STTS751 2.25 V low-voltage local digital temperature sensor Datasheet - production data  One-shot mode for power saving  Fast conversion time 21 ms (typ) 10-bit  Pull-up resistor value allows single pin to select one of four slave addresses UDFN-6L  Supports 400 kHz serial clock  SMBus 2.0 compatible – SMBus ALERT (ARA) support Feature – SMBus timeout  RoHS/green  Operating voltage 2.25 V to 3.6 V  Operating temperature –40 °C to +125 °C Applications  Programmable – 10 different conversion rates  Solid state drives 0.0625 to 32 conversions/sec.  Portable electronics 1 conversion/sec. - default  Notebook computers – 4 different resolutions 9-bit (0.5 °C/LSB) to12-bit (0.0625 °C/LSB)  Smart batteries 10-bit (0.25 °C/LSB) - default  Servers  Low supply current  Telecom – 50 μA (typ) for 8 conversions/sec. – 20 μA (typ) for 1 conversion/sec. – 3 μA (typ) standby  Accuracy – ±0.5 °C (typ) 0 °C to +85 °C – ±0.5 °C (typ) –40 °C to +125 °C Table 1. Device s ummary Order code Pull-up resistor value SMBus address Comments 7.5 K ±5% 1001 000 b 12 K ±5% 1001 001 b Address selection via resistor pull-up STTS751-0DP3F 20 K ±5% 0111 000 b on Addr/Therm pin 33 K ±5% 0111 001 b 7.5 K ±5% 1001 010 b 12 K ±5% 1001 011 b Address selection via resistor pull-up STTS751-1DP3F 20 K ±5% 0111 010 b on Addr/Therm pin 33 K ±5% 0111 011 b May 2019 DocID16483 Rev 7 1/35 This is information on a product in full production. www.st.com

Contents STTS751 Contents 1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2 Functional description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3 SMBus interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.1 SMBus protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2 WRITE byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.3 READ byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.4 SEND byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.5 RECEIVE byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.6 SMBus addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.7 SMBus timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3.8 Alert response address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4 STTS751 register summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.1 STTS751 register formats and details . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.2 Temperature register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.3 Temperature limit register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.4 Temperature examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.5 Status register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.6 Configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.7 Conversion rate register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.8 One-shot register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.9 Therm limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.10 Therm hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.11 SMBus timeout register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.12 STTS751 product ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.13 STTS751 manufacturer’s ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.14 STTS751 revision ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 5 EVENT output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2/35 DocID16483 Rev 7

STTS751 Contents 6 Addr/Therm output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 7 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 8 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 9 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 9.1 UDFN-6L package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 9.2 Packing information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 10 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 11 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 DocID16483 Rev 7 3/35 35

List of tables STTS751 List of tables Table 1. Device summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Table 2. Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Table 3. Pin descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Table 4. SMBus WRITE byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Table 5. SMBus READ byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Table 6. SMBus SEND byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Table 7. SMBus RECEIVE byte protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Table 8. SMBus protocol response to ARA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Table 9. Registers/pointers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 Table 10. Pointer register format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Table 11. Temperature register (two’s complement) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 Table 12. Temperature limit register (two’s complement format) . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Table 13. Temperature examples (two’s complement format) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 Table 14. Status register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 Table 15. Configuration register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Table 16. Conversion resolution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Table 17. Conversion rate register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18 Table 18. Conversion rates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Table 19. One-shot register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Table 20. Therm limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Table 21. Therm hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Table 22. SMBus timeout register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 Table 23. Product ID register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Table 24. Manufacturer’s ID register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Table 25. Revision ID register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Table 26. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Table 27. Operating and AC measurement conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Table 28. DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Table 29. AC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 Table 30. UDFN-6L (2 mm x 2 mm x 0.5 mm) package mechanical data . . . . . . . . . . . . . . . . . . . . .29 Table 31. Carrier tape dimensions for UDFN-6L package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Table 32. Reel dimensions for 8 mm carrier tape - UDFN-6L package . . . . . . . . . . . . . . . . . . . . . . .32 Table 33. Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Table 34. Document revision history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34 4/35 DocID16483 Rev 7

STTS751 List of figures List of figures Figure 1. Logic diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Figure 2. Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 Figure 3. Block diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Figure 4. Application hardware hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 Figure 5. SMBus timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Figure 6. EVENT output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 Figure 7. Therm output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 Figure 8. AC measurement I/O waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Figure 9. UDFN-6L (2 mm x 2 mm x 0.5 mm) package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Figure 10. UDFN-6L package footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 Figure 11. Carrier tape for UDFN-6L package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Figure 12. Reel schematic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 DocID16483 Rev 7 5/35 35

