Common-ground multi-output branch high-end current sampling circuit structure

Abstract

The utility model discloses a common-ground multi-output-branch high-end current sampling circuit structure, which comprises a plurality of current branches, the plurality of current branches share a common-ground bus, each current branch comprises a high-end shunt sampling unit connected to the high end of an output branch, and a high-end shunt sampling unit connected to the high end of the output branch. The output end of the high-end shunt sampling unit is connected with a current signal isolation processing unit, the output end of the current signal isolation processing unit is connected with the input end of a differential amplification unit, and the output end of the differential amplification unit outputs current sampling signals. A common ground bus is shared by a plurality of current branches, and a diverter is arranged at the high end of each current branch, so that accurate sampling of currents of a plurality of output branches is realized. Meanwhile, through the processing of the current signal isolation processing unit and the differential amplification unit, the accuracy and stability of current sampling are improved, the circuit design is simplified, the cost is reduced, and the reliability and efficiency of current sampling are improved at the same time.

Description

Technical Field

[0001] This utility model belongs to the field of power electronic system technology, and in particular relates to a common-ground multi-output branch high-end current sampling circuit structure. Background Technology

[0002] In the fields of power electronics systems and automation control, accurate current sampling is a crucial step in ensuring stable system operation and efficient control. Traditional current sampling methods often employ low-end current sampling, which involves acquiring the current signal at the low end of the load through a resistor or shunt. However, this method has limitations in situations with multiple output branches sharing a common ground, as it cannot achieve simultaneous and accurate sampling of the current from multiple output branches.

[0003] Furthermore, existing high-end current sampling solutions often suffer from problems such as large sampling device size and limited accuracy and linearity. Large sampling devices not only increase the overall size and weight of the system but also limit its application in space-constrained environments. At the same time, insufficient accuracy and linearity can lead to inaccurate sampling results, affecting the system's control accuracy and stability.

[0004] To overcome these limitations, the industry has been exploring more advanced and efficient current sampling technologies. While some high-end current sampling schemes have improved sampling accuracy and linearity to some extent, they often come at the cost of reduced size and flexibility. These schemes are often complex in structure, costly to design, and difficult to adapt to the needs of different application scenarios. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a common-ground multi-output branch high-end current sampling circuit structure. This structure solves the problems of large sampling device size, limited accuracy and linearity, and the inability to achieve common-ground multi-output branch current sampling when using low-end current sampling.

[0006] To achieve the above objectives, the utility model employs the following technical solution: a common-ground multi-output-branch high-side current sampling circuit structure, comprising: multiple current branches, the multiple current branches sharing a common-ground bus, each current branch including a high-side shunt sampling unit connected to the high end of the output branch, the output terminal of the high-side shunt sampling unit being connected to a current signal isolation processing unit, the output terminal of the current signal isolation processing unit being connected to the input terminal of a differential amplifier unit, and the output terminal of the differential amplifier unit outputting a current sampling signal.

[0007] The proposed solution achieves accurate sampling of current from multiple output branches by sharing a common ground bus and installing a shunt at the high end of each current branch. Simultaneously, the accuracy and stability of current sampling are improved through current signal isolation processing and differential amplification. This structure simplifies circuit design, reduces costs, and enhances the reliability and efficiency of current sampling. It effectively solves the problem of sampling current from multiple branches with a common ground, improving the linearity and accuracy of current sampling. Furthermore, it is smaller and more flexible than similar sampling solutions. Moreover, it significantly increases design accessibility and adaptability, reducing development and design costs and bringing substantial economic benefits to society.

[0008] Optionally, the input terminal of the current signal isolation processing unit is connected to an auxiliary power source. Providing an auxiliary power source for the current signal isolation processing unit ensures its normal operation, thereby improving the stability and reliability of current sampling. The introduction of an auxiliary power source can also provide the necessary power and voltage support for the current signal isolation processing unit.

[0009] Optionally, the current signal sampled by the high-side shunt sampling unit has a reference ground different from that of the output branch GND.

