TEST SIGNAL GENERATING CIRCUIT OF THIN FILM TRANSISTOR-LIQUID CRYSTAL DISPLAY MODULE

摘要

PURPOSE: A test signal generating circuit of a thin film transistor-liquid crystal display module is provided to generate a test signal used for testing instantaneous voltage drop in the event of mode conversion or output of radio-frequency data in a TFT-LCD module driving system. CONSTITUTION: A test signal generating circuit of a thin film transistor-liquid crystal display module includes a waveform generator(10) and a test signal generator(20). The waveform generator has a timer IC(12) that generates an AC signal waveform determined by a time constant of resistors and capacitors. The test signal generator is composed of an operational amplifier(22), the first and second voltage sources(VDD1,VDD2). The operational amplifier amplifies the AC signal waveform to a DC level controlled waveform to generate a test signal. The first and second voltage sources adjusts a DC level for the operational amplifier.