Driver Circuit

Summary

Transistors are also used in active‐matrix (AM) flat‐panel displays (FPDs). In an AM display, the backplane comprises a glass substrate on which the thin‐film transistors (TFTs) are formed. Amorphous silicon (a‐Si) TFT, low‐temperature polysilicon (LTPS) TFT, and oxide semiconductor field‐effect transistor (FET) typified by indium–gallium–zinc oxide (IGZO) are used as active layers of the backplane. This chapter explains a gate driver and a source driver, followed by a demultiplexer circuit using c‐axis‐aligned (CAAC) IGZO. AM FPDs are defined by their driving method and applications. Two important devices for all types of AM FPD are: the source‐driver integrated circuit (IC), which drives the pixel data lines for, e.g., LCDs and organic light‐emitting diode (OLED) displays, and a demultiplexer (DEMUX) circuit, which connects the panel and the source driver. The chapter describes the DEMUX circuits, followed by digital‐to‐analog converters (DACs) and amplifiers for 8‐ and 12‐bit‐driver ICs, and then finally discusses fulldriver ICs.