Four-Channel LDD for Driving LEDs Directly from a Battery

4th April 2007

ES Admin

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Catalyst Semiconductor has announced the CAT4004, a new four-channel LDD (low dropout driver) designed for emerging, power-conscious portables where the LEDs are driven directly from the battery. With the migration of white LEDs to lower forward voltages, a number of portable applications are now able to drive LEDs directly from the system battery without the need to boost voltage. The new CAT4004 is designed specifically to meet the needs of this emerging market requirement by achieving a low dropout voltage of 130mV, which maximizes LED performance as system battery voltage decays.

“When driving LEDs in portable systems, the end-of-life battery voltage is directly proportional to the sum of the LED forward voltage and the LED driver dropout voltage,” said Scott Brown, Vice President of Marketing for Catalyst Semiconductor. “As the market trends toward lower voltage LEDs, a portion of the market will choose to drive LEDs directly from the battery. The low dropout voltage of the CAT4004 LDD will enable these designers to significantly extend battery life.”

The CAT4004 LDD features tight current matching of +/-5 percent across a wide range of LED voltages. It also offers LED programming simplicity via Catalyst’s one-wire EZDim™ interface, which allows output enable/disable and LED dimming control all from a single I/O on the system microcontroller. LED current can be controlled at six levels: 100 percent (full-scale brightness), 50 percent, 25 percent, 12.5 percent, 6 percent and 3 percent.

The CAT4004 low dropout LED driver is priced at $0.52 each in 10,000 piece quantities. Samples are available now. Projected lead-time for production quantities is currently 6 to 8 weeks ARO.