TS1937

Boost (Step-up) WLED Driver

1/8

Version: C07

SOT-25

General Description

The TS1937 is a step-up DC/DC converter specifically designed to drive white LEDs with a constant current. The

device can drive 2 ~ 12 LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED

currents resulting in uniform brightness and eliminating the need for ballast resistors. The output capacitor can be as

small as 0.22µF, saving space versus alternative solutions. A low 95mV feedback voltage minimizes power loss for

better efficiency. Additional feature include over output voltage limiting when LEDs are disconnected.

The TS1937 switches at a fixed frequency of 1.2MHz, allowing the use of tiny, low profile inductors and capacitors to

minimize footprint and cost in space consideration applications for cellular phone backlighting or other hand held

equipment.

Application

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Cellular Phones

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Digital Still Cameras

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MP3 Players

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White LED Backlighting

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PDAs, Handheld computers

Features

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Inherently Matched LED Current

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High Efficiency: 88% Typical

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Drives Up to 6 LEDs @ Vin 5V

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Drives Up to 12 LEDs @ Vin 12~15V

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36V Rugged Bipolar Switch

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Fast 1.2MHz Switching Frequency

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Requires Only 0.22µF Output Capacitor

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PWM dimming control 1KHz to 10KHz

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Analog dimming control

Ordering Information

Part No.

Package

Packing

TS1937CX5 RF

SOT-25

3Kpcs / 7” Reel

Typical Application Circuit

Pin Definition:

1. SW

2. Ground

3. Feedback

4. CTRL

5. Input