TCN75A

TCN75A MICROCHIP | Alldatasheet

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© 2006 Microchip Technology Inc. DS21935C-page 1 TCN75A Features:

• Temperature-to-Digital Converter
• Accuracy: - ±1 (typ.) from -40°C to +125°C - ±2°C (max.) from +40°C to +125°C
• User-selectable Resolution: 0.5°C to 0.0625°C
• Operating Voltage Range: 2.7V to 5.5V
• 2-wire Interface: I2C™ Compatible
• Operating Current: 200 μA (typ.)
• Shutdown Current: 2 μA (max.)
• Power-saving One-shot Temperature Measurement
• Available Packages: MSOP-8, SOIC-8 Typical Applications:
• Personal Computers and Servers
• Hard Disk Drives and Other PC Peripherals
• Entertainment Systems
• Office Equipment
• Data Communication Equipment
• General Purpose Temperature Monitoring Typical Application Description: Microchip Technology Inc.’s TCN75A digital tempera- ture sensor converts temperatures between -40°C and +125°C to a digital word, with ±1°C (typ.) accuracy. The TCN75A product comes with user-programmable registers that provide flexibility for temperature-sensing applications. The register settings allow user-select- able, 0.5°C to 0.0625°C temperature measurement resolution, configuration of the power-saving Shutdown and One-shot (single conversion on command while in Shutdown) modes and the specification of both temperature alert output and hysteresis limits. When the temperature changes beyond the specified limits, the TCN75A outputs an alert signal. The user has the option of setting the alert output signal polarity as an active-low or active-high comparator output for thermo- stat operation, or as temperature event interrupt output for microprocessor-based systems. This sensor has an industry standard 2-wire, I2C™ compatible serial interface, allowing up to eight devices to be controlled in a single serial bus. These features make the TCN75A ideal for low-cost, sophisticated multi-zone temperature-monitoring applications. Package Types VDD R TCN75A SDA SCL I/O Ports RPULL-UP PIC® VDD SDA GND ALERT SCL Microcontroller ALERT VDD SDA GND ALERT SCL 8-Pin SOIC, MSOP VDD TCN75A 2-Wire Serial Temperature Sensor

© 2006 Microchip Technology Inc. 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings † †Notice: Stresses above those listed under “Maximum ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. DC CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground, and TA = -40°C to +125°C. Parameters Sym Min Typ Max Unit Conditions Power Supply Operating Voltage Range VDD 2.7 5.5 V Operating Current IDD 200 500 μA Continuous operation Shutdown Current ISHDN 0.1 μA Shutdown mode Power-On Reset (POR) Threshold VPOR 1.7 V VDD falling edge Power Supply Rejection Δ°C/ΔVDD 0.2 °C/V VDD = 2.7V to 5.5V Temperature Sensor Accuracy TA = -40°C to +125°C TACY VDD = 3.3V Internal ΣΔ ADC Conversion Time: 0.5°C Resolution tCONV ms 33 samples/sec (typ.) 0.25°C Resolution tCONV ms 17 samples/sec (typ.) 0.125°C Resolution tCONV 120 ms 8 samples/sec (typ.) 0.0625°C Resolution tCONV 240 ms 4 samples/sec (typ.) Alert Output (Open-drain) High-level Current IOH μA VOH = 5V Low-level Voltage VOL 0.4 V IOL= 3 mA Thermal Response Response Time tRES 1.4 s Time to 63% (89°C) 27°C (air) to 125°C (oil bath)

© 2006 Microchip Technology Inc. DS21935C-page 3 TCN75A Graphical Symbol Description DIGITAL INPUT/OUTPUT PIN CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground and TA = -40°C to +125°C. Parameters Sym Min Typ Max Units Conditions Serial Input/Output (SCL, SDA, A0, A1, A2) Input High-level Voltage VIH

0.7 VDD

V Low-level Voltage VIL

0.3 VDD

V Input Current IIN μA Output (SDA) Low-level Voltage VOL 0.4 V IOL= 3 mA High-level Current IOH μA VOH = 5V Low-level Current IOL mA VOL = 0.6V Capacitance CIN pF SDA and SCL Inputs Hysteresis VHYST

0.05 VDD

V VDD VIH VIL IIN Voltage Current time time VDD IOH Voltage Current time time INPUT OUTPUT VOL IOL TEMPERATURE CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, VDD = +2.7V to +5.5V and GND = Ground. Parameters Sym Min Typ Max Units Conditions Temperature Ranges Specified Temperature Range TA -40 +125 Note 1 Operating Temperature Range TA -40 +125 Storage Temperature Range TA -65 +150 Thermal Package Resistances Thermal Resistance, 8L-SOIC θJA 163 °C/W Thermal Resistance, 8L-MSOP θJA 206 °C/W Note 1: Operation in this range must not cause TJ to exceed Maximum Junction Temperature (+150°C).

