A highly reliable 16 output high voltage NMOS/CMOS logic IC with shielded source structure

A high voltage MOS IC which consists of 16 high voltage NMOS transistor array having 400 V, 0.5 A output characteristic and its control CMOS logic, was newly developed. High and low voltage NMOS transistors of the IC are equipped with shielded source structure to realize completely parasitic bipolar effect-free high voltage MOS ICs. Practically, this IC successfully drove a plasma display panel at 200 V, 2 MHz without any parasitic effect and its high operation reliability was verified. To examine high integration density possibility, parasitic bipolar effects due to the interferences between high and high voltage transistors low and low voltage transistors, and high and low voltage transistors, were experimentally investigated. As a result it was confirmed that the "shielded source structure" realizes high density high voltage MOS ICs.