8-bit PIC® MCU Slope Compensation Module

Last modified by Microchip on 2023/11/09 09:03

The Slope Compensation (SC) module is designed to provide the necessary slope compensation for fixed frequency, continuous current, and current mode switched power supplies. The SC module in a PIC® microcontroller (MCU) device works by quickly discharging an internal capacitor at the beginning of each Pulse Width Modulation (PWM) period of the switching power supply control signal. An internal current sink charges this capacitor at a programmable rate. As the capacitor charges, the capacitor voltage is subtracted from the current reference voltage, producing a linear voltage decay at the required rate.

slope compensation module example 1

SC Circuit Block Diagram

SC Circuit Block Diagram

The core of the SC module contains the following:

  • On-chip capacitor in series with the voltage source,
  • Shorting switch across the capacitor,
  • Calibrated current sink, and
  • One-shot pulse generator to ensure the switch is closed long enough to completely discharge the capacitor.


The input to the SC module can be connected to the following signals:

The output of the SC module can be connected to the following signals: