Dynamic DC ramp shift digital control technique for improved transient response

A new control scheme aiming to improve the dynamic behavior of digitally controlled DC-DC converters in terms of improved settling time and overshoot is presented in this paper. The proposed approach enhances the transient response by dynamically controlling the ramp of the Digital Pulse Width Modulator (DPWM) unit by applying DC shift to the conventional ramp-based PWM during load change. This will help the compensator reach the steady-state value faster. The dynamic DC ramp shift design method presented in this paper utilizes the existing system digital controller, and does not require any additional circuitry. The presented control scheme is first analyzed, then simulated and finally experimentally verified using a DSP implementation.