ALLEGRO MICROSYSTEMS STR4A100 series off-line PWM controllers incorporate both a sense MOSFET and a current mode PWM controller IC (developed by Sanken Electric Co.). Product series uses a secondary side regulation topology suitable for low power SMPS regulators in white goods and other applications. An auxiliary power supply, which is separated from the inverter or main power supply, may require high-efficiency and low stand-by power. Product makes it possible to lower the stand-by power to less than 10mW. The low standby power is accomplished by the automatic switching between the PWM operation in normal operation and the burst-oscillation under light load conditions. The end result yields a high cost-performance power supply system with few external components.
