Operational amplifier, integrated circuit and method for generating internal power supply of operational amplifier

Abstract

The invention discloses an operational amplifier, an integrated circuit and an internal power supply generation method of the operational amplifier. The operational amplifier comprises a first input end; a second input; a first power supply terminal; a second power supply terminal; the operational amplifier comprises an input end, an output end and an internal power supply generation circuit, and the internal power supply generation circuit is configured to generate corresponding third power supply voltage and fourth power supply voltage in different voltage ranges of the first input voltage based on the first input voltage to serve as working voltages of an internal circuit of the operational amplifier. And the voltage difference between the third power supply voltage and the fourth power supply voltage is smaller than or equal to a preset threshold value. In different input voltage ranges, the voltage difference between the third power supply voltage and the fourth power supply voltage which are used as the working voltage of the internal circuit can be kept in a small range, so that even if a part of the operational amplifier adopts low-voltage transistors, the operational amplifier can normally work under high input voltage, and the operational amplifier can normally work under high input voltage. And the area of the chip is saved.

Description

technical field [0001] The invention relates to the technical field of operational amplifiers, in particular to an operational amplifier, an integrated circuit and an internal power supply generation method for the operational amplifier. Background technique [0002] Operational amplifiers are the basis of analog circuits. When an operational amplifier (hereinafter referred to as an operational amplifier) ​​is working, it needs to provide an appropriate working voltage for the devices (such as transistors) in its internal circuit. [0003] In some specific applications, the input voltage range of the op amp is required to be wide, such as from negative high voltage to positive high voltage. In this case, it is difficult to select the power supply for the internal circuit of the op amp. If a fixed power supply voltage is used for direct power supply, it will either not be able to meet the requirements of the full range of the input voltage, or it will lead to two requirement...

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Problems solved by technology

In this case, it is more difficult to select the power supply of the internal circuit of the op amp. If a fixed power supply voltage is used for direct power supply, it will either not be able to meet the change requirements of the input voltage in the full range, or it will lead to the two required by the internal circuit of the op amp. The voltage difference of the power supply voltage is large. If a low-voltage process transistor is used in the design of the operational amplifier, the low-voltage process transistor is directly connected to a high-voltage environment, which is likely to cause problems such as device breakdown and burnout, which seriously affect the integrated circuit chip and corresponding communication. The normal operation of the terminal, and if a high-voltage process transistor is used in the design of the op-amp, the area of ​​the op-amp will increase due to the large volume of the transistor of the high-voltage process

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