TS1937 Datasheet, PDF (1/8 Pages) Taiwan Semiconductor Company, Ltd – Boost (Step-up) WLED Driver

TS1937
Boost (Step-up) WLED Driver
SOT-25
Pin Definition:

1. SW
2. Ground
3. Feedback
4. CTRL
5. Input
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.
Features
● Inherently Matched LED Current
● High Efficiency: 88% Typical
● Drives Up to 6 LEDs @ Vin 5V
● Drives Up to 12 LEDs @ Vin 12~15V
● 36V Rugged Bipolar Switch
● Fast 1.2MHz Switching Frequency
● Requires Only 0.22µF Output Capacitor
● PWM dimming control 1KHz to 10KHz
● Analog dimming control
Application
● Cellular Phones
● Digital Still Cameras
● MP3 Players
● White LED Backlighting
● PDAs, Handheld computers
Ordering Information
Part No.
TS1937CX5 RF
Package
SOT-25
Packing
3Kpcs / 7” Reel
Typical Application Circuit

1/8
Version: C07