The Slope Compensation (SC) module is designed to provide the necessary slope compensation for fixed frequency, continuous current, current mode switched power supplies. The SC module in a PIC® 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.
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.
Connections
The input to the SC module can be connected to the following signals:
The output of the SC module can be connected to the follow signals:
