MAX9814 Microphone Module
This fancy microphone amplifier module is a step above the rest, with built-in automatic gain control. The AGC in the amplifier means that nearby â€˜loudâ€™ sounds will be quieted so they donâ€™t overwhelm & â€˜clipâ€™ the amplifier, and even quiet, far-away sounds will be amplified. This amplifier is great for when you want to record or detect audio in a setting where levels change and you donâ€™t want to have to tweak the amplifier gain all the time.
The chip at the heart of the MAX9814 Microphone Module is as the name suggests X9814, and has a few options you can configure with the breakout. The default â€˜max gainâ€™ is 60dB, but can be set to 40dB or 50dB by jumpering the Gain pin to VCC or ground. You can also change the Attack/Release ratio, from the default 1:4000 to 1:2000 or 1:500. The output from the amp is about 2Vpp max on a 1.25V DC bias, so it can be easily used with any Analog/Digital converter that is up to 3.3V input. If you want to pipe it into a Line Input, just use a 1-100uF blocking capacitor in series (100uF sounds best).
MAX9814 Microphone Module Technical Specifications
- Supply Voltage: 2.7v-5.5v @ 3mA current
- Output: 2Vpp on 1.25V bias
- Frequency Response: 20Hz â€“ 20 KHz
- Programmable Attack and Release Ratio
- Automatic gain, selectable max from 40dB, 50dB or 60dB
- Low Input-Referred Noise Density of 30nV/
- Low THD: 0.04% (typ)