Metal-oxide-semiconductor circuit designs and methods for operating same

Abstract

Complimentary Metal-Oxide-Semiconductor (CMOS) circuits made with core transistors are capable of reliable operation from an IO power supply with voltage that exceeds the reliability limit of the transistors. In embodiments, biasing of an operational amplifier is changed in part to a fixed voltage corresponding to the reliability limit. In embodiments, switched capacitor networks are made with one or more amplifiers and switches including core transistors, but without exposing the core transistors to voltages in excess of their reliability limit. In embodiments, operational transconductance amplifiers (OTAs) include core transistors and operate from IO power supplies. Level shifters for shifting the levels of a power down signal may be used to avoid excessive voltage stress of the OTAs' core transistors during turn-off. Non-level shifting means may be used to clamp output voltages and selected internal voltages of the OTAs, also avoiding excessive voltage stress of the core transistors during turn-off.