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MEMS (Micro-Electro-Mechanical Systems) microphones are revolutionizing the audio landscape—offering compact size, high fidelity, and power efficiency for today’s smart devices. From smartphones to voice assistants, MEMS microphones are now the industry standard thanks to their consistent performance and scalability.
In this article, we break down the key MEMS microphone specifications engineers need to know when selecting the right component for their design. Whether you’re building next-gen wearables, AI voice interfaces, or IoT nodes, understanding these parameters will help ensure optimal audio performance.
Explore our high-performance MEMS microphone offerings here:
🔗 https://sistc.com/product-category/mems-microphone/
What Are MEMS Microphones?
MEMS microphones are silicon-based microphones with dimensions as small as 3x2x1 mm. Inside each device are two key components:
- MEMS transducer: A diaphragm that converts acoustic sound pressure into an electrical signal
- ASIC: An application-specific integrated circuit that amplifies and (in digital models) digitizes the signal
They come in both analog and digital output types, and in top-port or bottom-port configurations—offering flexibility for PCB layout and acoustic design.
Key Advantages Over Electret Microphones (ECMs)
MEMS microphones offer:
- Smaller footprints for compact devices
- High signal-to-noise ratio (SNR)
- Better resistance to environmental variability
- Tight device-to-device performance matching
- Low power consumption
- Robust silicon structures with predictable aging characteristics
These advantages make them ideal for consumer electronics, automotive audio, and always-on smart assistants.
How to Read a MEMS Microphone Datasheet
Understanding MEMS microphone performance starts with mastering a few key specs:
1. Sensitivity
Sensitivity indicates the microphone’s electrical response to a 94 dB SPL 1kHz tone.
- Analog MEMS: expressed in dBV (e.g., –38 dBV)
- Digital MEMS: expressed in dBFS (e.g., –26 dBFS)
Higher sensitivity means more signal output for the same sound pressure input.
📘 See SISTC’s analog and digital MEMS mics for options across sensitivity ranges.
2. Signal-to-Noise Ratio (SNR)
SNR measures the difference between the reference signal (94 dB SPL) and the acoustic noise floor. A higher SNR = clearer, cleaner voice pickup.
- Typical SNRs: 60–75 dB A-weighted
- Important for far-field voice recognition and noise cancellation
🔍 A microphone with 70+ dB SNR performs reliably even in noisy environments.
3. Total Harmonic Distortion (THD)
THD quantifies how much distortion is introduced at high input levels.
- 1% THD is generally considered the threshold for clean audio
- Modern MEMS mics can stay under 1% up to 122 dB SPL
- Digital MEMS include THD+N (Total Harmonic Distortion + Noise)
📈 Low THD ensures better voice clarity during loud recordings.
4. Acoustic & Electrical Noise Floor
This defines the smallest signal the microphone can detect before it gets lost in background or circuit noise.
- Typical acoustic noise floor: ~30 dB SPL
- Electrical noise floor: expressed in dBV or dBFS
Engineers designing for low-volume audio capture should prioritize microphones with a low noise floor and high SNR.
5. Acoustic Overload Point
This is the SPL level (e.g., 120–126 dB SPL) where the microphone begins to clip or distort due to internal mechanical limitations.
Choose microphones with high overload points if you expect to capture loud environments like concerts, factory floors, or automotive cabins.
Choosing the Right MEMS Microphone for Your Application
| Application | Key Spec Focus | Recommended Feature |
|---|---|---|
| Smart Speakers | SNR, THD | Digital top-port, high SNR |
| Earbuds & Hearables | Power, size | Analog bottom-port, low current |
| Voice Assistants | Far-field, clarity | 70+ dB SNR, beamforming |
| Automotive | Overload, PSRR | High THD headroom, EMI robustness |
Explore suitable products:
🔗 MEMS Microphones for Smart Devices
Additional Technical Resources
- For an in-depth review of MEMS microphone parameters, Cirrus Logic’s application note offers a detailed breakdown.
- If you’re optimizing VUI design, also read our article on High-SNR MEMS for Conversational AI
Conclusion
MEMS microphones have become the standard in modern audio capture, and understanding their specs helps engineers build more intelligent, high-performance audio systems.
Whether you need ultra-low noise, high dynamic range, or compact form factors, SISTC’s MEMS microphone portfolio supports a wide range of applications and architectures.
📢 Ready to build smarter voice-enabled products?
👉 Contact our engineering team