© 2006 Microchip Technology Inc. Timing Diagram SERIAL INTERFACE TIMING SPECIFICATIONS (NOTE 1) Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground, TA = -40°C to +125°C, CL = 80 pF and all limits measured to 50% point. Parameters Sym Min Typ Max Units Conditions 2-Wire I2C™ Compatible Interface Serial Port Frequency fSC 400 kHz Clock Period tSC 2.5 μs Low Clock tLOW 1.3 μs High Clock tHIGH 0.6 μs Rise Time tR 300 ns 10% to 90% of VDD (SCL, SDA) Fall Time tF 300 ns 90% to 10% of VDD (SCL, SDA) Data Setup Before SCL High tSU-DATA 0.1 μs Data Hold After SCL Low tH-DATA μs Start Condition Setup Time tSU-START 0.6 μs Start Condition Hold Time tH-START 0.6 μs Stop Condition Setup Time tSU-STOP 0.6 μs Bus Idle tB-FREE 1.3 μs Note 1: Specification limits are characterized but not product tested. tSU-START tH-START tSU-DATA tSU-STOP tB-FREE SCL SDA tH-DATA tHIGH tLOW tR, tF Start Condition Data Transmission Stop Condition

© 2006 Microchip Technology Inc. DS21935C-page 5 TCN75A 2.0 TYPICAL PERFORMANCE CURVES Note: Unless otherwise noted: VDD = 2.7V to 5.5V. FIGURE 2-1: Average Temperature Accuracy vs. Ambient Temperature, VDD = 3.3V. FIGURE 2-2: Average Temperature Accuracy vs. Ambient Temperature. FIGURE 2-3: Average Temperature Accuracy vs. Ambient Temperature, VDD = 3.3V. FIGURE 2-4: Temperature Accuracy Histogram, TA = +25°C. FIGURE 2-5: Supply Current vs. Ambient Temperature. FIGURE 2-6: Shutdown Current vs. Ambient Temperature. Note: The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore outside the warranted range. -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 -55 -35 -15 105 125 TA (°C) Temperature Accuracy (°C) 0.0625°C Resolution

160 Devices

VDD = 3.3V Specification Limits -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 -55 -35 -15 105 125 TA (°C) Temperature Accuracy (°C) 0.0625°C Resolution VDD = 2.7V VDD = 3.3V VDD = 5.5V VDD = 5.0V -3.0 -2.0 -1.0 0.0 1.0 2.0 3.0 -55 -35 -15 105 125 TA (°C) Temperature Accuracy (°C) 0.125°C 0.0625°C 0.5°C 0.25°C VDD = 3.3V 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Temperature Accuracy (°C) Occurrences TA = +25°C VDD = 3.3V 5 lots

32 Samples/lot

-55 -35 -15 105 125 TA (°C) IDD (µA) VDD = 2.7V VDD = 3.3V VDD = 5.5V VDD = 5.0V 0.2 0.4 0.6 0.8 -55 -35 -15 105 125 TA (°C ) ISHDN (µA)

© 2006 Microchip Technology Inc. DS21935C-page 7 TCN75A 3.0 PIN DESCRIPTION The descriptions of the pins are listed in Table 3-1. TABLE 3-1: PIN FUNCTION TABLE 3.1 Serial Data Pin (SDA) SDA is a bidirectional input/output pin, used to serially transmit data to and from the host controller. This pin requires a pull-up resistor to output data. 3.2 Serial Clock Pin (SCL) SCL is a clock input pin. All communication and timing is relative to the signal on this pin. The clock is generated by the host controller on the bus. 3.3 Power Supply Input (VDD) VDD is the power pin. The operating voltage, as specified in the DC electrical specification table, is applied on this pin. 3.4 Ground (GND) GND is the system ground pin. 3.5 ALERT Output The TCN75A’s ALERT pin is an open-drain output. The device outputs an alert signal when the ambient temperature goes beyond the user-programmed temperature limit. 3.6 Address Pins (A2, A1, A0) A2, A1 and A0 are device or slave address input pins. The address pins are the Least Significant bits (LSb) of the device address bits. The Most Significant bits (MSb) (A6, A5, A4, A3) are factory-set to <1001>. This is illustrated in Table 3-2. MSOP, SOIC Symbol Function SDA Bidirectional Serial Data SCL Serial Clock Input ALERT Temperature Alert Output GND Ground Address Select Pin (bit 2) Address Select Pin (bit 1) Address Select Pin (bit 0) VDD Power Supply Input TABLE 3-2: SLAVE ADDRESS Device TCN75A X X X Note: User-selectable address is shown by X.

