Analog MEMS Microphone (VM2020) Hookup Guide
QCPete
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Hardware Overview
The SparkFun Analog MEMS microphone breakout board breaks out the microphone for sound detection in loud environments. Each version breaks out the VM2020 on the top side of the board.
The board receives audio input from the bottom of the board. For users soldering straight headers, you may want to consider soldering them from the back.
- OUT− - Audio signal output for differential −output.
- OUT+ - Audio signal output for differential +output.
- VCC - Voltage input (1.6V to 3.6V). To power this lil' mic, use a DC voltage with a supply current of about 248μA for VM2020. We'll be using 3.3V from an Arduino.
- GND - Ground.
For technically-minded folks, here are some of the features of the VM2020 and a comparison with other SparkFun MEMS Microphone Breakout boards. Make sure to check out VM2020 datasheet in the Resources & Going Further for a complete overview of the microphone.
| Electrical Characteristics | ICS-10480 | SPH8878LR5H-1 | VM2020 |
|---|---|---|---|
| High Signal-to-Noise Ratio ("SNR") | 65dbA | 67dBA | 50dbA |
| Sensitivity | about -38dBV | about -44dBV | about -63dBV |
| Flat Frequency Response | 60Hz to 20kHz | 7Hz to 36kHz | 80Hz to 10kHz |
| Low Current Consumption | <260 μA @ 3.3V | <265 µA @ 3.6V | <248 μA @ 3.6V |
| Acoustic Overload Point (AOP) | 124 dB | 134 dB | 152 dB |
Note that the acoustic overload point of the VM2020 is greater than the other MEMS microphones. The audio is less likely to be clipped in louder settings (such as concerts, dance studios, etc.) or when the microphone is placed beside a speaker. Below is a table of typical sounds, their approximate decibel levels, and the AOP of the three microphones listed earlier. The information was gathered from a variety of sources online. Keep in mind noise-induced hearing loss varies depending on the sound intensity, the amount of exposure time, and how close your ears are to the sound source.
| Sound Source | Approximate Decibel Level [dB] | Sound Intensity | Microphone Type |
|---|---|---|---|
| Rocket Launch | 180 | Death of Hearing Tissue | |
| Shotgun Blast | 165 | ||
| Firecrackers | 150 | Reaching VM2020 AOP | |
| Jet Engine | 140 | Harmful | |
| Jackhammer | 130 | Reaching SPH8878LR5H-1 AOP | |
| Car Siren | 120 | Reaching ICS-10480 AOP | |
| Rock Concert | 115 | ||
| Lawn Mower | 90 | Risk of hearing loss when sustained levels of 90dB | |
| Loud City Traffic | 85 | Sounds above 85dB are harmful | |
| Normal Conversation | 60 | ||
| Quiet | 0 | Normal Hearing Threshold |
Board Dimensions
The board dimensions for the breakout are 0.40" x 0.55" (10.16mm x 13.97mm). The location of the header pins are different compared to previous versions with the extra pin for the differential output.
