This document describes the features of the MAX9814 audio amplifier.
The MAX9814 microphone amplifier provides automatic gain control (AGC) and a low‑noise microphone bias suitable for most electret microphones. It includes a fixed‑gain preamplifier, a variable‑gain amplifier (VGA) with three selectable gain settings (40 dB, 50 dB, 60 dB), and an output amplifier with programmable gain.
The device operates from a 2.7 V to 5.5 V supply, supports a temperature range of –40 °C to +85 °C, and offers features such as low‑power shutdown mode, programmable attack/release times, and a 2 V internal microphone bias. Pin‑out and package information are provided for the 14‑pin TDFN package.
| Supply Voltage Range | 2.7 V to 5.5 V |
|---|---|
| Gain Settings | 40 dB, 50 dB, 60 dB |
| Total Harmonic Distortion (THD) | 0.04 % typ |
| Microphone Bias Voltage | 2 V |
| Operating Temperature Range | –40 °C to +85 °C |
| AGC Hold Time | 30 ms (fixed) |
The device operates from 2.7 V to 5.5 V.
It offers three selectable gain settings: 40 dB, 50 dB, and 60 dB.
The AGC hold time is fixed at 30 ms.
The internal microphone bias voltage is 2 V.