[0010] Optionally, the differential amplifier unit employs a rail-to-rail operational amplifier. This ensures stable output over a wide input voltage range. Such operational amplifiers feature low noise, high accuracy, and high stability, contributing to further improvements in the accuracy and stability of current sampling.

[0011] Optionally, an RC filter circuit is provided between the high-side shunt sampling unit and the current signal isolation processing unit. This filter circuit helps to remove high-frequency noise and interference, further improving the accuracy and stability of the current sampling. The filter circuit design helps reduce the impact of noise on the sampled signal, ensuring the purity and accuracy of the sampled signal.

[0012] Optionally, the current signal isolation processing unit is configured with eight pins, wherein the first and fourth pins are connected to the auxiliary source, the second and third pins are connected to the high-side shunt sampling unit, and the sixth and seventh pins are connected to the differential amplifier unit.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] 1. This utility model achieves accurate sampling of the high-end current of multiple output branches by using multiple common ground current branches, each branch including a high-side shunt sampling unit, an auxiliary source, a current signal isolation processing unit, a differential amplifier unit, and an independent reference ground. This can effectively solve the problem of sampling current of multiple common ground branches and improve the linearity and sampling accuracy of current sampling.

[0015] 2. This utility model is smaller in size and more flexible in application than similar sampling schemes; in addition, it greatly increases design accessibility and adaptability, reduces development and design costs, and brings great economic benefits to society.

[0016] 3. This utility model adopts an independent reference ground design to avoid interference between current signals and improve the sampling accuracy;

[0017] 4. This utility model sets up a filter circuit between the high-end shunt sampling unit and the current signal isolation processing unit, which can filter out high-frequency noise and interference, further improving the accuracy and stability of current sampling. The design of the filter circuit helps to reduce the impact of noise on the sampling signal and ensure the purity and accuracy of the sampling signal. Attached Figure Description

[0018] Figure 1 This is a schematic block diagram of a common-ground multi-output branch high-side current sampling circuit structure according to an embodiment of the present invention;

[0019] Figure 2 This is a circuit diagram of a common-ground multi-output branch high-end current sampling circuit structure according to an embodiment of the present invention. Detailed Implementation

[0020] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "middle", "upper", "lower", "left", "right", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0022] like Figure 1As shown, this utility model embodiment provides a common-ground multi-output-branch high-side current sampling circuit structure, including: multiple current branches, the multiple current branches sharing a common-ground bus, each current branch including a high-side shunt sampling unit connected to the high-side of the output branch, the output terminal of the high-side shunt sampling unit being connected to a current signal isolation processing unit, the output terminal of the current signal isolation processing unit being connected to the input terminal of a differential amplifier unit, and the output terminal of the differential amplifier unit outputting a current sampling signal.

[0023] This utility model embodiment achieves accurate sampling of the high-end current of multiple output branches through multiple common-ground current branches. Each branch includes a high-side shunt sampling unit R1, an auxiliary source M1, a current signal isolation processing unit, and a differential amplifier unit. This effectively solves the problem of sampling current from multiple common-ground branches, improves the linearity and accuracy of current sampling, and is smaller in size and more flexible in application than similar sampling schemes. In addition, it greatly increases design accessibility and adaptability, reduces development and design costs, and brings good economic benefits to society. The independent reference ground design avoids interference between current signals and improves sampling accuracy.

[0024] In this embodiment, the high-end shunt in the high-end shunt sampling unit can be a product from the TTE Electronics CSS95 series. The rated resistance of the high-end shunt sampling unit is 2mΩ and the rated power is 5W.

[0025] In this embodiment, an auxiliary source is connected to the input of the current signal isolation processing unit to provide an auxiliary source for the unit, ensuring its normal operation and thus improving the stability and reliability of current sampling. The current signal sampled by the high-side shunt sampling unit has a reference ground different from the output branch GND. Equipping the high-side shunt sampling unit with an independent reference ground, separated from the output branch's reference ground, can further reduce interference and noise, improving the accuracy and stability of current sampling. This design helps reduce common-ground interference, ensuring the purity and accuracy of the current sampling signal.

