Critical Conduction Mode Operation

Internal 600V Power MOSFET

Gate Drive and No Auxiliary Winding

±3% LED Current Accuracy

Efficiency up to 93%

LED Short Circuit Protection

LED Open Circuit Protection

Current Sense Resistor Short Protection

Thermal Regulation Function

External PWM Dimming

 

Structure Type		Part NO.	MOS	Package	App. Watt		OVP	PDF
					176-264Vac	90-264Vac
Non-isolation	PF﹥0.5	WS9445P	5A/600V	DIP7	160V/400mA	80V/450mA	External Set

 

The WS9445P is a high precision buck constant current LED driver and is applied to non-isolated buck LED power system with AC input voltage of 85VAC-265VAC. The WS9445P integrates a 600V power MOSFET, and can achieve excellent constant current performance with very few external components, so the system cost and size are minimized. The driver operates in critical conduction mode, and the output current does not change with the inductance and LED output voltage. The operating current of the IC is 200uA, so it doesn’t need the auxiliary winding for supplying the chip, thus simplifying design and reducing cost.

The WS9445P adopts intelligent temperature control and thoroughly solves the problem of light flashing at high temperatures. It integrates an external dimming pin which inputs PWM signal and can dim by changing the duty cycle of the PWM signal. The WS9445P offers full protection functions to improve the system reliability, including LED open circuit protection, LED short circuit protection, CS resistor short circuit protection and thermal regulation function.

The WS9445P is available in DIP-7 Package.