SPH0645 MEMS I2S Output Digital Microphone Module

SPH0645 MEMS I2S Output Digital Microphone Module is a cutting-edge, high-performance acoustic sensor that provides direct digital audio output to microcontrollers and processors without the need for an external Analog-to-Digital Converter (ADC). This module integrates a tiny MEMS (Micro-Electro-Mechanical Systems) microphone with an I2S interface, delivering crystal-clear 24-bit audio data directly to your system. Consequently, engineers can eliminate noise-prone analog signals and simplify PCB layouts significantly. The SPH0645 handles the entire signal chain internally, from the acoustic transducer to the digital pulse-code modulation (PCM) output. Furthermore, its bottom-port design and ultra-small form factor make it an ideal choice for compact, voice-enabled electronics. Therefore, you should utilize this module when your project requires high-quality, interference-resistant audio capture in a space-constrained environment.

Key Features:

• Digital I2S Interface: This module outputs digital audio using the industry-standard I2S protocol, allowing direct connection to ESP32, Raspberry Pi, and STM32 boards.
• Bottom Port Design: The acoustic inlet is located on the bottom of the sensor, which provides better protection for the MEMS membrane and allows for sleek industrial designs.
• High Signal-to-Noise Ratio (SNR): Offering a high SNR of 65 dB, this microphone ensures clear voice capture even in environments with moderate background noise.
• Low Power Consumption: The device consumes very little current during operation, making it suitable for battery-powered wearable technology and portable recorders.
• Wide Frequency Response: It captures a broad range of frequencies from 100 Hz up to 10 kHz, ensuring faithful reproduction of the human voice and ambient sounds.

Technical Specifications:

• Supply Voltage (VDD): 1.6 V to 3.6 V
• Output Type: 24-bit Digital I2S (Integrated ADC)
• Signal-to-Noise Ratio (SNR): 65 dB(A)
• Sensitivity: −26 dBFS ±3 dB
• Current Consumption: ≈ 600 μA (Typical)
• Clock Frequency (SCK): 1.024 MHz to 4.096 MHz
• Operating Temperature Range: −40°C to +85°C

Mechanical Specifications:

• Sensor Technology: Silicon MEMS (Micro-Electro-Mechanical Systems)
• Acoustic Port: Bottom-Ported
• Mounting Type: SMT on module, Through-hole pins for breadboarding
• PCB Finish: Gold-plated pads for superior conductivity and oxidation resistance.

Dimensions:

• Module Length: ≈ 16.5 mm
• Module Width: ≈ 12.5 mm
• Module Thickness: ≈ 2.5 mm (excluding pins)
• Pin Pitch: 2.54 mm (Standard)

Pinout and Wiring:

• 3V: Connect to 1.8V – 3.3V DC power supply.
• GND: Connect to the common system ground.
• BCLK (Bit Clock): The clock signal that defines the rate of data bits on the data line.
• DOUT (Data Out): The digital audio data output pin.
• LRCL (Left/Right Clock): Selects between the left or right channel; connect to ground or VCC to set the channel.
• SEL (Select): Determines which I2S channel the microphone uses (Left or Right) depending on the wiring.

Datasheet Reference:

• Download Knowles SPH0645LM4H-B Datasheet

Commonly Used in:

• ESP32 Audio Projects: Building VoIP callers, voice recorders, and smart speakers using the ESP32’s native I2S peripheral.
• Raspberry Pi Development: Adding high-quality audio input for Python-based voice processing and AI assistants.
• Voice Recognition Modules: Serving as the primary audio sensor for offline or cloud-based speech-to-text engines.

Applications:

• Smart Home Assistants: Captures user commands for home automation hubs and smart displays.
• Wearable Devices: Fits into smartwatches and fitness trackers for voice memos and activity monitoring.
• Noise Monitoring: Measures environmental sound levels in industrial or urban settings using precise digital values.
• Teleconferencing Systems: Provides high-fidelity audio for clear communication in remote meeting hardware.

Equivalent Models:

• ICS-43434 (InvenSense): A widely used 24-bit I2S MEMS microphone that offers similar digital output and low power performance.
• INMP441: Another popular I2S digital microphone, however, it is often larger and features a top-port design compared to the SPH0645.
• MP34DT01 (STMicroelectronics): A PDM-based digital microphone, which requires a PDM-to-I2S converter but serves similar high-density audio needs.

Package Includes:

• 1 x SPH0645 MEMS I2S Output Digital Microphone Module
• 1 x 6-Pin Header Strip (Unsoldered)