Transient improvement by window transient enhancement and overshoot suppression techniques in current mode boost converter

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) applications. 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 reduces 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. Moreover, 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.