Description STTS751 1 Description The STTS751 is a digital temperature sensor which communicates over a 2-wire SMBus 2.0 compatible bus. The temperature is measured with a user-configurable resolution between 9 and 12 bits. At 9 bits, the smallest step size is 0.5 °C, and at 12 bits, it is 0.0625 °C. At the default resolution (10 bits, 0.25 °C/LSB), the conversion time is nominally 21 milliseconds. The open-drain EVENT output is used to indicate an alarm condition in which the measured temperature has exceeded the user-programmed high limit or fallen below the low limit. When the EVENT pin is asserted, the host can respond using the SMBus Alert Response Address (ARA) protocol to which the STTS751 will respond by sending its slave address. The STTS751 is a 6-pin device that supports user-configurable slave addresses. Via the pull-up resistor on the Addr/Therm pin, one of four different slave addresses can be specified. Two order numbers (STTS751-0 and STTS751-1) provide two different sets of slave addresses bringing the total available to eight. Thus, up to eight devices can share the same 2-wire SMBus without ambiguity, thereby allowing monitoring of multiple temperature zones in an application. The two-wire interface can support transfer rates up to 400 kHz. Figure 1. Logic diagram VDD (1) SDA EVENT STTS751-0 STTS751-1 SCL Addr/Therm GND AM03028v1 1. This pin may not float. Table 2. Signal names Symbol Type Description Addr/Therm Output Address selection pin / thermal status pin EVENT Output Event (alert) output SDA I/O SMBus interface data I/O SCL Input SMBus interface clock input V Power Device power supply DD GND Ground Device ground 6/35 DocID16483 Rev 7

STTS751 Description Figure 2. Pinout SCL 1 6 SDA EVENT 2 5 GND VDD 3 4 Addr/Therm AM03029v1 Table 3. Pin descriptions Pin Name Description 1 SCL SMBus clock Open-drain interrupt output. Output supports the SMBus Alert (ARA). 2 EVENT Note: This pin may not float. 3 V Power supply V DD DD Open-drain output that can be used to turn on/off a fan or throttle a CPU clock in the event of an overtemperature condition. The pin at power-up determines the SMBus slave address according to the pull-up resistor value as shown in Table 1. Addr/Therm This pin must have a pull-up resistor connected to the same voltage as V 4 DD or tied to GND (pin cannot float). Total capacitance on this pin must be <100 pF. Note: By tying Addr/Therm to ground, the device functions as one address device only. The Therm functionality is then not available. The address for device STTS751-0 is 72h and the address for device STTS751-1 is 76h. 5 GND GND 6 SDA SMBus data input/output DocID16483 Rev 7 7/35 35

Description STTS751 Figure 3. Block diagram V DD REGISTERS Address Pointers Temperature Registers Status SMBus Configuration SDA Interface Conversion Rate SCL High Limit Registers Interrupt Enabling EVENT VDD Low Limit Registers One-Shot Therm LIMIT Addr/Therm Therm HYSTERESIS Sensor Control Logic SMBus Timeout Product ID Manufacturer ID A to D Revision ID Converter Digital Comparator Alert Response GND AM03030v1 Figure 4. Application hardware hookup V DD SCL SDA Host STTS751-0 Controller EVENT R STTS751-1 Addr/Therm Fan Driver GND AM03031v1 8/35 DocID16483 Rev 7

STTS751 Functional description 2 Functional description The STTS751 digital temperature sensor acquires the temperature and stores it in the temperature register. The resolution is programmable which allows the host controller to select the optimal configuration between sensitivity and conversion times. The STTS751 can be placed in standby mode to minimize power consumption. The user can control the update rate of the temperature measurements via the configuration register (Table 15 on page 17). Sample rates can be adjusted from once every 16 seconds up to 32 samples per second, in powers-of-2 steps. These devices also offer a one-shot feature. When the device is in the standby mode, writing to the one-shot register initiates a single temperature conversion. The result is compared with the limit registers, and the outputs updated accordingly. Then the device returns to the standby mode. Operating the device in this mode allows for very low average power consumption, thereby making this device ideal for low power applications. The device supports the SMBus Alert Response address (ARA) protocol. The ARA is polled by the controller (host) device that supports this protocol whenever it detects that the EVENT pin has been asserted. The STTS751 will respond with its device address (refer to Section 3.8 on page 12). The STTS751 contains 16 registers. The register summary is shown in Table 9 on page 13. Using register addresses not specified in the table may result in an incorrect response. These registers and their functions are described in more detail in the following sections. DocID16483 Rev 7 9/35 35

