Emulated multi-path PID compensator for buck converters with large step-down ratio

An emulated multi-path PID compensator for buck converter with a large step-down ratio for application to a LCD TV is presented. The emulated multi-path PID compensator is adopted in order to avoid output noise and achieve fast transient characteristics. Furthermore, the proposed buck converter with the large amplitude of its sawtooth waveform is robust to noise such as ground bouncing voltage. The proposed chip is implemented in a 0.5-μm power BCD process. Overshoot and undershoot voltages are within 60mV and settling times are within 40μs for 1A load change. A maximum efficiency of 84.5% at an output power of 660mW is measured. The maximum load current is 1.2A.