Field-testable integrated circuit and method of testing

摘要

A field-testable integrated circuit that includes a plurality of analog signal channels for receiving a respective analog signal during a normal mode of operation is provided. Individual test circuits are built-in within the integrated circuit for selecting respective ones of the plurality of channels to receive predetermined reference signals during a test mode of operation while uninterruptedly providing the normal mode of operation in any remaining unselected channels. Each test circuit includes a channel decoder responsive to predetermined channel select signals for producing a respective channel decoder output signal. A multiplexer is responsive to predetermined reference select signals and to the decoder output signal for supplying during the test mode of operation a selected one of the predetermined reference signals to the respective analog channel being coupled to the individual test circuit therein. A switching gate is responsive to the respective channel decoder output signal so that during the normal mode of operation the switching gate is in a respective conducting state for allowing the respective analog signal to pass therethrough while during the test mode of operation the switching gate is in a respective nonconductive state for interrupting the respective analog signal from passing therethrough.