© 2006 Microchip Technology Inc. 4.0 SERIAL COMMUNICATION 4.1 2-Wire SMBus/Standard Mode I2C™ Protocol-Compatible Interface The TCN75A serial clock input (SCL) and the bidirectional serial data line (SDA) form a 2-wire bidirectional SMBus/Standard mode I2C compatible communication port (refer to the Digital Input/output Pin Characteristics Table and Serial Interface Tim- ing Specifications (Note 1) Table). The following bus protocol has been defined: TABLE 4-1: TCN75A SERIAL BUS PROTOCOL DESCRIPTIONS 4.1.1 DATA TRANSFER Data transfers are initiated by a Start condition (START), followed by a 7-bit device address and a read/write bit. An Acknowledge (ACK) from the slave confirms the reception of each byte. Each access must be terminated by a Stop condition (STOP). Repeated communication is initiated after tB-FREE. This device does not support sequential register read/ write. Each register needs to be addressed using the Register Pointer. This device supports the Receive Protocol. The register can be specified using the pointer for the initial read. Each repeated read or receive begins with a Start condition and address byte. The TCN75A retains the previously selected register. Therefore, it outputs data from the previously-specified register (repeated pointer specification is not necessary). 4.1.2 MASTER/SLAVE The bus is controlled by a master device (typically a microcontroller) that controls the bus access and generates the Start and Stop conditions. The TCN75A is a slave device and does not control other devices in the bus. Both master and slave devices can operate as either transmitter or receiver. However, the master device determines which mode is activated. 4.1.3 START/STOP CONDITION A high-to-low transition of the SDA line (while SCL is high) is the Start condition. All data transfers must be preceded by a Start condition from the master. If a Start condition is generated during data transfer, the TCN75A resets and accepts the new Start condition. A low-to-high transition of the SDA line (while SCL is high) signifies a Stop condition. If a Stop condition is introduced during data transmission, the TCN75A releases the bus. All data transfers are ended by a Stop condition from the master. 4.1.4 ADDRESS BYTE Following the Start condition, the host must transmit an 8-bit address byte to the TCN75A. The address for the TCN75A Temperature Sensor is ‘1001,A2,A1,A0’ in binary, where the A2, A1 and A0 bits are set externally by connecting the corresponding pins to VDD ‘1’ or GND ‘0’. The 7-bit address transmitted in the serial bit stream must match the selected address for the TCN75A to respond with an ACK. Bit 8 in the address byte is a read/write bit. Setting this bit to ‘1’ commands a read operation, while ‘0’ commands a write operation (see Figure 4-1). Term

Description

The device that controls the serial bus, typically a microcontroller. Slave The device addressed by the master, such as the TCN75A. Transmitter Device sending data to the bus. Receiver Device receiving data from the bus. START A unique signal from master to initiate serial interface with a slave. STOP A unique signal from the master to terminate serial interface from a slave. Read/Write A read or write to the TCN75A registers. ACK A receiver Acknowledges (ACK) the reception of each byte by polling the bus. NAK A receiver Not-Acknowledges (NAK) or releases the bus to show End-of-Data (EOD). Busy Communication is not possible because the bus is in use. Not Busy The bus is in the idle state, both SDA and SCL remain high. Data Valid SDA must remain stable before SCL becomes high in order for a data bit to be considered valid. During normal data transfers, SDA only changes state while SCL is low.

© 2006 Microchip Technology Inc. DS21935C-page 9 TCN75A FIGURE 4-1: Device Addressing. 4.1.5 DATA VALID After the Start condition, each bit of data in transmission needs to be settled for a time specified by tSU-DATA before SCL toggles from low-to-high (see “Sensor And EEPROM Serial Interface Timing Specifications” on Page 4). 4.1.6 ACKNOWLEDGE (ACK) Each receiving device, when addressed, is obliged to generate an ACK bit after the reception of each byte. The master device must generate an extra clock pulse for ACK to be recognized. The acknowledging device pulls down the SDA line for tSU-DATA before the low-to-high transition of SCL from the master. SDA also needs to remain pulled down for tH-DATA after a high-to-low transition of SCL. During read, the master must signal an End-of-Data (EOD) to the slave by not generating an ACK bit (NAK) once the last bit has been clocked out of the slave. In this case, the slave will leave the data line released to enable the master to generate the Stop condition. SCL SDA A2 A1 A0 Start Address Byte Slave Address R/W TCN75A Response Code Address A C K

