IS32LT3177/78 10-TO-200MA CONSTANT-CURRENT LED DRIVER FOR AUTOMOTIVE September 2020 GENERAL DESCRIPTION FEATURES The IS32LT3177 and IS32LT3178 are adjustable Low-side current sink linear current devices with excellent temperature - Adjustable from 10mA to 150mA (SOT23- stability. A single resistor is all that is required to set 6)/200mA (SOP-8-EP) with external resistor the operating current from 10mA to 200mA. The selection devices can operate from an input voltage from 2.9V Wide input voltage range from to 40V with a minimal voltage headroom of 1.0V - 2.9V to 40V (IS32LT3178) (Typ.) at 150mA. Designed with a low dropout - 5V to 40V (IS32LT3177) voltage the device can drive LED strings close to with a low dropout of typical 1.0V at 150mA the supply voltage without switch capacitors or Up to 1kHz PWM input (IS32LT3178 only) inductors. Protection features: - 0.6%/K current roll off at high temp over 145C The IS32LT3177/78 simplifies designs by for thermal protection providing a stable current without the additional - Output current limit requirement of inductors, FETs or diodes. The - Thermal shutdown complete constant current driver requires only a Up to 0.77W (SOT23-6)/2.32W (SOP-8-EP) current set resistor and a small PCB area making power dissipation in a small package designs both efficient and cost effective. RoHS compliant (Pb-free) package The EN Pin of the IS32LT3177 can be tied to V BAT AEC-Q100 Qualified or PSM (Power Supply Modulation) signal for high side dimming. The EN Pin of the IS32LT3178 can APPLICATIONS function as the PWM signal input used for MCU Automotive and avionic lighting PWM dimming. Stop/tail light As a current sink it is ideal for LED lighting Turn light applications or current limiter for power supplies. Retail lighting in fridge, freezer case and vending machines The device is provided in a lead (Pb) free, SOT23-6 and SOP-8-EP packages. Lumissil Microsystems www.lumissil.com 1 Rev. B, 09/25/2020IS32LT3177/78 TYPICAL APPLICATION CIRCUIT V BAT V C or IN BAT 0.1F C IN 2.9V~5.5V 1 2, 4, 5 1 2, 4, 5 0.1F or PSM EN GND EN GND IS32LT3177 IS32LT3178 PWM (SOT23-6) (SOT23-6) 6 6 ISET ISET 3 3 R OUT R OUT ISET ISET Optional Optional C C OUT OUT 1nF 1nF V BAT or V C BAT IN 0.1F C 2.9V~5.5V IN 35~8 35~8 0.1F or PSM EN GND EN GND IS32LT3177 IS32LT3178 PWM (SOP-8-EP) (SOP-8-EP) 4 4 ISET ISET 1,2 1,2 R R ISET OUT ISET OUT Optional Optional C OUT C OUT 1nF 1nF Figure 1 Typical Application Circuit Note 1: All GND pins must be connected to ground. Note 2: C must be placed close to IC. If no PSM dimming requirement, please use larger value for C . IN IN Note 3: C is optional. When the LED connection wire is long, the C should be placed close to OUT pin to avoid EMI interference. OUT OUT Note 4: R MUST be placed close to ISET and GND pins to improve the Electro-Magnetic Susceptibility (EMS) performance. ISET Lumissil Microsystems www.lumissil.com 2 Rev. B, 09/25/2020