LM75A Digital temperature sensor and thermal watchdog Rev. 04 — 10 July 2007 Product data sheet 1. General description The LM75A is a temperature-to-digital converter using an on-chip bandgap temperature sensor and Sigma-delta A-to-D conversion technique. The device is also a thermal detectorprovidinganovertemperaturedetectionoutput.TheLM75Acontainsanumberof data registers: Configuration register (Conf) to store the device settings such as device operation mode, OS operation mode, OS polarity and OS fault queue as described in Section 7 “Functional description”; temperature register (Temp) to store the digital temp reading, and set-point registers (Tos and Thyst) to store programmable overtemperature shutdown and hysteresis limits, that can be communicated by a controller via the 2-wire serial I2C-bus interface. The device also includes an open-drain output (OS) which becomes active when the temperature exceeds the programmed limits. There are three selectable logic address pins so that eight devices can be connected on the same bus without address conflict. The LM75A can be configured for different operation conditions. It can be set in normal mode to periodically monitor the ambient temperature, or in shutdown mode to minimize power consumption. The OS output operates in either of two selectable modes: OScomparator mode or OS interrupt mode. Its active state can be selected as either HIGH or LOW. The fault queue that defines the number of consecutive faults in order to activate the OS output is programmable as well as the set-point limits. The temperature register always stores an 11-bit 2's complement data giving a temperatureresolutionof0.125(cid:176) C.Thishightemperatureresolutionisparticularlyuseful in applications of measuring precisely the thermal drift or runaway. The device is powered-up in normal operation mode with the OS in comparator mode, temperature threshold of 80(cid:176) C and hysteresis of 75(cid:176) C, so that it can be used as a stand-alone thermostat with those pre-defined temperature set points. 2. Features n Pin-for-pin replacement for industry standard LM75 and offers improved temperature resolution of 0.125(cid:176) C and specification of a single part over power supply range from 2.8V to 5.5V n Small 8-pin package types: SO8 and TSSOP8 n I2C-bus interface with up to 8 devices on the same bus n Power supply range from 2.8V to 5.5V n Temperatures range from- 55(cid:176) C to +125(cid:176) C n 11-bit ADC that offers a temperature resolution of 0.125(cid:176) C

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog n Temperature accuracy of: u – 2(cid:176) C from- 25(cid:176) C to +100(cid:176) C u – 3(cid:176) C from- 55(cid:176) C to +125(cid:176) C n Programmable temperature threshold and hysteresis set points n Supply current of 3.5m A in shutdown mode for power conservation n Stand-alone operation as thermostat at power-up n ESD protection exceeds 2000V HBM per JESD22-A114, 200V MM per JESD22-A115 and 1000V CDM per JESD22-C101 n Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100mA 3. Applications n System thermal management n Personal computers n Electronics equipment n Industrial controllers 4. Ordering information Table 1. Ordering information Type number Package Name Description Version LM75AD SO8 plastic small outline package; 8 leads; SOT96-1 bodywidth3.9mm LM75ADP TSSOP8 plastic thin shrink small outline package; 8 leads; SOT505-1 bodywidth3mm 4.1 Ordering options Table 2. Ordering options Type number Topside mark Temperature range LM75AD LM75A T =- 55(cid:176) C to +125(cid:176) C amb LM75ADP L75A T =- 55(cid:176) C to +125(cid:176) C amb LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 2 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 5. Block diagram VCC LM75A BIAS POINTER CONFIGURATION REFERENCE REGISTER REGISTER TEMPERATURE BAND GAP COUNTER REGISTER TEMP SENSOR 11-BIT SIGMA-DELTA A-to-D TOS TIMER CONVERTER REGISTER OSCILLATOR COMPARATOR/ THYST INTERRUPT REGISTER POWER-ON RESET OS LOGIC CONTROL AND INTERFACE 002aad029 A2 A1 A0 SCL SDA GND Fig 1. Block diagram 6. Pinning information 6.1 Pinning SDA 1 8 VCC SDA 1 8 VCC SCL 2 7 A0 SCL 2 7 A0 LM75AD LM75ADP OS 3 6 A1 OS 3 6 A1 GND 4 5 A2 GND 4 5 A2 002aad027 002aad028 Fig 2. Pin configuration for SO8 Fig 3. Pin configuration for TSSOP8 6.2 Pin description Table 3. Pin description Symbol Pin Description SDA 1 Digital I/O. I2C-bus serial bidirectional data line; open-drain. SCL 2 Digital input. I2C-bus serial clock input. OS 3 Overtemp Shutdown output; open-drain. GND 4 Ground. To be connected to the system ground. A2 5 Digital input. User-defined address bit2. LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 3 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog Table 3. Pin description …continued Symbol Pin Description A1 6 Digital input. User-defined address bit1. A0 7 Digital input. User-defined address bit0. V 8 Power supply. CC 7. Functional description 7.1 General operation The LM75A uses the on-chip bandgap sensor to measure the device temperature with theresolutionof0.125(cid:176) Candstoresthe11-bit2'scomplementdigitaldata,resultedfrom 11-bitA-to-Dconversion,intothedeviceTempregister.ThisTempregistercanbereadat any time by a controller on the I2C-bus. Reading temperature data does not affect the conversion in progress during the read operation. Thedevicecanbesettooperateineithermode:normalorshutdown.Innormaloperation mode, the temp-to-digital conversion is executed every 100ms and the Temp register is updatedattheendofeachconversion.Inshutdownmode,thedevicebecomesidle,data conversion is disabled and the Temp register holds