Conversion circuit using common base as preceding stage V/I and post stage I/V

Abstract

The invention discloses a conversion circuit adopting a common base as a preceding stage V / I and a backward stage as I / V. (1) since the differential input stages in the analog amplifier are all composed of common-emitter circuits, the high-frequency and high-speed development of input signals is hindered, so that the input stage circuit composed of the common-base circuits is designed, we know that the fT bandwidth under the same tube common-base connection method is increased by beta times of the tube itself compared with the fT bandwidth under the common-emitter connection method; and a broadband and high-speed circuit can be designed by utilizing the advantage of the common-base circuit. And (2) a post-stage I / V conversion circuit is adopted, in an analog amplifier, in order to reduce crossover distortion caused by large-current push-pull of a tail tube, the static current of the tail-stage push-pull tube is generally designed to be a class A, but the static current of the tail-stage push-pull tube is designed to be a class B by only giving any crossover distortion to the small static current of the tail tube, so that the cost is saved, but the tone quality is obviously influenced, and the cost is reduced. Therefore, a super-A-class circuit is designed, the super-A-class circuit is composed of a common-base circuit, and crossover distortion can be eliminated only through B-class static current. The cost is reduced, and energy is saved. The invention belongs to the field of analog electronics for high-speed circuits or audios.

Description

technical field [0001] The present invention relates to (1) V / I that has common base input stage; The input stage replaces the common-emitter differential input stage; (2) the post-stage is used to eliminate the crossover distortion super class A circuit. [0002] It belongs to analog electronic technology, mainly used in high-speed circuit or audio field. Background technique [0003] (1) At present, in the digital age, circuits are developing towards high frequency and high speed. The analog circuits connected with digital circuits in the past can no longer adapt to the development of the current era. This is because the differential input amplifier circuits in the analog amplifier circuits are all composed of Composed of common emitter circuits, it hinders the development of input signals to high frequency and high speed. We know that f under the same tube common base connection T Than the f under cascode connection T , the bandwidth is increased by β times of the tube...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the frequency bandwidth problem caused by the design of the common-emitter differential circuit at present, the present invention (1) designs the non-inverting input terminal V / I composed of the common-base circuit, and the large-loop common-base current negative feedback conversion circuit of the inverting input terminal , which solves the problem of narrow operating frequency band of the current common-emitter differential circuit, and achieves the purpose of improving the bandwidth of the input stage

And the I / V of the rear stage of the present invention (2) uses the common base circuit to make the static large current of the class A final stage tube become the static small current of the class B final stage tube, and the performance is equivalent to the circuit of the class A, which solves the problem caused by the class B The problem of crossover distortion caused by the static small current of the final tube

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