UNISONIC TECHNOLOGIES CO., LTD

US3706

Preliminary

CMOS IC

www.unisonic.com.tw

1 of 8

Copyright © 2015 Unisonic Technologies Co., Ltd

QW-R129-001.b

CURRENT MODE PWM POWER

SWITCH



DESCRIPTION

The UTC US3706 combines a dedicated current mode PWM

current make the power reliable on startup design and a large

value resistor could be used in the startup circuit to minimize the

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 US3706 offers complete protection coverage with

automatic self-recovery feature including Cycle-by-Cycle current

limiting (OCP), over load protection (OLP), over temperature

protection (OTP),

over

voltage

voltage lockout (UVLO).

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 US3706 has such applications as: battery charger, power

adaptor, set-top box power supplies, ink jet printers, open-frame

SMPS.



FEATURES

TO-220F-6

1

* 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,OVPand OTP for higher security

* Fixed switch frequency 65kHz

* Low start-up current

* Cycle-by-cycle Current Limiting

* Under voltage lockout (UVLO)

* Leading edge blanking on source input

* Few external components required

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ORDERING INFORMATION

Ordering Number

Package

Packing

Lead Free

Halogen Free

US3706L-TF6-T

US3706G-TF6-T

TO-220F-6

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