[0026] The differential amplifier unit employs a rail-to-rail operational amplifier, specifically the RS6332P. This ensures stable output over a wide input voltage range. This operational amplifier features low noise, high precision, and high stability, contributing to further improvements in the accuracy and stability of current sampling.

[0027] like Figure 2As shown, an RC filter circuit is installed between the high-side shunt sampling unit and the current signal isolation processing unit. This filter circuit helps to remove high-frequency noise and interference, further improving the accuracy and stability of current sampling. The filter circuit design helps reduce the impact of noise on the sampled signal, ensuring the purity and accuracy of the sampled signal.

[0028] The current signal isolation processing unit is configured with eight pins, of which the first and fourth pins are connected to the auxiliary source, the second and third pins are connected to the high-side shunt sampling unit, and the sixth and seventh pins are connected to the differential amplifier unit.

[0029] Specifically, such as Figure 2 As shown, the "VIN" pin is used to receive the input voltage; the "SHTDN" pin is used to provide a protective connection that is isolated from the system ground potential; the "VDD2" and "VDD1" pins are used to provide power supply voltages for different parts of the circuit, respectively; the "GND1" and "GND2" pins serve as internal ground reference points; and the "OUTP" and "OUTN" pins are used to output differential current signals.

[0030] In addition, pin 8 is connected to the input terminal of the microcontroller unit (MCU), the output terminal of the MCU is connected to two capacitors, pin 7 and the other end of the two capacitors are connected to resistor R3, and the other end of resistor R3 is connected to the differential amplifier unit.

[0031] The working principle of the above embodiment is:

[0032] When current flows through the high-side shunt sampling unit R1, R1 generates a current signal. This signal is filtered by R2 and C12 before being sent to N1 for signal isolation. Because the reference grounds are different, signal isolation is necessary. M1 provides an isolated auxiliary power source to N1. Since this is a high-side current signal, its reference ground cannot be the output branch's GND; the current signal generated by R1 must have an independent reference ground. In this circuit, the reference ground is GND2. After isolation by N1, the current signal is sent to N2 through pins 6 and 7 for differential amplification, and finally output through pin 1 of N2 and R5. To ensure the accuracy and linearity of the final output signal, N2 must be a rail-to-rail operational amplifier.

[0033] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A common-ground multi-output branch high-side current sampling circuit structure, characterized in that, include: Multiple current branches share a common ground bus. Each current branch includes a high-side shunt sampling unit connected to the high end of the output branch. The output of the high-side shunt sampling unit is connected to a current signal isolation processing unit. The output of the current signal isolation processing unit is connected to the input of a differential amplifier unit. The output of the differential amplifier unit outputs a current sampling signal.

2. The common-ground multi-output branch high-side current sampling circuit structure according to claim 1, characterized in that: The input terminal of the current signal isolation processing unit is connected to an auxiliary source.

3. The common-ground multi-output branch high-side current sampling circuit structure according to claim 1, characterized in that: The current signal sampled by the high-end shunt sampling unit has a reference ground different from that of the output branch GND.

4. The common-ground multi-output branch high-side current sampling circuit structure according to claim 1, characterized in that: The differential amplifier unit employs a rail-to-rail operational amplifier.

5. The common-ground multi-output branch high-side current sampling circuit structure according to claim 1, characterized in that: An RC filter circuit is provided between the high-end shunt sampling unit and the current signal isolation processing unit.

6. The common-ground multi-output branch high-side current sampling circuit structure according to claim 1, characterized in that: The current signal isolation processing unit is configured with eight pins, wherein the first and fourth pins are connected to the auxiliary source, the second and third pins are connected to the high-side shunt sampling unit, and the sixth and seventh pins are connected to the differential amplifier unit.

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