High-voltage CdSe-Ge TFT driver circuits for passive AC-TFEL displays

Since an electroluminescent display (ELD) is a capacitive display driven at high voltage, it is necessary to fabricate high-voltage, large-current drivers. It is shown that a 20-/spl mu/m complementary CdSe-Ge thin-film transistor technology can be used to integrate the high-voltage section of the drive circuits on the substrate of an ELD. The realized column driver levels a 15 V CMOS signal up to a modulation voltage of 50 V. A novel tristate row driver circuit, which is based on the symmetric character of the thin-film transistor, handles row selecting voltages of about 200 V together with current pulses of approximately 100 mA. In this paper, the design, simulation, and measurement of these circuits are described. Technology problems due to high voltages were solved.