Transient Improvement by Window Transient Enhancement and Overshoot Suppression Techniques in Current Mode Boost Converter

Abstract—In this paper, a current mode boost converter using window transient enhancement (WTE) and overshoot suppression (OSS) technique is presented for digital still camera (DSC) appli-cations. The peak-to-peak transient overshoot voltage demand of a DSC motor driver is generally within 4%–5 % of the regulated value. However, conventional boost converters usually fail to pass this criterion during large load transient. The OSS technique re-duces the overshoot voltage when load current changes from heavy to very light. Experimental results show that compared with the use of a conventional current mode boost converter, the use of the technique reduces drop voltage about 62 % and overshoot voltage about 51 % when the load current has a load step of 400 mA. More-over, the settling time improves to 43%, which is better than in the conventional case of a 400 mA load current step. The overhead of the silicon area is about 4.5 % to achieve the overshoot reduction. The estimated high performance demonstrates that it is suitable for DSC applications. Index Terms—Boost converter, constant frequency regulation, dc-dc power converter, free-wheeling switching, on-chip compen-sation, OSS technique, overshoot suppression. I