CONSTANT VOLTAGE APPROACH TO CONDENSER MICROPHONE BIASING
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2001-Oct-30
The conventional way of biasing a condenser microphone is using a resistor to the supply voltage. This scheme is simple, but has several disadvantages such as poor supply line noise rejection, loss of microphone sensitivity due to the voltage divider formed by the microphone's internal impedance at the signal frequency and the bias resistor, and larger variation in microphone sensitivity due to variation in bias voltage caused by variation in the required bias current between microphones.