IS31LT3170 Datasheet, PDF (1/9 Pages) Integrated Silicon Solution, Inc – 10-TO-150MA CONSTANT-CURRENT LED DRIVER

IS31LT3170/71
10-TO-150MA CONSTANT-CURRENT LED DRIVER
Advanced Information
July 2014
GENERAL DESCRIPTION
The IS31LT3170 and IS31LT3171 are adjustable
linear current devices with excellent temperature
stability. A single resistor is all that is required to set
the operating current from 10mA to 150mA. The
devices can operate from an input voltage from 2.8V
to 42V with a minimal voltage headroom of 0.264V.
Designed with a low dropout voltage; the device can
drive LED strings close to the supply voltage without
switch capacitors or inductors.
The IS31LT3170/71 simplifies designs by
providing a stable current without the additional
requirement of input or output capacitors,
inductors, FETs or diodes. The complete constant
current driver requires only a current set resistor
and a small PCB area making designs both
efficient and cost effective.
The EN Pin (1) of the IS31LT3171 can function as
the PWM signal input used for LED dimming
purposes.
As a current sink it is ideal for LED lighting
applications or current limiter for power supplies.
The device is provided in a lead (Pb) free, SOT23-6
package.
FEATURES
 Low-side current sink
- Current preset to 10mA
- Adjustable from 10mA to 150mA with external
resistor selection
 Wide input voltage range from
- 2.8V to 42V (IS31LT3171)
- 5V to 42V (IS31LT3170)
with a low dropout of 0.5V
 Up to 10kHz PWM input (IS31LT3171 only)
 Protection features:
- 0.2%/K negative temperature coefficient for-
thermal protection
- Open circuit and over voltage protection
 Up to 1W power dissipation in a small SOT23-6
package
 RoHS compliant (Pb-free) package
APPLICATIONS
 Linear current sink
 Current limiter for power supplies
 LED signage
 Retail lighting in refrigerator, freezer case and
vending machines
 Instrumentation LED lighting
TYPICAL APPLICATION CIRCUIT
Figure 1 Typical Application Circuit
Integrated Silicon Solution, Inc. – www.issi.com
1
Rev. 00A, 05/20/2014