SMBus interface STTS751 3 SMBus interface 3.1 SMBus protocol The STTS751 communicates over a 2-wire serial interface compatible with the SMBus standard. Temperature data, alarm limits and configuration information are communicated over the bus. A detailed timing diagram is shown below in Figure 5. Figure 5. SMBus timing diagram TLOW THIGH THD; STA TSU:STO SMCLK TR TF THD; STA THD:DAT TSU:STA SMDATA TSU:DAT P S S P TBUF S - start condition P - stop condition AM03067v1 The STTS751 supports standard SMBus protocols (see Table 4, 5, 6, and 7).  WRITE byte  READ byte  SEND byte  RECEIVE byte  Alert response address 10/35 DocID16483 Rev 7

STTS751 SMBus interface 3.2 WRITE byte The WRITE byte protocol is used to write one byte of data to the registers as shown in Table 4. The gray data is sent by the STTS751 while the white data is sent by the host. Table 4. SMBus WRITE byte protocol Register Start Slave address WR ACK ACK Data ACK Stop address 1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 8 bits 1 bit 1 bit 3.3 READ byte The READ byte protocol is used to read one byte of data from the registers as shown in Table 5. Table 5. SMBus READ byte protocol Register Start Slave address WR ACK ACK Start Slave address RD ACK Data NACK Stop address 1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 1 bit 3.4 SEND byte The SEND byte protocol is used to set the internal address register to the correct address. It sends a register address with no data (see Table 6). The SEND byte can be followed by the RECEIVE byte protocol described below in order to read data from the register. Table 6. SMBus SEND byte protocol Start Slave address WR ACK Register address ACK Stop 1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 1 bit 3.5 RECEIVE byte The RECEIVE byte protocol is used to read data from the register when the internal register address pointer is known (see Table 7). This can be used for consecutive reads of the same register. Table 7. SMBus RECEIVE byte protocol Start Slave address RD ACK Data NACK Stop 1 bit 7 bits 1 bit 1 bit 8 bits 1 bit 1 bit DocID16483 Rev 7 11/35 35

SMBus interface STTS751 3.6 SMBus addresses The STTS751 is available in two versions. Each version has 4 slave addresses determined by the pull-up resistor value connected to the Addr/Therm pin. Refer to Table 1 for valid address and recommended resistor values. The device will not respond to an invalid slave address. 3.7 SMBus timeout The STTS751 supports SMBus timeout which is enabled by default at power-up. This can be disabled via bit 7 in the timeout register, refer to Section 4.11: SMBus timeout register. When timeout is enabled, the STTS751 will time out after 25 to 35 ms of inactivity. The STTS751 supports the SMBus timeout feature. If the host holds SCL low or the device drives SDA low for more than t (max), the STTS751 resets and releases the bus. TIMEOUT This feature is turned on by default. The STTS751 also supports timeout while in standby mode and when the device is driving SDA low. Note: The STTS751 never drives the clock line and it does not support clock stretching. 3.8 Alert response address The STTS751supports the SMBus alert response address (ARA) protocol. In the event of an out-of-limit temperature measurement, the EVENT output will be asserted. In response, the host (supporting the ARA protocol) will send the SMBus Alert Response Address to the general (slave) address of 0001_100b. All devices with active interrupts will respond with their client addresses as shown in Table 1 on page 1 (with the LSB bit set to 0). The STTS751 will acknowledge the ARA and respond with its slave device address. Table 8 shows the ARA transfer. See Section 5 for more information. Table 8. SMBus protocol response to ARA ALERT STTS751 Field START RESPONSE RD ACK SLAVE NACK STOP ADDRESS ADDRESS Bits 1 7 1 1 8 1 1 12/35 DocID16483 Rev 7

STTS751 STTS751 register summary 4 STTS751 register summary The STTS751 uses 8-bit registers. Variables longer than 8 bits are managed in byte pairs. For example, when reading a 10-bit temperature value (10 bits is the default resolution.) the application must read two registers and then concatenate the upper byte with the 2 most significant bits of the lower byte. Table 9 below summarizes the register map for the device. Accessing any invalid address results in indeterminate data. Table 9. Registers/pointers STTS751 register map Address Power-up default values pointers (h) binary (dec) Device registers name Size Type 00 Temperature value high byte 8 R undefined 01 Status 8 R undefined 02 Temperature value low byte 8 R undefined 03 Configuration 8 R/W 0000 0000 04 Conversion rate 8 R/W 0000 0100 05 Temperature high limit high byte 8 R/W 0101 0101 (85 °C) 06 Temperature high limit low byte 8 R/W 0000 0000 07 Temperature low limit high byte 8 R/W 0000 0000 (0 °C) 08 Temperature low limit low byte 8 R/W 0000 0000 0F One-shot 8 W N/A 20 THERM limit 8 R/W 0101 0101 (85 °C) 21 THERM hysteresis 8 R/W 0000 1010 (10 °C) 22 SMBus timeout enable 8 R/W 1000 0000 (Enabled) STTS751-0 [0000 0000] FD Product ID register 8 R STTS751-1 [0000 0001] FE Manufacturer ID 8 R 0101 0011 (53h) FF Revision number 8 R 0000 0001 In the following sections are the detailed descriptions of the registers along with their power- up default values. Examples are also included. DocID16483 Rev 7 13/35 35

