Current controlled full-balance differential current transmitter

Abstract

A current controlled fully balanced differential current conveyor has electronic control ability, and can better inhibit common mode signals. The invention consists of two pairs of voltage differential voltage input ends Y1, Y2, Y3 and Y4 with high input impedance, a pair of differential voltage tracking ends Xp and Xn, a pair of current output ends with the same phases Z1p and Z2p and a pair of current output ends with opposite phases Z1n and Z2n. A circuit controls a relationship of the voltage at the Xp and Xn ends and the input end of differential voltage by adjusting a bias current IB, which is expressed as follow: VXp=VY3 + (VY1-VY2) + IXp*RX, VXn=VY4-(VY1-VY2) + IXn*RX, wherein Rx=(4W25 / L25 * (kpL26IB / W26)<1 / 2>)<-1> represents the control resistances of the Xp and Xn. The circuit introduces a common mode inhibition circuit, and reduces or even eliminates the influence of the common mode signals as much as possible. The parameters (quality factors and natural frequencies) of a current mode filter composed of the current conveyor have electronic tuning characteristics. The circuit can greatly inhibit the common mode signals, conveniently control the circuit parameters, have characteristics of low voltage and low power consumption, and have good effects on aspects of simplifying structure, lowering the power consumption, expanding the frequency domain and reducing the noise or the like.

Description

Technical field [0001] The technology relates to a differential current transmitter, in particular to a CMOS second-generation current transmitter with electrical control properties that can effectively suppress common mode signals, and belongs to the field of analog integrated circuits. Background technique [0002] The second generation current conveyor (CCII) is a circuit block proposed by A.S.Sedra and K.C.Smith in 1970. figure 1 Is the circuit symbol of the second-generation current conveyor, such as figure 1 As shown, the second-generation current conveyor has a current input terminal X, a voltage input terminal Y, and a forward current output terminal Z + , A reverse current output terminal Z - . The transmission characteristics of this second-generation current conveyor are as follows: [0003] (1) Y input terminal is high impedance input terminal, its input current is zero, I Y =0; [0004] (2) Voltage V applied to Y input Y , Then the voltage at the X terminal is equal to ...

AI Technical Summary

Problems solved by technology

However, in analog-digital hybrid circuits, since non-ideal signals are easily generated, and digital circuit blocks generate noise due to clock signal feeding and charge injection

This noise not only affects the digital circuit module, but also affects the analog circuit part and the radio frequency circuit part through substrate crosstalk, circuit coupling, etc., and the second-generation current transmitter cannot provide a good ability to suppress interference signals. In addition, it cannot pass through The external current is used to control its port characteristics, that is, the parameters of the CCII cannot be adjusted by the external bias current or voltage, so that the application of the second-generation current transmitter and the filter circuit formed by it is greatly restricted.

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