AIC1628

3-Cell, High-Efficiency, Step-Up DC/DC Converter

Analog Integrations Corporation

4F, 9, Industry E. 9th Rd, Science Based Industrial Park, Hsinchu Taiwan, ROC

www.analog.com.tw

DS-1628-00

TEL: 886-3-5772500

FAX: 886-3-5772510

1

FEATURES

4V to 24V Input Voltage Operation.

Adjustable Output Voltage.

Low Quiescent Current at 100

µA.

Pulse-Skipping and Pulse-Frequency Modulation

Maintain High Efficiency (max. 95%).

90KHz to 250KHz Oscillator Frequency.

Power-Saving Shutdown Mode (8

µA Typical).

Push-Pull Driver Output.

APPLICATIONS

Flash Memory Programming Power Supply.

Positive LCD Contrast Bias for Notebook &

Palmtop Computers.

Step-Up DC/DC Converter Module.

Telecom Power Supply.

DESCRIPTION

The AIC1628 is a high performance step-up

DC/DC converter, designed to drive an external

power switch to generate programmable posi-

tive voltages. In the particularly suitable LCD

contrast bias and flash memory programming

power supply applications, typical full-load effi-

ciencies are 85% to 95%. 4V to 24V input op-

eration range allows the AIC1628 to be powered

directly by the battery pack in the most battery-

operated applications for greater efficiency.

Output voltage can be scaled to 40V or greater

by two external resistors. A Pulse-Frequency

Modulation scheme is employed to maintain

high efficiency conversion under wide input

voltage range. Quiescent current is about

100

µA and can be reduced to 8µA in shutdown

mode. Switching frequency being around 90KHz

to 250KHz range, small size switching compo-

nents are ideal for battery powered portable

equipments, like notebook and palmtop com-

puters.

TYPICAL APPLICATION CIRCUIT

AIC1628

CL

DHI

DLOW

FB

GND

SHDN

VIN

VREF

+36V

>50mA

1N5819

C5

+

C6

+5V ~ 24V

C1

120

µF

+

5V

*Buss Fuse MCR-2A

**Sumida CDR105

*Fuse

60m

Ω

68

µH

C2

R1

470K

R2

16.5K 0.033µF

C3

220

µF

0.1

µF

D1

2SK940

0.01

µF

C4

**L1

Q1

Load Current (mA)

0

50

100

150

200

80

85

90

95

Color LCD Contrast Bias Supply

Efficiency vs. Output Current