Design And FPGA Implementation Of Sliding Mode Controller For Buck Converter
This paper presents the digital design of Sliding Mode Controller (SMC) for synchronous buck converter for
high switching frequency and low power application. The buck converter is designed for a voltage mode control with PWM
technique having switching frequency of 3MHz. It will step down the input voltage of 3.6V to output voltage of 0.9V with
duty ratio of 25% and maximum load current of 800mA. The buck converter output voltage is maintained constant
irrespective of load variations. The digital SMC is implemented on Spartan 3E FPGA Kit using Xilinx System Generator
Tool. Using digitally controlled SMC, an Undershoot of 0.33% for load variations of 0.4A to 0.6A and 1.11% for load
variations of 0.4A to 0.8A with very fast Settling Time of 2.5μs is achieved.
Index Terms— Synchronous buck converter, Digital SMC, Spartan 3E FPGA Kit, Xilinx System Generator Tool,
Undershoot and Settling Time.