A Charge-Sensing-Capable Source Driver for TFT Array Testing in System-on-Panel Displays

Inside a modern flat-panel display, the TFT array acts as the analog memory that stores the image information. To ensure high overall yield, it is crucial to thoroughly test the TFT array before it enters the assembly line. However, TFT array testing gets complicated in systemon-panel displays because the peripheral circuits integrated on the same substrate as the array limit the access to the array’s inputs and outputs. This paper presents a builtin source driver design to facilitate TFT array testing for system-on-panel displays. In addition to writing data to the TFT array pixels, the proposed source driver is capable of executing the charge-sensing test and serial read-out of the charge-sensing results—both help reduce the required test equipment performance and complexity. The proposed source driver has been designed in LTPS technology. Circuit simulation results are shown to validate its performance.