US4651S Datasheet, PDF (1/9 Pages) Unisonic Technologies – LOW COST POWER-SAVING MODE PWM CONTROLLER

UNISONIC TECHNOLOGIES CO., LTD
US4651S
LINEAR INTEGRATED CIRCUIT
LOW COST POWER-SAVING
MODE POWER-SWITCH FOR
FLYBACK CONVERTERS
 DESCRIPTION
The UTC US4651S is a high performance current mode
power-switch ideally suited for low standby power. Drain start up
make the power reliable on startup design and lower standby
power. At no load condition, the IC operates in power-saving mode
for lower standby power, decreasing frequency for Higher
conversion efficiency at light load condition.
The UTC US4651S contains protection with automatic recovery
including OLP (over load protection), OTP (over temperature
protection), OVP (over voltage protection), UVLO (V_DD over voltage
SOP-8
clamp and under voltage lockout).To protect the power MOSFET, Gate-drive output is fixed up to 16V max. The UTC
US4651S contains protection OCP (cycle-by-cycle current limiting).
The internal slope compensation improves system stability at high PWM duty cycle output. Leading-edge
blanking on current sense input removes the signal glitch, which offering minimal external component count in the
design. Excellent EMI performance is achieved with UTC proprietary frequency hopping technique
(ZL201020615247.1) together with soft driver control. Audio noise is eliminated due to switch frequency more than
20kHz during operation.
The UTC US4651S has such applications as: battery charger, power adaptor, set-top box power supplies, ink jet
printers, open-frame SMPS.
 FEATURES
* UTC proprietary frequency hopping technology for Improved EMI
performance.
* Power-saving mode for high light-load and standby efficiency
* Soft Start
* Dynamic peak current limiting for constant output power
* Built-in synchronized slope compensation
* OLP,OVP,OTP and V_DD clamp for higher security
* Drain start up for lower standby power
* Fixed switch frequency 65kHz
* Gate output voltage clamped at 15V
* Low start-up current
* Cycle-by-cycle Current Limiting
* Under voltage lockout (UVLO)
* Few external components required
 ORDERING INFORMATION
Ordering Number
US4651SG-S08-R
Package
SOP-8
Packing
Tape Reel
US4651SG-S08-R
(1)Packing Type
(2)Package Type
(3)Green Package
(1) R: Tape Reel
(2) S08: SOP-8
(3) G: Halogen Free and Lead Free
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