Single wire bus interface for multidrop applications

Abstract

The present invention enables data communications between multiple devices over a single wire bus. This single-wire interface can be used for sensors, amplifiers, analog-to-digital converters (ADCs), or any other circuit which would normally have an electrical output. Advantages of the present invention include a reduction in device pin count, conservation of the limited number of I/O pins on the control device, and reduced board layout complexity. Speaking generally, each slave device coupled to the single wire bus interface is assigned a different response time window. This enables multiple slave devices to respond to an initial trigger signal generated by the master device without overlapping responses being generated on the single wire bus interface. A suitable slave electrical device includes application circuitry providing state information for the electrical device, an input/output pin suitable for making an electrical coupling external to the electrical device, and a single wire bus interface coupled to the input/output pin and the application circuitry. The single wire bus interface has conversion function circuitry defining a specific response time window for the electronic device. Further, the single wire bus interface is responsive to a start signal received on the input/output pin to generate a response signal within the specific response time window, the response signal indicative of the state information for the electrical device.