Testing of mixed signal integrated circuits generating analog signals from digital data elements

Abstract

Testing of a mixed signal integrated circuit (IC) potentially in the form of a die using a tested / calibrated integrated circuit. In an embodiment, the mixed signal IC generates an analog signal from a symbol, and transmits the analog signal to the calibrated integrated circuit. The calibrated IC determines a valid symbol corresponding to the signal level (e.g., voltage) of the received analog signal, and determines a deviation of the signal level of the received analog signal from the voltage level corresponding to the valid symbol. The deviation is deemed to represent the degree of defect of the mixed signal IC based on the assumption that the calibrated IC operates accurately. The deviation is used to either discard or qualify / accept the mixed signal IC.

Description

BACKGROUND OF INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to testing of integrated circuits, and more specifically to a method and apparatus for testing mixed signal integrated circuits which generate analog signals from digital data elements. [0003] 2. Related Art [0004] Mixed signal integrated circuits (IC) generally refer to circuits which operate on both analog and digital signals. [0005] Mixed signal ICs are used in several areas such as communications (both wireless and wire-based) in which digital data elements are converted into analog signals which are eventually transmitted. [0006] A receiving system (using another mixed signal IC) recovers the digital data elements from the analog signals. [0007] Other digital data elements may then be transferred in the reverse direction as well. The data thus exchanged is used to support several user applications (e.g., voice calls, networking), as is well known in the relevant arts. [0008] Testing is...

AI Technical Summary

Problems solved by technology

Thus, the prior approach of above enables testing of a transceiver, potentially when the corresponding IC is not yet packaged (and thus only as a stand-alone wafer). one problem with the approach is that many transceivers use common components in the transmit and receive paths, and simultaneous use of both the paths may not thus be possible.

In addition, loopback approaches often skip some portions / stages of the transmit / receive paths, and the test results may accordingly not be reliable.

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