MAX4466 Electret Microphone Amplifier Module

The MAX4466 Electret Microphone Amplifier Module is a high-sensitivity audio sensor designed for clear sound capture in micro-controller projects. It features an onboard electret condenser microphone and a Maxim Integrated MAX4466 low-noise op-amp, which is specifically optimized for use as a microphone preamplifier with excellent power supply noise rejection. 

Technical Specifications:
According to manufacturers and retailers like Adafruit and RoboticsBD, the module's key parameters include:

• Operating Voltage: 2.4V to 5.5V DC. For best performance, it is recommended to use the "quietest" supply available, such as a 3.3V line from an Arduino.
• Adjustable Gain: 25x to 125x, controlled via a small trimmer potentiometer on the back of the board.
• Output: Rail-to-rail analog audio signal (up to 5Vpp) with a DC bias of VCC/2.
• Frequency Response: 20Hz to 20kHz.
• Power Efficiency: Low quiescent supply current of less than 24µA.
• Rejection Ratios: Power-Supply Rejection Ratio (PSRR) of 112dB and Common-Mode Rejection Ratio (CMRR) of 126dB.
• Dimensions: Approximately 20.8 x 13.8 x 7.5 mm.

Usage and Applications:
This module is popular for hobbyist electronics due to its ease of integration and clean output signal.

• Ideal Projects: Voice converters, audio recording/sampling, and audio-reactive projects using Fast Fourier Transform (FFT).
• Connectivity: Requires only three pins: VCC (2.4-5V), GND (ground), and OUT (audio signal).
• Audio Coupling: The output is DC-coupled. If your device requires AC-coupled audio, a 100µF capacitor should be placed between the OUT pin and the device input.

Note: The OUT pin is not designed to drive speakers directly; it is intended for high-impedance inputs like a microcontroller ADC or a separate power amplifier.