Micro-power consumption, high-common-mode voltage and broadband capacitance coupled type isolation amplifying circuit

Abstract

The invention relates to a micro-power consumption, high-common-mode voltage and broadband capacitance coupled type isolation amplifying circuit. VI+ of a differential signal is connected to the third pin of a high-common-mode differential amplifier U1 through a coupling capacitor C2, a potentiometer RW1 and a resistor R2; VI- of the differential signal is connected to the second pin of the high-common-mode differential amplifier U1 through a coupling capacitor C3, a resistor R5 and a resistor R3; the seventh pin of the U1 is connected with a connection point of the capacitor C1 and the R1; the other end of the R1 is connected with a power supply positive electrode VCC; the other end of the capacitor C1 is connected with a power supply negative electrode GND2; the first pin and the fourth pin of the U1 are connected with the power supply negative electrode GND2; after being connected, the fifth pin and the sixth pin of the U1 output a signal Port; after being connected with a resistor R4 and a capacitor C4, the fifth pin and the sixth pin of the U1 are connected to the power supply negative electrode GND2; and, after passing through a resistor R6, the eighth pin of the U1 is connected to the power supply negative electrode GND2.

Description

technical field [0001] The invention relates to the field of signal amplifying circuit design, in particular to the application of high input common-mode voltage. Background technique [0002] In the industrial production process, the monitoring and control of the production process requires the use of various automation instruments, control systems and actuators, and various signal transmissions will occur between them; both weak to millivolt, There are small signals at the milliampere level; there are also large signals of tens of volts, and even super strong signals up to thousands of volts and hundreds of amperes; there are both low-frequency DC signals and high-frequency or pulse peak signals. , Various disturbances (celestial body discharge disturbance, corona spark discharge disturbance, electrical equipment frequency disturbance, induction disturbance, etc.) enter the measurement system through different coupling methods (capacitive coupling, electromagnetic coupling...

AI Technical Summary

Problems solved by technology

Due to the serious low-frequency distortion of electromagnetic isolation during use, complex modulation isolation structure, high power consumption, poor linearity of photoelectric isolation, high power consumption, and easy aging, etc.

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