Enhanced current mirror circuit by dual‐gate coplanar amorphous InGaZnO TFTs

Abstract

In this brief report, we state current mirror (CM) circuit employed by coplanar amorphous indium–gallium–zinc oxide (a‐IGZO) thin‐film transistors (TFTs) with dual‐gate structure. The 2‐TFT conventional structure with different mirroring ratios and 4‐TFT cascode type are investigated. We compared the CM circuit performances made of the dual‐gate (DG) and single‐gate (SG) TFTs. At higher mirror gain, the percentage of error increases due to the issues such as TFT performance uniformity and threshold voltage shift. It is found that the DG‐based CM circuit shows excellent mirror gain even at 10× with only 2% error.