High Performance Digital Microphone

The CS7250B is a low-profile digital microphone optimized for use in both high performance audio systems, as well as low power audio applications, including those with “always-on” voice control. The device incorporates Cirrus Logic’s proprietary CMOS/MEMS membrane technology, offering high reliability and excellent audio quality in a miniature, low-profile package. The CS7250B supports two operational modes selected according to the applied clock frequency. High performance mode offers low noise, wide dynamic range and class-leading THD even with very loud audio. Low power mode offers ultra low current consumption while maintaining excellent SNR. The CS7250B 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)
    • 160 µA (low power mode)
    • 650 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) 160
High Performance Mode Supply Current (µa) 650
Package 3.5 x 2.65 x 0.98 mm

Technical Documents

CS7250B Product Datasheet

May 17, 2017, DS1072PP1 : 434 Kb

CS7250B/57B Product Bulletin

May 17, 2017, n/a : 108 Kb

Design Resources

CDB7250B Demonstration Board Datasheet

May 17, 2017, DS1072DB1 : 277 Kb

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