IS31LT3172/73 10-TO-200MA CONSTANT-CURRENT LED DRIVER July 2016 GENERAL DESCRIPTION FEATURES The IS31LT3172 and IS31LT3173 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 200mA with external the operating current from 10mA to 200mA. 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 (IS31LT3173) device can drive LED strings close to the supply - 5V to 42V (IS31LT3172) voltage without switch capacitors or inductors. with a low dropout of typical 1V The IS31LT3172/73 simplifies designs by Up to 10kHz PWM input (IS31LT3173 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 1.8W power dissipation in a small SOP-8- and a small PCB area making designs both efficient and cost effective. EP package RoHS compliant (Pb-free) package The EN Pin (3) of the IS31LT3172 can be tied to VBAT or BCM PWM signal for high side dimming. APPLICATIONS The EN Pin (3) of the IS31LT3173 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, SOP-8-EP 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. C, 07/01/2016IS31LT3172/73 PIN CONFIGURATION Package Pin Configuration (Top View) SOP-8-EP PIN DESCRIPTION No. Pin Description 1, 2 OUT Current sink. 3 EN Enable pin (PWM input IS31LT3173 only). 4 REXT Optional current adjust. 5 GND Ground. 6 ~ 8 NC Floating or connect to GND. Thermal Pad Connect to GND. Lumissil Microsystems www.lumissil.com 2 Rev. C, 07/01/2016