Electric power bias circuit with negative feedback

Abstract

The invention relates to electrical source biasing circuit with negative feedback. It includes biasing generating circuit, mirror image branch circuit, feedback branch circuit, current output branch circuit. The biasing generating circuit is formed by electrical source I1, I2, NOMS tube n1, n2, used to generate bias current. The mirror image branch circuit is formed by PMOS tube p1 and NMOS tube n3, used to image the current to output branch circuit. The feedback branch circuit is formed by electrical source I3, equivalent switch, used to generate current feedback quantity, adjust bias current. The current output branch circuit is formed by PMOS tube p5, used to output stable bias current. The invention fixes the indifferent bias on the fixed value, can stabilize output bias current, and reduce source voltage sensitivity better compared with the existing current bias circuit. It inducts negative feedback, makes output bias current have higher precision by adjusting current in bias generating circuit.

Description

technical field [0001] The invention belongs to the field of analog integrated circuits, and in particular relates to a power supply bias circuit with negative feedback, which can effectively provide a bias current irrelevant to the power supply. Background technique [0002] With the development of society, people have higher and higher requirements on the performance of consumer electronic products. This puts higher and higher performance requirements on corresponding consumer ICs. The function of the bias circuit is mainly to provide suitable bias current for other working modules to determine the quiescent operating point of the amplifier. A high-quality bias circuit is usually required inside an integrated circuit to provide a stable bias current. For multi-channel integrated op amps, due to the basic use of a common bias circuit, it is even necessary to consider the mutual crosstalk between adjacent channels. [0003] The existing power-independent bias circuit usua...

AI Technical Summary

Problems solved by technology

[0004] In the classic book "Analog CMOS Integrated Circuit Design" published by Xi'an Jiaotong University Press and translated by Chen Guican and others, page 311 describes a power bias circuit, but it does not have any feedback circuit , so its power supply rejection ratio cannot achieve a higher accuracy, making it still unable to meet the requirements in high-precision applications

Moreover, it requires an additional startup circuit, and the cost performance of the overall structure is not high

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