IS31LT3353 Datasheet, PDF (1/15 Pages) Integrated Silicon Solution, Inc – 40V/1A BUCK LED DRIVER WITH INTERNAL SWITCH

IS31LT3353
40V/1A BUCK LED DRIVER WITH INTERNAL SWITCH
October 2014
GENERAL DESCRIPTION
The IS31LT3353 is a continuous mode inductive
step-down converter, designed for driving a single
LED or multiple series connected LEDs efficiently
from a voltage source higher than the LED voltage.
The chip operates from an input supply between 6V
and 40V and provides an externally adjustable output
current of up to 1A.
The IS31LT3353 includes an integrated output
switch and a high-side output current sensing circuit,
which uses an external resistor to set the nominal
average output current.
The output current can be dynamically adjusted by
adding either a digital PWM or analog voltage level
signal to the ADJ pin. A PWM signal will provide a
gated output current while a voltage signal will
generate a continuously linear output current.
Applying a voltage less than 0.2V to the ADJ pin
turns the output off and switches the chip into a low
current standby state.
The chip is assembled in SOT23-5 package. It
operates from 6V to 40V over the temperature range
of -40°C to +125°C.
FEATURES
 Up to 1A output current
 High efficiency (up to 97% )
 Wide input voltage range: 6V to 40V
 Internal 40V power switch
 Simple low parts count
 Typical 3% output current accuracy
 Single pin on/off and brightness control using
DC voltage or PWM
 Up to 1MHz switching frequency
 Inherent LED open-circuit/short-circuit
protection
 Thermal shutdown protection circuitry
 Up to 1200: 1 dimming rate
APPLICATIONS
 LED MR16, MR11 spot light
 LED street light
 PAR light
 Industrial lighting
 Refrigeration lights
 Other LED lighting
APPLICATION CIRCUIT
Figure 1 Typical Application Circuit
Note: The capacitor, C₂, can’t be removed. And it should be placed as close as possible to the VIN and GND pins, otherwise the operation
might be abnormal.
Integrated Silicon Solution, Inc. – www.issi.com
1
Rev. A, 10/13/2014