the latest result; however, the device I2C-bus interface is still active and register write/read operation can be performed. The deviceoperationmodeiscontrollablebyprogrammingbitB0oftheconfigurationregister. The temperature conversion is initiated when the device is powered-up or put back into normal mode from shutdown. Inaddition,attheendofeachconversioninnormalmode,thetemperaturedata(orTemp) in the Temp register is automatically compared with the overtemperature shutdown thresholddata(orTos)storedintheTosregister,andthehysteresisdata(orThyst)stored in the Thyst register, in order to set the state of the device OS output accordingly. The device Tos and Thyst registers are write/read capable, and both operate with 9-bit 2'scomplement digital data. To match with this 9-bit operation, the Temp register uses only the 9MSB bits of its 11-bit data for the comparison. The way that the OS output responds to the comparison operation depends upon the OS operationmodeselectedbyconfigurationbitB1,andtheuser-definedfaultqueuedefined by configuration bits B3 and B4. In OS comparator mode, the OS output behaves like a thermostat. It becomes active when the Temp exceeds the T , and is reset when the Temp drops below the T . os hyst Reading the device registers or putting the device into shutdown does not change the state of the OS output. The OS output in this case can be used to control cooling fans or thermal switches. In OS interrupt mode, the OS output is used for thermal interruption. When the device is powered-up, the OS output is first activated only when the Temp exceeds the T ; then it os remains active indefinitely until being reset by a read of any register. Once the OS output hasbeenactivatedbycrossingT andthenreset,itcanbeactivatedagainonlywhenthe os TempdropsbelowtheT ;thenagain,itremainsactiveindefinitelyuntilbeingresetbya hyst read of any register. The OS interrupt operation would be continued in this sequence: T trip, Reset, T trip, Reset, T trip, Reset, T trip, Reset, etc. os hyst os hyst LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 4 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog In both cases, comparator mode and interrupt mode, the OS output is activated only if a number of consecutive faults, defined by the device fault queue, has been met. The fault queue is programmable and stored in the two bits, B3 and B4, of the Configuration register. Also, the OS output active state is selectable as HIGH or LOW by setting accordingly the configuration register bit B2. Atpower-up,thedeviceisputintonormaloperationmode,theT issetto80(cid:176) C,theT os hyst issetto75(cid:176) C,theOSactivestateisselectedLOWandthefaultqueueisequalto1.The temp reading data is not available until the first conversion is completed in about 100ms. The OS response to the temperature is illustrated inFigure4. Tos Thyst reading temperature limits OS reset OS active OS output in comparator mode OS reset (1) (1) (1) OS active OS output in interrupt mode 002aad032 (1) OSisresetbyeitherreadingregister.ItisassumedthatthefaultqueueismetateachT and os T crossing point. hyst Fig 4. OS response to temperature 7.2 I2C-bus serial interface The LM75A can be connected to a compatible 2-wire serial interface I2C-bus as a slave deviceunderthecontrolofacontrollerormasterdevice,usingtwodeviceterminals,SCL andSDA.ThecontrollermustprovidetheSCLclocksignalandwrite/readdatato/fromthe devicethroughtheSDAterminal.NoticethatiftheI2C-buscommonpull-upresistorshave not been installed as required for I2C-bus, then an external pull-up resistor, about 10kW , is needed for each of these two terminals. The bus communication protocols are described inSection7.10. 7.3 Slave address The LM75A slave address on the I2C-bus is partially defined by the logic applied to the deviceaddresspinsA2,A1andA0.EachofthemistypicallyconnectedeithertoGNDfor logic0, or to V for logic1. These pins represent the three LSB bits of the device 7-bit CC address. The other four MSB bits of the address data are preset to ‘1001’ by hard wiring inside the LM75A.Table4 shows the device’s complete address and indicates that up to LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 5 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 8devices can be connected to the same bus without address conflict. Because the input pins,SCL,SDAandA2toA0,arenotinternallybiased,itisimportantthattheyshouldnot be left floating in any application. Table 4. Address table 1 = HIGH; 0 = LOW. MSB LSB 1 0 0 1 A2 A1 A0 7.4 Register list The LM75A contains four data registers beside the pointer register as listed inTable5. The pointer value, read/write capability and default content at power-up of the registers are also shown inTable5. Table 5. Register table Register Pointer R/W POR Description name value state Conf 01h R/W 00h Configuration register: contains a single 8-bit data byte;tosetthedeviceoperatingcondition;default=0. Temp 00h read only n/a Temperature register: contains two 8-bit data bytes; tostore the measured Temp data. Tos 03h R/W 5000h Overtemperature shutdown threshold register: contains two 8-bit data bytes; to store the overtemperature shutdown T limit; default=80(cid:176) C. os Thyst 02h R/W 4B00h Hysteresis register: contains two 8-bit data bytes; tostore the hysteresis T limit; default=75(cid:176) C. hyst 7.4.1 Pointer register The Pointer register contains an 8-bit data byte, of which the two LSB bits represent the pointervalueoftheotherfourregisters,andtheother6MSBbitsareequalto0,asshown inTable6 andTable7. The Pointer register is not accessible to the user, but is used to select the data register for write/read