A current sampling circuit

Abstract

The application relates to a current sampling circuit, which comprises a current sampling signal input end, a first signal filtering module, an operational amplifier module and a second signal filtering module; wherein the current sampling signal input end is connected with the first signal filtering module, the current sampling signal enters the operational amplifier module for signal amplification through the first signal filtering module, the operational amplifier module is connected with the second signal filtering module, and the output signal of the first signal filtering module is filtered again by the second signal filtering module after being amplified by the operational amplifier module. The technical scheme of the application can effectively reduce the interference of interference factors and improve the stability of the sampling signal of the acquisition circuit.

Description

Technical Field

[0001] This application relates to the field of circuit technology, and in particular to a current sampling circuit structure. Background Technology

[0002] In the current control stage of power electronic systems, accurate acquisition of current signals is crucial. In certain operating modes, such as the freewheeling phase during the conduction of the three lower transistors, current sampling is necessary to obtain critical control information. Based on the freewheeling principle, acquiring the current value at the midpoint of this freewheeling period effectively reflects the average current, providing an important basis for system control.

[0003] Common current sampling methods in existing technologies mainly include three-resistor, two-resistor, and single-resistor sampling. However, these traditional sampling methods have significant drawbacks. On the one hand, the resistors used for sampling generate significant power consumption during operation, which not only reduces the overall efficiency of the system but may also affect the performance and lifespan of the resistors and surrounding components due to heat generation. On the other hand, the stability of the acquired current signal is poor, and it is easily affected by various interference factors in the circuit, resulting in large signal fluctuations, which in turn affects the accuracy and reliability of system control. Utility Model Content

[0004] This application provides a current sampling circuit to solve the problem of unstable signals acquired by sampling circuits in the prior art.

[0005] Therefore, in a first aspect, embodiments of this application provide a current sampling circuit, including:

[0006] The system includes a current sampling signal input terminal, a first signal filtering module, an operational amplifier module, and a second signal filtering module.

[0007] The current sampling signal input terminal is connected to the first signal filtering module. The current sampling signal enters the operational amplifier module for signal amplification through the first signal filtering module. The operational amplifier module is connected to the second signal filtering module. The output signal of the first signal filtering module is amplified by the operational amplifier module and then filtered out for interference again by the second filtering module.

[0008] In one possible implementation of this application, the current sampling signal input terminal includes a +12VA current sampling signal and a +12VB current sampling signal, which is the voltage drop generated by the output current through the sampling resistor.

[0009] The first signal filtering module includes a first capacitor, and the operational amplifier module includes an operational amplifier, a first resistor, a second resistor, and a third resistor. The first resistor, the second resistor, and the third resistor are connected to the input terminal of the operational amplifier. The current sampling signal is first filtered out for interference by the first capacitor, and then amplified by the first resistor, the second resistor, the third resistor, and the operational amplifier.

[0010] The second signal filtering module includes a second capacitor, a fourth resistor, a fifth resistor, and a sixth resistor. The output terminal of the operational amplifier is connected to the fourth resistor and the sixth resistor, and one end of the sixth resistor is also connected to the fifth resistor. The output voltage of the operational amplifier is RC filtered by the second capacitor, the fourth resistor, the fifth resistor, and the sixth resistor.

[0011] In one possible implementation of this application, the output terminal of the second filtering module is further connected to a first diode and a second diode, and the first diode and the second diode are further connected to a sampling information output terminal, which is used to connect to a server power terminal.

[0012] A current sampling circuit according to an embodiment of this application includes: a current sampling signal input terminal, a first signal filtering module, an operational amplifier module, and a second signal filtering module;

[0013] The current sampling signal input is connected to a first signal filtering module. The current sampling signal passes through the first signal filtering module and then enters an operational amplifier module for signal amplification. The operational amplifier module is connected to a second signal filtering module. The operational amplifier output signal, after being amplified by the operational amplifier module, passes through the second filtering module again to filter out interference. In this circuit, the sampling signal is first filtered and then amplified by the operational amplifier, converting small, difficult-to-detect signals into larger signals. The converted signal is then regulated and filtered before flowing into the server power terminal. This technical solution effectively reduces interference from various factors and improves the stability of the sampling signal from the acquisition circuit. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort. In addition, in the drawings, the same parts use the same reference numerals, and the drawings are not drawn to scale.

[0015] Figure 1 This is a schematic diagram of a current sampling circuit provided in an embodiment of this application;

[0016] Figure 2This is a schematic diagram illustrating the specific composition and structure of a current sampling circuit provided in an embodiment of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] This invention aims to improve upon the problems existing in current sampling circuits in the prior art. Through innovative design and technical means, it provides a stable current sampling circuit that can perform current sampling more stably, reduce power consumption, protect and report sampling information, improve the stability of the acquired signal, and thus enhance the performance and reliability of the entire power electronic system.

[0019] The purpose of this utility model.

[0020] See Figure 1 As shown, this application embodiment provides a current sampling signal input terminal 100, a first signal filtering module 102, an operational amplifier module 104, and a second signal filtering module 106.

[0021] The current sampling signal input terminal 100 is connected to the first signal filtering module 102. The current sampling signal enters the operational amplifier module 104 for signal amplification through the first signal filtering module 102. The operational amplifier module 104 is connected to the second signal filtering module 106. After the output signal of the first signal filtering module 102 is amplified by the operational amplifier module 104, it is filtered out for interference again by the second filtering module 106.

