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Chip-specific ADC information
17.1.5 Hardware trigger
The ADC hardware trigger is selectable from intermodule crossbar, which source can be
from any input of intermodule crossbar, such as PDBs, FTM, PWM, analog comparators,
package pins. The MCU can be configured to use any of those hardware trigger sources
in run and wait modes. The stand alone analog comparator can be used as ADC hardware
trigger in STOP mode.
17.1.6 Temperature sensor
The ADC module integrates an on-chip temperature sensor. Following actions must be
performed to use this temperature sensor.
• Configure ADC for long sample with a maximum of 1 MHz clock
• Convert the bandgap voltage reference channel (AD23)
• By converting the digital value of the bandgap voltage reference channel using
the value of V
• Convert the temperature sensor channel (AD22)
• By using the calculated value of V
voltage, V
TEMP
The following equation provides an approximate transfer function of the on-chip
temperature sensor for V
and configured for long sample.
where:
• V
is the voltage of the temperature sensor channel at the ambient temperature
TEMP
• V
is the voltage of the temperature sensor channel at 25 °C
TEMP25
• m is the hot or cold voltage versus temperature slope in V/°C
For temperature calculations, use the V
In application code, you read the temperature sensor channel, calculate V
compare it to V
TEMP25
in the above equation. If V
258
the user can determine V
BG
= 5.0V, Temp = 25°C, using the ADC at f
DD
TEMP25
. If V
is greater than V
TEMP
is less than V
TEMP
MC9S08SU16 Reference Manual, Rev. 5, 4/2017
.
DD
, convert the digital value of AD22 into a
DD
and m values in the data sheet.
, the cold slope value is applied
TEMP25
the hot slope value is applied.
TEMP25
= 1.0 MHz
ADCK
, and
TEMP
NXP Semiconductors
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