MAX9814 Microphone AGC Amplifier Module Code: 18861692

The MAX9814 is a low-cost, high-performance microphone amplifier featuring Automatic Gain Control (AGC) and low-noise microphone bias. Ideal for portable electronics and DIY audio projects, it operates on a 2.7V to 5.5V supply and consumes just 3mA of current.

Key Specifications & Features

• Operating Voltage:7V to 5.5V DC
• Selectable Gain:40dB, 50dB, or 60dB
• Automatic Gain Control (AGC):Automatically adjusts volume levels to prevent audio distortion.
• Frequency Response:20Hz – 20kHz
• Low THD (Total Harmonic Distortion):04% (typical)
• Microphone Bias:Built-in, low-noise 2V bias for electret microphones

How the AGC Works

The MAX9814 contains a low-noise preamplifier, a variable gain amplifier (VGA), and an output amplifier. If the input audio volume exceeds a set threshold, the AGC kicks in and automatically reduces the VGA gain to compress the audio, preventing clipping and distortion.

Module Pinout & Configuration

When purchased as a breakout board, the module generally includes the following pins:

• VDD:Power Supply (2.7V – 5.5V)
• GND:Ground
• OUT:Analog Audio Output (Typically centered at a 1.25V bias with
• GAIN:Sets the baseline gain (Leave floating for 60dB, connect to VDD for 40dB, connect to GND for 50dB)
• A/R:Attack-to-Release ratio (Leave floating for 1:4, connect to VDD for 1:1, connect to GND for 1:2)