Digital proportional plus derivative controller for switching dc-dc converters

Digital proportional plus derivative (D-PD) controller with zero steady-state error is introduced for buck dc-dc converters. The proposed D-PD controller decreases the number of look-up tables from three to two, and decreases the adder input from four to three in the compensator circuits in contrast with digital proportional plus integral plus derivative (D-PID) controller. A new technique, called as error-shift technique, is proposed to eliminate steady-state error without increasing any hardware cost. Therefore, the proposed D-PD controller can greatly reduce the layout area. Simulation shows that D-PD controller is better than D-PID controller for the gross performance of switching dc-dc converters.