MAX9814 Microphone Amplifier Module with Auto Gain Control
🎙️ MAX9814 Electret Microphone Amplifier – Auto Gain Control
Capture clear audio across varying environments with this simple yet powerful MAX9814-based microphone amplifier. Featuring built-in AGC, it's ideal for voice-activated devices, sound detection, and audio-sensitive DIY projects.
📊 Specifications & Features
| Parameter | Value & Details |
|---|---|
| Chipset | MAX9814: low-noise preamp + VGA + AGC circuitry |
| Supply Voltage | 2.7–5.5 V (3 V typical, 5 V supported) |
| Supply Current | ≈ 3 mA |
| Gain Settings | 40 dB, 50 dB, or 60 dB (via Gain pin jumper) |
| AGC Attack/Release Ratio | Adjustable: 1:500, 1:2000, or 1:4000 (via AR jumper) |
| Frequency Response | 20 Hz–20 kHz |
| Output Level | ~2 V peak-to-peak on 1.25 V DC bias |
| Noise & Distortion | Input noise ~30 nV/√Hz; THD ≈0.04% |
| AGC Hold Time | ~30 ms |
| Operating Temp | −40 °C to +85 °C |
| Package | Breakout board with electret mic and 5-pin header |
🔧 Wiring Guide (Arduino Compatible)
- VCC → 3.3 V or 5 V
- GND → Ground
- OUT → Arduino analog input (e.g., A0)
- GAIN → Set maximum gain:
- GND → 40 dB
- Float → 60 dB
- VCC → 50 dB
- AR → Set Attack/Release:
- Float → 1:4000 (default)
- GND → 1:500
- VCC → 1:2000
📋 Sample Arduino Code
CopyEditconst int micPin = A0; void setup() { Serial.begin(9600); Serial.println("MAX9814 Mic Ready"); } void loop() { int val = analogRead(micPin); Serial.println(val); delay(10); }