3.3.4.28 EMAFE_ADCI0Enable Function

void EMAFE_ADCI0Enable(bool tempEnable);

Summary

Enable ADC I0.

Description

Enable ADC I0.

Precondition

None.

Parameters


Param	Description
tempEnable	Temperature Measurement Activation.

Returns

None.

Example


EMAFE_ADCI0Enable(true);

Remarks

Temperature Sensor

The internal die temperature is measured by a dedicated conversion channel driven by an analog on-die temperature sensor connected to channel 0. By measuring the die temperature periodically and by using the calibration bits, channel gain drifts over temperature due to the voltage reference can be corrected.

Once the temperature measurement is enabled, the ADC starts to output samples corresponding to the temperature sensor. The first four samples account for internal digital filter settling and must be ignored. Then, in order to have a repeatable temperature acquisition, the user must average the ADC output over a minimum of 64 samples. By following this procedure, the temperature acquisition exhibits a standard deviation of less than 0.25°C in repeatability.

To calculate the real die temperature from the ADC acquisition, the following formula applies:

TJ(°C) = ( (ADC_TEMP_OUT / 224) x INT_REF_VOLTAGE - 0.110) / 0.00049

, where ADC_TEMP_OUT is the 24-bit output of ADC I0, averaged over 64 samples. For example, if ADC_TEMP_OUT = 1777345, the corresponding die temperature is TJ = 22.8°C.

Note: The inherent offset of the temperature sensor is not calibrated, so the absolute temperature reading exhibits a large deviation (typically ±15°C).