© 2006 Microchip Technology Inc. 5.0 FUNCTIONAL DESCRIPTION The TCN75A temperature sensor consists of a band- gap type temperature sensor, a ΣΔ Analog-to-Digital Converter (ADC), user-programmable registers and a 2-wire I2C protocol-compatible serial interface. FIGURE 5-1: Functional Block Diagram. 5.1 Temperature Sensor The TCN75A uses the difference in the base-emitter voltage of a transistor while its collector current is changed from IC1 to IC2. With this method, the ΔVBE depends only on the ratio of the two currents and the ambient temperature, as shown in Equation 5-1. EQUATION 5-1: 5.2 ΣΔ Analog-to-Digital Converter A Sigma-Delta ADC is used to convert ΔVBE to a digital word that corresponds to the transistor temperature. The converter has an adjustable resolution from 0.5°C (at 30 ms conversion time) to 0.0625°C (at 240 ms conversion time). Thus, it allows the user to make trade- offs between resolution and conversion time. Refer to Section 5.3.2 “Sensor Configuration Register (CONFIG)” and Section 5.3.4.7 “ΣΔ ADC Resolution” for details. Resolution 0.5°C 0.25°C 0.125°C 0.0625°C Temperature THYST TSET Register Register Register Register Pointer I2C™ Interface Configuration Register ΣΔ ADC Band-Gap Temperature Sensor One-Shot Shutdown Fault Queue Alert Polarity Alert Comp/Int ΔVBE kT ln IC1 IC2 Where: T = temperature in kelvin ΔVBE = change in diode base-emitter voltage k = Boltzmann's constant q = electron charge IC1 and IC2 = currents with n:1 ratio

© 2006 Microchip Technology Inc. DS21935C-page 11 TCN75A 5.3 Registers The TCN75A has four registers that are user-accessi- ble. These registers are specified as the Ambient Temperature (TA) register, the Temperature Limit-set (TSET) register, the Temperature Hysteresis (THYST) register and device Configuration (CONFIG) register. The Ambient Temperature register is a read-only register and is used to access the ambient temperature data. The data from the ADC is loaded in parallel in the register. The Temperature Limit-set and Temperature Hysteresis registers are read/write registers that provide user-programmable temperature limits. If the ambient temperature drifts beyond the programmed limits, the TCN75A outputs an alert signal using the ALERT pin (refer to Section 5.3.4.3 “ALERT Output Configuration”). The device Configuration register provides access for the user to configure the TCN75A’s various features. These registers are described in further detail in the following sections. The registers are accessed by sending register pointers to the TCN75A using the serial interface. This is an 8-bit pointer. However, the two Least Significant bits (LSbs) are used as pointers and all other bits need to be cleared <0>. This device has additional registers that are reserved for test and calibration. If these registers are accessed, the device may not perform according to the specification. The pointer description is shown below. FIGURE 4-2: Register Block Diagram. ALERT Output Control Logic ALERT Output Resolution Temperature THYST TSET Register Register Register Configuration Register One-Shot Shutdown Fault Queue Alert Polarity Alert Comp/Int REGISTER 5-1: REGISTER POINTER U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-0 bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7-3 Unimplemented: Read as ‘0’ bit 2-0 Pointer bits 00 = Temperature register (TA) 01 = Configuration register (CONFIG) 10 = Temperature Hysteresis register (THYST) 11 = Temperature Limit-set register (TSET)

© 2006 Microchip Technology Inc. TABLE 5-1: BIT ASSIGNMENT SUMMARY FOR ALL REGISTERS Register Pointer P1 P0 MSB/ LSB Bit Assignment Ambient Temperature Register (TA) 0 0 MSB Sign 26°C 25°C 24°C 23°C 22°C 21°C 20°C LSB 2-1°C 2-2°C 2-3°C 2-4°C Sensor Configuration Register (CONFIG) 0 1 LSB One-Shot Resolution Fault Queue ALERT Polarity COMP/INT Shutdown Temperature Hysteresis Register (THYST) 1 0 MSB Sign 26°C 25°C 24°C 23°C 22°C 21°C 20°C LSB 2-1°C Temperature Limit-Set Register (TSET) 1 1 MSB Sign 26°C 25°C 24°C 23°C 22°C 21°C 20°C LSB 2-1°C