STTS751 register summary STTS751 4.1 STTS751 register formats and details The STTS751 register set is comprised of the 16 addresses shown in Table 9. The individual registers are accessed by transferring their addresses via the SMBus interface as shown in Section 3.2, 3.3, and 3.4. In the case of the RECEIVE byte sequence (Section 3.5) the address used is the address sent in the previous WRITE, READ or SEND byte sequence. An example read sequence of the Therm hysteresis register, address 21h, with its default value, 0Ah, is shown below. The slave address used is 90h. The gray data is sent by the STTS751 while the white data is sent by the host. Table 10. Pointer register format SLAVE REGISTER SLAVE STO START WR ACK ACK START RD ACK DATA NACK ADDRESS ADDRESS ADDRESS P 1001_000 0 0010_0001 1001_000 1 0000_1010 Note: All eight bits are used to select the register. 4.2 Temperature register format The temperature data is a 12-bit number and is stored in two's complement format spanning the high byte and low byte registers as shown in Table 11. Table 11. Temperature register (two’s complement) Power-up ADDR R/W Register b7 b6 b5 b4 b3 b2 b1 b0 default (hex) (hex) 00 R Temperature - high byte sign 64 °C 32 °C 16 °C 8 °C 4°C 2 °C 1 °C 00 02 R Temperature - low byte ½ °C ¼ °C 1/ °C 1/ °C 0 0 0 0 00 8 16 The integer portion of the temperature is stored in the high byte, and the fractional portion in the low byte. The lower four bits of the low byte will always read 0. At power-up, the STTS751 defaults to 10-bit resolution. Thus, bits b5 and b4 of the lower byte will also read 0 until the device is configured to a higher resolution (via the Tres bits in the configuration register). 14/35 DocID16483 Rev 7

STTS751 STTS751 register summary 4.3 Temperature limit register format The high and low limit registers have the same format as the temperature register with the integer portion of the two's complement value stored in the high byte and the fractional portion in the low byte. These registers are read-write. Note that the high limit defaults to 85 °C. Table 12. Temperature limit register (two’s complement format) ADDR Power-up R/W Register b7 b6 b5 b4 b3 b2 b1 b0 (hex) default (hex) 05 R/W High limit - high byte sign 64 °C 32 °C 16 °C 8 °C 4°C 2 °C 1 °C 55 (85 °C, dec) 06 R/W High limit - low byte ½ °C ¼ °C 1/ °C 1/ °C 0 0 0 0 00 8 16 07 R/W Low limit - high byte sign 64 °C 32 °C 16 °C 8 °C 4°C 2 °C 1 °C 00 08 R/W Low limit - low byte ½ °C ¼ °C 1/ °C 1/ °C 0 0 0 0 00 8 16 4.4 Temperature examples The table below shows several examples of how the data is arranged in the high and low byte pairs used for the temperature and limit registers. Table 13. Temperature examples (two’s complement format) b7 b6 b5 b4 b3 b2 b1 b0 High byte sign 64 °C 32 °C 16 °C 8 °C 4°C 2 °C 1 °C Weighting of the bits Low byte ½ °C ¼ °C 1/ °C 1/ °C 0 0 0 0 8 16 High byte 1 1 0 0 0 0 0 0 –64 °C Low byte 0 0 0 0 0 0 0 0 High byte 1 1 0 0 0 0 0 1 –63 °C Low byte 0 0 0 0 0 0 0 0 High byte 1 1 1 1 1 1 1 1 –1 °C Low byte 0 0 0 0 0 0 0 0 High byte 0 0 0 0 0 0 0 1 +1 °C Low byte 0 0 0 0 0 0 0 0 High byte 0 0 0 0 0 1 0 1 +5.3125 °C(1) Low byte 0 1 0 1 0 0 0 0 High byte 0 1 1 1 1 1 0 1 +125 °C Low byte 0 0 0 0 0 0 0 0 1. With 12-bit resolution selected. Note: The maximum and minimum values for the temperature registers are 127.9375 (7F:F0h, high byte : low byte) and –64 (C0:00h), respectively. This also applies to the high and low limit registers. DocID16483 Rev 7 15/35 35

