Description

MAX9814 Electret Microphone Amplifier Module with Auto Gain Control (AGC) – For Arduino & Audio Projects

Product Description

Add high-quality sound detection to your electronics project with the MAX9814 Electret Microphone Amplifier Module with Automatic Gain Control (AGC). This compact, reliable board is designed for Arduino, microcontrollers, and audio-reactive projects.

Featuring a built-in low-noise electret microphone, a powerful MAX9814 amplifier IC, and automatic gain adjustment, this module ensures crystal-clear audio capture across a wide frequency range of 20Hz–20kHz. The AGC automatically adjusts sensitivity, making it ideal for voice recognition, sound sampling, recording, and reactive applications such as LED sound visualizers or FFT-based projects.

Unlike many other microphone boards, the MAX9814 delivers low noise, low distortion (THD: 0.04% typ), and excellent power supply rejection, making it stable even in noisy environments.

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Key Features

• Automatic Gain Control (AGC) – Adjustable gain levels at 40dB, 50dB, or 60dB

• Low Noise Performance – Input-referred noise density as low as 30nV/√Hz

• Frequency Response – Full audio spectrum: 20Hz to 20kHz

• Low THD (Total Harmonic Distortion) – 0.04% (typical) for clean sound capture

• Flexible Power Supply – Operates from 2.7V to 5.5V at ~3mA current

• Output – 2Vpp on 1.25V bias, rail-to-rail capability up to 5Vpp

• Compact Size – Space-saving 14-pin TDFN package on a breakout board

• Wide Temperature Range – Operates from -40°C to +85°C

• Low-Power Shutdown Mode

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Technical Specifications

• Supply Voltage: 2.7V – 5.5V

• Current Consumption: ~3mA

• Output: 2Vpp on 1.25V bias, rail-to-rail up to 5Vpp

• Gain Settings: 40dB / 50dB / 60dB (selectable)

• Frequency Response: 20Hz – 20kHz

• Input Noise Density: 30nV/√Hz

• THD: 0.04% typical

• Operating Temp Range: -40°C to +85°C

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How to Use

1. Wiring:

   • Connect VCC to 2.4–5VDC (use the quietest supply possible, e.g., 3.3V on Arduino).

   • Connect GND to ground.

   • Connect OUT to your microcontroller ADC pin or audio input device.

2. Output Signal:

   • The output signal is DC-biased at VCC/2. For AC-coupled equipment, use a 100µF capacitor between OUT and your device.

3. Applications:

   • Voice changers

   • Sound recording & sampling

   • Audio-reactive LED/music projects

   • FFT-based frequency analysis

   • Microphone input for Arduino/MCU projects

⚠️ Note: This module cannot directly drive speakers. For audio output, pair with a power amplifier.

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Package Includes

• 1 × MAX9814 Electret Microphone Amplifier Module