Ultra-low bias current design method based on bipolar amplifier and circuit thereof

Abstract

The invention discloses an ultra-low bias current design method based on a bipolar amplifier and a circuit thereof, and relates to a semiconductor integrated circuit. A real-time sampling current elimination design method is adopted, and an amplifier circuit comprises a starting bias circuit, a common-emitter and common-base input differential circuit and a base current compensation core circuit. The starting bias circuit enables the system to get rid of the constraint of a degeneracy point to work normally after a power supply is powered on, and provides a stable direct current bias point for the system after starting is completed; the common-emitter common-base input differential circuit comprises a same-type super-beta NPN transistor differential pair, and achieves the functions of input signal amplification and double-to-single conversion. The base current compensation core circuit comprises a bias current monitoring circuit and a compensation circuit, input geminate transistor base current copying is achieved through a precise current mirror and negative feedback, and base current synchronous compensation is achieved. The problem that an existing current operational amplifier is too large in input bias current and low in weak signal processing precision is solved. The low-bias current operational amplifier is widely applied to the technical field of low-bias current operational amplifiers.

Description

technical field [0001] The present invention relates to a semiconductor integrated circuit, more specifically, to a bipolar semiconductor integrated circuit, in particular, to an ultra-low bias current design method based on a bipolar amplifier and its circuit. Background technique [0002] Bipolar operational amplifier is an extremely important part of analog integrated circuits. Because of its excellent characteristics such as high transconductance current ratio, high gain, low noise, and high linearity, it is widely used in weak signal processing circuits to realize signal addition and subtraction. Operations such as multiplication and division. With the development of high-precision intelligent instruments and meters, it is inevitable to process and calculate weak signals. As the core component of signal processing circuits, operational amplifiers play a vital role in the amplification of weak signals. The market demand will become more and more big. Therefore, the inp...

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problems of excessive input bias current and low precision of weak signal processing in existing low bias current operational amplifiers

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