Temperature Sensor
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
34-1
Chapter 34
Temperature Sensor
34.1
Overview
PXR40 MCUs include an on-board temperature sensor that monitors device temperature and produces a
voltage directly proportional to the internal junction temperature. Internal junction temperature must be
calculated by software based on the sampled temperature sensor voltage, sampled bandgap voltage and
calibration parameter values stored in internal flash memory.
34.2
Detailed Description
The temperature sensor generates a voltage that increases linearly with temperature. Since the voltage is
an amplified version of a
V
BE
voltage it is proportional to absolute temperature. This voltage,
V
TSENS
(T), is read by software using the on-board eQADC module and used with the bandgap voltage and
constants stored in flash memory during factory test to calculate device junction temperature.
Five calibration parameters are stored in flash memory during factory test:
•
T
LOW
is the low temperature factory calibration temperature value.
•
T
HIGH
is the hot factory calibration temperature value.
•
V
BG_CODE
(T
LOW
) is the bandgap voltage at low calibration temperature (T
LOW
) sampled by the
eQADC and converted to a 14-bit value.
•
T
TSENS_CODE
(T
LOW
) is the temperature sensor voltage at low calibration temperature (T
LOW
)
sampled by the eQADC and converted to a 14-bit value.
•
T
TSENS_CODE
(T
HIGH
) is the temperature sensor voltage at high calibration temperature (T
HIGH
)
sampled by the eQADC and converted to a 14-bit value.
The calibration points are illustrated in
.
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Page 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
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