Description
The TinySwitch-II integrates a 700 V power MOSFET, oscillator, switched high-voltage power source, current limiter and thermal shutdown on a monolithic device. Starting and operating power is derived directly from the voltage at the DRAIN pin, eliminating the need for a bias winding and associated circuitry. Automatic restart, under-voltage detection and frequency jitter. An innovative design minimises the audio frequency components in the simple ON/OFF control scheme to virtually eliminate audible noise with a standard taped/painted transformer design. The fully integrated auto-restart circuitry safely limits output power under fault conditions such as output short circuit or open loop, reducing the number of components and secondary feedback circuit costs. An optional line sensing resistor externally programs an undervoltage threshold that eliminates shutdown errors caused by the slow discharge of input storage capacitors that occur in applications such as standby supplies. The 132 kHz operating frequency is jittered to include both quasi-peak and average EMI, minimising filter costs.
