STTS751 | GUILCOR SENSORS

STTS751
Temperature sensors

Flexible digital temperature sensor with programmable resolution, ideal for thermal monitoring in electronics.

Measurement range
-40 / 125°C

Temperature accuracy
+/- 0,5°K

Resolution (Rh and T°)
9 to 16 bits

Power supply voltage
2,25 → 3,6V

Conversion time
1ms / 125ms

Typical current
100µA(active)

I²C Speed
0x48

Price
Medium

What is a STTS751 sensor ?

The STTS751 is a precise and fast digital temperature sensor developed by STMicroelectronics.

It offers a calibrated output of 9 to 16 bits, allowing for resolution adjustment based on the trade-off between accuracy, speed, and power consumption.

It is a very popular sensor for embedded thermal monitoring, particularly in electronic boards, servers, embedded systems, or portable devices.

Operating principle

The STTS751 relies on a calibrated silicon diode, whose voltage varies with temperature.

This voltage is amplified, converted by a delta-sigma ADC, and then digitally compensated.

The result is directly accessible for reading via the I²C bus.

Conversion formula (16-bit mode):

T(°C) = Signed codex / 256

where each bit represents 1/256 °C ≈ 0.0039 °C.

Example of conversion

Raw value (signed hex)	Temperature (°C)
0x0000	0,0
0x1000	16,0
0x1900	25,0
0x3200	50,0
0x6400	100,0

🧮 Selectable resolution: 9 bits (0.5 °C) to 16 bits (0.0039 °C).

Principle diagram (I²C connection)

+3.3V
 │
[STTS751]
 │ SDA ─────────┐
 │ SCL ─────────┤── [I²C Microcontroller]
 │ ADD0 / ADD1 ─┘ (address configuration)
 │ GND

💡 I²C address between 0x48 and 0x4F according to the ADD0/ADD1 pins.

Application areas

💻 Thermal surveillance of electronic boards and CPUs

🧠 Embedded systems and microcontrollers

🏭 Compact industrial applications

🔋 Low power equipment

🧪 Fast portable instrumentation

Should I choose a STTS751 sensor ?

Strengths points

⚡ Very fast and configurable
→ Conversion time <125 ms, with resolution choice up to 16 bits.
🎯 Good accuracy for its price→ ±0.5 K typical, more than sufficient for embedded applications.
🧰 Flexible interface
→ Compatible I²C and SMBus, configurable addresses, built-in alert switches.
🔋 Low consumption
→ Less than 1 µA in standby, ideal for battery-powered sensors.

Weaknesses points

📏 Less accurate than the metrological models
→ Less suitable for calibrations or scientific measurements (prefer TMP117, ADT7410, Si7051 for that).
📡 Only temperature
→ No measurement of humidity or other environmental parameters.
💾 System requirements
→ Resolution, mode, and thresholds must be initialized after power on.

Useful information

Here is some useful information regarding the STTS751 sensors.

Main Registers (I²C)

Adress (hex)	Name	Function
0x00 / 0x01	Temperature MSB / LSB	Temperature measurement
0x02	Status	Indicate end of conversion
0x03	Configuration	Resolution, mode, and polarity
0x04	T_HIGH	High alert threshold
0x05	T_LOW	Low threshold
0x06	T_CRIT	Critical threshold
0x07	Hysteresis	Alert hysteresis
0x0B	Product ID	Sensor ID ST

I²C Reading Example (pseudo-code)

i2c_start();
i2c_write(0x48 << 1);
i2c_write(0x00);
i2c_start();
i2c_write((0x48 << 1) | 1);
MSB = i2c_read_ack();
LSB = i2c_read_nack();
i2c_stop();

raw = (MSB << 8) | LSB;
if (raw & 0x8000) raw -= 65536; // Signed conversion
temp = raw / 256.0; // 16-bit mode

✅ Example:

MSB = 0x19, LSB = 0x00 → (0x1900 / 256) = 25.0 °C

Typical integration diagram

3.3V ───────────┐ │ [STTS751] │ SDA ───────┐ │ SCL ───────┤── MCU (Arduino, STM32, ESP32…) │ ALERT ─────┘ (alert exit) │ GND

💡 The ALERT brooch provides an immediate signal in case of overheating.

Configuration Register (0x03)

Bit	Name	Description
[7:5]	Fault queue	Number of samples before alert
[4]	Polarity	Polarity of the alert signal
[3:2]	Resolution	00 = 9 bits … 11 = 16 bits
[1:0]	Mode	00 = continue / 01 = standby / 10 = one-shot