High-Gain Operational Transconductance Amplifiers in a Printed Complementary Organic TFT Technology on Flexible Foil

This paper presents the design and experimental results of advanced analog blocks manufactured in a printed complementary organic TFT technology on flexible foil. Operational transconductance amplifiers exhibiting open-loop gain from 40 to 50 dB and gain-bandwidth product from 55 Hz to 1.5 kHz have been implemented by using different circuit topologies. An extensive amplifier characterization in both time and frequency domain (i.e., gain, gain-bandwidth product, phase margin, settling time, harmonic distortion) has been carried out, which demonstrates the performance of the adopted technology in analog circuit implementations. Finally, a 40-dB 1.5-kHz amplifier has been employed in a switched capacitor comparator that proved fully functionality up to input frequency of 50 Hz.