Patent attributes
A dual-wire communications bus circuit, compatible with existing two-wire bus protocols, includes a first and second part of the communications bus circuit to couple to a communications bus. The bus has a first line for carrying data signals from a master device to one or more slave devices and a second line to carry a clock signal between the devices. A pullup resistor is located in each part of the communications bus circuit; the pullup resistor in the first part couples to the first line of the communications bus and the pullup resistor in the second part couples to the second line of the communications bus. To improve data throughput and reduce noise, an active pullup device, working in conjunction with the pullup resistor, is located in each part of the communications bus circuit, providing a high logic level on at least one of the communications bus lines.
