Sigma-delta modulation based wafer-level testing for TFT-LCD source driver ICs

Output variation testing of TFT-LCD source driver ICs is very expensive and time-consuming due to the large amount of analog output channels and levels to measure. This paper presents a low-cost on-scribe-line BIST technique for wafer-level source driver IC testing. Based on the BIST structure and the sigma-delta modulation principle, we propose a two-stage test flow and construct a generalized test cost function to find the optimal test setup parameters.