STTS751 register summary STTS751 4.5 Status register Table 14. Status register Power-up ADDR R/W Register b7 b6 b5 b4 b3 b2 b1 b0 default (hex) (hex) 01 R Status Busy T T RFU RFU RFU RFU THRM undefined HIGH LOW The STTS751 status register is read-only and located at address 01h. The various status bits function as described below. Busy: [7] Bit =1 when a temperature conversion is in progress. T : [6] Bit = 1 indicates temperature high limit has been exceeded (T > high limit). HIGH A T is cleared when the status register is read, provided the condition no longer exists. HIGH T : [5] Bit = 1 indicates the is at or below the low limit (T low limit). T is cleared LOW A LOW when the status register is read, provided the condition no longer exists. RFU: [4:1] Not used - reserved. THRM: [0] Bit = 1 indicates the measured temperature has crossed the Therm limit. The THRM bit will go low when the temperature falls below the Therm limit minus the Therm Hysteresis. When the THRM bit is high, the Addr/Therm output will be asserted low. 16/35 DocID16483 Rev 7

STTS751 STTS751 register summary 4.6 Configuration register The STTS751 configuration register is read/write and controls the functionality of temperature measurements. It is located at address 03h. The configuration register bits function as described below. Table 15. Configuration register Power-up ADDR R/W Register b7 b6 b5 b4 b3 b2 b1 b0 default (hex) (hex) 03 R/W Configuration MASK1 RUN/STOP 0 RFU Tres1 Tres0 RFU RFU 00 Description MASK1: [bit 7] 0: EVENT is enabled. Any out-of-limit condition asserts the EVENT pin (active low). 1: EVENT is disabled. RUN/STOP: [bit 6] 0: Device is running in continuous conversion mode. 1: Device is in standby mode drawing minimum power. The RUN/STOP bit controls temperature conversions by the ADC. When this bit is 0, the ADC converts temperatures in continuous mode, at a rate as selected by the Conversion Rate register (Section 4.7). When the RUN/STOP bit is 1, the ADC will be in standby mode, thus reducing current supply significantly. Note: The device can still be accessed via the SMBus while in standby mode. When RUN/STOP is 1 and the one-shot register is written to, the ADC will execute a temperature measurement and then return to standby mode. [bit 5]: This bit must always be 0. RFU: [bit 4] Not used - reserved. DocID16483 Rev 7 17/35 35

STTS751 register summary STTS751 Tres1:Tres0 [bits 3 and 2] These bits select one of the four programmable resolutions for temperature data on the STTS751 providing resolutions down to 0.0625 °C/LSB. The default resolution is 10 bits, 0.25 °C/LSB. Table 16. Conversion resolution Tres1:Tres0 Temperature resolution LSB step size (°C) 00 10 bits (default) 0.25 01 11 bits 0.125 11 12 bits 0.0625 10 9 bits 0.5 RFU [bits 1 and 0] Not used - reserved. 4.7 Conversion rate register The STTS751 conversion rate register is read/write and controls the number of times the temperature value will be updated each second. Table 17. Conversion rate register ADDR Power-up R/W Register b7 b6 b5 b4 b3 b2 b1 b0 (hex) default (hex) 04 R/W Conversion rate 0 0 0 0 CONV[3:0] 04 (1/sec) The upper four bits of the register are reserved and default to 0 on power-up. The lower four bits control the conversion rate as shown in the table below. The power-up default is 1 conversion per second. The current draw is proportional to the conversion rate, and goes up at higher rates. 18/35 DocID16483 Rev 7

STTS751 STTS751 register summary Table 18. Conversion rates CONV[3:0] Conversions per second Typical current (μA) Comment (hex) 0 0.0625 15 1 0.125 2 0.25 3 0.5 4 1 20 5 2 6 4 7 8 50 8 16 9, 10, or 11-bit resolutions only 9 32 125 9 or 10-bit resolutions only A-F reserved Note: The user must program the conversion rate and resolution bits (Tres1:Tres0 in the configuration register, address 03h) to be consistent with this table. For a sampling rate of 32 conversions per second, the maximum resolution is 10 bits. For 16 conversions per second, the maximum is 11 bits. 4.8 One-shot register The STTS751 can be configured to perform a single temperature conversion on demand. When the device is placed in standby mode (by setting RUN/STOP to 1 in the configuration register) a write to the one-shot register will invoke a temperature conversion. The device will set the busy bit while the conversion is in progress. The conversion is complete when the busy bit is cleared. The STTS751 returns to standby mode upon completion of the conversion. The one-shot register is write-only and is located at address 0Fh. The value written to invoke the one-shot conversion is a don't care. The device responds only to the write at address 0Fh and ignores the value written. Note: Writes to the one-shot register will be ignored when the STTS751 is in continuous conversion mode (ie. when RUN/STOP=0). Table 19. One-shot register ADDR Power-up R/W Register b7 b6 b5 b4 b3 b2 b1 b0 (hex) default (hex) 0F W One shot X X X X X X X X n/a DocID16483 Rev 7 19/35 35

