Built-in650V Power MOSFET

Constant current control without secondary sense and feedback circuit.

No Auxiliary winding for sensing and supplying

Ultra low operating current to improve efficiency

Universal input voltage

±5% LED current accuracy

LED short and open circuit protection

CS resistor short circuit protection

VCC under-voltage protection

Over temperature protection

Available in SOP-7 package

 

Structure Type		Part NO.	MOS	Package	App. Watt		OVP	PDF
					176-264Vac	90-264Vac
Isolation	PF﹥0.5	WS9221B	0.5A/650V	SOP7	5W	3W	External Set

 

The WS9221B is a high precision primary-side feedback and regulation controller for LED lighting, it operates in constant current control mode and is designed to work in inductor current discontinuous conduction mode and especially suitable for flyback convertor under universal input.The output power of system is recommended to less than 3W.

The WS9221B integrates 650V power MOSFET. Since adopting primary sense and feedback control technology, the secondary sense and feedback circuit is eliminated. The loop compensation components are also removed while maintaining stability overall operating conditions. The operating current is very low, and it doesn’t need the auxiliary winding for sensing the output current and supplying the chip.The low component counts and small system size arerealized.Since using the proprietary high accurate current sense method, theWS9221B realizes ±5% accuracy of LED current along with excellent line and load regulation.

The WS9221B offers rich protection functions including LED open/short circuit protection, CS resistor short circuit protection, over-temperature protection, VCC under voltage protection.