HIGH RELIABILITY AND LOW WASTE TYPE BOOST CIRCUIT

摘要

PURPOSE: To obtain a circuit for controlling switch on of a power device while reducing power consumption and achieving insensitivity to noise along with a control method thereof. CONSTITUTION: The highly reliable low power consumption boost circuit comprises a zero-detection circuit 0-DETECT forming a first logic signal when the voltage on the secondary winding Ls of a flyback inductance L has become zero, a comparator COMP forming a second signal, a logic AND gate generating a third signal based on both signals, and a pulse width modulation circuit PWM driving a power device Pw, based on the third signal.