The LTC4306 is a 4-channel, 2-wire bus multiplexer with bus buffers to provide capacitive isolation between the upstream bus and downstream buses. Through software control, the LTC4306 connects the upstream 2-wire bus to any desired combination of downstream buses. Each channel can be pulled up to a supply voltage ranging from 2.2V to 5.5V, independent of the LTC4306 supply voltage. The downstream channels are also provided with ALERT1-ALERT4 inputs for fault reporting.