Analog quantity current output system

Abstract

The invention relates to an analog quantity current output system comprising a rail voltage power supply selection module, a voltage and current conversion module and a voltage comparison module. A first input terminal of the voltage and current conversion module receives a control voltage signal, and a second input terminal of the voltage and current conversion module is connected with the outputterminal of the rail voltage power supply selection module; the voltage comparison module comprises a Schmitt trigger, the first input terminal of the Schmitt trigger is connected with the feedback signal terminal of the voltage and current conversion module, the second input terminal is used for obtaining first reference voltage and second reference voltage, and the output terminal is connectedwith the control terminal of the rail voltage power supply selection module to output a voltage control signal for controlling the output voltage of the rail voltage power supply selection module based on a comparison result of the feedback signal, the first reference voltage and the second reference voltage; the rail pressure power supply selection module is used for outputting rail voltage changing along with the output voltage of the Schmitt trigger to the voltage and current conversion module. The system has the advantages of being low in cost and small in size.

Description

technical field [0001] The invention relates to the technical field of integrated circuits, in particular to an analog current output system. Background technique [0002] The analog current (such as 4mA~20mA) output system is often used to drive and control the actuators of the production site and public works, and the general driving voltage is 24V. Due to the different actuators, their impedances are different. In the process of driving and controlling the actuator by the output current, when the product of the input impedance of the actuator and the output current is small, it will cause a voltage drop inside the analog current output system. It is so large that a large amount of power is consumed inside the analog current output system, especially on the voltage regulator tube, which not only causes a lot of waste of electric energy, but also greatly increases the internal temperature of the analog current output system, greatly Shorten the life of electronic component...

AI Technical Summary

Problems solved by technology

However, the existing method must have a voltage adjustment module and a voltage regulator feedback voltage output module

Among them, the adjustable voltage output module needs a series of components such as power chips and inductors, and has high requirements for load adjustment performance, which may easily cause instability of the feedback output module.

At the same time, because of the large circuit scale and high cost, it is not conducive to the future trend of miniaturization and low cost of circuit scale.

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