The NCN1154 is a DP3T switch for combined true-ground audio, USB 2.0 high speed data, and UART applications. It allows portable systems to use a single port to pass either USB data or audio signals from an external headset; the 3 channels being compliant to USB 2.0, USB 1.1 and USB 1.0. The switch is capable of passing signals with negative voltages as low as 2 V below ground. The NCN1154 features shunt resistors on the audio ports. These resistors are switched in when the audio channel is off and provide a safe path to ground for any charge that may build up on the audio lines. This reduces Pop & Click noise in the audio system. The device has an extended VCC range which can operate off VCC up to 4.2 V while passing true ground audio signals down to -2 V.