BURST MODE SWITCHING MODE POWER SUPPLY

摘要

PURPOSE: A burst mode SMPS(switching mode power supply) is provided to reduce switching loss by switching in a ready mode and then stopping the switching for a while to decrease input power. CONSTITUTION: A burst mode SMPS comprises a power supply(100), a feedback circuit unit(200), a switching controller(300) and a mode setting unit(400). The power supply(100) comprises a main switch(SW1) coupled to a primary coil of a transformer. The main switch(SW1) is switched with predetermined duty ratio during normal mode and is switched with the duty ratio for only second section during ready mode. The feedback circuit unit(200) switches the main switch into the normal or ready mode by controlling mode setting voltage coupled to secondary output of the transformer. The switching controller(300) has a slave current source and a first capacitor to the slave current source.