STLD40D Datasheet, PDF (1/14 Pages) STMicroelectronics – White led power supply for large display backlight

STLD40D
White led power supply for large display backlight
General Features
s Inductor switches boost controller
s PFM mode control
s High efficiency over wide range of input voltage
from 3.0V to 5.5V
s Overvoltage protection with automatic restart
s Adjustable peak current limit
s Enable pin with possibility of PWM dimming
control
s Low shutdown current <1uA
s Small external component
s Good load and line regulation
s QFN 3mm x 3mm x 1mm 8 leads
Application
s White Led supply for LCD backlight
s Mobile phone
s PDA and organizers
s Any handsets powered form 3.0V to 5.5V
Description
STLD40D is a boost converter that operates from
3.0V to 5.5V and can provide an output voltage as
QFN8 (3mm x 3mm)
high as 37V and can drive up to 10 white LEDs in
series. The converter is a PFM (pulse frequency
modulation) inductor switches and can work in
discontinuous (DCM) mode operation. A minimum
OFF time of the embedded boost switch T_SW is
fixed internally and allows limiting the switching
frequency. The output current capability is 20mA
with an output voltage of 37V.
The regulation is done by sensing the led current
through the resistor R_LED.
The device can be turned ON/OFF through the
logic enable signal pin EN. By applying a low
frequency PWM signal the LEDs can be dimmed.
The maximum peak inductor current can be
programmed by connected a resistor R_SET to the
pin R_SET.
Order code
Part number
STLD40DPMR
April 2006
Package
QFN8L (3mm x 3mm)
Rev. 2
Comments
4500 parts per reel
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