GENERAL DESCRIPTION
The MAX14627/MAX14628 provide a simple solution for detecting the insertion and managing the operation of a 3.5mm stereo headset with a microphone. These devices integrate all circuitry needed to detect SEND/END button press events and generate required microphone bias voltages, and are fully compatible with Windows Mobile 7. The devices need only three GPIOs from the host controller to select between call mode and standby mode, and monitor the SEND/END and jack insertion status. In call mode, the low-noise LDO is enabled to provide DC bias to the externally preamplified microphone. In standby mode, microphone low-power pulsing is enabled to reduce supply current while waiting for a SEND/END button press event. Two open-drain outputs signal the host controller when an insertion/removal or SEND/END button press event occurs. If a 3P headset without a microphone is inserted, the low-power pulsing can be disabled by setting the MODE input to high impedance. Additionally, the MAX14628 features open microphone detection.
Maxim Integrated
