Test strategies for adaptive equalizers

This paper provides an overview of the test strategies for both continuous-time and digitally-assisted adaptive equalizers. Conventionally, an equalizer is characterized by the explicit measurement of the eye diagram at its output, which requires a lengthy testing time and is too costly for production testing. Design for testability and special test stimuli have been developed to facilitate circuit performance characterization and go/no-go production testing. In addition, for digitally assisted adaptive equalizers, digital signatures extracted from the tap coefficients in the digital adaptation unit can be used for performance prediction and fault detection.