Sawtooth burst mode control with minimum peak current in stand-by operation of power supply

Abstract

The hysteresis burst mode can save the power consumption at light loads by reducing switching losses. However, the hysteresis burst mode can not be used at very low power levels because variable group frequency can cause acoustic noise. To solve this problem, a sawtooth burst mode is proposed to maintain constant group frequency. Moreover, minimum peak current function is used to sawtooth burst mode to minimizing the power consumption at light loads. By using minimum peak current function, the number of switching can be reduced. This decreases the power consumption at light loads. The 60W ac/dc converter is implemented to verify the proposed sawtooth burst mode with minimum peak current.