INMP621: Wide Dynamic Range Microphone with PDM Digital Output


InvenSense MEMS Microphone

The INMP621 is a high sound pressure level (SPL), ultralow noise, low power, digital output, bottom ported omnidirectional MEMS microphone. This microphone clips at 133 dB SPL, which is useful for clearly capturing audio in loud environments. The INMP621 consists of a MEMS microphone element and an impedance converter amplifier followed by a fourth-order Σ-Δ modulator. The digital interface allows the pulse density modulated (PDM) output of two microphones to be time multiplexed on a single data line using a single clock. The INMP621 is pin compatible with the INMP421 and INMP521 microphones, providing an easy upgrade path.

The INMP621 has a high SNR of 65 dBA and sensitivity of −46 dBFS. The INMP621 has an extended wideband frequency response, resulting in natural sound with high intelligibility. Low current consumption and a sleep mode with less than 5.5 µA of current consumption enables long battery life for portable applications.

The INMP621 is available in a thin 4 mm × 3 mm × 1 mm surface-mount package. It is reflow solder compatible with no sensitivity degradation.

† – 7” Tape and reel to be discontinued. Contact for availability.

INMP621 Functional Block Diagram

INMP621 Functional Block Diagram


  • Smartphones and feature phones
  • Microphone arrays
  • Tablet computers
  • Teleconferencing systems
  • Digital still and video cameras
  • Bluetooth headsets
  • Notebook PCs
  • Security and surveillance

Features and Benefits

  • 133 dB SPL acoustic overload point
  • Small and thin 4 mm × 3 mm × 1 mm surface-mount package
  • Omnidirectional response
  • Very high SNR: 65 dBA
  • Sensitivity of −46 dBFS
  • Extended frequency response from 45 Hz to >20 kHz
  • Low current consumption: 1.2 mA
  • Sleep mode for extended battery life, 5.5 µA consumption
  • High power supply rejection (PSR): −100 dBFS
  • Fourth-order Σ-Δ modulator
  • Digital pulse density modulation (PDM) output
  • Compatible with Sn/Pb and Pb-free solder processes
  • RoHS/WEEE compliant



Application Notes (General)

Application Notes (Specific)

Evaluation Board User Guides


Part # Output Port Location SNR Equivalent
Input Noise
Frequency Response
Maximum SPL Sensitivity @1kHz Sensitivity Tol Package Size Documentation Flex Board Evaluation Board Device
UNITS: (dBA) (dBA) (min - max) +/- dB mm (.pdf) (add to cart) (add to cart) (add to cart)

PDM Bottom 65dB 29dB 45Hz - 20kHz 133dB SPL -46 dBFS 2dB 3.00x4.00x1.00 Datasheet

  • Disclaimer

    • InvenSense sensors should not be used or sold in the development, storing, production and utilization of any conventional or mass-destructive weapons or any other weapons or life-threatening applications as well as in any other life-critical applications including but not limited to medical equipment, transportation, aerospace and nuclear instruments, undersea equipment, power plant equipment, disaster prevention and crime prevention equipment. In devices or systems whereby malfunction of these products can be expected to result in personal injury and casualties, InvenSense customers using or selling these products do so at their own risk and agree to keep InvenSense harmless from any consequences. InvenSense reserves the right to make changes to this product, including its circuits and software, in order to improve its design and/or performance, without prior notice.

      InvenSense makes no warranty, either expressed or implied with respect to any product, and specifically disclaims all other warranties, including warranties for merchantability, non-infringement, and fitness for any particular purpose. For more information go to Terms and Conditions.

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