UNISONIC TECHNOLOGIES CO., LTD

UC3750

Preliminary

CMOS IC

www.unisonic.com.tw

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Copyright © 2009 Unisonic Technologies Co., Ltd

QW-R502-360.a

600kHZ PWM/PFM STEP-DOWN

DC-DC CONTROLLER

DESCRIPTION

The UTC UC3750 is a high frequency, micropower, voltage mode

step-down DC-DC controller IC and is designed for battery operated

hand-held electronic products. It can provide up to 2.0A loading

current with conversion efficiency by connection of appropriate

external P-type MOSFET. It also can be applied to operate for voltage

regulation with minimum external components and board space.

The UTC UC3750 can operate in the constant -frequency PWM

(Pulse Width Modulation) mode that provide low output ripple noise in

the normal operation and will automatically switch to PFM(Pulse

Frequency Modulation) mode at low output loads for higher efficiency.

Moreover, it is ideal for portable applications profited from Chip

Enable (CE) to reduce IC off-stage current and integrated feedback

resistor network.

The UTC UC3750 is suitable for applications, such as PDA,

camcorders and digital still camera, hand-held instrument, distributed

power system, computer peripheral, conversion from four NiMH or

NiCd or one Lithium-ion cells to 3.3V/1.8V.

FEATURES

* High efficiency: 92% (Typ.)

* Low quiescent bias current :50μA

* Low shutdown current:0.3μA (Typ.)

* Output voltage:1.8V~3.3V ±2.0%

* Low output voltage ripple:50mV (Typ.)

* Built-in soft-start (SS)

* Pulse Width Modulation (PWM)switching frequency:600kHz

* Automatic PWM/PFM switchover under light load condition

* Very low dropout operation, 100% max. duty cycle

* Chip enable(CE) pin with on-chip 150nA pull-up current source

* Input voltage：2.45V- 5.5V

* Internal under-voltage lockout (UVLO) protection

* Low profile and minimum external components

* Halogen free

ORDERING INFORMATION

Ordering Number

Package

Packing

UC3750G-xx-AF5-R

SOT-25

Tape Reel

Note: xx: Output Voltage, refer to Marking Information.