MC68HC08AB16A Datasheet, PDF (226/380 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Analog-to-Digital Converter (ADC)
14.7.1 ADC Analog Power Pin (V_DDAREF)
The ADC analog portion uses V_DDAREF as its power pin. Connect the
V_DDAREF pin to the same voltage potential as V_DD. External filtering may
be necessary to ensure clean V_DDAREF for good results.
NOTE: For maximum noise immunity, route V_DDAREF carefully and place
bypass capacitors as close as possible to the package.
14.7.2 ADC Analog Ground Pin (A_VSS/V_REFL)
The ADC analog portion uses A_VSS/V_REFL as its ground pin. Connect
the A_VSS/V_REFL pin to the same voltage potential as V_SS.
NOTE: Route A_VSS/V_REFL cleanly to avoid any offset errors.
14.7.3 ADC Voltage Reference High Pin (V_REFH)
V_REFH is the reference voltage for the ADC.
14.7.4 ADC Voltage In (V_ADIN)
V_ADIN is the input voltage signal from one of the eight ADC channels to
the ADC module.
14.8 I/O Registers
These I/O registers control and monitor ADC operation:
• ADC status and control register (ADSCR)
• ADC data register (ADR)
• ADC clock register (ADCLK)
Technical Data
226
MC68HC08AB16A — Rev. 2.0
Analog-to-Digital Converter (ADC)
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