MAX4466 Electret Microphone Amplifier with Adjustable Gain Module

The MAX4466 Electret Microphone Amplifier with Adjustable Gain Module comes fully assembled and tested, featuring a 20-20KHz electret microphone soldered onto the board. It utilizes the Maxim MAX4466, an op-amp tailored for this sensitive task, boasting excellent power supply noise rejection. This results in a high-quality sound that is significantly less noisy and scratchy compared to other microphone amplifier breakouts.

Ideal for projects involving voice changes, audio recording/sampling, and audio-reactive applications that utilize FFT, the module includes a small trimmer pot on the back for gain adjustment. The gain can be set anywhere from 25x to 125x.

For normal speaking volumes approximately 6 inches away, the output is around 200mVpp, which is suitable for devices expecting line level input without clipping. It can also reach up to about 1Vpp, perfect for interfacing with a microcontroller ADC. Additionally, the output is rail-to-rail, allowing for a maximum output of up to 5Vpp when the sound levels are high.

How to Use 

1. Connect GND to ground, VCC to 2.4-5VDC.
2. The audio waveform will come out of the OUT pin. The output will have a DC bias of VCC/2 so when it’s perfectly quiet; the voltage will be a steady VCC/2 volt (DC couple).
3. If the audio equipment you’re using requires AC coupled audio; place a 100uF capacitor between the output pin and the input of your device.
4. If you’re connecting to an audio amplifier that has differential inputs or includes decoupling capacitors; the 100uF cap is dont require.
5. The output pin is not designed to drive speakers or anything but the smallest in-ear headphones- you’ll need an audio amplifier (such as 3.7W stereo amp)
6. If you want to connect the amp directly to speakers. If you’re connecting to a microcontroller pin, you don’t need an amplifier or decoupling capacitor; connect the OUT pin directly to the microcontroller ADC pin.
7. For audio-reactive projects; we suggest using an FFT driver library which can take the audio input and translate it into frequencies.

Features

+2.4V to +5.5V Supply Voltage Operation.

Versions with 5nA Complete Shutdown Available (MAX4467/MAX4468).

Excellent Power-Supply Rejection Ratio: 112dB.

Excellent Common-Mode Rejection Ratio: 126dB.

High AVOL: 125dB (RL = 100k).

Rail-to-Rail Outputs.

Low 24A Quiescent Supply Current.

Gain Bandwidth Product:
200kHz (MAX4465/MAX4467/MAX4469)
600kHz AV 5 (MAX4466/MAX4468)

Available in Space-Saving Packages
5-Pin SC70 (MAX4465/MAX4466)
8-Pin SOT23 (MAX4467/MAX4468/MAX4469)

Package Includes:

1 xMAX4466 Electret Microphone Amplifier with Adjustable Gain Module.

1 x Header Set (Without Soldered).

MAX4466 Datasheet