SM8122AD 参数 Datasheet PDF下载

SM8122A

White LED Driver IC

OVERVIEW

The SM8122A is a high efficiency step-up DC/DC converter. Due to high voltage CMOS process realizing

25V output supply as maximum value, 2 to 6 lights of white LED connected in series can be lighted. By con-

necting in series, current variation among LED is eliminated. Current value sent to white LED can be set by

external resistors. In addition, brightness can also be adjusted by control to FB pin or CE pin. Since the

SM8122A has an over voltage protection circuit built-in, it dispenses with the existing external ZD (zener

diode). Besides, the switching frequency of the SM8122A is higher (2.0MHz) than the existing product

(SM8121A), so that it can respond to lower inductance value.

FEATURES

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PINOUT

(Top view)

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Boost-up control using PWM

2 to 6 lights of white LED (connected in series)

lighted

Output current value can be set by external resis-

tors (51

Ω

: 9.8mA, 33

Ω

: 15.2mA, 24

Ω

: 20.8mA)

Brightness adjustable by control to FB pin or CE

pin

Current variation among LED decreased by high

precision

High efficient drive by step-up model

Over voltage protection circuit built-in

Supply voltage range: 2.3 to 5.5V

Maximum output voltage: 25V

Quiescent current: 820

µ

A (typ)

Standby current: 1.0

µ

A (max)

R

ON

(Switching MOS-Tr): 2

Ω

(typ)

Switching frequency: 2.0MHz (typ)

Output current detection accuracy:

±

2%

Package: SOT23-6W (SM8122AH)

MSON-6 (SM8122AD)

SOT23-6W

SW

1

6

VDD

VOUT

2

5

VSS

FB

3

4

CE

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MSON-6

VDD 1

6

5

4

VOUT

VSS

FB

APPLICATIONS

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Cellular phone

Pager

Digital still camera

Handy terminal

PDAs

Portable games

White LED drive

LCD bias supply

Flash memory supply

SW 2

CE 3

ORDERING INFORMATION

Device

SM8122AH

SM8122AD

Package

SOT23-6W

MSON-6

NIPPON PRECISION CIRCUITS INC.—1