STTS751 register summary STTS751 4.9 Therm limit The Therm limit is a read/write register located at address 20h. The power-on default value is 85 °C (55h). The format is 8-bit, two's complement integer. This is the same format as the upper byte of the temperature register (Section 4.2: Temperature register format). Whenever the temperature exceeds the value of the therm limit, the Addr/Therm output will be asserted (low). See Section 6 for more information. Table 20. Therm limit ADDR Power-up R/W Register b7 b6 b5 b4 b3 b2 b1 b0 (hex) default (hex) 20 R/W Therm sign 64 °C 32 °C 16 °C 8 °C 4 °C 2 °C 1 °C 55 (85 °C, dec) 4.10 Therm hysteresis The Therm hysteresis values controls the hysteresis for Addr/Therm output. Once Therm output has asserted, it will not de-assert until the temperature has fallen below the respective therm limit minus the therm hysteresis value. See Section 5 for more information. The therm hysteresis register is read/write and is located at address 21h. The power-up default value is 10 °C (0Ah). The format is 8-bit, two's complement integer. Table 21. Therm hysteresis ADDR Power-up R/W Register b7 b6 b5 b4 b3 b2 b1 b0 (hex) default (hex) 21 R/W Therm hysteresis sign 64 °C 32 °C 16 °C 8 °C 4 °C 2 °C 1 °C 0A (10 °C, dec) 4.11 SMBus timeout register At power-up, the STTS751 is configured with an SMBus timeout of 25 to 35 milliseconds (t ). See Section 3.7 for more information. TIMEOUT Table 22. SMBus timeout register ADDR Power-up R/W Register b7 b6 b5 b4 b3 b2 b1 b0 (hex) default (hex) 22 R/W SMBus timeout TIMEOUT 0 0 0 0 0 0 0 80 TIMEOUT: [bit 7] 1: SMBus timeout is enabled. Default condition. 0: SMBus timeout is disabled. [bits 6:0] Not used - reserved. 20/35 DocID16483 Rev 7

STTS751 STTS751 register summary 4.12 STTS751 product ID The two versions of the STTS751 as shown in Table 1 can be identified via the read-only Product ID register at address FDh. The STTS751-0 has a Product ID of 00h. The STTS751-1 has a Product ID of 01h. Table 23. Product ID register ADDR R/W Register b7 b6 b5 b4 b3 b2 b1 b0 hex (hex) 0 0 0 0 0 0 0 0 00: STTS751-0 FD R Product ID 0 0 0 0 0 0 0 1 01: STTS751-1 4.13 STTS751 manufacturer’s ID The read-only manufacturer's ID is located at address FEh. For the STTS751, the value is 53h. Table 24. Manufacturer’s ID register ADDR R/W Register b7 b6 b5 b4 b3 b2 b1 b0 hex (hex) FE R Mfg ID 0 1 0 1 0 0 1 1 53 4.14 STTS751 revision ID The STTS751 revision ID register pointer is read-only and can be accessed at address FFh. The value is formatted as an unsigned, 8-bit integer. Table 25. Revision ID register ADDR R/W Register b7 b6 b5 b4 b3 b2 b1 b0 (hex) FF R Revision ID 0 0 0 0 0 0 0 1 DocID16483 Rev 7 21/35 35

EVENT output STTS751 5 EVENT output The STTS751 EVENT output is open drain and requires a pull-up resistor. The EVENT pin is asserted (low) whenever the temperature exceeds the high limit or is equal to or below the low limit. Once asserted, the output will remain asserted until the STTS751 receives an SMBus Alert Response Address (ARA) from the host and acknowledges with its slave address. The output will be deasserted when the ARA is acknowledged. If the triggering condition is still true, the output will be reasserted at the next temperature conversion. Figure 6 below shows how the EVENT output functions. Figure 6. EVENT output Temperature Temperature high limit Temperature low limit Time EVENT SMBus ARA acknowledged AM03032v1 22/35 DocID16483 Rev 7

STTS751 Addr/Therm output 6 Addr/Therm output The Addr/Therm pin functions normally as an output to alert the system of an over temperature condition. It is open drain and requires a pull-up resistor. During power-up, the pull-up value is sensed by the STTS751 to determine what its slave address will be as depicted in Table 1. The Therm output is asserted low whenever the temperature exceeds the Therm limit (address 20h). Only the upper 8 bits of the temperature register are used in the comparison with the Therm limit. Once asserted, Therm will remain asserted until temperature falls below the Therm limit minus the therm hysteresis value. For example, if the Therm limit is 25 °C, and the therm hysteresis value is 10 °C, the Therm output will assert when the temperature exceeds 25 °C. It will remain asserted until the temperature falls down to or below 15 °C (25 – 10). This pin can be used to control a fan or other failsafe device as shown in Figure 4 on page 8. Figure 7 below shows how the Therm output functions. Figure 7. Therm output Temperature Therm Hysteresis Therm limit Therm Limit minus Therm Hysteresis Time Addr/Therm AM03033v1 DocID16483 Rev 7 23/35 35

