MEMS Microphones
Digital/Analog/Smart MIC series
MEMS (Micro-Electro-Mechanical Systems) microphones utilize semiconductor manufacturing technology to create miniature devices with electro-mechanical functionality. They offer superior tolerance to high temperatures and high-frequency noise, allowing for integration into highly complex designs without concerns regarding noise interference. Silicon-based MEMS microphones enable the seamless integration of MEMS structures with ASIC, resulting in a significant reduction in component size. Their ultra-compact dimensions align with the ongoing trend toward thinner and smaller designs in consumer electronics.
Basic Operating Principle
1. Sound Entry: Sound pressure (air vibration) enters the microphone through tiny holes in the housing (top or bottom ports).
2. Structural Displacement: Sound waves strike an internal, ultra-lightweight movable diaphragm, causing it to vibrate mechanically.
3. Signal Conversion:
3.a. Captive (most common): A capacitor is formed between the diaphragm and a fixed backplate. As the diaphragm vibrates, the distance between the two changes, causing the capacitance value to fluctuate.
3.b. Piezoelectric: The diaphragm utilizes piezoelectric material, directly converting the deformation caused by applied force into electrical energy.
4. Signal Amplification and Output: Since the change in capacitance is minute, an internal ASIC (Application-Specific Integrated Circuit) chip is typically used to convert and amplify these subtle changes into an analog or digital (like PDM/I2S interface) electrical signal output.
Key Advantages
1. Compact Size and High Integration: Combines the semiconductor and preamplifier; ideal for multi-microphone arrays and compact devices.
2. High-Temperature Resistance: Supports Surface Mount Technology (SMT) and automated reflow soldering.
3. Excellent Consistency: High temperature stability and uniform performance.
