POWER INTEGRATIONS LYT0002P

The LYTSwitch-0 family is specifically designed for low cost LED bulb replacement applications. LYTSwitch-0 devices integrate a 700 V power MOSFET, oscillator, simple ON/OFF control scheme, a high-voltage switched current source, frequency jittering, cycle-by-cycle current limit and thermal shutdown circuitry into a monolithic IC. The start-up and operating power are derived directly from the voltage on the DRAIN pin. This eliminates the need for a bias supply and associated circuitry plus allowing low-cost discrete inductors to be used. The fully integrated auto-restart circuit in the LYTSwitch-0 family safely limits output power during fault conditions such as short-circuit or open-loop, reducing component count and lower system cost. Package options for thru-hole and surface-mount suit different manufacturing requirements. LYTSwitch-0 combines a high-voltage power MOSFET switch with a power supply controller in one device. Unlike conventional PWM (pulse width modulator) controllers, LYTSwitch-0 uses a simple ON/OFF control to regulate the output voltage. The LYTSwitch-0 controller consists of an oscillator, feedback (sense and logic) circuit, 5.8 V regulator, BYPASS pin undervoltage circuit, over-temperature protection, frequency jittering, current limit circuit, leading edge blanking and a 700 V power MOSFET. The LYTSwitch-0 incorporates additional circuitry for auto-restart.

• High power factor meeting EU and USA requirements
• Very low component count
• Frequency jitter reduces EMI
• No bias supply or transformer required
• The typical oscillator frequency is internally set to an average of 66 kHz
• The LYTSwitch-0 oscillator incorporates circuitry that introduces a small amount of frequency jitter, typically 4 kHz peak-to-peak, to minimize EMI emission
• The modulation rate of the frequency jitter is set to 1 kHz to optimize EMI reduction for both average and quasi-peak emissions