Maximum ratings STTS751 7 Maximum ratings Stressing the device above the rating listed in the absolute maximum ratings table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the operating sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 26. Absolute maximum ratings Symbol Parameter Value Unit T Storage temperature (V off) –55 to 150 °C STG DD T (1) Lead solder temperature 260 °C SLD V Input or output voltage –0.3 to V + 0.3 V IO DD V Supply voltage 5.0 V DD I Output current 20 mA O  Thermal resistance (junction to ambient) UDFN-6L 78 °C/W JA 1. Reflow at peak temperature of 260 °C. The time above 255 °C must not exceed 30 seconds. 24/35 DocID16483 Rev 7

STTS751 DC and AC parameters 8 DC and AC parameters This section summarizes the operating measurement conditions, and the DC and AC characteristics of the device. The parameters in the DC and AC characteristics tables that follow, are derived from tests performed under the measurement conditions summarized in Table 27: Operating and AC measurement conditions. Designers should check that the operating conditions in their circuit match the operating conditions when relying on the quoted parameters. Table 27. Operating and AC measurement conditions Parameter Conditions Unit V supply voltage - temperature sensor 2.25 to 3.6 V DD Ambient operating temperature (T ) –40 to +125 °C A Input rise and fall times 5 ns Input pulse voltages 0.2 V to 0.8 V V DD DD Input and output timing reference voltages 0.3 V to 0.7 V V DD DD Figure 8. AC measurement I/O waveform Input levels Input and output timing reference levels 0.8 * VDD 0.7 * VDD 0.2 * VDD 0.3 * VDD AM04731v1 DocID16483 Rev 7 25/35 35

DC and AC parameters STTS751 Table 28. DC and AC characteristics Symbol Description Test condition(1) Min Typ(2) Max Unit V Supply voltage 2.25 3.6 V DD 0.0625 15 35 μA conversions/second(3) I Operating current dependent upon 1 conversion/second(3) 20 40 μA DD conversion rate 8 conversions/second 50 85 μA 32 conversions/second 125 250 μA I Standby current 3 8 μA SB Temperature measurement 0 °C to 85 °C ±0.5 ±1.5 °C Accuracy(4) 2.25 V to 3.6 V –40 °C to +125 °C ±0.5 ±2.5 °C 9-bit 0.5 °C/LSB temperature data 9 bits 10-bit temperature data 0.25 °C/LSB (default) 10 bits STTS751 is programmable from 9 bits Resolution to 12 bits (0.5 °C/LSB to 0.0625 °C) 0.125 °C/LSB 11-bit temperature data 11 bits 0.0625 °C/LSB 12-bit temperature data 12 bits 9-bit 10.5 14 ms 10-bit (default) 21 28 ms t Conversion time CONV 11-bit 42 56 ms 12-bit 84 112 ms Low level output voltage V I = 4 mA 0.4 V OL Addr/Therm, EVENT OL High level output leakage current I V = V 1 μA OH EVENT, SDA, Addr/Therm OH DD SMBus interface inputs (SDA, SCL) 0.7 x V Input logic high (SCL, SDA) 2.3 V V 3.6 V V IH DD V DD 0.3 x V Input logic low (SCL, SDA) 2.3 V V 3.6 V V IL DD V DD I Logical "1" input current 0 V V V –1 1 μA HI IN DD I Logical "0" input current 0 V V  V –1 1 μA LI IN DD C Input capacitance (SDA) 5 pF IN I SMBus output low sink current SDA forced to 0.6 V 6 mA SINK 26/35 DocID16483 Rev 7

STTS751 DC and AC parameters Table 28. DC and AC characteristics (continued) Symbol Description Test condition(1) Min Typ(2) Max Unit Pull-up supply voltage (Addr/Therm) –0.3 3.6 V V PV (open drain) EVENT, SDA, SCL –0.3 5.5 V Power On Reset threshold V V falling edge 1.75 V POR (POR) - TS DD t SMBus timeout(5) 25 35 ms TIMEOUT Spike suppression Input filter on SCL and t Pulse width of spikes that must 50 ns SP SDA be suppressed by the input filter 1. Valid for ambient operating temperature: T = –40 to +125 °C; V = 2.25 V to 3.6 V (except where noted). A DD 2. Typical numbers are for T = +25 °C; V = 3.0 V A DD 3. Not tested, guaranteed by design. 4. Accuracy measurements made at resolutions > 10 bits. 5. SMBus timeout min and max are valid for T = –30 to +125 °C. A Table 29. AC characteristics Symbol Description Min Typ Max Unit f SMBus/I2C clock frequency 10 400 kHz SCL t Clock high period 600 ns HIGH t Clock low period 1.3 μs LOW t Clock/data rise time 300 ns R t Clock/data fall time 300 ns F t Data setup time 100 ns SU:DAT t Data in hold time 0 ns HD:DI t Data out hold time 300 ns HD:DAT t Start condition setup time 600 ns SU:STA Hold time after (repeated) start condition. After this period, t 600 ns HD:STA the first clock cycle is generated. t Stop condition setup time 600 ns SU:STO t Bus free time between stop (P) and start (S) conditions 1.3 μs BUF DocID16483 Rev 7 27/35 35

