation) R17 = 1 /Ge0 sleep mode (power down) Register reset to low by the Wake-up Interface. Wake-up = low (high / low edge) /Ge0 R17<0:0> set to low R17<0:0> SLEEP start up values

Revision 1.8, Date 2005-03-17 Page 21 of 35 Failure Registers and Test Mode Register (on chip temperature detection) R18<7:0> FAILURE_STAT R18<0> /Ge0 Poverc (bit 0 contains the over current status) R18<1> /Ge0 PVover (bit 1 contains the over voltage status of Vbat) R18<2> /Ge0 PVunder (bit 2 contains the under voltage status of Vbat) R18<3> /Ge0 PTover_in (bit 3 contains the on chip over temperature status) R18<4> /Ge0 PTover_ex (bit 4 contains the external over temperature status) R18<5> /Ge0 VDDover (bit 5 contains the over voltage status of VDD, 5 V) R18<6> /Ge0 VDDunder (bit 6 contains the under voltage status of VDD, 5 V) R18<7> = 0 /Ge0band gap Voltage is the reference voltage for the on chip over temperature detection (normal function) R18<7> = 1 /Ge0the voltage at pin TP is the reference voltage for the on chip over temperature detection (test mode) Registers R18<6:0> set and reset by Three-Wire Interface and only set by corresponding failure detection units (Three Wire-Interface has write priority) Register R18<6:0> read by Three-Wire Interface and corresponding logic Register R18<7> write by Three-Wire Interface only Register R18<7> read by Three-Wire Interface and corresponding analog switch TEMP_TEST VDDunder VDDover PTover_ex PTover_in PVunder PVover Poverc 0 0 0000 0 0 start up values Table 14 Summary of the programming capabilities of the AS 8446

Revision 1.8, Date 2005-03-17 Page 23 of 35 Communication Protocol The Three-Wire Interface -interface acts as communication interface between the µP or PC and the registers within the AS8446. For efficient register access, a protocol has been defined with the following features: Purely master-slave protocol with µP or PC as master Two different frames: One read and one write frame Frame is delimited by the status of CS (CS = frame delimiter or chip select signal), one frame consists of 16 Bits (header byte and data byte). Special remark for interface lock condition : If a frame does not consist of 16 bits (can be caused e.g. by spiking, noise or interrupt), the interface will be locked. In order to leave this lock situation CS = high and one or several clock pulses must be set. Setting CS = high alone will not be sufficient. Referring to Figure 10 and Figure 11, a Clk pulse with CS = high must be set in order to reset the interface and to ensure a sa fe communication. Data Fields HEADER H MSB H LSB R / W - - A 4A 3A 2A 1A 0 A4, A3, A2, A1, A0: Address A (Register address to read or to write) R/W = MSB, A0 = LSB. R/W: Read or Write R/W =0: Read (Data are read/transmitted from the AS8446 via the DATAout pin.) R/W =1: Write (Data are write/transmitted from the µP or PC to the AS8446 via the DATAin pin.) DATA D MSB D LSB D7 D6 D5 D4 D3 D2 D1 D0 D0: Data (Denotes the data of the register addressed. D7=MSB, D0=LSB) Note: To ensure a correct register setting the use of µP based verification (Write, Read-Back, Verify) is mandatory.

