49.35 MHz GBW and 33.43 MHz GBW amplifiers in flexible a-IGZO TFT technology

Abstract

The authors present the implementation of two amplifiers in a commercial flexible amorphous Indium Gallium Zinc Oxide (a-IGZO) thin-film transistor (TFT) technology: a Cherry Hooper (CH) amplifier and a 4-stage common source amplifier. The CH amplifier is designed as a pre-amplifier for wireless receivers. It is optimised for a high gain-bandwidth product (GBW). From a supply voltage of VDD = 8 V it provides 19.4 dB gain and has a −3 dB-bandwidth of 5.3 MHz, while consuming 0.2 mW. It has a GBW of 49.35 MHz, which is more than a factor two better than previously reported a-IGZO TFT amplifiers. The 4-stage common source amplifier is designed as output buffer, has a very wide range of operating conditions and strong robustness against manufacturing tolerances. From a supply voltage of VDD = 8 V it provides 28.9 dB gain, has a −3 dB-bandwidth of 1.2 MHz, and a GBW product of 33.43 MHz, while consuming 14.2 mW. Both circuits can operate from a supply voltage between 2.5 and 10 V.