Chapter 29Comparator (CMP)29.1 IntroductionNOTEFor the chip-specific implementation details of this module'sinstances see the chip configuration information.The comparator (CMP) module provides a circuit for comparing two analog inputvoltages. The comparator circuit is designed to operate across the full range of the supplyvoltage, known as rail-to-rail operation.The Analog MUX (ANMUX) provides a circuit for selecting an analog input signal fromeight channels. One signal is provided by the 6-bit digital-to-analog converter (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 voltagereference for applications where voltage reference is needed. The 64-tap resistor laddernetwork divides the supply reference Vin into 64 voltage levels. A 6-bit digital signalinput selects the output voltage level, which varies from Vin to Vin/64. Vin can be selectedfrom two voltage sources, Vin1 and Vin2. The 6-bit DAC from a comparator is availableas an on-chip internal signal only and is not available externally to a pin.29.2 CMP featuresThe CMP has the following features:• Operational over the entire supply range• Inputs may range from rail to rail• Programmable hysteresis controlKL25 Sub-Family Reference Manual, Rev. 3, September 2012Freescale Semiconductor, Inc. 509
