INTEGRATED CIRCUIT FOR CONTROL OF SWITCHING POWER, AND SWITCHING TYPE POWER SUPPLY

摘要

PROBLEM TO BE SOLVED: To enable the volume decrease of a power supply itself and the reduction of its cost, by curtailing circuit components.;SOLUTION: A current comparator 1 detects the value of a current flowing to a switching element in every switching cycle and controls its ON period by means of a flip flop circuit 2. A leveling circuit 5 converts the peak values of a load current into a time average, and when the comparator 6 detects an overcurrent state from the load current, a latch circuit 8 stops the switching action of the switching element for a certain period. In a delay circuit 7, a delay time from the detection of the overcurrent state of a load to the stoppage of the switching action of the switching element is set. Here, the first reference value (Vth1) of a current comparator 1 is set higher than the second reference value (Vth2) of the comparator 6.;COPYRIGHT: (C)2008,JPO&INPIT