The SPH0645 is a digital MEMS microphone that uses the I²S interface to send audio directly in digital format, eliminating the need for analog conversion. This small module integrates a silicon microphone and an internal processor that captures sound, digitizes it, and transmits it over its I²S data lines. It operates by synchronizing with the master clock provided by the microcontroller, sending audio data in real time with low noise and high sensitivity.
The SPH0645 I2S MEMS Digital Microphone is widely used in projects requiring clear and compact audio capture, such as voice assistants, command recognition, digital recording, sound level (SPL) measurement, acoustic analysis, and IoT systems that need to monitor their environment. Thanks to its I²S output , it is compatible with development boards that support this interface, including ESP32 , Raspberry Pi , Teensy 3.x/4.x , Arduino Nano 33 BLE Sense , STM32 , and various ARM microcontroller-based boards. Its high sensitivity, low noise, and digital communication make it ideal for both professional and educational projects.
SPECIFICATIONS AND FEATURES
Type: Digital MEMS Microphone.
Output: I²S (digital interface).
Supply voltage (VDD): typically 1.62 V to 3.6 V.
Data format: 24 bits in two's complement, MSB first.
Actual data precision: 18 bits (unused bits are set to 0).
Clock speed (BCLK): supports between 2,048 KHz and 4,096 KHz .
Signal-to-noise ratio (SNR): 65 dB (A) typical.
Current consumption: ~600 µA in active mode.
Operating modes:
Active : when the clock is greater than ~1 MHz.
Sleep (rest) : when the clock drops below ~1 kHz; in this mode the data pin is in “high impedance” and certain circuits are turned off to save power.
Sensitivity: 94 dB SPL @ 1 KHz.
RF shielding: Yes, it is protected to prevent radio frequency interference.
Operating Temperature: -40 °C to 105 °C.
Includes: 6-pin header strip for soldering.
Dimensions: 11 mm x 15 mm x 2 mm.
Weight: 0.96 g.
GRADES:
The microphone is a mono device. You can select whether you want it on the left or right channel by connecting the Select pin to power or ground. If you have two microphones, you can configure them in stereo by sharing the clock, WS, and data lines, but connecting one to ground and the other to high voltage.
This MEMS I²S microphone has a bottom port, so make sure the hole in the base is facing the sounds you want to read ( keep this in mind when soldering the headers ).
 
ADDITIONAL INFORMATION
Pin Description.
3V: This is the power input pin. Technically, it can be powered from as little as 1.6V up to 3.6V, but you must ensure the logic level matches.
GND: Ground .
BCLK:  (the bit clock, also known as the data clock or simply "clock") comes from the main I2S signal to tell the microphone when it's time to transmit data. It should run at 2-4 MHz, but we've found that it can often run a little slower and still work correctly.
DOUT: This is the microphone's data output.
LRCLK: The left/right clock, also known as WS  (word selection), tells the microphone when to start transmitting. When  LRCLK  is low, the left channel will transmit. When LRCLK is high, the right channel will transmit.
SEL: This is  the channel select pin. By default, this pin is low, so it transmits on the left mono channel. Connecting it to a high logic voltage will instantly start the microphone transmitting on the right channel.