C8051F50X Datasheet, PDF (72/312 Pages) Silicon Laboratories – Mixed Signal ISP Flash MCU Family

C8051F50x-F51x
7. Temperature Sensor
An on-chip temperature sensor is included on the C8051F50x-F51x devices which can be directly
accessed via the ADC multiplexer in single-ended configuration. To use the ADC to measure the tempera-
ture sensor, the ADC multiplexer channel should be configured to connect to the temperature sensor. The
temperature sensor transfer function is shown in Figure 7.1. The output voltage (V_TEMP) is the positive
ADC input is selected by bits AD0MX[4:0] in register ADC0MX. The TEMPE bit in register REF0CN
enables/disables the temperature sensor, as described in SFR Definition 8.1. While disabled, the tempera-
ture sensor defaults to a high impedance state and any ADC measurements performed on the sensor will
result in meaningless data. Refer to Table 5.10 for the slope and offset parameters of the temperature sen-
sor.
V_TEMP = (Slope x Temp_C) + Offset
Temp_C = (V_TEMP - Offset) / Slope
Slope (V / deg C)
Offset (V at 0 Celsius)
Temperature
Figure 7.1. Temperature Sensor Transfer Function
72
Rev. 1.1