© 2006 Microchip Technology Inc. DS21935C-page 13 TCN75A 5.3.1 AMBIENT TEMPERATURE REGISTER (TA) The TCN75A has a 16-bit read-only Ambient Temperature register that contains 9-bit to 12-bit temperature data. (0.5°C to 0.0625°C resolutions, respecively). This data is formatted in two’s complement. The bit assignments, as well as the corresponding resolution, is shown in the register assignment below. The refresh rate of this register depends on the selected ADC resolution. It takes 30 ms (typ.) for 9-bit data and 240 ms (typ.) for 12-bit data. Since this register is double-buffered, the user can read the register while the TCN75A performs Analog-to-Digital conversion in the background. The decimal code to ambient temperature conversion is shown in Equation 5-2: EQUATION 5-2: TA Code 2 4 Where: TA = Ambient Temperature (°C) Code = TCN75A output in decimal REGISTER 5-2: AMBIENT TEMPERATURE REGISTER (TA) - ADDRESS <0000 0000>b Upper Half: R-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0 Sign 26 °C 25 °C 24 °C 23 °C 22 °C 21 °C 20 °C bit 15 bit 8 Lower Half: R-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0 2-1 °C/bit 2-2 °C 2-3 °C 2-4 °C bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown Note 1: When the 0.5°C, 0.25°C or 0.125°C resolutions are selected, bit 6, bit 7 or bit 8 will remain clear <0>, respectively.

© 2006 Microchip Technology Inc. FIGURE 5-2: Timing Diagram for Reading +25.25°C Temperature from the TA Register (See Section 4.0 “Serial Communication”). SDA A C K A TA Pointer A C K S A A SCL Address Byte A C K A MSB Data A C K N A K S P A A Address Byte LSB Data R TCN75A TCN75A TCN75A Master Master W SDA SCL Note: It is not necessary to select the register pointer if it was set from the previous read/write. (see Section 4.1.1)

© 2006 Microchip Technology Inc. DS21935C-page 15 TCN75A 5.3.2 SENSOR CONFIGURATION REGISTER (CONFIG) The TCN75A has an 8-bit read/write Configuration register that allows the user to select the different features. These features include shutdown, ALERT output select as comparator or interrupt output, ALERT output polarity, fault queue cycle, temperature measurement resolution and One-shot mode (single conversion while in shutdown). These functions are described in detail in the following sections. REGISTER 5-3: CONFIGURATION REGISTER (CONFIG) - ADDRESS <0000 0001>b R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 One-Shot Resolution Fault Queue ALERT Polarity COMP/INT Shutdown bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown bit 7 ONE-SHOT bit 1 = Enabled 0 = Disabled (Power-up default) bit 5-6 ΣΔ ADC RESOLUTION bits 00 = 9 bit or 0.5°C (Power-up default) 01 = 10 bit or 0.25°C 10 = 11 bit or 0.125°C 11 = 12 bit or 0.0625°C bit 3-4 FAULT QUEUE bits 00 = 1 (Power-up default) 01 = 2 10 = 4 11 = 6 bit 2 ALERT POLARITY bit 1 = Active-high 0 = Active-low (Power-up default) bit 1 COMP/INT bit 1 = Interrupt mode 0 = Comparator mode (Power-up default) bit 0 SHUTDOWN bit 1 = Enable 0 = Disable (Power-up default)

© 2006 Microchip Technology Inc. FIGURE 5-3: Timing Diagram for Writing and Reading from the Configuration Register (See Section 4.0 “Serial Communication”). SDA A C K A CONFIG Pointer A C K S A A SCL Address Byte A C K A Data N A K S P A A Address Byte R TCN75A TCN75A TCN75A W SDA SCL

• Reading the CONFIG Register.
• Writing to the CONFIG Register to change the resolution to 0.0625°C <0110 0000>b. SDA A C K A A C K S A A SCL Address Byte W TCN75A TCN75A MSB Data A C K P CONFIG Pointer TCN75A Note: It is not necessary to select the register pointer if it was set from the previous read/write (see Section 4.1.1).

© 2006 Microchip Technology Inc. DS21935C-page 17 TCN75A 5.3.3 TEMPERATURE HYSTERESIS REGISTER (THYST) The TCN75A has a 16-bit read/write Temperature Hysteresis register that contains a 9-bit data in two’s compliment format. This register is used to set a hysteresis for the TSET limit. Therefore, the data represents a minimum temperature limit. If the ambient temperature drifts below the specified limit, the TCN75A asserts an alert output (refer to Section 5.3.4.3 “ALERT Output Configuration”). This register uses the nine Most Significant bits (MSbs) and all other bits are don’t cares. The power-up default value of THYST register is 75°C, or <0100 1011 0>b in binary. REGISTER 5-4: TEMPERATURE HYSTERESIS REGISTER (THYST) - ADDRESS <0000 0010>b Upper Half: R/W-0 R/W-1 R/W-0 R/W-0 R/W-1 R/W-0 R/W-1 R/W-1 Sign 26 °C 25 °C 24 °C 23 °C 22 °C 21 °C 20 °C bit 15 bit 8 Lower Half: R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0 2-1 °C bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

