Operational amplifier circuit and method implementing the same

摘要

The disclosure provides an operational amplifier circuit, in which a power supply of an amplifying circuit is coupled to a first voltage clamping circuit, and the first voltage clamping circuit clamps a supply voltage of the amplifying circuit when the supply voltage exceeds a normal-operation allowable voltage of the amplifying circuit. The disclosure also provides a method for implementing the operational amplifier circuit. According to the disclosure, the operational circuit may be avoided from subject to an excessive supply voltage, which may damage devices in the amplifying circuit of the operational amplifier.

主权项

1. A system comprising:
a first voltage clamping circuit; and an amplifying circuit, wherein the first voltage clamping circuit is coupled to a power supply of the amplifying circuit, and is configured to clamp a supply voltage of the amplifying circuit when the supply voltage exceeds a normal-operation allowable voltage of the amplifying circuit, and wherein the first voltage clamping circuit comprises a first N-type metal oxide semiconductor field-effect transistor (NMOS) and a first P-type metal oxide semiconductor field-effect transistor (PMOS) coupled in a cascode structure.