This datasheet is about the ADMP421 microphone model, which is a high-performance, low-power, digital output bottom-ported omnidirectional MEMS microphone. The microphone has a small and thin 3 mm × 4 mm × 1 mm surface-mount package, a high signal-to-noise ratio of 61 dB, a high sensitivity of −26 dBFS, a flat frequency response from 100 Hz to 15 kHz, low current consumption of <650 µA, a sleep mode for extended battery life, a high PSR of 80 dBFS, a fourth-order Σ-Δ modulator, a digital PDM output, and is compatible with Sn/Pb and lead-free soldering processes. It meets the RoHS/WEEE standards.
The ADMP421 is a high‑performance, low‑power, bottom‑ported omnidirectional MEMS microphone with a small 3 mm × 4 mm × 1 mm surface‑mount package. It offers a high signal‑to‑noise ratio of 61 dBA, high sensitivity of –26 dBFS, and a flat frequency response from 100 Hz to 15 kHz, making it suitable for far‑field audio in smartphones, video cameras, and Bluetooth headsets.
The handbook provides detailed specifications such as supply voltage range (0.3 V–3.6 V), normal‑mode current consumption (650 µA) and sleep‑mode current (50 µA), as well as timing characteristics, pin‑out descriptions, PCB land‑pattern guidelines, and typical performance graphs. It also includes revision history, absolute maximum ratings, and handling instructions for reliable integration into designs.
| Sensitivity | -26 dBFS |
|---|---|
| Signal‑to‑Noise Ratio (SNR) | 61 dBA |
| Power Supply Rejection (PSR) | 80 dBFS |
| Supply Current (Normal mode) | 650 µA |
| Supply Current (Sleep mode) | 50 µA |
| Frequency Response | 100 Hz – 15 kHz (flat) |
The device can operate with a supply voltage from 0.3 V to 3.6 V.
The wake‑up time from sleep mode is 10 ms.
The microphone can tolerate a peak acoustic input of 120 dB SPL.