SG3540

SG1540/SG2540/SG3540 OFF-LINE START-UP CONTROLLER DESCRIPTION The SG1540 is an integrated circuit designed to efficiently provide start-up power from a high-voltage DC bus to a PWM control circuit in a switching power supply. When used on the primary side, it reduces start-up current to less than 1mA and allows any standard PWM control circuit to be used a...