Revision 1.8, Date 2005-03-17 Page 25 of 35 PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Off threshold for Reset generation Voff_PORS 2.1 3.5 4.5 V Ramp up Hysteresis of Reset signal Hyst_PORS 0.1 0.8 V Sleep / wake up system The whole IC is put in sleep mode (power down mode) by th e control signal SLEEP set via the Three Wire Interface (SLEEP = high, content register R17). The whole start up and sleep mode behavior is shown in figure 4. In sleep mode the following actions are done: - the power FET driver output OUT is hold at low (VSS) - the oscillator, the charge pump and all other blocks are put in a high ohmic status - the 5 V regulator is switched off (no external supply at pin VDD, this way all devices on the motor regulator board supplied by VDD, e.g. the µP and the external temperature sensor, are powered down) - a raw internal 5 V supply V DDraw is generated to supply the wake up system and the whole logic block - the total current consumption of the IC is less than 90 µA During sleep mode the Wake-up Pin must be at high level (V BAT ). Applying a “low”-pulse on the wake-up pin will wake up the IC. PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Current Consumption in Sleep Mode (Tamb = -40 oC to 125 oC) Ivbat_pd 90 µA Current Consumption in Sleep Mode (Tamb = -40 oC to 27 oC) (1) Ivbat_pd27 (50) µA R17<0> = 1 (SLEEP = high) Note (1): only as information. Will not be tested. Reference Current Generator The reference current generator uses a bandgap based 1 V reference voltage to generate a buffered 1 V voltage reference at pin Iref . A 22 k Ω external resistor must be used to generate the 45 µA current reference. PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Voltage at pin Iref Vref 0.95 1.0 1.05 V High Side Power FET Driver / Slew Rate Regulation The supply voltage of this driver is about 10 V higher than the Vbat (n-channel power FET to drive) and is delivered by the on chip charge pump at pin Vpump. The Power FET driver is controlled in two different ways: First by the digital output of the PWM generator of the µP to realizing a certain duty cycle of the motor drive and so to regulate the motor current, voltage or speed in a closed loop. The driver output OUT is set to low (the motor is switched off) independently of the PWM signal under the following conditions:

• over current condition: The over current signal Poverc is set to high by the over (Poverc = high ) current detection unit and reset to low via the Three Wire Interface
• under voltage condition of Vbat: The under voltage signal PVunder is set and reset by the voltage (PVunder = high) monitor.
• over voltage condition of Vbat: The over voltage signal PVover is set and reset by the voltage (PVover = high ) monitor.

Revision 1.8, Date 2005-03-17 Page 26 of 35

• charge pump voltage Vpump - Vbat is too low: The charge pump OK signal VPok is set and reset by the charge pump (VPok = low ) monitor. The threshold values of these parameters are programmable (see section Summary of all programmable registers (parameters, functions) ).
• the calibration of the motor current measurement unit is not yet finished: Mcalib = low. The motor current must be zero respectively the voltage (V CMP - V CMN ) must be zero during the calibration. This calibration is done after the start up of the system including the ready signal of the charge pump: power on reset signal nPOR and Vpok = high starts the calibration. The calibration procedure needs about 200 µs (see figure 4). Summary of logic driver function: OUT = PWM and /Poverc and /PVunder and /PVover and VPok and Mcalib Second by the analog motor voltage to regulate the slew rate during the rising and falling edge of the motor voltage (EMC conform technology). This slew rate control respectively regulation is executed by a feedback of the motor voltage V motor available at the pin Vmo. The characteristics (parameters) of this slew rate regulation can be programmed via the Three-Wire Interface independently for the falling and rising edge of the motor voltage and can therefore be adapted to a specific application (motor and its environment). This programming of the output current characteristics (gate current of the external power FET) in both directions is shown in section Summary of all programmable registers (parameters, functions) . PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Tolerances of driver output current (pin OUT), sourcing IOUTon -50% +50% I out_on = I SRon-stat + I SRon + I SRon_min The relative tolerances between adjacent programming steps of the driver current are less than 10%. Tolerances of driver output current (pin OUT), sinking IOUToff -50% +50% I out_off = I SRoff-stat + I SRoff The relative tolerances between adjacent programming steps of the driver current are less than 10%. - max. pulse duration = 1 µs @ 20 kHz or max. external charge to load: 250 nC @ 20 kHz - valid for I OUT = 5 mA ... 500 mA and Vbat = 12 V , Vpump = 22 V - Programmable by the registers R1 to R6

