The MAX1916 low-dropout bias supply for white LEDs is a high-performance alternative to the simple ballast resistors used in conventional white LED designs. The MAX1916 uses a single resistor to set the bias current for three LEDs, which are matched to 0.3%. The MAX1916 consumes only 40µA of supply current when enabled and 0.05µA when disabled.
The MAX1916's advantages over ballast resistors include significantly better LED-to-LED bias matching, much lower bias variation with supply voltage variation, significantly lower dropout voltage, and in some applications, significantly improved efficiency. The MAX1916 requires a 200mV dropout at a 9mA load on each output to match the LED brightness.
The MAX1916 is available in a space-saving 6-pin Thin SOT23 package.