MEMS Microphone Construction, Pinout, and Circuit Diagram
Hey, in this article, we are going to see MEMS Microphone Construction, Pinout, and Circuit Diagram. The full form of MEMS is Micro-Electro-Mechanical Systems. It is a type of microphone that uses tiny mechanical parts to convert sound waves into electrical signals. It is basically a miniature microphone. It is made using microfabrication techniques, similar to those used in semiconductor manufacturing.
MEMS microphones consist of a small diaphragm (generally made of silicon or polymer) suspended over a cavity. When sound waves hit the diaphragm, it vibrates, causing a change in capacitance or resistance. This change is then converted into an electrical signal, which is amplified and processed.
MEMS Microphone Construction
First of all let's see the constructional diagram of a MEMS Microphone so we can understand easily.
As per the above constructional diagram, the MEMS Microphone has the following parts,
1. MEMS Transducer (TR or Sensor): It is the heart of the microphone. It is responsible for converting sound waves into electrical signals. It consists of a diaphragm, backplate, air gap, and suspension.
2. CAN (Capacitor and Lead Frame): It is basically a metal frame that surrounds the MEMS transducer. It provides mechanical support and electrical connections. It also acts as a capacitor plate.
3. Sound Port: It is a small opening that allows sound waves to enter the microphone and reach the MEMS transducer.
4. Glob Top Molding: It is a protective layer of epoxy or other materials that covers the MEMS transducer and CAN. It helps to seal the sensitive components from the environment.
5. PCB (Printed Circuit Board): A small Printed Circuit Board is used to connect the MEMS microphone to external electronic circuits by providing a pathway for signals and power.
6. Sealing: It may be additional protection layers, such as epoxy or silicone, that seal the sound port and prevent moisture and contaminants from entering the microphone.
7. Gold Wire: The thin gold wires that connect the MEMS transducer to the CAN and PCB, providing electrical connections.
8. ASIC (Application-Specific Integrated Circuit): A small integrated circuit that amplifies, filters, and processes the electrical signals from the MEMS transducer, preparing them for external use.
These above components work together to create a compact, reliable, and high-quality MEMS microphone. The MEMS transducer detects sound waves, while the CAN, PCB, and ASIC support and process the signals. The sound port allows sound waves to enter, and the glob top molding, sealing, and gold wire ensure protection and connectivity.
MEMS Microphone Pinout
Here, you can see the Pinout Diagrams of Analog and Digital MEMS Microphones.
Here is the function of each pin of an analog MEMS microphone,
1. The VDD Pin(Power Supply) provides the necessary power to the microphone typically ranging from 1.8V to 3.3V, depending on the specific microphone. It connects to a power source, such as a battery or a voltage regulator.
2. The Output Pin carries the analog audio signal from the microphone to the external circuitry. It is basically a time-varying voltage signal that represents the sound waves. It needs to be connected to an amplifier, filter, or other signal-processing components.
3. The GND (Ground) Pin provides a reference point for the power supply and signal. It connects to the system ground or a common ground plane. It helps to reduce noise and interference by providing a stable reference.
Here is the function of each pin of a Digital MEMS microphone,
1. Here, VDD (Power Supply) and GND (Ground) pins have the same function as we see in the analog microphone.
2. The Select (L/R) Pin is used to select the audio channel (Left or Right) in stereo microphones. Sometimes it may also be used for other configuration settings.
3. The Clock Pin provides a clock signal for synchronous data transfer. It is generally a square wave signal with a frequency range of 1-4 MHz.
4. The Data Pin is used to transfer digital audio data from the microphone to external circuitry. It is basically a serial data stream, such as I2S (Inter-IC Sound) or PDM (Pulse Density Modulation).
MEMS Microphone Circuit Diagram
Here, you can see the Internal Circuit Diagrams of Analog and Digital MEMS Microphones.
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MEMS Microphone Construction, Pinout, and Circuit Diagram
Reviewed by Author
on
August 07, 2024
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Reviewed by Author
on
August 07, 2024
Rating: