A high slew-rate OTA with hybrid dynamic current boosting technique

Abstract

This paper presents a high slew-rate operational transconductance amplifier (OTA). The slew-rate enhancement (SRE) circuit is separated into two paths for dynamic current boosting. The main path provides dynamic bias current, while the other auxiliary path applies dynamic current to the output of the core amplifier. Therefore, both the slew rate and the settling response can be improved. By utilizing the hybrid dynamic current boosting technique in a current-mirror amplifier, simulation results show that the average SR is increased by more than 10 times, and the average 1% settling time is reduced by more than 50% with less than 38.6% power consumption overhead. The proposed OTA and two other OTAs using different SRE techniques have been fabricated in a 0.18-µm CMOS process. Measurement results have proved that the proposed design has the best overall performance.