UNISONIC TECHNOLOGIES CO., LTD
USL3638
CMOS IC
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, VCC under voltage protection. The industry leading OVP
voltage accuracy ensures the best LED open circuit protection.
FEATURES
* Built-in 650V Power MOSFET
* ±5% LED current accuracy
* 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
* Choice for maximum duty cycle and OVP voltage
* CS resistor short circuit protection
* LED short and open circuit protection
* Over temperature protection
* VCC under-voltage protection
ORDERING INFORMATION
Ordering Number
Lead Free
Package
Packing
Halogen Free
USL3638G-S08-R
USL3638G-D08-T
USL3638L-S08-R
SOP-8
DIP-8
Tape Reel
Tube
USL3638L-D08-T
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