Datasheet

Chapter 20
Analog comparator (ACMP)
20.1 Introduction
The analog comparator module (ACMP) provides a circuit for comparing two analog
input voltages. The comparator circuit is designed to operate across the full range of the
supply voltage (rail-to-rail operation).
The analog mux provides a circuit for selecting an analog input signal from eight
channels. One signal provided by the 6-bit DAC. The mux circuit is designed to operate
across the full range of the supply voltage. The 6-bit DAC is 64-tap resistor ladder
network which provides a selectable voltage reference for applications where voltage
reference is needed. The 64-tap resistor ladder network divides the supply reference V
in
into 64 voltage level. A 6-bit digital signal input selects output voltage level, which varies
from V
in
to V
in
/64. V
in
can be selected from two voltage sources.
20.1.1 Features
ACMP features include:
• Operational over the whole supply range of 2.7 V to 5.5 V
• On-chip 6-bit resolution DAC with selectable reference voltage from V
DD
or internal
bandgap
• Configurable hysteresis
• Selectable interrupt on rising edge, falling edge, or both rising or falling edges of
comparator output
• Selectable inversion on comparator output
• Up to four selectable comparator inputs
• Operational in stop3 mode
MC9S08PA60 Reference Manual, Rev. 1, 9/2012
Freescale Semiconductor, Inc. 557