The MAX9814 Microphone Amplifier Module is available in the space-saving, 14-pin TDFN package. This device is also 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.

Applications

1. Bluetooth Headsets
2. Two-Way Communicators
3. High-Quality Portable Recorders
4. IP Phones/Telephone Conferencing

Technical Specifications

1. Supply Voltage: 2.7v-5.5v @ 3mA current
2. Output: 2Vpp on 1.25V bias
3. Frequency Response: 20Hz – 20 KHz
4. Programmable Attack and Release Ratio
5. Automatic gain, selectable max from 40dB, 50dB or 60dB
6. Low Input-Referred Noise Density of 30nV/
7. Low THD: 0.04% (type)

Documents and Downloads

1. MAX9814 Datasheet
2. MAX9814 Arduino Library

Package Includes

1 x MAX9814 Microphone Amplifier Module

An internal link is any link from one page on your website to another page on your website. Both your users and search engines use links to find content on your website. Your users use links to navigate through your site and to find the content they want to find. Search engines also use links to navigate your site. They won’t find a page if there are no links to it.

There are several types of internal links. In addition to links on your homepage, menu, post feed, etc, you can also add links within your content. We call those contextual links. Contextual links point your users to interesting and related content. Moreover, they allow search engines to find out what content on your site is related and to determine the value of that content. The more links an important page receives, the more important it will seem to search engines. Therefore, good internal links are crucial to your SEO.