TNY290PG

TinySwitch-4 combines a high-voltage power MOSFET switch with a power supply controller in one device. Unlike conventional PWM (pulse width modulator) controllers, it uses a simple ON/OFF control to regulate the output voltage. The controller consists of an oscillator, enable circuit (sense and logic), current limit state machine, 5.85V regulator, BYPASS/MULTIFUNCTION pin undervoltage, overvoltage circuit, and current limit selection circuitry, over-temperature protection, current limit circuit, leading edge blanking, and a 725V power MOSFET. TinySwitch-4 incorporates additional circuitry for line undervoltage sense, auto-restart, adaptive switching cycle on-time extension, and frequency jitter. Figure 3 shows the functional block diagram with the most important features.

• 725 V rated MOSFET
• Line compensated overload power – no additional components
• ±5% turn on UV threshold: line voltage sense with single external resistor
• Simple ON/OFF control, no loop compensation needed
• Selectable current limit through BP/M capacitor value
• ON-time extension – extends low-line regulation range/hold-up time to reduce input bulk capacitance
• Self-biased: no bias winding or bias components
• Frequency jittering reduces EMI filter costs
• Accurate hysteretic thermal shutdown protection with automatic recovery eliminates need for manual reset
• Auto-restart delivers <lt/>3% of maximum power in short-circuit and open loop fault conditions
• Output overvoltage shutdown with optional Zener

Applications

Computers & Computer Peripherals, Consumer Electronics, Portable Devices