Single-Wire Serial Bus Carries Isolated Power and Data

Abstract: An interface circuit uses the Dallas Semiconductor 1-Wire serial bus to provide isolated power and bidirectional communications between a master (MCU) and a sensing element.
Mar 23, 2006

Abstract: An interface circuit uses the Dallas Semiconductor 1-Wire serial bus to provide isolated power and bidirectional
communications between a master (MCU) and a sensing element.

Medical and industrial applications often requiregalvanic isolationof 2500VAC or higher for the safety of patients and equipment
operators. The isolation barrier conveys not only power to the sensing element, but also data to or from that element. Each data
signal crossing the barrier requires isolation, so one typically saves costs in these applications by choosing a serial bus rather than
aparallelbus. Serial buses includeSPI,IC, and the Dallas 1-Wire bus.

The Dallas Semiconductor 1-Wire requires only a single data line (plus ground) for bidirectional communications. Because opto-
isolators