A New High-Gain Operational Amplifier Using Transconductance-Enhancement Topology Integrated With Metal Oxide TFTs

This paper presents an integrated operational amplifier (OPAMP) consisting of only n-type metal oxide thin-film transistors. In addition to using positive feedback in the input differential pair, a transconductance-enhancement topology is applied to improve the gain of the OPAMP. The OPAMP has a voltage gain ( $A_{v}$ ) of 29.54 dB over a 3-dB bandwidth of 9.33 kHz at a supply voltage of 15 V. The unity-gain frequency, phase margin (PM), and dc power consumption ( $P_{\mathrm{ DC}}$ ) are 180.2 kHz, 21.5° PM and 5.07 mW, respectively.