Microphone biasing circuitry and method thereof

摘要

The host device has a device connector for forming a mating connection with a respective peripheral connector. A source of bias 102 is arranged to supply an electrical bias to a device microphone contact 117 of the device connector via a biasing path. A capacitor 225 is connected between a reference voltage (ground) node and a capacitor node 304 of the biasing path. A first switch 301 is located between the capacitor node 304 and the device microphone contact 117. Detection circuitry (602, fig 6a) detects disconnection of the peripheral connector and device connector; and control circuitry (601, fig 6a) controls the switch to disable the biasing path within 100µs. This removal of the bias voltage from the connector is said to reduce the occurrence of undesirable clicks or pops. Several embodiments of the invention are discussed.