Open AccessHigh current operational amplifier with current limiting protection circuit
Author(s) -
Wang Yang,
Ding Liqiang,
Bao Zhanying,
Yang Hongjiao,
Jin Xiangliang
Publication year - 2020
Publication title -
iet circuits, devices and systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.251
H-Index - 49
eISSN - 1751-8598
pISSN - 1751-858X
DOI - 10.1049/iet-cds.2019.0289
Subject(s) - operational amplifier , current limiting , amplifier , current feedback operational amplifier , direct coupled amplifier , electrical engineering , operational transconductance amplifier , overcurrent , capacitance , current (fluid) , computer science , engineering , physics , cmos , electrode , quantum mechanics
In this work, a class‐AB operational amplifier is to be presented, which is developed in a 0.5 μm CDMOS technology. The proposed amplifier is composed of a folded cascade input stage and a class‐AB output stage. Owing to the special design of the operational amplifier, the robustness of the whole circuit has been enhanced. The proposed system can drive a wide resistance load range from 10 Ω to 100 kΩ with a 10 pF capacitance load without distortion and stability problems. In addition, a current‐limit technique that stems from the design of a low dropout linear regulator is adopted to protect the output stage of the operational amplifier from being damaged by a huge transient current under unexpected conditions (when the output terminal is shorted to ground or V DD ). Measurement results show that the maximum output current is nearly 390 mA with an 800 mA DC current limiting protection circuit on the single 5 V power supply at room temperature. This design can stably work at the industrial temperature range from −40 to 125°C. What is more, the total static current consumption of the whole circuit is 624 μA and the chip area is 0.419 mm 2 .