Adafruit PDM Microphone Breakout with JST SH Connector

Introducing the PDM MEMS Microphone—an exciting new addition to the Adafruit shop! This microphone uses PDM (Pulse Density Modulation), a unique digital audio interface that differs from traditional analog or I2S microphones. While these microphones are widely used in consumer electronics, they are rarely found in maker projects, which is why we’ve decided to offer this breakout for your next project.

Key Features:

• Digital Output (No Analog Output): Unlike electret microphones, this mic does not provide an analog signal, making it perfect for chips that lack analog inputs.
• Pulse Density Modulation (PDM) Interface: The microphone outputs a 1-bit PDM signal (similar to PWM but distinct from PWM and I2S). You’ll need a chip with a PDM interface (most 32-bit processors support this).
• Simple Clocking: The mic is clocked with a 1 MHz to 3 MHz clock rate, and the data line produces a square wave that syncs with the clock. The density of the wave reflects the analog value when averaged.

Integration Options:

• High-Speed Hardware Support: Some chips, like the nRF52840, have built-in peripherals and libraries to manage the data, apply filters, and output the analog value easily.
• Manual Data Management: Chips like the ATSAMD21 have hardware peripherals for basic data handling, but you’ll need to perform filtering and decimation yourself (example code available).
• Custom Integration: If your chip lacks native support, you can use SPI to manage the data or generate a clock and apply an analog filter for analog value readings (though this requires some creativity!).

Additional Features:

• Each order includes one fully assembled and tested microphone.
• 4-JST SH connector with 3V, GND, DAT, and CLK connections for flexible microphone setup when paired with JST-SH cables.
• Option to switch between Left and Right channels with an onboard solder jumper.
• For users who prefer breakout headers, we also offer a version with those included.

This PDM MEMS Microphone is ideal for those looking to experiment with digital microphones and expand their project capabilities, though it requires a bit of knowledge of PDM handling.

Technical Details:

• Voltage Range: 1.8-3.3V
• Clock rate: 1 - 3.25 MHz
• Current draw: 0.6mA
• SNR: 61 dB
• Sensitivity: ~-26 dBFS

Product Dimensions: 14.0mm x 14.0mm x 4.5mm / 0.6" x 0.6" x 0.2"

Product Weight: 0.7g / 0.0oz