INMP441 MEMS High Precision Omnidirectional Microphone Module

INMP441 MEMS High Precision Omnidirectional Microphone Module is a high-performance, low-power, digital-output MEMS (Micro-Electro-Mechanical System) microphone designed for modern digital audio capture. This module utilizes the robust INMP441 IC, which consists of a MEMS sensor and an audio signal conditioning circuit, seamlessly converting acoustic signals into a digital Pulse Density Modulation (PDM) output. The digital interface minimizes the risk of noise pickup and signal degradation that often plague analog microphone circuits. Consequently, the INMP441 offers a high signal-to-noise ratio (SNR) and high sensitivity, delivering clear and precise audio capture. Therefore, you should choose this omnidirectional module for applications requiring studio-quality sound acquisition with simple integration into microcontrollers like ESP32 and Arduino Due.

Key Features:

• Digital PDM Output: The module directly outputs a Pulse Density Modulation (PDM) signal, eliminating the need for complex and noisy external A/D converters.
• High Signal-to-Noise Ratio (SNR): Features an excellent SNR of 61 dBA, ensuring exceptional clarity in the captured audio signal.
• High Sensitivity: Offers a sensitivity of −26 dBFS, allowing the device to efficiently capture subtle acoustic details.
• Omnidirectional Pickup Pattern: This microphone captures sound equally well from all directions (360°), making it perfect for voice command and conferencing applications.
• Compact Design: The small PCB footprint simplifies integration into space-constrained wearable and portable electronic devices.

Technical Specifications:

• Component IC: InvenSense INMP441
• Acoustic Overload Point (AOP): 120 dB SPL (Sound Pressure Level)
• Signal-to-Noise Ratio (SNR): 61 dBA
• Sensitivity: −26 dBFS ± 1 dB
• Operating Voltage (V_DD): 1.8 V to 3.3 V
• Current Consumption: Typically 1.4 mA (Low power draw for battery-operated devices)
• Interface: PDM (Pulse Density Modulation) Digital Output

Mechanical Specifications:

• Microphone Type: MEMS (Micro-Electro-Mechanical System)
• Pickup Pattern: Omnidirectional (360°)
• Port Position: Top Port (Sound enters from the top surface of the MEMS element)
• Package Type: Small PCB module with header pins.

Dimensions:

• Module Board Size: ≈ 14 mm x 12 mm
• Pin Pitch: 2.54 mm (Standard for breadboard compatibility)
• Weight: ≈ 1 g (Extremely lightweight)
• Mounting: Through-Hole header pins.

Pinout and Wiring:

• VCC: Connect to the 3.3 V power supply. This is the main voltage rail.
• GND: Connect to the circuit ground reference.
• SCK (Clock): Input from the host microcontroller (MCU). The MCU drives this clock to synchronize the PDM data output.
• SD (Data): Digital PDM data output pin. Connect this to the MCU’s PDM/I2S data input pin.
• LR (Left/Right Select): Selects the microphone’s channel (Left or Right) when two microphones share the same clock line. For single-mic setups, you typically tie this pin to VCC or GND.

Datasheet Reference:

• Download TDK InvenSense INMP441 Datasheet

Commonly Used in:

• Microcontroller Platforms: Widely used with ESP32, ESP8266, and advanced Arduino boards like the Due for digital audio projects.
• Voice User Interfaces (VUI): Providing the input for Amazon Alexa-type smart devices and voice command systems.
• Digital Recorders: Used in high-fidelity portable digital recording equipment and audio analysis tools.

Applications:

• Acoustic Monitoring: Facilitating the capture of environmental sound data for noise level analysis.
• Conferencing Systems: Deploying the module in multi-microphone arrays for directional sound capture or beamforming.
• Security and Surveillance: Enabling reliable audio recording for monitoring systems and proximity sensors.
• Wearable Devices: Its small size and low power are critical for smartwatches and health monitoring devices.

Equivalent Models:

• SPK0838HT4HSB (Knowles): A similar high-performance, omnidirectional MEMS microphone with a digital PDM interface.
• MP34DT01 (STMicroelectronics): Another common digital MEMS microphone that outputs PDM, offering a comparable alternative for digital systems.
• ICS-40730 (InvenSense): A newer generation digital MEMS mic that potentially offers even lower power consumption, however, it may require slightly different timing configuration.

Package Includes:

• 1 x INMP441 MEMS High Precision Omnidirectional Microphone Module