A 30-V row/column driver for flat-panel liquid crystal displays

An 80-output row/column driver has been developed for flat-panel liquid crystal displays (LCDs) using multiplex rates of up to 1:300. A p-well polysilicon-gate CMOS process was enhanced to provide 30-V p-channel and 15-V n-channel transistors using double-diffused drains. By means of a cascode circuit structure, voltage capability on the n-channel side was boosted to 30 V. Parasitic surface channels were avoided by a systematic approach to high-voltage layout. Important circuit features include low power consumption, display border control, and overtemperature protection. Chip size is 25.65 mm/sup 2/. Packaging in an 18.6 mm*15.2 mm, three-sided, 120-lead, tape-automated-bonding module is optimized for wiring on single-sided assembly substrates.<
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