© 2006 Microchip Technology Inc. FIGURE 5-4: Timing Diagram for Writing and Reading from the Temperature Hysteresis Register (See Section 4.0 “Serial Communication”). SDA A C K A A C K S A A SCL Address Byte A C K A MSB Data A C K N A K S P A A Address Byte LSB Data R TCN75A TCN75A TCN75A Master Master W SDA SCL

• Reading the THYST Register.
• Writing to the THYST Register to set the temperature hysteresis to 95°C <0101 1111 0000 0000>b. SDA A C K A A C K S A A SCL Address Byte W TCN75A TCN75A MSB Data A C K A C K P LSB Data THYST Pointer TCN75A TCN75A Note: It is not necessary to select the register pointer if it was set from the previous read/write (see Section 4.1.1). THYST Pointer

© 2006 Microchip Technology Inc. DS21935C-page 19 TCN75A 5.3.4 TEMPERATURE LIMIT-SET REGISTER (TSET) The TCN75A has a 16-bit read/write Temperature Limit-Set register (TSET) which contains a 9-bit data in two’s compliment format. This data represents a maxi- mum temperature limit. If the ambient temperature exceeds this specified limit, the TCN75A asserts an alert output. (Refer to Section 5.3.4.3 “ALERT Output Configuration”). This register uses the nine Most Significant bits (MSbs) and all other bits are “don’t cares”. The power-up default value of the TSET register is 80°C, or <0101 0000 0>b in binary. REGISTER 5-5: TEMPERATURE LIMIT-SET REGISTER (TSET) - ADDRESS <0000 0011>b Upper Half: R/W-0 R/W-1 R/W-0 R/W-1 R/W-0 R/W-0 R/W-0 R/W-0 Sign 26 °C 25 °C 24 °C 23 °C 22 °C 21 °C 20 °C bit 15 bit 8 Lower Half: R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 R-0 2-1 °C bit 7 bit 0 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ -n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown

© 2006 Microchip Technology Inc. FIGURE 5-5: Timing Diagram for Writing and Reading from the Temperature Limit-set Register (See Section 4.0 “Serial Communication”). SDA A C K A TSET Pointer A C K S A A SCL Address Byte A C K A MSB Data A C K N A K S P A A Address Byte LSB Data R TCN75A TCN75A TCN75A Master Master W SDA SCL

• Reading the TSET Register.
• Writing to the TSET Register to set the temperature limit to 90°C, <0101 1010 0000 0000>b SDA A C K A A C K S A A SCL Address Byte W TCN75A TCN75A MSB Data A C K A C K P LSB Data TSET Pointer TCN75A TCN75A Note: It is not necessary to select the register pointer if it was set from the previous read/write. (see Section 4.1.1)

