Abstract: An on-chip analog to digital converter (ADC) test circuit comprises a waveform generator for developing a known arbitrary waveform. A switch selectively connects the waveform generator to the ADC in a test mode or an internal analog input to the ADC in an operate mode. In the test mode the ADC develops a known sequence of digital codes. A signature register is connected to an output of the ADC for receiving and compressing the sequence of digital codes during the test mode. The register develops a single compressed signature representative of the entire ADC digital output sequence. The compression method may be used to test ADC monotonicity, linearity, and that there are no missing codes.

Abstract: A method and structure for testing an A to D converter containing a plurality of discrete components is provided. The testing methodology includes dividing the circuit into a number of segments of the discrete components (for testing purposes only) with each segment having the same number of discrete components or an unequal but known number of discrete components. The value of the components individually and collectively of each segment is tested and compared with the value of the corresponding components of at least one other segment, and an output signal is generated of the compared value of the segments being tested. Preferably, the components are in a ladder configuration and are either resistors or capacitors.