operation by including the pointer data byte in the bus command. Table 6. Pointer register B7 B6 B5 B4 B3 B2 B[1:0] 0 0 0 0 0 0 pointer value Table 7. Pointer value B1 B0 Selected register 0 0 Temperature register (Temp) 0 1 Configuration register (Conf) 1 0 Hysteresis register (Thyst) 1 1 Overtemperature shutdown register (Tos) Because the Pointer value is latched into the Pointer register when the bus command (which includes the pointer byte) is executed, a read from the LM75A may or may not include the pointer byte in the statement. To read again a register that has been recently read and the pointer has been preset, the pointer byte does not have to be included. To LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 6 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog read a register that is different from the one that has been recently read, the pointer byte must be included. However, a write to the LM75A must always include the pointer byte in the statement. The bus communication protocols are described inSection7.10. At power-up, the Pointer value is equal to 0 and the Temp register is selected; users can then read the Temp data without specifying the pointer byte. 7.4.2 Configuration register The Configuration register (Conf) is a write/read register and contains an 8-bit non-complement data byte that is used to configure the device for different operation conditions.Table8 shows the bit assignments of this register. Table 8. Conf register Legend: * = default value. Bit Symbol Access Value Description B[7:5] reserved R/W 000* reserved for manufacturer’s use; should be kept as zeroes for normal operation B[4:3] OS_F_QUE[1:0] R/W OS fault queue programming 00* queue value = 1 01 queue value = 2 10 queue value = 4 11 queue value = 6 B2 OS_POL R/W OS polarity selection 0* OS active LOW 1 OS active HIGH B1 OS_COMP_INT R/W OS operation mode selection 0* OS comparator 1 OS interrupt B0 SHUTDOWN R/W device operation mode selection 0* normal 1 shutdown 7.4.3 Temperature register The Temperature register (Temp) holds the digital result of temperature measurement or monitor at the end of each analog-to-digital conversion. This register is read-only and contains two 8-bit data bytes consisting of one Most Significant Byte (MSByte) and one LeastSignificantByte(LSByte).However,only11bitsofthosetwobytesareusedtostore theTempdatain2’scomplementformatwiththeresolutionof0.125(cid:176) C.Table9showsthe bit arrangement of the Temp data in the data bytes. Table 9. Temp register MSByte LSByte 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 7 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog When reading register Temp, all 16bits of the two data bytes (MSByte and LSByte) are provided to the bus and must be all collected by the controller to complete the bus operation. However, only the 11 most significant bits should be used, and the 5 least significantbitsoftheLSBytearezeroandshouldbeignored.Oneofthewaystocalculate the Temp value in(cid:176) C from the 11-bit Temp data is: 1. IftheTempdataMSBytebitD10=0,thenthetemperatureispositiveandTempvalue ((cid:176) C)=+(Temp data)· 0.125(cid:176) C. 2. If the Temp data MSByte bit D10=1, then the temperature is negative and Tempvalue((cid:176) C)=- (2’s complement of Temp data)· 0.125(cid:176) C. Examples of the Temp data and value are shown inTable10. Table 10. Temp register value 11-bit binary Hexadecimal value Decimal value Value (2’scomplement) 011 1111 1000 3F8 1016 +127.000(cid:176) C 011 1111 0111 3F7 1015 +126.875(cid:176) C 011 1111 0001 3F1 1009 +126.125(cid:176) C 011 1110 1000 3E8 1000 +125.000(cid:176) C 000 1100 1000 0C8 200 +25.000(cid:176) C 000 0000 0001 001 1 +0.125(cid:176) C 000 0000 0000 000 0 0.000(cid:176) C 111 1111 1111 7FF - 1 - 0.125(cid:176) C 111 0011 1000 738 - 200 - 25.000(cid:176) C 110 0100 1001 649 - 439 - 54.875(cid:176) C 110 0100 1000 648 - 440 - 55.000(cid:176) C Obviously, for 9-bit Temp data application in replacing the industry standard LM75, just use only 9MSB bits of the two bytes and disregard 7LSB of the LSByte. The 9-bit Temp data with 0.5(cid:176) C resolution of the LM75A is defined exactly in the same way as for the standard LM75 and it is here similar to the Tos and Thyst registers. 7.4.4 Overtemperature shutdown threshold (Tos) and hysteresis (Thyst) registers Thesetworegisters,arewrite/readregisters,andalsocalledset-pointregisters.Theyare used to store the user-defined temperature limits, called overtemperature shutdown threshold(Tos)andhysteresistemperature(Thyst),forthedevicewatchdogoperation.At the end of each conversion the Temp data will be compared with the data stored in these two registers in order to set the state of the device OS output; seeSection7.1. Eachoftheset-pointregisterscontainstwo8-bitdatabytesconsistingofoneMSByteand one LSByte the same as register Temp. However, only 9bits of the two bytes are used to store the set-point data in 2’s complement format with the resolution of 0.5(cid:176) C.Table11 andTable12 show the bit arrangement of the Tos data and Thyst data in the data bytes. Notice that because only 9-bit data are used in the set-point registers, the device uses only the 9MSB of the Temp data for data comparison. LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 8 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog Table 11. Tos register MSByte LSByte 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X X Table 12. Thyst register MSByte LSByte 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X X X X Whenaset-pointregisterisread,all16bitsareprovidedtothebusandmustbecollected by the controller to complete the bus