TMP117 | GUILCOR SENSORS

TMP117
Temperature sensors

High-precision digital temperature sensor offering ±0.1 °C accuracy for industrial and medical applications.

Maximum precision
+/- 0,1°K

Measurement range
-55 / 150°C

Resolution
16 bits

Power supply voltage
1,8 → 5,5V

Conversion speed

15,5 to 1mS

I2C adress
0 x 48

Typical current
3,5µA(active)

Price
Medium

What is a TMP117 sensor ?

The TMP117 is a high-precision digital temperature sensor from Texas Instruments.

It is the direct successor to the TMP102, but with quadrupled resolution and metrological accuracy suitable for medical and industrial applications.

It features a factory-calibrated 16-bit ADC, integrated thermal compensation, and a programmable offset, making it perfectly usable without external calibration.

Operating principle

The TMP117 converts the temperature of a calibrated internal diode via a 16-bit ΔΣ converter.

The measurement is stored in an internal register, accessible via the I²C bus.

Each bit represents 0.0078125 °C, with a signed 16-bit format (two's complement).

T(°C) = Binare code x 0,0078125

This resolution allows for a sensitivity of 7.8 mK, which is finer than the thermal variation of a human finger on a sensor.

Temperature curve / numerical value (16-bit resolution)

Temperature (°C)	Numerical value (hex)	Binary output (12bits)
-40	0xF580	1111 0101 1000 0000
0	0x0000	0000 0000 0000 0000
25	0x0800	0000 1000 0000 0000
100	0x2000	0010 0000 0000 0000
150	0x2E00	0010 1110 0000 0000

💡 Resolution: 1 LSB = 0.0078125 °C → 128 steps per degree Celsius.

Principle diagram (I2C connection)

+3.3V │ [TMP117] │ SDA ─────────┐ │ SCL ─────────┤── [I²C Microcontroller] │ ALERT ───────┘ │ GND

💡 A single I²C bus can control up to 4 TMP117s through address selection (0x48 → 0x4B).

Application areas

🩺 Medical devices (thermography, patient monitoring)

🧪 Laboratories, metrology, and calibration

⚙️ Precision industrial control

🔋 Thermal management of batteries and sensitive equipment

Should I choose a TMP117 sensor ?

Strengths points

🎯 Metrological precision
→ Ideal for autonomous objects, it consumes only a few microamperes in standby.
🧠 Extreme resolution (16 bits)
→ Each LSB represents less than 8 thousandths of a degree, perfect for detecting micro-thermal variations.
💤 Ultra low power consumption
→ Negligible consumption, ideal for autonomous connected devices.
🔧 Programmable calibration and offset
→ Allows for correcting offsets or adjusting measurements according to the setup.

Weaknesses points

🌡️ More limited range than thermocouples
→ Not suitable beyond +150 °C (internal electronics limited).
⚙️ Strict I²C Communication
→ Not compatible with SPI or 1-Wire — requires an active I²C interface.
💸 Slightly more expensive
→ But the price/performance ratio remains excellent for the category.

Useful information

Here is some useful information regarding the TMP117 sensors.

RMain registers (7-bit address: 0x48 → 0x4B)

Adress	Registry Name	Function
0x00	Temperature Result	Contains the measured temperature (16 signed bits)
0x01	Configuration Register	Sampling modes and alerts
0x02	T_High Limit	High alert threshold
0x03	T_Low Limit	Low alert threshold
0x04	EEPROM Unlock / Offset	Calibrations and internal memories
0x0F	Device ID / Revision	Sensor Identification (read-only)

Application example – Digital reading I²C

i2c_start();
i2c_write(0x48 << 1);     // Address TMP117 (writing)
i2c_write(0x00);          // Temperature log
i2c_start();
i2c_write((0x48 << 1) | 1); // Lecture
MSB = i2c_read_ack();
LSB = i2c_read_nack();
i2c_stop();

raw = (MSB << 8) | LSB;
if (raw > 0x7FFF) raw -= 65536; // Gestion du signe
temp = raw * 0.0078125; // Conversion en °C

✅ Example: MSB = 0x08, LSB = 0x00 →

Temperature = (0x0800 × 0.0078125) = 25.0 °C

Typical integration diagram

3.3V ───────────────┐ │ [TMP117] │ SDA ─────┐ │ SCL ─────┤── MCU (Arduino, ESP32, STM32) │ ALERT ───┘ │ GND

💡 Pull-up resistors of 4.7 kΩ on SDA and SCL ensure stable communication.

Example of configuration (CONFIG register)

Bit	Nom	Description
[15:12]	Mode	0000 : Continu, 0001 : One-shot
[11:9]	Conversion rate	000 → 15,5 ms / 111 → 1 s
[8]	Alert polarity	0 : Active low / 1 : Active high
[7:5]	Averaging	Average over 1, 8, 32, 64 samples
[4:0]	Shutdown / Reset / EEPROM	Low energy management