What is Microphone Bias Voltage?

Microphone bias voltage is the voltage that a microphone needs in order to power on and and record sound.

Without this voltage, a microphone wouldn't have the power to record sound and wouldn't function at all. It is the same concept as any electronic device, such as a gameboy or flashlight, needing batteries to function. Without the batteries, without the power, it can't turn on and do its task.

Bias Voltage

Bias voltage is the voltage that a device and needs and is designed to receive in order to function properly.

In the case of microphones, it is the voltage that a microphone is supposed to receive in order to be able to power on and record signals at full levels.

Microphone Bias Power

Microphones usually need about 2 volts in order to power on. However, check your datasheet for the power requirements of the microphone in use to be sure of the bias voltage needed for operation.

When designing a microphone circuit, be sure that the microphone receives this level of power. If a microphone receives lower than this amount of power, it may not be enough power for it to sufficient record signals. Thus, you may get clipped signals and, otherwise, weak signals. If a microphone receives too much power, it may be destroyed by the excess voltage. Thus, it's important to design to receive just around its rated voltage.