Revision 1.8, Date 2005-03-17 Page 27 of 35 Charge Pump and internal Oscillator The charge pump is a one-stage pump that generates a pumped voltage Vpump about 10 V higher than the supply voltage Vbat for Vbat > 13.5 V. It uses two external capacitors only, the capacitor Cp12 as the switched capacitor and Cp0 as the storage capacitor. The pumped voltage (Vpump - Vbat) is monitored to detect over or under voltages (protection of the power FET gate): (Vpump - Vbat) = 10 V to 12 V : Normal voltage regulation of the charge pump (Vpump - Vbat) < (Vpump - Vbat) low : The digital signal VPok is indicating this under voltage and disabling the power FET driver. The threshold value (Vpump - Vbat) low can be programmed to be 6 V or 4 V (VPUMP_MIN). PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Pumped voltage Vpump - Vbat 10 10.5 12 V Vbat = 13.5 V, Iload = 5 mA Pumped voltage Vpump - Vbat 4.0 5.0 V Vbat = 6.5 V, Iload = 2.5 mA Pumped voltage Vpump - Vbat 4.0 V 6.0V ≤ Vbat < 6.5V (low-Battery- mode), Iload = 250µA Under voltage threshold (VPUMP_MIN = 1) (Vpump - Vbat) low 5.4 6.0 6.6 V falling (Vpok) Under voltage threshold (VPUMP_MIN = 0) (Vpump - Vbat) low 3.4 4.0 4.6 V falling (Vpok) regulated voltage threshold (Vpump - Vbat) high 10 10.5 12 V rising frequency f pump 40 50 70 kHz Motor Current Measurement Unit / Over Current Detection The motor current measurement unit functions with an external current measurement resistor R meas in the high side motor line. The chip has two measurement amplification channels with separately programmable amplification factors AVmeas_normal = V A_current / (V CMp – V CMn ) (analogue output A_current ) and AV meas_over = V A_overc / (V CMp – V CMn ) (analogue output A_overc ). The maximal valid nominal analogue output voltage level V A_current and V A_overc of theses channels is 4.0 V (100% value of the output voltage V A_current (nominal value). In general, all programming possibilities can be used to build up a measurement system within the defined limits. It is recommended to use a nominal differential voltage (V CMp – V CMn ) > 50 mV to avoid larger tolerances of the amplification factor caused by offset. The programming of theses two amplification channels is usually realized in a way that the measurement range of the over current measurement channel is wider than the normal current measurement channel. In the whole system the analogue outputs A_current and A_overc are used via an ADC in the controlling µP to regulate and control the system. There is one exception only: The over current detection and protection is realized directly by the over current measurement channel to be able to act very fast in case of an over current situation (short circuit). The measurement unit contains a low pass filter to prevent wrong measurement if short transients of the measurement input voltage occurs (cut-off frequency about 500 kHz). The motor current measurement unit is endowed with an auto calibration procedure for the offset voltage. The motor current respectively the measurement voltage (Vcmp - Vcmn) must be zero during this calibration. This calibration is done after the start up of the system including the ready signal of the charge pump: power on reset signal nPOR and Vpok = high starts the calibration. The calibration procedure needs about 200 µs.

Revision 1.8, Date 2005-03-17 Page 28 of 35 a) Motor current measurement (normal current amplification channel: A CMV_normal , programmed by AV_RANGE_norm (Register R8<1:0>) and AV_TRIMM (Register R7<4:0> ) The nominal measurement differential voltage V meas_nom (corresponding to 100% of the nominal motor current) Vmeas_nom = (V CMp – V CMn )nom = I motor_nom * R meas must be fixed by the value of R meas . So the value of this measurement resistor is given by R meas = (V CMp – V CMn )nom / I motor_nom . The voltage amplification of this motor current measurement unit AV meas_normal = V A_current / (V CMp – V CMn ) is programmable in the range AV_RANGE_norm * AV_TRIMM = (1, 2, 3, 4) * (70, 71, 89, 90) Examples: AV_RANGE_norm = 1: A CMV_normal = 70, 71, 72, , 80, , 89, 90 AV_RANGE_norm = 4: A CMV_normal = 280, 284, 288, , 320, , 360 (The programming values of AV_RANGE_norm >1 are intended for a measurement of low currents with a higher digital resolution, but in this cases the tolerances of the amplification factor is high due to the remaining offset of the measurement amplifier.) This way the analog output value V A_current of the current measurement unit can be adapted to the external measurement resistor Rmeas (trimming of this resistor in the range + 12.5%). The nominal (respectively 100%) voltage of the measurement unit V A_current (this is the nominal input voltage of the ADC on the µP) must be 4.0 V. b) Over current detection and protection (over current amplification channel A CMV_over ) The over current amplification channel uses the same input voltage V meas = (V CMp – V CMn ) as the normal current amplification channel. The voltage amplification of this over current measurement channel A CMV_over = V A_overc / (V CMp – V CMn ) is programmable by AV_RANGE_over (Register R10<1:0>) and AV_TRIMM (Register R7<4:0> ) in the range A CMV_over = AV_RANGE_over * AV_TRIMM = (1/4, 2/4, 3/4, 4/4) * (70, 71, 89, 90)