operation. However, only the 9most significant bits should be used and the 7LSB of the LSByte are equal to zero and should be ignored. Table13 shows examples of the limit data and value. Table 13. Tos and Thyst limit data and value 11-bit binary Hexadecimal value Decimal value Value (2’scomplement) 0 1111 1010 0FA 250 +125.0(cid:176) C 0 0011 0010 032 50 +25.0(cid:176) C 0 0000 0001 001 1 +0.5(cid:176) C 0 0000 0000 000 0 0.0(cid:176) C 1 1111 1111 1FF - 1 - 0.5(cid:176) C 1 1100 1110 1CE - 50 - 25.0(cid:176) C 1 1001 0010 192 - 110 - 55.0(cid:176) C 7.5 OS output and polarity The OS output is an open-drain output and its state represents results of the device watchdog operation as described inSection7.1. In order to observe this output state, an external pull-up resistor is needed. The resistor should be as large as possible, up to 200kW ,tominimizetheTempreadingerrorduetointernalheatingbythehighOSsinking current. The OS output active state can be selected as HIGH or LOW by programming bit B2 (OS_POL) of register Conf: setting bit OS_POL to logic 1 selects OS active HIGH and setting bit B2 to logic 0 sets OS active LOW. At power-up, bit OS_POL is equal to logic 0 and the OS active state is LOW. 7.6 OS comparator and interrupt modes As described inSection7.1, the device OS output responds to the result of the comparison between register Temp data and the programmed limits, in registers Tos and Thyst, in different ways depending on the selected OS mode: OS comparator or OSinterrupt. The OS mode is selected by programming bit B1 (OS_COMP_INT) of register Conf: setting bit OS_COMP_INT to logic 1 selects the OS interrupt mode, and setting to logic 0 selects the OS comparator mode. At power-up, bit OS_COMP_INT is equal to logic 0 and the OS comparator is selected. LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 9 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog The main difference between the two modes is that in OS comparator mode, the OS output becomes active when Temp has exceeded T and reset when Temp has dropped os belowT ,readingaregisterorputtingthedeviceintoshutdownmodedoesnotchange hyst the state of the OS output; while in OS interrupt mode, once it has been activated either byexceedingT ordroppingbelowT ,theOSoutputwillremainactiveindefinitelyuntil os hyst reading a register, then the OS output is reset. Temperature limits T and T must be selected so that T > T . Otherwise, the OS os hyst os hyst output state will be undefined. 7.7 OS fault queue Fault queue is defined as the number of faults that must occur consecutively to activate the OS output. It is provided to avoid false tripping due to noise. Because faults are determined at the end of data conversions, fault queue is also defined as the number of consecutive conversions returning a temperature trip. The value of fault queue is selectable by programming the two bits B4 and B3 (OS_F_QUE[1:0]) in register Conf. Notice that the programmed data and the fault queue value are not the same.Table14 shows the one-to-one relationship between them. At power-up, fault queue data=0 and fault queue value=1. Table 14. Fault queue table Fault queue data Fault queue value OS_F_QUE[1] OS_F_QUE[0] Decimal 0 0 1 0 1 2 1 0 4 1 1 6 7.8 Shutdown mode The device operation mode is selected by programming bit B0 (SHUTDOWN) of register Conf.SettingbitSHUTDOWNtologic1willputthedeviceintoshutdownmode.Resetting bit SHUTDOWN to logic 0 will return the device to normal mode. In shutdown mode, the device draws a small current of approximately 3.5m A and the power dissipation is minimized; the temperature conversion stops, but the I2C-bus interface remains active and register write/read operation can be performed. The OS output remains unchanged. 7.9 Power-up default and power-on reset The LM75A always powers-up in its default state with: • Normal operation mode • OS comparator mode • T = 80(cid:176) C os • T = 75(cid:176) C hyst • OS output active state is LOW • Pointer value is logic 0 LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 10 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog When the power supply voltage is dropped below the device power-on reset level of approximately 1.9V (POR) and then rises up again, the device will be reset to its default condition as listed above. 7.10 Protocols for writing and reading the registers The communication between the host and the LM75A must strictly follow the rules as defined by the I2C-bus management. The protocols for LM75A register read/write operations are illustrated inFigure5 toFigure10 together with the following definitions: 1. Beforeacommunication,theI2C-busmustbefreeornotbusy.ItmeansthattheSCL and SDA lines must both be released by all devices on the bus, and they become HIGH by the bus pull-up resistors. 2. The host must provide SCL clock pulses necessary for the communication. Data is transferred in a sequence of 9SCL clock pulses for every 8-bit data byte followed by 1-bit status of the acknowledgement. 3. During data transfer, except the START and STOP signals, the SDA signal must be stable while the SCL signal is HIGH. It means that the SDA signal can be changed only during the LOW duration of the SCL line. 4. S: START signal, initiated by the host to start a communication, the SDA goes from HIGH to LOW while the SCL is HIGH. 5. RS: RE-START signal, same as the START signal, to start a read command that follows a write command. 6. P: STOP signal, generated by the host to stop a communication, the SDA goes from LOW to HIGH while the SCL is HIGH. The bus becomes free thereafter. 7. W: write bit, when the write/read bit = LOW in a write command. 