LED Driver Integrates Input Noise Filter

To reduce noise levels, the LTC3201 charge-pump, white LED driver integrates an input noise filter and uses a constant frequency switching topology to minimize input current noise. This results in an input current noise level below 30 mA P-P. A complete drive circuit requires only two 0.22 µF capacitors and two 1 µF flying capacitors. Dimming control is via an integrated two-bit D/A converter. The component can drive up to six LEDs in parallel from a single-cell Li-Ion battery. Available in a 10-lead MSOP, price is $1.90 each/1,000. LINEAR TECHNOLOGY CORP., Milpitas, CA. (408) 432-1900.