Revision 1.8, Date 2005-03-17 Page 29 of 35 Examples: AV_RANGE_over = 1/4: A CMV_over = 17.5, 17.75, 18, , 20, , 22.25 , 22.5 AV_RANGE_over = 4/4: A CMV_over = 70, 71, 72, , 80, , 89, 90 The adjustment (trimming) of the measurement resistor R meas is realized by the same programming parameter AV_TRIMM (+ 12.5%) like in a) . The maximal output voltage of the over current amplification channel V A_overc (this is the nominal input voltage of the ADC on the µP) must be 4.0 V. The threshold value of the over current detection can be programmed by the programming parameters OVERC_level (in conjunction with AV_RANGE_over and AV_TRIMM ) in the following way. The voltage over the external measurement resistor where the over current situation is detected (Vmeas_over) is given by: Vmeas_over = OVERC_level / ( AV_TRIMM * AV_RANGE_over) with OVERC_level = 0.5 V, 1.0 V, 1.5 V, 4.0 V See also section Summary of all programmable registers (parameters, functions) for the programming of the parameters above. PARAMETER SYMBOL MIN MAX UNIT NOTE (Programming, nominal amplification) - 6 + 6 % V meas = 50 mV, R8 = 0 /Ge0 80 - 10 + 10 % V meas = 25 mV, R8 = 1 /Ge0 160 - 20 + 20 % V meas = 16.67mV, R8 = 2 /Ge0 240 Tolerance of voltage amplification, normal current measurement channel 1) ∆ACMV_normal - 20 + 20 % V meas = 12.5 mV, R8 = 3 /Ge0 360 - 6 + 6 % V meas = 200 mV, R10 = 0 /Ge0 20 - 6 + 6 % V meas = 100 mV, R10 = 1 /Ge0 40 - 6 + 6 % V meas = 60.6 mV, R10 = 2 /Ge0 60 Tolerance of voltage amplification, over current measurement channel 1) ∆ACMV_over - 6 + 6 % V meas = 50 mV, R10 = 3 /Ge0 80 Tolerance of linearity ACMV_normal ∆lincurrent - 3 + 3 % ((∆VA_current / ∆Vmeas_nom ) - A CMV_normal ) / A CMV_normal Tolerance of linearity ACMV_overc ∆linoverc - 3 + 3 % ((∆VA_overc / ∆Vmeas_nom ) - A CMV_overc ) / A CMV_overc Tolerance of over current thresholds ∆overclevel - 10 + 10 % R10 = 0, R9 ≤ 3, Tamb > 25 oC Tolerance of over current thresholds ∆overclevel - 20 + 10 % R10 = 0, R9 ≤ 3, Tamb = -40 oC Tolerance of over current thresholds ∆overclevel - 20 + 20 % R10 = 0, R9 > 3, Tamb = (-40 to 125) oC Cut off frequency fcut-off 400 800 kHz Note (1): The offset voltage of the current measurement unit at calibration temperature V meas_offset is < 1.5 mV (typical: 0.5 mV), the maximal offset temperature drift is + 20 µV / K.

