ZXSC380FHTA Diodes Incorporated

ZXSC380 Single or multi cell LED driver solution Description The ZXSC380 is a highly integrated single or The IC can start up under full load and operates multi cell LED driver for applications where down to an input voltage of only 0.9V typical. step-up voltage conversion from a very low The ZXSC380 is offered in the space saving input voltage is required. These applications SOT23 package or in die form, offering an mainly operate from 1.5V or 1.2V cells. The IC excellent cost vs performance solution for generates constant current pulses that are single cell LED driving applications. ideal for driving single or multiple LEDs over a wide range of operating voltages. The ZXSC380 provides a simple to use, low cost, space saving and easy to layout solutions. The ZXSC380 uses a PFM control technique to drive an internal switching transistor which has a low saturation resistance. This ensures high efficiency, even for input voltages as low as 1V. SOT23 Features Applications 80% efficiency LED flashlights and torches User adjustable output current LED backlights Single cell operation White LED driver Low saturation voltage switching transistor Simple application circuit Low external component count SOT23 package Available also in die form Pin connections Typical application circuit V IN L1 1 V CC 1 V CC 3 GND 2 V ZXSC380 OUT GND 2 V OUT 3 LED1 Top view GND Issue 3 - September 2007 1 www.zetex.com Zetex Semiconductors plc 2007ZXSC380 Absolute maximum ratings Supply voltage (V ) -0.6V to 10V CC Output voltage (V ) -0.6V to 20V OUT Supply current 20mA Output switch current 200mA Power dissipation SOT23-3 450mW Power dissipation die 1W Operating temperature range 0C to +85C Storage temperature range -55C to +150C Electrical characteristics Measured at T = 25C, L = 100 H and V = 1.5V unless otherwise specified. amb CC Parameter Conditions Limits Units Min. Typ. Max. Supply voltage operating range 0.8 6 V Minimum supply start-up voltage 0.9 1.0 V Switch current V = 1.0V 65 80 95 mA OUT Switch saturation voltage IV = 50mA 0.3 0.5 V OUT Mean LED current V = 3.5V 18 mA LED Efficiency V = 3.5V 75 % LED Operating frequency V = 3.5V 160 kHz LED Discharge pulse width 1.4 2.2 3.0 s Pin descriptions 1 V CC 3 GND V 2 OUT Top view Pin descriptions Pin No. Name Description 1V Supply voltage, generally Alkaline, NiMH or NiCd single cell CC 2V Switch output external inductor/LED OUT 3 GND Ground Ordering information Device Package Part Mark ZXSC380FH SOT23 380 Issue 3 - September 2007 2 www.zetex.com Zetex Semiconductors plc 2007