Se rendre au contenu

 TMP102 
 Temperature sensors 

Low-power digital temperature sensor with I²C interface, ideal for portable devices and embedded systems.

 Maximum precision
+/- 0,5°K

 Measurement range
-40 / 125°C

 Resolution
12 bits

 Power supply voltage
1,4 → 3,6V

Conversion speed

25 to 150ms

I2C adress
0 x 48

 Typical current
10µA(active)

 Price
Low

What is a TMP102 sensor ?Operating principleTemperature curve / numerical value (12-bit resolution)Principle diagram (I2C connection)Application areas

What is a TMP102 sensor ?

The TMP102 is a digital temperature sensor with an I²C interface, designed by Texas Instruments.

Compact, precise, and with very low power consumption, it is ideal for embedded applications, connected objects, and compact electronic boards (Arduino, ESP32, Raspberry Pi, etc.).

Its operation is based on an integrated diode sensor and a 12-bit analog-to-digital conversion (ADC), providing the temperature directly in the form of digital data.

Operating principle

The TMP102 measures internal temperature using a PN junction whose voltage varies with temperature (similar principle to a diode thermometer).

This voltage is converted by a ΔΣ (Delta-Sigma) converter into a digital value, transmitted via the I²C bus.

​T(°C) = Binare code x 0,0625

Each increment (LSB) represents 0.0625 °C.

The unit communicates on the I²C bus according to the master/slave protocol.

Temperature curve / numerical value (12-bit resolution)

Temperature (°C) Numeric value (hex)

Binary output (12 bits)

-40

 0xF580

1111 0101 1000 0000
0 0x0000

0000 0000 0000 0000

25

0x1900

0001 1001 0000 0000

Type 85of case 0x5500

0101 0101 0000 0000

125

0x7D00

0111 1101 0000 0000

💡 Each LSB = 0.0625 °C, which allows for very fine resolution for a compact sensor.

Principle diagram (I²C connection)

     +3.3V
       │
      [TMP102]
       │ SDA ─────────┐
       │ SCL ─────────┤── [I²C Microcontroller]
       │ ALERT (option)
       │ GND ─────────┘

💡 The I²C bus allows multiple sensors to be connected on the same SDA/SCL lines using distinct addresses.

Application areas

🌡️ Thermal surveillance of electronic boards

🧠 Embedded IoT sensors and wearables

🔋 Batteries, servers, laptops

🧪 Precision instrumentation (DAQ, microcontrollers)


Should I choose a TMP102 sensor ?

Strengths points

  • 🔋 Ultra low power consumption
         → Ideal for autonomous objects, it consumes only a few microamperes in standby.
  • 🧠 Simple and universal interface
         → The 1 kΩ NTC is inexpensive, standardized, and compatible with most electronic boards and microcontrollers.
  • 📈 Remarkable precision for its size
         → ±0.5 K accuracy over the useful range, without external calibration.
TMP102 sensors

Weaknesses points

  • 🌡️ Limited beach
         → Works up to about 125 °C, so not suitable for extreme industrial environments.
  • ⚡ Slow conversion
         → Up to 150 ms for a complete measurement at 12 bits — not well suited for ultra-fast measurements.
  • 📡 I²C noise sensitive
         → Requires suitable pull resistors and short lines to avoid communication errors.

Useful information

Here is some useful information regarding the TMP102 sensors.

Address
 Registry Name
 Function
0x00 Temperature Register Contains the temperature measurement (12 bits)
0x01 Configuration Register Defines the resolution, the alert, the sleep mode
0x02 T_LOW Register Low temperature threshold (alert)
0x03 T_HIGH Register High temperature threshold (alert)
i2c_start();
i2c_write(0x48 << 1);   // TMP102 Address (write) 
i2c_write(0x00);        // Pointer to the temperature register
i2c_start();
i2c_write((0x48 << 1) | 1); // Lecture
MSB = i2c_read_ack();
LSB = i2c_read_nack();
i2c_stop();

temp = ((MSB << 4) | (LSB >> 4)) * 0.0625;

💡 The reading is done on two bytes, the conversion to °C is simply calculated using the factor 0.0625.

+3.3V
 │
[ TMP102 ]
 │ SDA ───────────┐
 │ SCL ───────────┤── MCU I²C
 │ ALERT (option) │
 │ GND ───────────┘

💡 Add two pull-up resistors (4.7 kΩ typical) on SDA and SCL to stabilize the communication.

If the reading returns:

MSB = 0x1A, LSB = 0x10,

we have:

Température = ((0x1A × 16) + (0x10 >> 4)) × 0,0625 = 26,06 °C

✅ Measured temperature ≈ 26.1 °C

 We integrate any sensor into any probe 

Smooth tube probe

 Smooth tube 

Waterproof probe

 Waterproof

Bayonet probe

 Bayonet

Slot probe

 Slot

Ambient probe

 Atmosphere

Head connection probe

Termal block

Stick-in probe

Stick-in

Thread probe

Thread

Contact probe

Contact

Jacketed probe

Jacketed

PCBA Design

PCBA design

Winding probe

Winding

Plus de 1 000 000 sondes livrées en 2025

Contactez-nous pour une offre personnalisée

Contact Us

Need a TMP102 sensor?

Que vous ayez besoin de quelques pièces pour un prototype ou de plusieurs centaines pour une ligne de production, nous vous accompagnons à chaque étape.

Submit