This figure illustrates a circuit that implements DVS. The 3.3-V system power supply on the ADZS-BF533 EZLITE Lite® evaluation board powers the ADP2102 buck converter, whose output voltage is set to 1.2V using the external resistive dividers R1 and R2. A GPIO pin from the DSP is used to select a requested core voltage. Varying the feedback resistor adjusts the core voltage from 1.2V to 1.0V. An N-channel MOSFET modifies the voltage divider by inserting resistor R3 in parallel with R2. Feedforward capacitor CFF is needed for better transient performance and improved load regulation.