Driving White LEDs out of one Battery Cell 0.9V Boost Driver PR4402 for up to 40mA
	PREMA ASICS Application Examples The Way to your ASIC Integration, your Benefit ASIC DESIGN ASIC Functions Chip Design Tools IC Design Seminar WAFER PRODUCTION ModuS U6 ASIC Process Clean Room Technology Quality Management PREMA SEMICONDUCTOR About us Press Our City Imprint CONTACT INFO Brochure Request Distributors How to find PREMA Jobs & Careers	Mainz, Germany, April  19, 2007 With PR4402 PREMA Semiconductor offers the next IC in a family of 0.9V LED boost drivers, operating white LEDs from one battery cell. While PR4401 is best suited for LED currents of up to 20mA, PR4402 is capable of 40mA. The current is set by the inductor value, resulting in a low number of external components. Applications are pocket torches, key ring pendants or head lights and LCD back lighting in single-cell devices like MP3 players. The one-cell battery operation is very attractive. It allows design of smaller and light weighted products at lower cost. In multiple-cell operation of rechargeable batteries often one cell can be destroyed by a deep discharge. With the PR4401/4402 there is no more reason for using several battery cells or for implementing the classical light bulb. With one battery cell and depending on the application one inductor only as external component, a very small-sized circuitry can be realized with the PR4401/4402, both SOT23 packaged. The driven LED current is almost independent from the supply voltage, which guarantees a constant brightness even with a discharging battery. Samples and demo boards are available upon request. PR4401 and PR4402 samples are available upon request. Data sheets can be downloaded from our web site www.prema.com/Application/whiteleddriver.html.   General information about PREMA Semiconductor GmbH, Mainz - Germany PREMA offers design and production of mixed-signal ASICs and ASSPs - with supply voltages from 0.9V up to 100V  - for the ultra low power range up to medium power  - development, design, production and test, all in one hand.  ASICs and ASSPs created and produced by PREMA can be found in - low noise audio electronics  - battery management of household devices - mobile phones and moving sensors - bar code readers and sensors (light and magnetic field)  - LED drivers We cordially invite you to visit our website: www.prema.com to find more information about us and our services. Picture (103kB)       Block Diagram (64kB) Contact: Anne Stroot, PREMA Semiconductor GmbH Phone: +49-6131-5062-202 prema@prema.com