Rutgers, the State University of New Jersey

Rajesh Ramadoss

Michael L Bushnell

The present invention relates to a method and apparatus for testing analog and mixed analog and digital circuits in which test waveforms are generated for testing the analog circuit. The analog circuit can be represented by a directed circuit graph. The directed circuit graph represents nodes of components of the circuit under test connected by directed edges for components having inputs or outputs which effect other components and undirected edges for components in the circuit that are bidirectional. For example, undirected edges are assigned to bidirectional elements such as resistors and capacitors and directed edges are assigned to transistors. The directed graph is partitioned into partitions that carry a signal from the primary inputs toward the primary outputs in the circuit under test. Feedback and local feedback are captured in a single partition. The partition of a faulty component is determined and the operating point of the partition is established to activate the fault. The fault effects on the transfer function of each partition are determined by fault sensitization and fault effect propagation.

Test generation for analog circuits using partitioning and inverted system simulation

The present invention relates to a method and apparatus for generating test patterns to test an analog or mixed signal circuit. A signal flow graph of the analog circuit is determined. The signal flow graph is inverted and reverse simulated with good and bad outputs to determine component tolerances of the circuit given circuit output tolerances. The inverted signal flow graph is backtraced from analog outputs to obtain analog input sinusoids which justify the analog outputs.

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Piscataway, NJ, United States of America

Rajesh Ramadoss