A High Performance Operational Amplifier Using Coplanar Dual Gate a-IGZO TFTs

Abidur Rahaman,Md Mehedi Hasan,Yuanfeng Chen,Jin Jang

doi:10.1109/jeds.2019.2923208

Abidur Rahaman, Md Mehedi Hasan + Show 2 more

Open Access

https://doi.org/10.1109/jeds.2019.2923208

Copy DOI

Abstract

We fabricate an operational amplifier (op-amp) composed with the coplanar amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs). The circuit consisted of 19-TFTs and designed on a glass substrate in both dual gate (DG) and single gate (SG) structure for performance evaluation. Having the yield of a total voltage gain ( $A_{v}$ ) of 23.5 dB, a cutoff frequency ( $f_{c}$ ) of 500 kHz, a unit gain frequency ( $f_{\mathrm{ ug}}$ ) of 2.37 MHz, gain-bandwidth product (GBWP) of 7500 kHz, a slew rate (up/down) of (2.1/1.2) V/ $\mu \text{s}$ , and a phase margin (PM) of 102° at a supply voltage of ±10 V, the fabricated DG TFT op-amp demonstrates good performance among all a-IGZO-based literature.

Highlights

Amorphous–indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) and related circuits are becoming a potential player in the vast analog and digital electronics industry
This paper presented a coplanar dual gate (DG) a-IGZO TFT based opamp for the first time
With a voltage gain (AV) of 23.52 dB, a cutoff frequency of 500 kHz, a unit gain frequency of 2.37 MHz and phase margin (PM) of 102◦, the DG coplanar op-amp stands as the best performer among the concurrent a-IGZO technology

Summary

Introduction

Amorphous–indium-gallium-zinc-oxide (a-IGZO) TFTs and related circuits are becoming a potential player in the vast analog and digital electronics industry. A-IGZO TFT op-amp reports are handful [6], [10]–[12], [15] in comparing to CMOS counterpart. We fabricate the op-amp using coplanar SG and DG TFTs while all other reports [10]–[13], [15] used SG inverted staggered structure.

Results

Conclusion