Single-power-source isolation amplifier

Abstract

The invention provides a single-power-source isolation amplifier which comprises a photoelectric coupling tube T1A, a photoelectric coupling tube T1B, an operational amplifier A, a direct-current power source VCC, five resistors, an adjustable resistor, a capacitor C1 and a capacitor C2. One end of the resistor R1 is connected with an anode of the photoelectric coupling tube T1A, an emitting electrode of the photoelectric coupling tube T1A is grounded through the resistor R2 and the capacitor C1 and connected with an anode of the operational amplifier A through the resistor 3, an emitting electrode of the photoelectric coupling tube T1B is grounded through the resistor R5 and the capacitor C2 and connected with a cathode of the operational amplifier A through the resistor R4, an output end of the operational amplifier A is connected with an anode of the photoelectric coupling tube T1B, a cathode of the photoelectric coupling tube T1B is connected with one end of the adjustable resistor RW, and the other end of the adjustable resistor RW is grounded. The single-power-source isolation amplifier has the advantages of simple structure, high reliability and low cost.

Description

technical field [0001] The invention relates to an amplifier, in particular to a single power supply isolation amplifier. Background technique [0002] In the field of data acquisition, because some acquisition objects are in a high-voltage environment, for the sake of safety and reliability, the data processing chip is often electrically isolated from the acquisition object; figure 1 As shown, the existing isolation amplifier is designed as an amplifier in the form of electrical isolation. Part B of the amplifier is connected to the data processing chip U1 and powered by the internal power supply VCC. Part A of the amplifier is connected to the object under test JC and powered by a DC isolated power supply U2. . [0003] At present, most of the common isolation amplifiers adopt the above-mentioned circuit structure, and the so-called single-supply isolation amplifiers on the market actually integrate the DC isolation power supply into the amplifier chip or module. In actua...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the common isolation amplifiers adopt the above-mentioned circuit structure, and the so-called single-supply isolation amplifiers on the market actually integrate the DC isolation power supply into the amplifier chip or module. In actual use, it is not difficult to find that: Each isolated amplifier needs a separate DC isolated power supply, which inevitably has the problems of complex circuit structure, reduced reliability, and increased cost; in order to solve the above problems, people have been looking for an ideal technical solution

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