MAX9814 Microphone AGC Amplifier Module with CMA-4544PF-W Electret Mic

The MAX9814 high-performance amplifier module simplifies audio recording by applying automatic gain control (AGC) to incoming sound signals. Whether you are building a voice recorder, a hands-free communication device, or a field microphone system, this module maintains consistent output levels even when the speaker moves closer or further from the microphone. Its three selectable gain settings (40dB, 50dB, and 60dB) allow you to match the module's sensitivity to your specific recording environment. The built-in 2V low noise microphone bias means you can connect an electret condenser microphone directly without additional circuitry. Operating from a 2.7V to 5.5V supply, the MAX9814 integrates seamlessly with Arduino, Raspberry Pi, and other microcontroller platforms.

Features and Construction

The MAX9814 module combines AGC functionality with low distortion and programmable control. Its surface-mount construction keeps the footprint compact while maintaining reliable performance.

Automatic Gain Control

The AGC continuously monitors the input signal and adjusts gain to prevent clipping or excessive noise. With programmable attack and release time ratios, you can tailor the response for speech or music applications. The module's low distortion (0.04% typical) ensures the audio remains clear even during gain transitions.

Gain Selection and Power

Three fixed gain options (40dB, 50dB, and 60dB) cover a wide range of input levels from quiet speech to loud sounds. The wide supply voltage range (2.7V to 5.5V) allows battery or USB bus power. A dedicated shutdown mode reduces quiescent current to near zero for power-sensitive projects.

Built-in Microphone Bias

The integrated 2V low noise bias voltage directly powers electret condenser microphones such as the included CMA-4544PF-W. This eliminates the need for external bias resistors or voltage regulators, simplifying your circuit design.

Uses and Placement

The MAX9814 module suits a variety of audio capture and processing tasks, from hobbyist projects to professional prototyping.

Voice Recording and Dictation

For voice recording, the AGC ensures that natural variations in speaking volume produce consistent audio levels. The programmable time constants let you minimise pumping effects during pauses. Three gain settings let you optimise sensitivity for close-mic or ambience recording.

Speech Recognition Systems

In voice-controlled devices, consistent input amplitude improves speech recognition accuracy. The module's low distortion and wide dynamic range preserve the details needed for reliable word matching. Its small size allows integration into custom enclosures or wearable electronics.

Field and Remote Recording

For battery-powered field recording, the wide supply voltage range and low-power shutdown mode extend operating time. The electret microphone's small footprint fits into handheld or concealed setups. The AGC reduces the need for manual level adjustment in changing environments.

Benefits and Buying Value

This module provides a complete microphone amplifier solution with minimal external components, reducing design complexity and build time.

Ease of Integration

The ready-to-use module includes all critical components, so you can focus on your project's firmware and enclosure. The included microphone (CMA-4544PF-W) matches the bias voltage perfectly, ensuring optimal performance straight away. The simple three-wire interface (power, ground, audio output) suits breadboard and prototype wiring.

Flexible Gain Control

The three fixed gain settings cover common use cases without requiring external resistors. The programmable AGC time constants give you control over how the module reacts to sudden volume changes. For applications requiring custom gain values, the module can be configured via external components as detailed in the MAX9814 datasheet.

Low Distortion and Noise

Typical distortion of 0.04% preserves the natural sound of the original signal. The built-in microphone bias is low noise, so it does not degrade the signal-to-noise ratio of the electret capsule. This combination makes the module suitable for both voice and instrument recording where clarity matters.