1. Introduction
The DollaTek INMP441 is a high-performance, low-power, omnidirectional MEMS microphone with a digital I2S output. This module is designed for direct connection to digital processors like DSPs and microcontrollers, including ESP32, eliminating the need for an additional audio codec. It offers high-precision 24-bit data output, a high signal-to-noise ratio (SNR), and a flat wideband frequency response for natural sound reproduction.
2. Product Features
- I²S Digital Interface: Provides high-precision 24-bit data output.
- High SNR: Features a 61 dBA signal-to-noise ratio, suitable for near-field applications.
- High Sensitivity: -26 dBFS sensitivity.
- Flat Frequency Response: Covers 60 Hz to 15 kHz for natural sound.
- Low Power Consumption: Operates with a low current of 1.4 mA.
- High PSR: -75 dBFS Power Supply Rejection.
- Compact Size: Small surface mount package measuring 4.72 x 3.76 x 1 mm.
- Environmental Compliance: Compatible with Sn/Pb and lead-free soldering processes, RoHS/WEEE compliant, and halogen-free.
3. Package Contents
The package includes the following item:
- 1 x DollaTek INMP441 Microphone Module
4. Setup and Connection
This section details the physical connections required to integrate the INMP441 module into your project. The module features a standard I2S interface for digital audio communication.
4.1 Pinout Diagram
Refer to the diagram below for the pin assignments of the INMP441 module.
Image: Pinout diagram for the DollaTek INMP441 module, showing connections for GPIO14, GPIO15, GND, GPIO32, VDD3.3, and L/R, WS, SCK, SD pins.
4.2 Connection Table
Connect the INMP441 module to your microcontroller (e.g., ESP32) according to the following table:
| INMP441 Pin | Description | Typical ESP32 Connection |
|---|---|---|
| VDD | Power Supply (3.3V) | 3.3V |
| GND | Ground | GND |
| SD (DATA) | I2S Serial Data Output | GPIO32 (or other I2S DATA pin) |
| WS (LRCLK) | I2S Word Select (Left/Right Clock) | GPIO15 (or other I2S LRCLK pin) |
| SCK (BCLK) | I2S Serial Clock (Bit Clock) | GPIO14 (or other I2S BCLK pin) |
| L/R | Left/Right Channel Select (Connect to GND for Left, VDD for Right) | GND (for Left channel) |
Note: The specific GPIO pins for I2S on your microcontroller may vary. Consult your microcontroller's documentation for correct pin assignments. For mono operation, connecting the L/R pin to GND typically selects the left channel.
5. Operating Instructions
Once connected, the INMP441 module can be operated by configuring the I2S peripheral on your microcontroller. The module acts as an I2S slave device, receiving clock signals from the master (your microcontroller) and transmitting digital audio data.
- Microcontroller Configuration: Configure your microcontroller's I2S peripheral to operate in master mode, generating the necessary BCLK (Bit Clock) and LRCLK (Word Select) signals.
- Data Format: The INMP441 outputs 24-bit audio data. Ensure your microcontroller's I2S peripheral is configured to receive this data format.
- Sampling Rate: The module supports various sampling rates. Common rates include 16 kHz, 44.1 kHz, or 48 kHz, depending on your application's requirements and microcontroller capabilities.
- Software Libraries: For platforms like ESP32, dedicated I2S libraries are available to simplify configuration and data acquisition. Refer to the ESP-IDF documentation or community resources for examples.
Applications: The INMP441 is suitable for a wide range of applications, including teleconferencing systems, remote controls, gaming consoles, mobile devices, laptops, tablets, and security systems where high-quality digital audio input is required.
6. Maintenance
The DollaTek INMP441 module is a robust electronic component designed for long-term operation with minimal maintenance.
- Cleaning: Keep the module free from dust and debris. If cleaning is necessary, use a soft, dry brush or compressed air. Avoid liquid cleaners.
- Environmental Conditions: Operate and store the module within its specified temperature and humidity ranges to ensure optimal performance and longevity. Avoid exposure to extreme temperatures, moisture, or corrosive environments.
- Physical Handling: Handle the module with care to prevent physical damage to the MEMS sensor or solder joints. Avoid applying excessive force or bending the PCB.
7. Troubleshooting
If you encounter issues with your INMP441 module, consider the following troubleshooting steps:
- No Audio Output:
- Verify all connections (VDD, GND, SD, WS, SCK, L/R) are correct and secure.
- Ensure the power supply (3.3V) is stable and within the module's operating range.
- Check your microcontroller's I2S configuration. Confirm it is set to master mode and generating the correct clock signals (BCLK, LRCLK).
- Confirm the I2S data format (24-bit) is correctly configured on the microcontroller.
- Test with a known working I2S example code for your microcontroller.
- Distorted or Noisy Audio:
- Check for electrical noise on the power supply lines. Add decoupling capacitors if necessary.
- Ensure proper grounding.
- Verify the L/R pin is correctly set (e.g., connected to GND for left channel).
- Reduce the distance between the microphone module and the microcontroller to minimize signal integrity issues.
- Ensure no physical obstructions or vibrations are affecting the microphone element.
- Module Not Detected:
- The INMP441 is a slave device and does not have a unique address for detection. Its presence is confirmed by receiving valid I2S data. Refer to "No Audio Output" steps.
8. Specifications
Detailed technical specifications for the DollaTek INMP441 module:
| Feature | Specification |
|---|---|
| Model Name | INMP441 |
| Brand | DollaTek |
| Microphone Type | MEMS, Omnidirectional |
| Output Interface | I2S Digital |
| Data Precision | 24-bit |
| Signal-to-Noise Ratio (SNR) | 61 dBA |
| Sensitivity | -26 dBFS |
| Frequency Response | 60 Hz to 15 kHz |
| Current Consumption | 1.4 mA (low power) |
| Power Supply Rejection (PSR) | -75 dBFS |
| Package Size | 4.72 x 3.76 x 1 mm (MEMS sensor) |
| Compatible Devices | Laptops, Gaming Consoles, PCs, Tablets, Microcontrollers (e.g., ESP32) |
| Connectivity Technology | Wired (I2S) |
| Number of Channels | 1 (Mono, configurable L/R) |
| Housing Material | Plastic (module PCB) |
Image: Dimensions of the DollaTek INMP441 module, showing a 14mm x 14mm (0.55 inch x 0.55 inch) footprint.
9. Warranty and Support
DollaTek products are typically covered by a standard manufacturer's warranty against defects in materials and workmanship. For specific warranty details, return policies, or technical support, please refer to the retailer's website where the product was purchased or contact DollaTek customer service directly. Keep your proof of purchase for warranty claims.
For further assistance, you may visit the DollaTek brand page on Amazon or consult online forums and communities dedicated to microcontrollers and I2S audio for project-specific guidance.
10. Additional Product Views
Image: Top view of the DollaTek INMP441 module, showing the MEMS sensor component.
Image: Bottom view of the DollaTek INMP441 module, showing the I2S pin labels (SD, VDD, GND, L/R, WS, SCK).
Image: The DollaTek INMP441 module held between fingers, illustrating its compact size.
Image: The DollaTek INMP441 module with header pins soldered, ready for breadboard or prototype use.
