Dynamic Performance Characterization of Embedded Single-Ended Mixed-Signal Circuits

Abstract

The inherent fault-masking characteristic of the traditional loopback test produces overly pessimistic estimates of device-under-test (DUT) performance, which negatively impacts product yield, although the loopback test provides a promising low-cost test solution. The proposed method overcomes the fault-masking shortcomings of the loopback test for single-ended mixed-signal circuits by accurately characterizing the performance parameters of the individual DUTs, based on the imbalance generation technique of our previous work. Basically, the proposed method is the case study of the previous work to validate the expansibility to a single-ended circuit testing. A sinusoidal stimulus is applied to the DUT, and our loopback configuration converts the external single-ended loopback path to differential mode, in order to generate the phase imbalance between the differential pair. The imbalanced differential signals then switch back to a single-ended mode and stimulate the DUT, in order to introduce the DUT loopback responses of different weight. The nonlinear characteristic equations are then derived to characterize the individual DUT performances. Hardware measurements show that our cost-effective test approach can accurately predict DUT performance parameters.