The MAX4063 is a differential-input microphone preamplifier optimized for high-performance, portable applications. The device features two selectable inputs, differential outputs, adjustable gain, an integrated lownoise bias source, and a low-power shutdown mode. Two input paths provide both differential and singleended microphone sensing. The high-noise rejection of the differential input is ideally suited to an internal microphone where system noise and long-run PC board traces can degrade low-level signals. The single-ended input provides a simple connection to an external microphone. The differential and single-ended inputs have independent, adjustable gains that are set with a single external resistor. Differential outputs provide a full-scale signal of up to 6VP-P from a single 3V supply, optimizing the dynamic range of the amplified signal. A complete shutdown mode reduces the supply current to only 0.3A and disables the microphone bias for the ultimate in power savings.