8. R: read bit, when the write/read bit = HIGH in a read command. 9. A: device acknowledge bit, returned by the LM75A. It is LOW if the device works properly and HIGH if not. The host must release the SDA line during this period in order to give the device the control on the SDA line. 10. A’: master acknowledge bit, not returned by the device, but set by the master or host in reading 2-byte data. During this clock period, the host must set the SDA line to LOW in order to notify the device that the first byte has been read for the device to provide the second byte onto the bus. 11. NA: Not Acknowledge bit. During this clock period, both the device and host release the SDA line at the end of a data transfer, the host is then enabled to generate the STOP signal. 12. In a write protocol, data is sent from the host to the device and the host controls the SDA line, except during the clock period when the device sends the device acknowledgement signal to the bus. 13. Inareadprotocol,dataissenttothebusbythedeviceandthehostmustreleasethe SDAlineduringthetimethatthedeviceisprovidingdataontothebusandcontrolling the SDA line, except during the clock period when the master sends the master acknowledgement signal to the bus. LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 11 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 0 0 0 0 1 A 0 0 0 D4 D3 D2 D1 D0 A P device address pointer byte configuration data byte START write device device STOP acknowledge acknowledge device acknowledge 001aad624 Fig 5. Write configuration register (1-byte data) 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL (next) SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 0 0 0 0 1 A RS (next) device address pointer byte START write device RE-START acknowledge device acknowledge 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL (cont.) SDA (cont.) 1 0 0 1 A2 A1 A0 R A D7 D6 D5 D4 D3 D2 D1 D0 NA P device address data byte from device read master not STOP acknowledged device acknowledge 001aad625 Fig 6. Read configuration register including pointer byte (1-byte data) 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL SDA S 1 0 0 1 A2 A1 A0 R A D7 D6 D5 D4 D3 D2 D1 D0 NA P device address data byte from device START read master not STOP acknowledged device acknowledge 001aad626 Fig 7. Read configuration register with preset pointer (1-byte data) LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 12 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL (next) SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 0 0 0 P1 P0 A (next) device address pointer byte START write device acknowledge device acknowledge 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL (cont.) SDA (cont.) D7 D6 D5 D4 D3 D2 D1 D0 A D7 D6 D5 D4 D3 D2 D1 D0 A P MSByte data LSByte data device STOP acknowledge device acknowledge 002aad036 Fig 8. Write Tos or Thyst register (2-byte data) 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 0 SCL (next) SDA S 1 0 0 1 A2 A1 A0 W A 0 0 0 0 0 0 P1 P0 A RS (next) device address pointer byte START write device RE-START acknowledge device acknowledge 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL (cont) SDA (cont) 1 0 0 1 A2 A1 A0 R A D7 D6 D5 D4 D3 D2 D1 D0 A' D7 D6 D5 D4 D3 D2 D1 D0 NA P device address MSByte from device LSByte from device read master master not STOP acknowledge acknowledged device acknowledge 002aad037 Fig 9. Read Temp, Tos or Thyst register including pointer byte (2-byte data) 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 SCL SDA S 1 0 0 1 A2 A1 A0 R A D7 D6 D5 D4 D3 D2 D1 D0 A' D7 D6 D5 D4 D3 D2 D1 D0 NA P device address MSByte from device LSByte from device START read master master not STOP acknowledge acknowledged device acknowledge 002aad038 Fig 10. Read Temp, Tos or Thyst register with preset pointer (2-byte data) LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 13 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 8. Application design-in information power supply 0.1 m F BUS 10 kW 10 kW VCC 10 kW PULL-UP RESISTORS SCL 8 2 I2C-BUS SDA 1 OS DETECTOR OR LM75A 3 A2 INTERRUPT LINE 5 A1 DIGITAL LOGIC 6 A0 7 4 GND 002aad030 Fig 11. Typical application 9. Limiting values Table 15. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Symbol Parameter Conditions Min Max Unit V supply voltage - 0.3 +6.0 V CC voltage at input pins - 0.3 +6.0 V current at input pins - 5.0 +5.0 mA I output sink current on pin OS - 10.0 mA O(sink) V output voltage on pin OS - 0.3 +6.0 V O V electrostatic discharge human body model - 2000 V esd voltage machine model - 200 V T storage temperature - 65 +150 (cid:176) C stg T junction temperature - 150 (cid:176) C j 10. Recommended operating conditions Table 16. Recommended operating characteristics Symbol Parameter Conditions Min Typ Max Unit V supply voltage 2.8 - 5.5 V CC T ambient temperature - 55 - +125 (cid:176) C amb LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 14 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 11. Static characteristics Table 17. Static characteristics V =2.8V to 5.5V; T =- 55(cid:176) C to +125(cid:176) C; unless otherwise specified. CC amb Symbol Parameter Conditions Min Typ[1] Max Unit T temperature accuracy T =- 25(cid:176) C to +100(cid:176) C - 2 - +2 (cid:176) C ACC amb T =- 55(cid:176) C to +125(cid:176) C - 3 - +3 (cid:176) C amb T temperature resolution 11-bit digital temp data - 0.125 - (cid:176) C res T temperature conversion normal mode - 100 - ms CONV(T) time I supply current normal mode: I2C-bus inactive - 100 - m A DD normal mode: I2C-bus active - - 1.0 mA shutdown mode - 3.5 - m A V HIGH-level input