New Industry Products

PREMA ICs Drive White LEDs Out of One 9V Battery Cell

May 09, 2007 by Jeff Shepard

PREMA Semiconductor GmbH introduced its PR4402, offering the next IC in a family of 0.9V LED boost drivers that operate white LEDs from one battery cell. While the PR4401 is best suited for LED currents of up to 20mA, the 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 said to allow for the design of smaller and light weight products at lower cost. In multiple-cell operation of rechargeable batteries, one cell can often be destroyed by a deep discharge. With the PR4401/4402 there is said to be no more reason for using several battery cells or for implementing a light bulb. With one battery cell and, depending on the application, one inductor only as external component, it is claimed that 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 is said to guarantee a constant brightness even with a discharging battery.

Samples and demo boards are available upon request.