Microphones

Introduction

Some CoCon units have a fixed microphone. This microphone has a unidirectional response for optimum performance even in noisy conditions, and has a very low susceptibility to interference from mobile phones.

Electrical and acoustic properties

Parameter	Description
Transducer type	Back electret (condenser)
Operating principle	Pressure gradient
Polar pattern	Unidirectional, cardioid
Frequency response	130 Hz – 15000 Hz
Nominal impedance	1kOhm (at 1 kHz, drop resistance = 1k2, Vdd = 3.3VDC )
Load impedance	> 5kOhm
Max. SPL at 1 kHz	120 dB SPL
Free field sensitivity	7mV/Pa, +/- 3 dB at 1 kHz or (-43dB, 0dB=1V/Pa at 1kHz)
Power supply	3.3V DC, 0.5 mA
Consumption	0.5 mA (without LED ring); max. 25 mA (with illuminated ring)