STLD20D_06 Datasheet, PDF (1/31 Pages) STMicroelectronics – White LED power supply

STLD20D
White LED power supply
General features
■ Typical guaranteed efficiency: 80%
■ Drives up to 4 LEDs in series from a 2.8V up to
4.2V supply voltage
■ Constant current regulation over the whole
operating voltage range
■ PWM control mode
■ Integrated load disconnect switch that opens
the LEDs path in shutdown mode
■ Integrated soft start peak inductor current
■ Programmable peak inductor current
(STLD20D-C8 only)
■ Shutdown pin allows digital dimming control up
to 10kHz
■ Over voltage and over temperature protection
with automatic restart
■ Low shutdown current (< 1µA)
■ Small external inductor (10µH)
■ Tiny external ceramic capacitor (1µF)
Application
■ White Led supply for LCD backlight
■ Mobile phone
■ PDA and organizers, MP3 players, Toys
QFN 3x3 8L
SOT23-8L
Description
The STLD20D is a constant switching frequency
boost regulator mainly dedicated to supply up to 4
white LEDs connected in series. A constant LED
current is achieved by sensing the LED current
through a sensing resistor R_LED (see Figure 3.).
The device also includes a supply voltage
rejection circuit that prevents from any possible
flickering effect on the display that might happen
during input supply voltage variation. An
integrated Load Disconnect Switch open the LED
path to eliminate the current consumption in
shutdown mode. The maximum peak inductor
current can be programmed (STLD20D-C8 only).
Order code
Part number
STLD20D-C8
STLD20D-DEF
October 2006
Package
SOT23-8L
QFN 3x3 8L
Rev 4
Marking
L2D
L2D
Packing
Tape and reel
Tape and reel
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