Class AB amplifier with integrated microphone front-end
The MAX4061ETA+T is a Class AB mono amplifier from Analog Devices, designed as a complete analog front-end for electret condenser microphone (ECM) applications. It integrates differential inputs, a microphone bias voltage generator, and a shutdown pin into a single 8-TDFN 3x3mm package.
What the supply voltage and output mean for the BOM
The 2.4V minimum supply means the amplifier stays operational down to the near-end-of-discharge voltage of a single-cell Li-ion battery (3.0V nominal, 2.7V cutoff). No boost converter is needed for the audio rail in battery-powered designs. The 1-channel mono output drives a single speaker or earpiece. The differential input pair rejects common-mode noise picked up on long microphone wires — useful in hands-free kits or intercoms where the mic cable runs past switching converters.
Housed in an 8-WDFN with exposed pad (3x3mm body), the MAX4061ETA+T requires a thermal pad on the PCB for heat sinking. The exposed pad is electrically connected to ground — the datasheet layout recommendation is a 2x2 array of vias under the pad to the ground plane. Surface-mount only — no through-hole variant exists.