A novel CMOS high accuracy fast speed OTA for switched-capacitor filters

Abstract

A novel high accuracy fast speed operational transconductance amplifier (OTA) for switched-capacitor filters in 0.35µm CMOS technology is presented in this paper. The proposed OTA employs nonlinear current mirror and cross-pair structure to enhance the DC, AC and transient performance. Both simulation and experimental results are presented to show the performance boosting of the proposed OTA. Under the condition of 33µA quiescent current and a 30pF load capacitance, the experimental results of the DC gain, Gain Bandwidth, positive and negative slew rate have achieved as high as 62.5dB, 4.9MHz, 6.3V/µs and 8V/µs, respectively. Both GBW and SR are boosted more than one order compared to the conventional OTA.