© 2006 Microchip Technology Inc. DS21935C-page 21 TCN75A 5.3.4.1 Shutdown Mode The Shutdown mode disables all power-consuming activities (including temperature sampling operations) while leaving the serial interface active. The device consumes 2 μA (max.) in this mode. It remains in this mode until the Configuration register is updated to enable continuous conversion or until power is recycled. In Shutdown mode, the CONFIG, TA, TSET and THYST registers can be read or written to; however, the serial bus activity will increase the shutdown current. 5.3.4.2 One-Shot Mode The TCN75A can also be used in a One-shot mode that can be selected using bit 7 of the CONFIG register. The One-shot mode performs a single temperature measurement and returns to Shutdown mode. This mode is especially useful for low-power applications where temperature is measured upon command from a controller. For example, a 9-bit TA in One-shot mode consumes 200 μA (typ.) for 30 ms and 0.1 μA (typ.) during shutdown. To access this feature, the device needs to initially be in Shutdown mode. This is done by sending a byte to the CONFIG register with bit 0 set <1> and bit 7 cleared <0>. Once the device is in Shutdown mode, the CONFIG register needs to be written to again, with bit 0 and bit 7 set <1>. This begins the single conversion cycle of tCONV, 30ms for 9-bit data. Once the conversion is completed, TA is updated and bit 7 of CONFIG becomes cleared <0> by the TCN75A. TABLE 5-6: SHUTDOWN AND ONE-SHOT MODE DESCRIPTION 5.3.4.3 ALERT Output Configuration The ALERT output can be configured as either a comparator output or as Interrupt Output mode using bit 1 of CONFIG. The polarity can also be specified as an active-high or active-low using bit 2 of CONFIG. The following sections describe each output mode, while Figure 5-6 gives a graphical description. 5.3.4.4 Comparator Mode In Comparator mode, the ALERT output is asserted when TA is greater than TSET. The pin remains active until TA is lower than THYST. The Comparator mode is useful for thermostat-type applications, such as turning on a cooling fan or triggering a system shutdown when the temperature exceeds a safe operating range. In Comparator mode, if the device enters the Shutdown mode with asserted ALERT output, the output remains active during shutdown. The device must be operating in continuous conversion, with TA below THYST, for the ALERT output to be deasserted. 5.3.4.5 Interrupt Mode In Interrupt mode, the ALERT output is asserted when TA is greater than TSET. However, the output is deasserted when the user performs a read from any register. This mode is designed for interrupt-driven, microcontroller- based systems. The microcontroller receiving the inter- rupt will have to acknowledge the interrupt by reading any register from the TCN75A. This will clear the interrupt and the ALERT pin will become deasserted. When TA drifts below THYST, the TCN75A outputs another interrupt and the controller needs to read a register to deassert the ALERT output. Shutting down the device will also reset, or deassert, the ALERT output. FIGURE 5-6: Alert Output. Operational Mode One-Shot (Bit 7) Shutdown (Bit 0) Continuous Conversion Shutdown Continuous Conversion (One-shot is ignored) One-shot (Note 1) Note 1: The shutdown command <01> needs to be programmed before sending a one- shot command <11>. TSET THYST ALERT ALERT Comparator mode Interrupt mode Active-low Active-low TA Register Read * See Section 5.3.4.5 “Interrupt Mode”

© 2006 Microchip Technology Inc. 5.3.4.6 Fault Queue The fault queue feature can be used as a filter to lessen the probability of spurious activation of the ALERT pin. TA must remain above TSET for the consecutive num- ber of conversion cycles selected using the Fault Queue bits. Bit 3 and bit 4 of CONFIG can be used to select up to six fault queue cycles. For example, if six fault queues are selected, TA must be greater than TSET for six consecutive conversions before ALERT is asserted as a comparator or an interrupt output. This queue setting also applies for THYST. If six fault queues are selected, TA must remain below THYST for six consecutive conversions before ALERT is deas- serted (Comparator mode) or before another interrupt is asserted (Interrupt mode). 5.3.4.7 ΣΔ ADC Resolution The TCN75A provides access to select the ADC resolution from 9-bit to 12-bit (0.5°C to 0.0625°C resolution) using bit 6 and bit 5 of the CONFIG register. The user can gain better insight into the trends and characteristics of the ambient temperature by using a finer resolution. Increasing the resolution also reduces the quantization error. Figure 2-3 shows accuracy versus resolution. Table 5-1 shows the TA register conversion time for the corresponding resolution. TABLE 5-1: RESOLUTION AND CONVERSION TIME 5.4 Summary of Power-up Condition The TCN75A has an internal Power-on Reset (POR) circuit. If the power supply voltage VDD glitches down to the 1.7V (typ.) threshold, the device resets the registers to the power-up default settings. Table 5-2 shows the power-up default summary. TABLE 5-2: POWER-UP DEFAULTS At power-up, the TCN75A has an inherent 2 ms (typ.) power-up delay before updating the registers with default values and start a conversion cycle. This delay reduces register corruption due to unsettled power. After power-up, it takes tCONV for the TCN75A to update the TA register with valid temperature data. Bits Resolution tCONV (typ.) 0.5 30 ms 0.25 60 ms 0.125 120 ms 0.0625 240 ms Register Data (Hex) Power-up Defaults TA 0000 0°C TSET A000 80°C THYST 9600 75°C Pointer Temperature register CONFIG Continuous Conversion Comparator mode Active-low Output Fault Queue 1 9-bit Resolution

© 2006 Microchip Technology Inc. 7.0 PACKAGING INFORMATION 7.1 Package Marking Information 8-Lead SOIC (150 mil) Example: XXXXXXXX XXXXYYWW NNN TCN75AV OA^^0645 256 8-Lead MSOP Example: XXXXX YWWNNN N75A/E 645256 Legend: XX...X Customer-specific information Y Year code (last digit of calendar year) YY Year code (last 2 digits of calendar year) WW Week code (week of January 1 is week ‘01’) NNN Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( ) can be found on the outer packaging for this package. Note: In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. e e e