Revision 1.8, Date 2005-03-17 Page 30 of 35 Battery Voltage Monitor and Over / Under Voltage Detection The Battery voltage monitor has to deliver an analog voltage Vbat_mon in the 5V range which is proportional to the high voltage supply Vbat (normally VDDH = Vbat). The measurement range of the supply voltage Vbat is programmable via the register R11<2:0> to adapt the AS8446 to different application supply voltages. Programming of the MEASUREMENT RANGE of Vbat (programmed by register R11<2:0> /Ge0 VBAT_RANGE) PARAMETER Programming Register R11 SYMBOL MIN MAX UNIT NOTE R11= 0 /Ge0 VBAT_RANGE = 5 Vbat max1 20 V R11= 1 /Ge0 VBAT_RANGE = 8 Vbat max2 32 V R11= 2 /Ge0 VBAT_RANGE = 10 Vbat max3 40 V R11= 3 /Ge0 VBAT_RANGE = 15 Vbat max4 60 V Programmable Measurement Voltage Ranges of Vbat R11= 4 /Ge0 VBAT_RANGE = 20 Vbat max5 80 V (1) Note (1): The programmable value of VBAT_RANGE determines the max. value of Vbat measurable by the voltage monitor (condition: Vbat / VBAT_RANGE < 4 V). Note (2): VBAT must not exceed the sp ecified abs. Max. ratings (see Table 3) PARAMETER SYMBOL MIN MAX UNIT NOTE Tolerance of the division factor ∆VBAT_RANGE - 6 + 6 % Tolerance of the programmed over voltage threshold ∆Vovervolt -10 +10 % Tolerance of the programmed ounder voltage threshold ∆Vundervolt -10 +10 % a) Programming of the OVER VOLTAGE detection level of Vbat (programmed by register R12<2:0> /Ge0 OVER_VOLT and R11<2:0> /Ge0 VBAT_RANGE ) Remark: The maximum over voltage limit of Vbat for safe functionality of AS8446 is limited to Vbat < 30 V and must be respected by appropriate programming . During an over voltage situation the write access to th e Three Wire Interface is blocked and the driver is switched off. b) Programming of the UNDER VOLTAGE detection level of Vbat (programmed by register R13<2:0> /Ge0 UNDER_VOLT and R11<2:0> /Ge0 VBAT_RANGE) Remark: The minimium Vbat for full functionality of AS8446 is limited to Vbat > 6.5 V (except for Low-battery- mode reduced functionality is still given between 6V and 6.5V, see Table 4Operating Conditions).

Revision 1.8, Date 2005-03-17 Page 31 of 35 Over Temperature Detection On Chip Over Temperature Detection The on chip temperature detection sets the signal PTover_in high if the chip temperature climbs above the specified level. This over temperature detection has a hysteresis of about 20 °C. PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Recovery Temperature T recovery +130 +140 +150 °C Information Parameter Shutdown Temperature T shutdpwn +150 +160 +170 °C Information Parameter On chip temperature voltage VTEMP 1 1.4 V T ON_CHIP = 27 °C threshold voltage of the on chip over temperature comparator VOTI 0.8 1 V Information Parameter Hysteresis of the over temperature comparator VOTIHYST 30 50 mV Information Parameter External Over Temperature Detection The over temperature detection is realized with an external temperature sensor (e.g. NTC). The threshold value of the voltage at pin TP is defined to V th_TP = 0.5* VDD (typical 2.5 V) and has a hysteresis. PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Over Temperature threshold value Vth_TP VDD/2 – 0.05 VDD/2 + 0.05 V Negative Hysteresis Vth_TP_HYS_N 30 70 mV The over temperature signal PTover_ex is defined in the following way: PTover_ex = high if V IN < V th_TP (over temperature) PTover_ex = low if V IN > V th_TP (no over temperature) Analog MUX and Analog Output Buffer The following analog measurement channels and digital signals are output via an analog MUX and an analog buffer to the pin ADC, the MUX is controlled by register R15<3:0> Analog MUX function PARAMETER SYMBOL TYP NOTE A_current Normal motor current measurement channel R15 = 0 A_overc Motor over current measurement channel R15 = 1 Vbat_mon Battery voltage monitoring R15 = 2 TP Temperature sensor analog value R15 = 3 Used in normal application to control / regulate the system Vtemp Temperature voltage R15 = 4 PVover Over voltage signal R15 = 5 PVunder Under voltage signal R15 = 6 PTover_ex Over temperature signal, extern R15 = 7 PTover_in Over temperature signal, intern R15 = 8 Used for test purposes only

