FPGA-based controllers for switching converters

This paper presents a FPGA-based digital control for a DC-DC converter. The main difference from DSP-based solution is that FPGA allows simultaneous execution of all control procedures, enabling high performance and novel control methods. The control algorithm has been developed using a VHDL language or CAD state graphical approach based on the use of logical state diagram. The FPGA switching controller has been designed as simple as possible while maintaining good accuracy and dynamic response. A sliding mode switching controller via Lyapunov design presented in this paper has been implemented on a SPARTAN 3 for a prototype buck converter. The high computation power of FPGA allows digital implementation of more advanced control algorithms such as sliding mode controller. Simulations and experimental results show the feasibility of the proposed method, opening interesting possibilities in motion and power electronics converter control.