MC68HC908LD64 Datasheet, PDF (182/362 Pages) Freescale Semiconductor, Inc – Microcontrollers

Analog-to-Digital Converter (ADC)
13.6.2 Stop Mode
The ADC module is inactive after the execution of a STOP instruction.
Any pending conversion is aborted. ADC conversions resume when the
MCU exits stop mode. Allow one conversion cycle to stabilize the analog
circuitry before attempting a new ADC conversion after exiting stop
mode.
13.7 I/O Signals
The ADC module has six channels that are shared with port C I/O pins,
PTC5/ADC5–PTC0/ADC0.
13.7.1 ADC Analog Power Pin (VDDA)
NOTE:
The ADC analog portion uses VDDA as its power pin. Connect the
VDDA pin to the same voltage potential as VDD. External filtering may
be necessary to ensure clean VDDA for good results.
Route VDDA carefully for maximum noise immunity and place bypass
capacitors as close as possible to the package.
13.7.2 ADC Analog Ground Pin (VSSA)
The ADC analog portion uses VSSA as its ground pin. Connect the
VSSA pin to the same voltage potential as VSS.
13.7.3 ADC Voltage Reference High Pin (VRH)
VRH is the high voltage reference for the ADC.
13.7.4 ADC Voltage Reference Low Pin (VRL)
VRL is the low voltage reference for the ADC.
13.7.5 ADC Voltage In (ADCVIN)
ADCVIN is the input voltage signal from one of the six ADC channels to
the ADC module.
Data Sheet
182
Analog-to-Digital Converter (ADC)
MC68HC908LD64 — Rev. 3.0
Freescale Semiconductor