Revision 1.8, Date 2005-03-17 Page 32 of 35 Analog buffer characterization PARAMETER SYMBOL MIN TYP MAX UNIT NOTE Input/Output voltage range V IO 0.0 4.0 V Offset voltage V offset 80 mV Slew rate SR buffer 1.0 V/ µs (1) Note (1): C Load = 20 pF Failure Feedback Signal There are two different ways to detect failures in the whole regulator system:

• System failures detected directly on chip (e.g. over current, under voltage, ) and indicated by the appropriate failure signal (e.g. Poverc, PVunder, , respectively FAIL)
• System failures detected by software of the controlling µP via the monitoring of the motor current, motor speed, battery voltage, temperature and duty cycle of the PWM signal (e.g. motor failures like blocked motor, open wires, ). This part of system failures must be defined by the motor and system know how of the customer. The following system failures are detected directly on the AS8446 chip: 1. Over current of the motor (signal: Poverc) 2. Under voltage of the battery voltage Vbat (signal: PVunder) 3. Over voltage of the battery voltage Vbat (signal: PVover) 4. Over temperature of external temperature (signal: PTover_ex) 5. Over temperature of on chip temperature (signal: PTover_in) 6. Under voltage of VDD (5 V) (signal: VDDunder) 7. Over voltage of VDD (5 V) (signal: VDDover) All these seven failures are stored in register R18 and can be read by the controlling µP via the Three Wire Interface. A failure signal FAIL is created by OR conjunction of these failures and put to the pin FAIL (can be used as an interrupt signa l for the µP to start a read access via the Three Wire Interface to the failure register R18): FAIL = Poverc or PVunder or PVover or PTover_ex or PTover_in or VDDunder or VDDover or TEMP_TEST The first three failures (over current, over and under voltage) are used to switch off the driver output OUT immediately by on chip hardware, the two temperature failure and the VDD over / under voltage failure are only detected and can be treated by software of the µP. The signal TEMP_TEST is only used for test purposes and must be set low in the normal application. If there is a wrong value (high) of TEMP_TEST during the normal application the FAIL signal is set and must be reset via the Three Wire Interface. Wake-up System (Pin Wake-up) PARAMETER SYMBOL MIN TYP MAX UNIT NOTE DC Characteristics Low Level Input Voltage V IL -8 0.4 V BAT V High Level Input Voltage V IH 0.6 V BAT VBAT V Input Hysteresis V HYS 0.05 V BAT 0.1 V BAT VV IH - V IL Pull- up Current on Input I PU -400 5 µA > 30 k Ω internal pull- up @ V IH = 0.7 V BAT Watch Dog and RESET The watch dog can be used to supervise the function of the controlling µP. In cases where this supervising is not necessary, the watch dog is switched off via the Three Wire Interface by sending a zero to R16<0:0>. The default value after the start up of the system is R16<0:0> = 0 (watch dog is not active).

Revision 1.8, Date 2005-03-17 Page 33 of 35 The trigger of the watch dog is done by the high / low edge of the external signal WD (start of the counter). The output signal of the watch dog WDout goes high if the watch dog time is over. The output signal of the watch dog WDout or the nPOR are generate the low active sign al RESET (used for external µP only): if nPOR = low or ( WDout = high) and R16<0> = high) /Ge0 RESET = low PARAMETER SYMBOL MIN TYP MAX UNIT NOTE time out of the watch dog T watch 110 160 190 ms RESET pulse duration T watch_d 14 20 25 µs Package Drawing and Marking Figure 14 Physical Dimensions (SOIC28) of AS 8446 Physical Dimensions SOIC28 (millimeters) D E H A A1 e b L α

1.27 BSC

0.48 1.02 8 ° EH 123 AA1 e b D TOP VIEW SIDE VIEW END VIEWL α

Revision 1.8, Date 2005-03-17 Page 35 of 35 Contact austriamicrosystems AG A 8141 Schloss Premstätten, Austria T. +43 (0) 3136 500 0 F. +43 (0) 3136 525 01 info@austriamicrosystems.com Copyright Copyright © 2003 austriamicrosystems. Trademarks registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. To the best of its knowledge, austriamicrosystems asserts that the information contained in this publication is accurate and correct.