May 2011

Doc ID 12203 Rev 7

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STLD40D

White LED power supply for large display backlight

Features

from 3.0 V to 5.5 V

control

Applications

Description

STLD40D is a boost converter that operates from

3.0 V to 5.5 V. It can provide an output voltage as

high as 37 V and can drive up to 10 white LEDs in

series. The converter is a PFM (pulse frequency

modulation) inductor switch that can work in

discontinuous (DCM) mode operation. A minimum

fixed internally and allows limiting the switching

frequency. The output current capability is 20 mA

with an output voltage of 37 V. The regulation is

done by sensing the LED current through the

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

QFN8 (3 x 3 mm)

Table 1.

Device summary

Order code

Package

Packaging

STLD40DPUR

QFN8 (3 x 3 mm)

3000 parts per reel

www.st.com