2014 SID Display Week, San Diego, USA

2014 SID Display Week, San Diego, USA

June 3-6, 2014 (Tuesday - Friday), San Diego Convention Center

 

<Poster Session : P-51>

a-IGZO TFT Based Operational Amplifier and Comparator Circuits for the Adaptive DC-DC Converter

Kichan Kim, Keun-Yeong Choi, Dong-Hyuk Choi, and Hojin Lee

Abstract

In this paper, we present an operational amplifier (op-amp) based on amorphous Indium-Gallium-Zinc-Oxide thin-film transistors (a-InGaZnO TFTs) to achieve a comparator operated by pulse-width-modulation (PWM) control-loop structure, which can be used for dc-dc converter circuits integrated in the display driving system. Based on electrical characteristics of the fabricated a-InGaZnO TFT, we proposed a novel NMOS opamp to achieve the overall gain of 19.2dB. On the basis of the proposed op-amp, we fabricated a-InGaZnO TFT comparator circuit, which could successfully operate at 100 Hz to control the duty ratio from 25% to 75% with the slew rate of 0.625V/μs.