Clarification on A3G4250D Temperature Sensor Output at 25°C

[shalinich67]

Dear STMicroelectronics Support Team,

I am currently working with the A3G4250D gyroscope and evaluating its temperature sensor output over I²C.

According to the datasheet, the temperature sensor output change versus temperature is specified as −1 °C per digit. I would like to clarify one point regarding the absolute digital value.

At an ambient temperature of 25°C, is there a specified or typical digital output value for the OUT_TEMP register? Or is the temperature output only defined relative to an internal reference without a guaranteed absolute value at 25°C?

In other words, should we expect a specific digital code at 25°C, or is the temperature register intended purely for relative temperature measurement and compensation?

Your clarification would help ensure correct implementation and validation during thermal chamber testing.

[Federica Bossi]

Hi @shalinich67 ,

The A3G4250D gyroscope’s OUT_TEMP register is intended for relative temperature measurement and internal compensation only. There is no specified or typical digital output value at 25 °C, nor any guaranteed offset at room temperature. The only parameter defined in the datasheet is the sensitivity (−1 LSB/°C), which allows you to track temperature changes but not to determine the absolute temperature. No factory calibration constant or formula is provided to convert OUT_TEMP into an absolute temperature. For thermal chamber testing, you should therefore use OUT_TEMP to monitor relative temperature variation, not to validate absolute temperature.