HIGH PRECISION PSR CONSTANT CURRENT LED DRIVER

DESCRIPTION

The UTC USL3638 is a high performance, high precision

primary-side feedback and regulation and constant current

controller for LED lighting, The UTC USL3638 operates in

discontinuous conduction mode for inductor current. It is suitable

for flyback convertor under the 90V~264V universal input. The

system output power for UTC USL3638 (SOP8) and UTC

USL3638 (DIP8) is recommended to be less than 8W and 11W.

The UTC USL3638 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. Low operating current, and using particular diver architecture and

demagnetization sensing technology make the auxiliary winding for sensing the output current and supplying the

chip also needless. The low component counts and small system size are realized.

Since using the proprietary high accurate current sense method, the UTC USL3638 realizes ±5% accuracy of

LED current along with excellent line and load regulation.

The UTC USL3638 has integrated rich protection functions including LED short/open circuit protection, CS

resistor short circuit protection, over-temperature protection, V CC under voltage protection. The industry leading OVP

voltage accuracy ensures the best LED open circuit protection.

FEATURES

* Built-in 650V Power MOSFET

* No Auxiliary winding for sensing and supplying

* Constant current control without secondary sense and feedback circuit.

* Ultra low operating current to improve efficiency

* Universal input voltage

* ±5% LED current accuracy

* Choice for maximum duty cycle and OVP voltage

* CS resistor short circuit protection

* LED short and open circuit protection

* Over temperature protection

* V CC under-voltage protection