[0022] Furthermore, according to the current sampling circuit provided in this application embodiment, the sampled signal is first filtered, and then amplified by an operational amplifier to convert a small, difficult-to-detect signal into a large signal. The converted signal is then regulated and filtered before flowing into the server power terminal. This technical solution can effectively reduce interference from various factors and improve the stability of the sampled signal from the acquisition circuit.

[0023] Reference Figure 2 In one specific embodiment shown, the current sampling signal input terminal includes +12VA and +12VB current sampling signals, which are the voltage drop generated by the output current passing through the sampling resistor.

[0024] The aforementioned first signal filtering module includes a first capacitor C101, and the operational amplifier module includes an operational amplifier and a first resistor R.143 Second resistor R 144 Third resistor R 148 The aforementioned first resistor R 143 Second resistor R 144 Third resistor R 148 Connecting to the input of operational amplifier U12, the current sampling signal first passes through the first capacitor C101 to filter out interference, and then passes through the first resistor R. 143 Second resistor R 144 Third resistor R 148 It is amplified by operational amplifier U12.

[0025] The aforementioned second signal filtering module 106 includes a second capacitor C106 and a fourth resistor R. 145 Fifth resistor R 146 and the sixth resistor R 151 The output of operational amplifier U12 is connected to the fourth resistor R. 145 The sixth resistor R 151 The sixth resistor R 151 One end is also connected to the fifth resistor R 146 The output voltage of operational amplifier U12 passes through the second capacitor C106 and the fourth resistor R. 145 Fifth resistor R 146 and the sixth resistor R 151 Perform RC filtering.

[0026] In one possible embodiment of this application, the output terminal of the second filtering module is further connected to a first diode D50 and a second diode D51. The first diode D50 and the second diode D51 are also connected to the sampling information output terminal Io_Sense, which is used to connect to the server power supply terminal. The first diode D50 and the second diode D51 serve to protect the circuit and rectify the signal.

[0027] In the technical solution provided by this utility model, the signal is amplified and stabilized and filtered by using an operational amplifier, and the signal is transmitted to the server power terminal at the same time to reduce the instability of the signal.

[0028] Operational amplifier U12 amplifies the voltage difference between the inverting and non-inverting terminals, thereby acquiring the circuit current signal. Resistor R... 145 R 146 R 151 and capacitor C 106 RC filtering makes the output voltage signal more stable.

[0029] In this circuit, an operational amplifier is configured to amplify the difference between two values: the voltage drop across the sampling resistor caused by the current. The sampled signal is amplified by the operational amplifier, converting a small, difficult-to-detect signal into a larger one. The converted signal is then regulated and filtered before flowing into the server power supply terminal, where it is processed. If an anomaly occurs, the server power supply terminal issues a protection signal.

[0030] The server power supply terminal monitors the current of the collected signals and can also perform current sharing control through this circuit.

[0031] Specifically, see the appendix again. Figure 2 The specific embodiment shown takes the downstream current sampling circuit as an example. Here, +12VA is the +12VB current sampling signal, which is the voltage drop generated by the output current through the sampling resistor. U12 is an operational amplifier, +24VCC is the input voltage of the operational amplifier during normal operation, and VDDA3.3_S is the reference voltage provided by the auxiliary circuit during normal operation. The current sampling signal is first filtered for interference by C101, and then passed through R... 143 R 144 R 148 This is amplified by operational amplifier U12. The voltage at pin 1 of the operational amplifier is... The output voltage U1 then passes through R 151 R 146 R 145 C 106 RC filtering is applied to stabilize the acquired information and reduce interference, effectively protecting and reporting the sampled information. The processed sampled information flows from Io_Sense into the server power terminal. The server power terminal processes the protection signal and sampling feedback signal output by the operational amplifier to achieve current monitoring and simultaneously perform current sharing control.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0033] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A current sampling circuit, characterized by, include: The system includes a current sampling signal input terminal, a first signal filtering module, an operational amplifier module, and a second signal filtering module. The current sampling signal input terminal is connected to the first signal filtering module. The current sampling signal enters the operational amplifier module for signal amplification through the first signal filtering module. The operational amplifier module is connected to the second signal filtering module. The output signal of the first signal filtering module is amplified by the operational amplifier module and then filtered out for interference again by the second filtering module.

2. The current sampling circuit according to claim 1, characterized in that, The current sampling signal input terminal includes a +12VA current sampling signal and a +12VB current sampling signal, which is the voltage drop generated by the output current through the sampling resistor; The first signal filtering module includes a first capacitor, and the operational amplifier module includes an operational amplifier, a first resistor, a second resistor, and a third resistor. The first resistor, the second resistor, and the third resistor are connected to the input terminal of the operational amplifier. The current sampling signal is first filtered out for interference by the first capacitor, and then amplified by the first resistor, the second resistor, the third resistor, and the operational amplifier. The second signal filtering module includes a second capacitor, a fourth resistor, a fifth resistor, and a sixth resistor. The output terminal of the operational amplifier is connected to the fourth resistor and the sixth resistor, and one end of the sixth resistor is also connected to the fifth resistor. The output voltage of the operational amplifier is RC filtered by the second capacitor, the fourth resistor, the fifth resistor, and the sixth resistor.

3. The current sampling circuit according to claim 1 or 2, characterized in that, The output of the second filter module is also connected to a first diode and a second diode. The first diode and the second diode are also connected to a sampling information output terminal, which is used to connect to the server power terminal.

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