© 2006 Microchip Technology Inc. DS21935C-page 25 TCN75A 8-Lead Plastic Micro Small Outline Package (UA) (MSOP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging L ϕ c A b NOTE 1 e E D N Number of Pins Pitch Overall Height Molded Package Thickness Standoff Overall Width Molded Package Width Overall Length Foot Length Footprint Foot Angle Lead Thickness Lead Width Units Dimension Limits N e A E D L ϕ c b 0.75 0.00 0.40 0.08 0.22

0.65 BSC

0.85

4.90 BSC

3.00 BSC

0.60

0.95 REF

1.10 0.95 0.15 0.80 0.23 0.40 MIN NOM MAX MILLIMETERS Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.15 mm per side. 3. Dimensioning and tolerancing per ASME Y14.5M BSC: Basic Dimension. Theoretically exact value shown without tolerances. REF: Reference Dimension, usually without tolerance, for information purposes only. Microchip Technology Drawing No. C04–111, Sept. 8, 2006

© 2006 Microchip Technology Inc. 8-Lead Plastic Small Outline (OA) – Narrow, 150 mil Body (SOIC) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Foot Angle φ β Mold Draft Angle Bottom α Mold Draft Angle Top 0.51 0.42 0.33 .020 .017 .013 B Lead Width 0.25 0.23 0.20 .010 .009 .008 c Lead Thickness 0.76 0.62 0.48 .030 .025 .019 L Foot Length 0.51 0.38 0.25 .020 .015 .010 h Chamfer Distance 5.00 4.90 4.80 .197 .193 .189 D Overall Length 3.99 3.91 3.71 .157 .154 .146 Molded Package Width 6.20 6.02 5.79 .244 .237 .228 E Overall Width 0.25 0.18 0.10 .010 .007 .004 Standoff 1.55 1.42 1.32 .061 .056 .052 Molded Package Thickness 1.75 1.55 1.35 .069 .061 .053 A Overall Height 1.27 .050 p Pitch n Number of Pins MAX NOM MIN MAX NOM MIN Dimension Limits MILLIMETERS INCHES* Units D n p B E h L β c 45° φ α A * Controlling Parameter Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010” (0.254mm) per side. JEDEC Equivalent: MS-012 Drawing No. C04-057 § Significant Characteristic

© 2006 Microchip Technology Inc. DS21935C-page 27 TCN75A APPENDIX A:

REVISION HISTORY

Revision C (November 2006)

• Updated accuracy specification limits
• Numerous edits throughout data sheet
• Updated package outline drawings
• Added disclaimers to package outline drawings
• Updated package marking information for pb-free markings. Revision B (May 2006)
• Revised Product ID System; Added OA713 and UA713 packages. Revision A (January 2005)
• Original release of this document.

© 2006 Microchip Technology Inc. NOTES:

© 2006 Microchip Technology Inc. DS21935C-page 29 TCN75A PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. Device: TCN75A: Temperature Sensor Temperature Range: V = -40°C to +125°C Package: OA Plastic SOIC, (150 mil Body), 8-lead OA713 Plastic SOIC, (150 mil Body), 8-lead, Tape & Reel UA Plastic Micro Small Outline (MSOP), 8-lead UA713 Plastic Micro Small Outline (MSOP), 8-lead Tape & Reel PART NO. X /XX Package Temperature Range Device Examples: TCN75AVOA: 8LD SOIC package. TCN75AVOA713: Tape and Reel, 8LD SOIC package. TCN75AVUA: 8LD MSOP package. TCN75AVUA713: Tape and Reel, 8LD MSOP package.

© 2006 Microchip Technology Inc. NOTES:

© 2006 Microchip Technology Inc. DS21935C-page 31 Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer’s risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, Accuron, dsPIC, KEELOQ, microID, MPLAB, PIC, PICmicro, PICSTART, PRO MATE, PowerSmart, rfPIC, and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. AmpLab, FilterLab, Migratable Memory, MXDEV, MXLAB, SEEVAL, SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Analog-for-the-Digital Age, Application Maestro, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, ECAN, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, Linear Active Thermistor, Mindi, MiWi, MPASM, MPLIB, MPLINK, PICkit, PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal, PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, rfPICDEM, Select Mode, Smart Serial, SmartTel, Total Endurance, UNI/O, WiperLock and ZENA are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. © 2006, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Note the following details of the code protection feature on Microchip devices: Microchip products meet the specification contained in their particular Microchip Data Sheet. Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. Microchip is willing to work with the customer who is concerned about the integrity of their code. Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as “unbreakable.” Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Microchip received ISO/TS-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona, Gresham, Oregon and Mountain View, California. The Company’s quality system processes and procedures are for its PIC® 8-bit MCUs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip’s quality system for the design and manufacture of development systems is ISO 9001:2000 certified.

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