IS31LT3135

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

Rev.A, 11/08/2011

1

MAIN/SUB DUAL-CHANNEL LED DRIVER

November 2011

GENERAL DESCRIPTION

IS31LT3135 is a main/sub dual-channel LED driver.

When the main channel works，it is a constant current

source driving the main LED and the current is set by

only 0.1v dropout voltage for 200mA output current.

When the sub-channel works, the chip will pull down

the sub LED’s cathode to ground.

Normally there is only one channel on, the main

channel and the sub channel can switch between each

other. Sweeping power supply from high voltage to low

voltage, main channel switches to sub-channel while

UV pin is below the undervoltage threshold 1.17V

(IS31LT3135-V1 typical) or 1.23V (IS31LT3135-V2

typical). Sweeping power supply from low voltage to

high voltage, the sub-channel switches to the main

channel while UV pin is 80mV (typical) higher than the

undervoltage threshold. Additionally, the main channel

has short protection function, when the main LED is

shorted，the chip will switch to sub-channel

automatically.

FEATURES



Power supply undervoltage detect



Main channel short protection



Over-temperature protection



Input voltage range: 2.7V~5.5V



Main and sub-channel current set by external

resistor



Main channel Vdp=0.1V



Low quiescent current



Assembled in SOP-8 package

APPLICATIONS



Miner lamp



Other LED lighting

TYPICAL APPLICATION CIRCUIT

Figure 1

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IS31LT3135

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