voltage digital pins (SCL, SDA, A2toA0) 0.7· V - V +0.3 V IH CC CC V LOW-level input voltage digital pins - 0.3 - 0.3· V V IL CC V input voltage hysteresis SCL and SDA pins - 300 - mV IHYS A2, A1, A0 pins - 150 - mv I HIGH-level input current digital pins; V =V - 1.0 - +1.0 m A IH I CC I LOW-level input current digital pins; V = 0V - 1.0 - +1.0 m A IL I V LOW-level output voltage SDA and OS pins; I =3mA - - 0.4 V OL OL I =4mA - - 0.8 V OL I output leakage current SDA and OS pins; V =V - - 10 m A LO OH CC OSQ OS fault queue programmable 1 - 6 Conv[2] T overtemperature default value - 80 - (cid:176) C os shutdown threshold T hysteresis temperature default value - 75 - (cid:176) C hyst C input capacitance digital pins - 20 - pF i [1] Typical values are at V =3.3V and T =25(cid:176) C. CC amb [2] “Conv” = device A-to-D conversion. LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 15 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 12. Dynamic characteristics Table 18. I2C-bus interface dynamic characteristics[1] V =2.8V to 5.5V; T =- 55(cid:176) C to +125(cid:176) C; unless otherwise specified. CC amb Symbol Parameter Conditions Min Typ Max Unit T SCL clock period seeFigure12 2.5 - - m s CLK t HIGH period of the SCL clock 0.6 - - m s HIGH t LOW period of the SCL clock 1.3 - - m s LOW t hold time (repeated) START condition 100 - - ns HD;STA t data set-up time 100 - - ns SU;DAT t data hold time [2] 0 - - ns HD;DAT t set-up time for STOP condition 100 - - ns SU;STO t fall time SDA and OS outputs; - 250 - ns f C =400pF; I =3mA L OL [1] These specifications are guaranteed by design and not tested in production. [2] The data hold time minimum value is 10ns for the SCL clock period of 10m s or higher. TCLK tHIGH tLOW SCL tHD;STA tSU;DAT tHD;DAT tSU;STO SDA 002aad031 Fig 12. Timing diagram LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 16 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 13. Package outline SO8: plastic small outline package; 8 leads; body width 3.9 mm SOT96-1 D E A X c y HE v M A Z 8 5 Q A2 A1 (A 3 ) A pin 1 index q Lp 1 4 L e w M detail X bp 0 2.5 5 mm scale DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT mAax. A1 A2 A3 bp c D(1) E(2) e HE L Lp Q v w y Z(1) q 0.25 1.45 0.49 0.25 5.0 4.0 6.2 1.0 0.7 0.7 mm 1.75 0.25 1.27 1.05 0.25 0.25 0.1 0.10 1.25 0.36 0.19 4.8 3.8 5.8 0.4 0.6 0.3 8o 0.010 0.057 0.019 0.0100 0.20 0.16 0.244 0.039 0.028 0.028 0o inches 0.069 0.01 0.05 0.041 0.01 0.01 0.004 0.004 0.049 0.014 0.0075 0.19 0.15 0.228 0.016 0.024 0.012 Notes 1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included. 2. Plastic or metal protrusions of 0.25 mm (0.01 inch) maximum per side are not included. OUTLINE REFERENCES EUROPEAN ISSUE DATE VERSION IEC JEDEC JEITA PROJECTION 99-12-27 SOT96-1 076E03 MS-012 03-02-18 Fig 13. Package outline SOT96-1 (SO8) LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 17 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog TSSOP8: plastic thin shrink small outline package; 8 leads; body width 3 mm SOT505-1 D E A X c y HE v M A Z 8 5 A2 A1 (A3) A pin 1 index q Lp L 1 4 detail X e w M bp 0 2.5 5 mm scale DIMENSIONS (mm are the original dimensions) UNIT mAax. A1 A2 A3 bp c D(1) E(2) e HE L Lp v w y Z(1) q mm 1.1 0.15 0.95 0.25 0.45 0.28 3.1 3.1 0.65 5.1 0.94 0.7 0.1 0.1 0.1 0.70 6(cid:176) 0.05 0.80 0.25 0.15 2.9 2.9 4.7 0.4 0.35 0(cid:176) Notes 1. Plastic or metal protrusions of 0.15 mm maximum per side are not included. 2. Plastic or metal protrusions of 0.25 mm maximum per side are not included. OUTLINE REFERENCES EUROPEAN ISSUE DATE VERSION IEC JEDEC JEITA PROJECTION 99-04-09 SOT505-1 03-02-18 Fig 14. Package outline SOT505-1 (TSSOP8) LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 18 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 14. Soldering Thistextprovidesaverybriefinsightintoacomplextechnology.Amorein-depthaccount of soldering ICs can be found in Application NoteAN10365 “Surface mount reflow soldering description”. 14.1 Introduction to soldering Soldering is one of the most common methods through which packages are attached to PrintedCircuitBoards(PCBs),toformelectricalcircuits.Thesolderedjointprovidesboth the mechanical and the electrical connection. There is no single soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high densities that come with increased miniaturization. 14.2 Wave and reflow soldering Wavesolderingisajoiningtechnologyinwhichthejointsaremadebysoldercomingfrom a standing wave of liquid solder. The wave soldering process is suitable for the following: • Through-hole components • Leaded or leadless SMDs, which are glued to the surface of the printed circuit board Not all SMDs can be wave soldered. Packages with solder balls, and some leadless packages which have solder lands underneath the body, cannot be wave soldered. Also, leaded SMDs with leads having a pitch smaller than ~0.6mm cannot be wave soldered, due to an increased probability of bridging. The reflow soldering process involves applying solder paste to a board, followed by component placement and exposure to a temperature profile. Leaded packages, packages with solder balls, and leadless packages are all reflow solderable. Key characteristics in both wave and reflow soldering are: • Board specifications, including the board finish, solder masks and vias • Package footprints, including solder thieves and orientation • The moisture sensitivity level of the packages • Package placement • Inspection and repair • Lead-free soldering versus PbSn soldering 14.3 Wave soldering Key characteristics in wave soldering are: • Process issues, such as application of adhesive and