IS31LT3918

Integrated Silicon Solution, Inc. – www.issi.com

Rev. A, 09/01/2011

2

PIN CONFIGURATION

Package

Pin Configurations

SOP-8

PIN DESCRIPTION

Pin Name

Pin Number

Description

DIM1

1

These two pins configure the dimming levels as follows:

DIM1=“floating”DIM2=“floating”, no dimming (100% only)；

DIM1=“floating”DIM2=“GND” , 100%-30%-100%

DIM1=“GND”DIM2=“floating”, 100%-50%-100%

DIM1=“GND”DIM2=“GND”, 100%-50%-20%-100%

DIM2

2

ADJ

3

Linear and PWM dimming input pin.

Linear dimming range: 0.5V to 2.5V.

PWM dimming frequency range: 200Hz -1kHz.

GND

4

Ground pin. All internal currents return through this pin.

GATE

5

This pin connects to the external NMOS’s gate

CS

6

Current detect pin, uses an external resistor to sense the peak inductor current.

Toff

7

This pin sets the off time for the switch by connecting a resistor between this pin and

GND.

Vin

8

8V – 450V supply voltage is connected to this pin via an external resistor. It is internally

clamped and must be bypassed using a capacitor to GND.

ORDERING INFORMATION

INDUSTRIAL RANGE: -40°C TO +85°C

Order Part No.

Package

QTY/Reel

IS31LT3918–GRLS2-TR SOP-8, Lead-free

2500