MAX9814 Microphone Amplifier Module


The MAX9814 is available in the space-saving, 14-pin TDFN package. This device is specified over the -40°C to +85°C extended temperature range. MAX9814 is a low-cost, high-quality microphone amplifier with automatic gain control (AGC) and low-noise microphone bias. The device features a low-noise preamplifier, variable gain amplifier (VGA), output amplifier, microphone-bias-voltage generator, and AGC control circuitry. The low-noise preamplifier has a fixed 12dB gain, while the VGA gain automatically adjusts from 20dB to 0dB, depending on the output voltage and the AGC threshold.

The output amplifier offers selectable gains of 8dB, 18dB, and 28dB. With no compression, the cascade of the amplifiers results in an overall gain of 40dB, 50dB, or 60dB. A trilevel digital input programs the output amplifier gain. An external resistive divider controls the AGC threshold and a single capacitor Program the attack/release times. A trilevel digital input programs the ratio of attack-to-release time. The hold time of the AGC is fixed at 30ms. The low-noise microphone-bias-voltage generator can bias most electret microphones


  • Programmable Attack and Release Ratio
  • Automatic Gain, Selectable max from 40dB, 50dB or 60dB
  • Low Input-Referred Noise Density of 30nV


Pin NamePin Description
VCCModule power supply – 2.7-5.5 V
 OUTAnalog data output to the microcontroller
 GainAdjusting maximum module output*
ARAdjusting module accuracy*


Supply Voltage2.7v-5.5v @ 3mA current
Output2Vpp on 1.25V bias
Frequency Response20Hz – 20 KHz
Low THD0.04% (type)


  • Bluetooth Headsets
  • Two-Way Communicators
  • High-Quality Portable Recorders
  • IP Phones/Telephone Conferencing


Download the Datasheet of MAX9814 Microphone Amplifier Module from the link given below.