摘要：该电路从3.3V电源并联驱动多达四个白光LED ，并调整总LED电流从1mA到106毫安在64个步骤，每一个为1dB 。Maxim/Dallas > App Notes > AUTOMOTIVE DIGITAL POTENTIOMETERS DISPLAY DRIVERS Keywords: portable power, white LEDs, logarithmic dimming, charge pump, digital potentiometer Jul 20, 2004 APPLICATION NOTE 3287 White-LED Driver Provides 64-Step Logarithmic Dimming This circuit drives as many as four white LEDs in parallel from a 3.3V source, and adjusts the total LED current from 1mA to 106mA, in 64 steps of 1dB each. The circuit of Figure 1 is designed for portable-power applications that require white LEDs with adjustable, logarithmic dimming levels. It drives as many as four white LEDs from a 3.3V source, and adjusts the total LED current from 1mA to 106mA in 64 steps of 1dB each. The driver is a charge pump that mirrors the current ISET (sourced from U3's SET terminal)……