flux, clinching of leads, board transport, the solder wave parameters, and the time during which components are exposed to the wave • Solder bath specifications, including temperature and impurities LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 19 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 14.4 Reflow soldering Key characteristics in reflow soldering are: • Lead-freeversusSnPbsoldering;notethatalead-freereflowprocessusuallyleadsto higher minimum peak temperatures (seeFigure15) than a PbSn process, thus reducing the process window • Solder paste printing issues including smearing, release, and adjusting the process window for a mix of large and small components on one board • Reflow temperature profile; this profile includes preheat, reflow (in which the board is heated to the peak temperature) and cooling down. It is imperative that the peak temperatureishighenoughforthesoldertomakereliablesolderjoints(asolderpaste characteristic). In addition, the peak temperature must be low enough that the packages and/or boards are not damaged. The peak temperature of the package depends on package thickness and volume and is classified in accordance with Table19 and20 Table 19. SnPb eutectic process (from J-STD-020C) Package thickness (mm) Package reflow temperature ((cid:176) C) Volume (mm3) < 350 ‡ 350 < 2.5 235 220 ‡ 2.5 220 220 Table 20. Lead-free process (from J-STD-020C) Package thickness (mm) Package reflow temperature ((cid:176) C) Volume (mm3) < 350 350 to 2000 > 2000 < 1.6 260 260 260 1.6 to 2.5 260 250 245 > 2.5 250 245 245 Moisture sensitivity precautions, as indicated on the packing, must be respected at all times. Studies have shown that small packages reach higher temperatures during reflow soldering, seeFigure15. LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 20 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog maximum peak temperature = MSL limit, damage level temperature minimum peak temperature = minimum soldering temperature peak temperature time 001aac844 MSL: Moisture Sensitivity Level Fig 15. Temperature profiles for large and small components For further information on temperature profiles, refer to Application NoteAN10365 “Surface mount reflow soldering description”. 15. Abbreviations Table 21. Abbreviations Acronym Description A-to-D Analog-to-Digital CDM Charged Device Model ESD ElectroStatic Discharge HBM Human Body Model I2C-bus Inter-Integrated Circuit bus I/O Input/Output LSB Lease Significant Bit LSByte Least Significant Byte MM Machine Model MSB Most Significant Bit MSByte Most Significant Byte POR Power-On Reset LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 21 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 16. Revision history Table 22. Revision history Document ID Release date Data sheet status Change notice Supersedes LM75A_4 20070710 Product data sheet - LM75A_3 Modifications: • The format of this data sheet has been redesigned to comply with the new identity guidelines of NXP Semiconductors. • Legal texts have been adapted to the new company name where appropriate. • added (new)Section 4.1 “Ordering options” • added separate pin configuration drawings for SO8 and TSSOP8 (Figure2 andFigure3) • Table 15 “Limiting values”: – table title changed from “Absolute maximum ratings” toTable 15 “Limiting values” – symbol and parameter descriptions modified to new presentation standards • Table 18 “I2C-bus interface dynamic characteristics[1]”: – parameter descriptions modified to new presentation standards – addedTable note2 and its reference at t HD;DAT LM75A_3 20060627 Product data sheet - LM75A_2 LM75A_2 20041005 Product data sheet - LM75A_1 (939775014174) LM75A_1 20010716 Product data ECN853-226626719 - (939775008571) dated 16July2001 LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 22 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 17. Legal information 17.1 Data sheet status Document status[1][2] Product status[3] Definition Objective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheet Production This document contains the product specification. [1] Please consult the most recently issued document before initiating or completing a design. [2] The term ‘short data sheet’ is explained in section “Definitions”. [3] Theproductstatusofdevice(s)describedinthisdocumentmayhavechangedsincethisdocumentwaspublishedandmaydifferincaseofmultipledevices.Thelatestproductstatus information is available on the Internet at URLhttp://www.nxp.com. 17.2 Definitions result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore Draft —The document is a draft version only. The content is still under such inclusion and/or use is at the customer’s own risk. internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any Applications —Applications that are described herein for any of these representations or warranties as to the accuracy or completeness of products are for illustrative purposes only. NXP Semiconductors makes no informationincludedhereinandshallhavenoliabilityfortheconsequencesof representation or warranty that such applications will be suitable for the use of such information. specified use without further testing or modification. Short data sheet —A short data sheet is an extract from a full data sheet Limiting values —Stress above one or more limiting values (as defined in withthesameproducttypenumber(s)andtitle.Ashortdatasheetisintended theAbsoluteMaximumRatingsSystemofIEC60134)maycausepermanent forquickreferenceonlyandshouldnotbereliedupontocontaindetailedand damagetothedevice.Limitingvaluesarestressratingsonlyandoperationof full information. For detailed and full