Overview
IEC 62047-50:2025 is the International Electrotechnical Commission standard that specifies test conditions and test methods for the performance of MEMS capacitive microphones. Applicable to MEMS capacitive microphone devices, the standard defines how to measure and report key performance parameters to ensure repeatable, comparable results across design, production and quality-assurance activities.
Key Topics
This standard focuses on practical, measurable microphone performance characteristics and the procedures to evaluate them. Main technical topics include:
- Performance parameters covered: output impedance, sensitivity (analog and digital), noise floor (A‑weighted), signal‑to‑noise ratio (SNR), dynamic range, frequency response, polarity, equivalent input noise (EIN), total harmonic distortion (THD), power‑supply rejection ratio (PSRR), and acoustic overload point (AOP).
- Test methods: detailed procedures for acoustic and electrical measurements, including two methods for output‑impedance measurement (direct load comparison and bridge method), sensitivity testing at 94 dB SPL / 1 kHz, and A‑weighted noise floor measurement across 20 Hz–20 kHz.
- Test setups and sampling: use of probe stations for MEMS capacitive sensor die testing, five‑point wafer sampling strategy, and requirements for sound isolation (silencer/anechoic chambers) during acoustic tests.
- Ratings and limits: specification of essential ratings such as supply voltage, operating/storage temperature, atmospheric conditions, mechanical shock, acceleration and vibration.
- Calculation guidance: formulas and procedures for converting measured voltages to sensitivity (mV/Pa, dBV or dBFS), deriving SNR, and calculating dynamic range relative to AOP.
Applications and Who Uses It
IEC 62047-50 is intended for professionals and organizations involved in the design, manufacture, testing and qualification of MEMS capacitive microphones:
- MEMS microphone manufacturers for product specification, R&D validation and production test methods.
- Test and calibration laboratories to standardize measurement procedures and to produce comparable datasheets.
- OEMs and system integrators (smartphones, headsets, hearing aids, IoT devices, automotive audio) that need consistent microphone performance data for system design and supplier assessment.
- Quality assurance and compliance teams for incoming inspection plans and production acceptance criteria.
Practical benefits include consistent microphone datasheets, improved comparability across suppliers, reproducible production testing, and clearer acceptance criteria for acoustic performance.
Related Standards
- IEC 61193-2 - sampling plans for inspection of electronic components (referenced for five‑point wafer sampling).
- IEC 60268-1 - methods for A‑weighted noise measurements (referenced for noise floor measurement).
- Other parts of the IEC 62047 series (micro‑electromechanical devices) for broader MEMS testing guidance.
Keywords: IEC 62047-50, MEMS capacitive microphones, microphone performance testing, sensitivity, noise floor, frequency response, acoustic overload point, MEMS microphone standards.