US1651G-S08-R datasheet(6/7 Pages) UTC

6 / 7 page

US1651

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

6 of 7

www.unisonic.com.tw

QW-R129-005.a



OPERATION DESCRIPTION (Cont.)

Adjustable Drive Capability

The internal power MOSFET in UTC US1651 is driven by a dedicated gate driver for power switch control. Too

weak the gate drive strength results in higher conduction and switch loss of MOSFET while too strong gate drive

compromises EMI. A good tradeoff is achieved through the built-in totem pole gate design with right output strength

control. The gate drive strength can be adjusted externally by a resistor connected between VDD and VDDG, The low

idle loss and good EMI system design is possible with this dedicated control scheme.

Protection Control

Good power supply system reliability is achieved with its comprehensive protection features including VDD

over-voltage protection, VDD Clamp, GATE Clamp, Power on soft start, Cycle-by-cycle current limiting, short circuit

protection, leading edge blanking, OTP and UVLO, etc.

VDD is supplied by transformer auxiliary winding output. The output of UTC US1651 is shutdown when VDD drops

below VTH(OFF) and the power converter enters power on start-up sequence thereafter.

US1651G-S08-R Datasheet(PDF) 6 Page - Unisonic Technologies