information see the relevant full data the device at these or any other conditions above those given in the sheet, which is available on request via the local NXP Semiconductors sales Characteristics sections of this document is not implied. Exposure to limiting office. In case of any inconsistency or conflict with the short data sheet, the values for extended periods may affect device reliability. full data sheet shall prevail. Terms and conditions of sale —NXP Semiconductors products are sold subjecttothegeneraltermsandconditionsofcommercialsale,aspublished 17.3 Disclaimers athttp://www.nxp.com/profile/terms, including those pertaining to warranty, intellectual property rights infringement and limitation of liability, unless explicitly otherwise agreed to in writing by NXP Semiconductors. In case of General —Information in this document is believed to be accurate and any inconsistency or conflict between information in this document and such reliable.However,NXPSemiconductorsdoesnotgiveanyrepresentationsor terms and conditions, the latter will prevail. warranties,expressedorimplied,astotheaccuracyorcompletenessofsuch No offer to sell or license —Nothing in this document may be interpreted information and shall have no liability for the consequences of use of such or construed as an offer to sell products that is open for acceptance or the information. grant,conveyanceorimplicationofanylicenseunderanycopyrights,patents Right to make changes —NXPSemiconductorsreservestherighttomake or other industrial or intellectual property rights. changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice.Thisdocumentsupersedesandreplacesallinformationsuppliedprior 17.4 Trademarks to the publication hereof. Notice:Allreferencedbrands,productnames,servicenamesandtrademarks Suitability for use —NXP Semiconductors products are not designed, are the property of their respective owners. authorized or warranted to be suitable for use in medical, military, aircraft, space or life support equipment, nor in applications where failure or I2C-bus —logois a trademark of NXP B.V. malfunctionofaNXPSemiconductorsproductcanreasonablybeexpectedto 18. Contact information For additional information, please visit:http://www.nxp.com For sales office addresses, send an email to:salesaddresses@nxp.com LM75A_4 © NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 — 10 July 2007 23 of 24

LM75A NXP Semiconductors Digital temperature sensor and thermal watchdog 19. Contents 1 General description. . . . . . . . . . . . . . . . . . . . . . 1 19 Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3 Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4 Ordering information. . . . . . . . . . . . . . . . . . . . . 2 4.1 Ordering options. . . . . . . . . . . . . . . . . . . . . . . . 2 5 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3 6 Pinning information. . . . . . . . . . . . . . . . . . . . . . 3 6.1 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 6.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 3 7 Functional description . . . . . . . . . . . . . . . . . . . 4 7.1 General operation. . . . . . . . . . . . . . . . . . . . . . . 4 7.2 I2C-bus serial interface. . . . . . . . . . . . . . . . . . . 5 7.3 Slave address. . . . . . . . . . . . . . . . . . . . . . . . . . 5 7.4 Register list. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.4.1 Pointer register . . . . . . . . . . . . . . . . . . . . . . . . . 6 7.4.2 Configuration register. . . . . . . . . . . . . . . . . . . . 7 7.4.3 Temperature register. . . . . . . . . . . . . . . . . . . . . 7 7.4.4 Overtemperature shutdown threshold (Tos) and hysteresis (Thyst) registers . . . . . . . . . . . . 8 7.5 OS output and polarity . . . . . . . . . . . . . . . . . . . 9 7.6 OS comparator and interrupt modes . . . . . . . . 9 7.7 OS fault queue . . . . . . . . . . . . . . . . . . . . . . . . 10 7.8 Shutdown mode . . . . . . . . . . . . . . . . . . . . . . . 10 7.9 Power-up default and power-on reset. . . . . . . 10 7.10 Protocols for writing and reading the registers 11 8 Application design-in information . . . . . . . . . 14 9 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 14 10 Recommended operating conditions. . . . . . . 14 11 Static characteristics. . . . . . . . . . . . . . . . . . . . 15 12 Dynamic characteristics . . . . . . . . . . . . . . . . . 16 13 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 17 14 Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 14.1 Introduction to soldering. . . . . . . . . . . . . . . . . 19 14.2 Wave and reflow soldering . . . . . . . . . . . . . . . 19 14.3 Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . 19 14.4 Reflow soldering. . . . . . . . . . . . . . . . . . . . . . . 20 15 Abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . 21 16 Revision history. . . . . . . . . . . . . . . . . . . . . . . . 22 17 Legal information. . . . . . . . . . . . . . . . . . . . . . . 23 17.1 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 23 17.2 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 17.3 Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . 23 17.4 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 23 18 Contact information. . . . . . . . . . . . . . . . . . . . . 23 Pleasebeawarethatimportantnoticesconcerningthisdocumentandtheproduct(s) described herein, have been included in section ‘Legal information’. © NXP B.V. 2007. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com Date of release: 10 July 2007 Document identifier: LM75A_4

Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: N XP: LM75AD,112 LM75ADP,118 LM75AD,118 LM75ADP/DG,118