High Performance SoundWire Microphone

The CS7257B is a low profile digital microphone with SoundWire® interface optimized for use in high performance audio systems, as well as low power audio applications featuring “always-on” voice control. The CS7257B is manufactured using Cirrus Logic’s proprietary CMOS/MEMS membrane technology offering high reliability and excellent audio quality in a miniature, low profile package. The device incorporates a SoundWire interface compatible with the MIPI SoundWire bus interface and incorporates two operational modes that can be selected according to the applied clock frequency. High performance mode offers a low noise, wide dynamic range, plus class-leading THD even with very loud audio. Low power mode offers ultra low current consumption while maintaining excellent SNR. The CS7257B offers tight tolerance on the microphone sensitivity, giving reduced variation between parts and removing the need for in-line production calibration of part-to-part microphone variations.

Features

  • High SNR (66 dB)
  • High AOP (131 dB SPL)
  • Excellent THD (1% at 125 dB SPL)
  • 35 Hz low frequency rolloff
  • Low current consumption
    • 5µA (Sleep)
    • 260 µA (low power mode)
    • 770 µA (high performance mode)
  • PDM digital audio output
  • Proprietary ADC technology
    • Reduced clock-jitter sensitivity
    • Low noise floor
    • Stable in overload condition
  • Bottom Port LGA Package

Parametric Specifications

Port Bottom
Voice Mode SNR (dB) 62
Record Mode SNR (dB) 66
AOP at 10% THD (dB SPL) 131
Sensitivity (dBV/Pa) -36
Sensitivity Tolerance +/- 1
Power Supply (V) 1.62-1.98
Low Power Mode Supply Current (µa) 260
High Performance Mode Supply Current (µa) 770
Package 3.5 x 2.65 x 0.98 mm

Design Resources

WAN_0284 General Design Considerations for MEMS Microphones

Jan 6, 2016, WAN0284 rev 1.2 : 506 Kb

WAN_0263 Interfacing WM72xx Digital Microphones

Nov 5, 2015, WAN0263 rev 1.2 : 326 Kb

WAN_0273 MEMS MIC Assembly and Handling Guidelines

Nov 5, 2015, WAN0273 rev 1.3 : 624 Kb

WAN_0285 Microphone Power Gating

Nov 5, 2015, WAN0285 rev 1.1 : 508 Kb

WAN_0290 An Introduction to MEMS Microphone Specifications

Jun 15, 2015, WAN0290 rev 1.0 : 538 Kb

Applications

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Comprehensive Solutions