IS31LT3910 Datasheet | ISSI

DESCRIPTION The IS31LT3910 is a peak current mode control LED driver IC. The IS31LT3910 operates in constant off-time mode. It allows efficient operation of High Brightness (HB) LEDs with voltage sources ranging from 8VDC to 450DC or 110VAC/220VAC. The IS31LT3910 includes a PWM dimming input that can accept an external control signal with a duty ratio of 0 - 100% and a frequency of up to a few kilohertz. It also includes a 0 240m V linear dimming input which can be used both for linear dimming and temperature pensation of the LED current. The IS31LT3910 is ideally suited for buck LED drivers. Since the IS31LT3910 operates in peak current mode control, the controller achieves good output current regulation without the need for any loop pensation. It achieves good PWM dimming response because the response time is limited only by the rate of rise and fall of the inductor current, enabling very fast rise and fall time. APPLICATION CIRCUIT November 2011 FEATURES - Wide input range from 8VDC to 450DC or 110VAC/220 VAC - Temperature pensation to regulate LED current - Application from a few m A to more than 1A output - Constant off-time operation - Linear and PWM dimming capability - Switch mode controller for single switch LED drivers - Requires few external ponents for operation APPLICATIONS - DC/DC or AC/DC LED driver applications - General purpose constant current source - Signal and decorative LED lighting - backlighting LED driver http://..net/ Vin DC 8~450V D1 L1 Rin LEDS C1 NTC VIN VREF GATE Q1 R1 Cin LD PWMD TOFF CS GND C2 COFF Integrated Silicon Solution, Inc. - .issi. Rev.A, 11/08/2011 1 datasheet pdf - http://..net/ PIN CONFIGURATIONS Package Pin Configurations (Top View) VREF PWMD VIN TOFF CS GATE SOP-8 LD GND PIN DESCRIPTION Pin VREF PWMD Pin No. 1 2 Description This pin provides reference a voltage of 1.2V, no bypass capacitor is needed. This is the PWM dimming input of the IC. When this pin is pulled to GND, the gate...