Package information STTS751 9 Package information In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ECOPACK is an ST trademark. 28/35 DocID16483 Rev 7

STTS751 Package information 9.1 UDFN-6L package information Figure 9. UDFN-6L (2 mm x 2 mm x 0.5 mm) package outline 8187820_A Table 30. UDFN-6L (2 mm x 2 mm x 0.5 mm) package mechanical data mm inches Sym Min Typ Max Min Typ Max A 0.45 0.50 0.55 0.018 0.020 0.022 A1 0.00 0.05 0.000 0.002 A3 0.065 0.003 b 0.20 0.25 0.30 0.008 0.010 0.012 D 1.95 2.00 2.05 0.077 0.079 0.081 E 1.95 2.00 2.05 0.077 0.079 0.081 e 0.65 0.026 L 0.50 0.60 0.70 0.020 0.024 0.028 DocID16483 Rev 7 29/35 35

Package information STTS751 Figure 10. UDFN-6L package footprint 8187820_A(LP) 30/35 DocID16483 Rev 7

STTS751 Package information 9.2 Packing information Figure 11. Carrier tape for UDFN-6L package P0 E D P2 T A0 F TOP COVER TAPE W B0 CENTER LINES P1 OF CAVITY K0 USER DIRECTION OF FEED AM03073v1 Table 31. Carrier tape dimensions for UDFN-6L package Package W D E P P F A B K P T Unit 0 2 0 0 0 1 1.50 8.00 1.75 4.00 2.00 3.50 2.20 2.20 0.75 4.00 0.25 UDFN-6L +0.10/ mm 0.30 0.10 0.10 0.05 0.05 0.10 0.10 0.10 0.10 0.05 –0.00 DocID16483 Rev 7 31/35 35

Package information STTS751 Figure 12. Reel schematic T 40mm min. Access hole At slot location B D C N A G measured Tape slot In core for Full radius At hub Tape start 2.5mm min.width AM04928v1 Table 32. Reel dimensions for 8 mm carrier tape - UDFN-6L package A B D N T C G (max) (min) (min) (min) (max) 180 mm 13 mm 8.4 mm 1.5 mm 20.2 mm 60 mm 14.4 mm (7 inch) 0.2 mm + 2/–0 mm Note: The dimensions given in Table 32 incorporate tolerances that cover all variations on critical parameters. 32/35 DocID16483 Rev 7

STTS751 Part numbering 10 Part numbering Table 33. Ordering information scheme Example: STTS751-0 DP 3 F Device type STTS751-0 STTS751-1 Package DP = UDFN-6L Temperature range 3 = –40 °C to 125 °C Shipping method F = ECOPACK package, tape & reel For other options, or for more information on any aspect of this device, please contact the ST sales office nearest you. DocID16483 Rev 7 33/35 35

Revision history STTS751 11 Revision history Table 34. Document revision history Date Revision Changes 06-Nov-2009 1 Initial release. Updated Features; removed Therm2 throughout document (from Section 1, 2, 3.8, 4.6, 4.10, 5, Figure 1, 2, 3, 4, 6, Table 2, 3, 15, 28); 21-Jan-2010 2 updated Figure 3, Section 3.4, Section 4.6, Section 4.8, Section 4.10, Table 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 25; added package footprints (Figure 11 and 12); minor textual changes. Updated Section 3.7, Section 40.11, Section 5; Figure 6, 7, 11, 12; Table 12-May-2010 3 3, 9, 25, 28, 31; added tape and reel information (Figure 13, 14 and Table 32, 33); minor textual changes in title and document. Document status promoted to full datasheet; updated cover page; 01-Jul-2010 4 added footnote to Table 28; minor textual changes. 20-Jul-2010 5 Removed footnote from Table 28. 10-Sep-2018 6 Updated Accuracy in Features and Table 28: DC and AC characteristics 17-May-2019 7 Removed SOT23-6L package option 34/35 DocID16483 Rev 7

STTS751 IMPORTANT NOTICE – PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers’ products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. For additional information about ST trademarks, please refer to www.st.com/trademarks. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. © 2019 STMicroelectronics – All rights reserved DocID16483 Rev 7 35/35 35

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