IS31LT3170/71 10-TO-150MA CONSTANT-CURRENT LED DRIVER June 2018 GENERAL DESCRIPTION FEATURES The IS31LT3170 and IS31LT3171 are adjustable Low-side current sink linear current devices with excellent temperature - Current preset to 10mA stability. A single resistor is all that is required to set - Adjustable from 10mA to 150mA with external the operating current from 10mA to 150mA. The resistor selection devices can operate from an input voltage from 2.5V Wide input voltage range from to 42V with a minimal voltage headroom of 1V (typical). Designed with a low dropout voltage the - 2.5V to 42V (IS31LT3171) device can drive LED strings close to the supply - 5V to 42V (IS31LT3170) voltage without switch capacitors or inductors. with a low dropout of typical 1V The IS31LT3170/71 simplifies designs by Up to 10kHz PWM input (IS31LT3171 only) providing a stable current without the additional Protection features: requirement of input or output capacitors, - 0.26%/K negative temperature coefficient at inductors, FETs or diodes. The complete constant high temp for thermal protection current driver requires only a current set resistor Up to 1W power dissipation in a small SOT23-6 and a small PCB area making designs both efficient and cost effective. package RoHS compliant (Pb-free) package The EN pin (1) of the IS31LT3170 can be tied to Vbat or BCM PWM signal for high side dimming. APPLICATIONS The EN Pin (1) of the IS31LT3171 can function as Architectural LED lighting the PWM signal input used for low side dimming. Channel letters for advertising, LED strips for As a current sink it is ideal for LED lighting decorative lighting applications or current limiter for power supplies. Retail lighting in fridge, freezer case and The device is provided in a lead (Pb) free, SOT23-6 vending machines package. Emergency lighting (e.g. steps lighting, exit way sign etc.) TYPICAL APPLICATION CIRCUIT Figure 1 Typical Application Circuit Lumissil Microsystems www.lumissil.com 1 Rev. D, 05/28/2018IS31LT3170/71 PIN CONFIGURATION Package Pin Configuration (Top View) SOT23-6 PIN DESCRIPTION No. Pin Description 1 EN Enable pin (PWM input IS31LT3171 only). 2,3,5 OUT Current sink. 4 GND Ground. 6 REXT Optional current adjust. Lumissil Microsystems www.lumissil.com 2 Rev. D, 05/28/2018