Even if it seems that this board is nothing more than a mic soldered into a PCB, there is more than meets the eye! The Artekit AK-MAX9814 is a board with an electret microphone coupled to a fully-featured high-gain amplifier: the Maxim MAX9814, capable of gaining 40dB, 50dB and 60dB and with Automatic Gain Control (AGC).

Due to its high gain settings, this board is the perfect fit for ambient audio applications, but even if the board is placed close to the audio source, the AGC kicks in, avoiding saturation.

The AK-MAX9814 is pretty simple to use. Just apply a power supply (2.7V to 5.5V typical) and select the gain with the GAIN pin: leave it open to set the gain to uncompressed 60dB gain, or connect it to GND to select 50dB gain or connect it to VCC to select 40dB gain.

Additionally, the board has a A/R pin you can use to control the Attack-to-Release setting: leave it open to set A/R to 1:4000, or connect it to GND to set A/R to 1:500 or connect to VCC to set A/R to 1:2000.

We have prepared a detailed user guide with all the information you need.

Features

• Automatic Gain Control (AGC)
• Three gain settings (40dB, 50dB, 60dB)
• Programmable attack time
• Programmable attack and release ratio
• 2.7V to 5.5V supply voltage range
• Dedicated pin for gain selection
• Dedicated pin for Attack/Release ratio selection
• Low input-referred noise density of 30nV/√Hz
• Low THD: 0.04% (typical)
• Low-power shutdown mode
• Internal low-noise microphone bias, 2V
• -40°C to +85°C extended temperature range
• Microphone characteristics:
  • Sensitivity: -42±3dB (0dB=1V/Pa.1KHz)
  • Output impedance: 2.2KΩ
  • Frequency range: 100-20KHz
  • Current consumption: 0.5mA (max)
  • Signal/Noise ratio: ≥58dB
  • Sound pressure level: 110dB.
• High quality PCB
• Two mounting holes
• Easy to use

Documents

• User manual

Hardware

• Schematics
• Eagle files
• Board dimensions
• Kobitone microphone datasheet
• Maxim MAX9814 datasheet