Voltage stabilizing circuit on high-speed signal line

Abstract

The utility model discloses a voltage stabilizing circuit on a high-speed signal line, which is connected to the high-speed signal line and comprises a grounding voltage stabilizing diode and a first capacitor body arranged between the voltage stabilizing diode and the signal line, and the capacitance value of the first capacitor body is smaller than the parasitic capacitance value of the voltage stabilizing diode; wherein the resistance value of the first capacitor body between the signal line and the voltage stabilizing diode is lower than a set value. The voltage stabilizing diode is configured to ensure that the signal voltage on the signal line does not exceed the target voltage, and the first diode is used to ensure that the high-speed signal on the signal line is not influenced; the current limiting device is used for limiting the input current, it is ensured that the current does not exceed the forward current of the first diode, and it is ensured that power consumption generated on the Zener diode does not damage the Zener diode.

Description

Technical Field

[0001] The utility model relates to the technical field of voltage stabilizing circuits, and more specifically, to a voltage stabilizing circuit on a high-speed signal line. Background Art

[0002] For circuits that strictly prohibit high-voltage input, safety protection measures are required to limit the voltage on the line to a certain range. Conventional methods include limiting the voltage through a voltage regulator tube, or cutting off the input after voltage detection of high voltage. However, these two methods are not applicable to high-speed signal lines for the following reasons:

[0003] (1) Using a voltage regulator to limit voltage: The junction capacitance of a voltage regulator is very large, and the above capacitance will affect the transmission of high-speed signals. Therefore, the method of directly using a voltage regulator to limit voltage is not suitable for high-speed signal transmission lines;

[0004] (2) Detecting and controlling high voltage input through semiconductor solutions: This method has a complex circuit and has a certain delay from detection to response control. For circuits that need to eliminate transient high voltage, this delay is unacceptable. In addition, in the case of negative voltage input, the above control circuit will be more complicated.

[0005] How to provide a simple and effective voltage stabilization circuit for high-speed signal lines that can provide overvoltage protection without affecting the transmission of high-frequency signals is a problem that needs to be solved urgently. Utility Model Content

[0006] In view of the problem that the voltage regulator tube in the traditional voltage regulator circuit is easy to cause adverse effects on the signal transmission of the high-speed signal line in actual application, the purpose of this application is to propose a voltage regulator circuit on the high-speed signal line, which has a simple and reliable structure and can protect the high-speed signal line without affecting the signal transmission. The specific scheme is as follows:

[0007] A voltage stabilizing circuit on a high-speed signal line, connected to the high-speed signal line, comprises a grounded voltage stabilizing diode, and a first capacitor disposed between the voltage stabilizing diode and the signal line, wherein the capacitance value of the first capacitor is smaller than the parasitic capacitance value of the voltage stabilizing diode;

[0008] The resistance of the first capacitor between the signal line and the voltage-stabilizing diode is lower than a set value.

[0009] Through the above technical solution, a first capacitor is connected between the grounded voltage regulator diode and the signal line. Since the capacitance value of the first capacitor is small, according to the capacitance calculation formula of the capacitors in series, the overall capacitance value of the voltage regulator circuit is greatly reduced. At the same time, based on the low resistance of the first capacitor, the voltage regulator diode can work normally and will not affect the high-frequency signal transmitted in the signal line.

[0010] Furthermore, the first capacitor is configured as a first diode, the first diode is connected in series in the forward direction between the signal line and the voltage-stabilizing diode, and the parasitic capacitance value of the first diode is smaller than that of the voltage-stabilizing diode.

[0011] Through the above technical solution, without affecting the conduction between the signal line and the voltage stabilizing diode, the parasitic capacitance of the first diode can be used to reduce the capacitance value of the entire voltage stabilizing circuit, thereby ensuring the normal transmission of high-frequency signals in the signal line.

[0012] Furthermore, a capacitance-adjusting voltage source is connected between the first diode and the voltage-stabilizing diode, and the capacitance-adjusting voltage source is connected to the cathode of the first diode via a resistor.

[0013] Through the above technical solution, the parasitic capacitance value of the first diode can be adjusted, and then the capacitance value of the entire voltage stabilizing circuit can be adjusted, so that it can be flexibly applied to signal transmission lines of different frequencies.

[0014] Further, the capacitance-adjusting voltage source is connected to the controller control, configured as a program-controlled voltage source or directly electrically connected to the control data pin of the controller;

[0015] The signal line is also connected to a frequency acquisition module for acquiring the signal transmission frequency in the signal line and outputting it to the controller;

[0016] The controller receives and controls the voltage output value of the capacitance-adjusting voltage source in response to the signal transmission frequency detection value.

[0017] Through the above technical solution, the controller can be used to accurately adjust the size of the above-mentioned capacitance-adjusting voltage source, so that the capacitance value of the entire voltage-stabilizing circuit can be accurately adjusted; at the same time, the controller can also serve as the central node of feedback control, automatically adjusting the above-mentioned capacitance-adjusting voltage source according to the signal transmission frequency in the collected signal line, thereby realizing adaptive adjustment of the capacitance value of the entire voltage-stabilizing circuit, and has strong applicability.

[0018] Furthermore, the output end of the capacitance regulating voltage source is grounded via a voltage regulator tube.

[0019] Through the above technical solution, when the voltage of the capacitance regulating voltage source is too high, it can be stabilized to avoid reverse breakdown of the first diode. At the same time, the first diode itself is also reversely pressurized and does not conduct, which can isolate the direct influence of the capacitance regulating voltage source on the signal line.

[0020] Furthermore, a current limiting device is connected in series on the signal line.

[0021] Through the above technical solution, a current limiting device is used to limit the input current, ensuring that the current does not exceed the forward current of the diode, and ensuring that the power consumption generated on the Zener diode will not damage the Zener diode.

[0022] Furthermore, the number of the current limiting devices is at least two, and the connection point between the first capacitor and the signal line is located between two adjacent current limiting devices.

[0023] Furthermore, the voltage stabilizing circuit is configured as multiple circuits.

[0024] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0025] (1) By configuring a voltage stabilizing diode to ensure that the signal voltage on the signal line does not exceed the target voltage, a first diode is used to ensure that the high-speed signal on the signal line is not affected;

[0026] (2) By using a current limiting device to limit the input current, ensure that the current does not exceed the forward current of the first diode, and ensure that the power consumption generated in the Zener diode will not damage the Zener diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an overall schematic diagram of the voltage stabilizing circuit of the present application (Implementation Method 1);

[0028] Figure 2 This is an overall schematic diagram of the voltage stabilizing circuit of the present application (Implementation Method 2).

[0029] Figure numerals: 1. voltage-stabilizing diode; 2. first diode; 3. controller; 4. current-limiting device. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation methods of the present invention are not limited thereto.

[0031] A voltage stabilizing circuit on a high-speed signal line, such as Figure 1 As shown, it is connected to the high-speed signal line, and can be configured as multiple paths in actual applications, including a grounded Zener diode 1 and a first capacitor disposed between the Zener diode 1 and the signal line. The first capacitor can be configured as a varactor, a resistor or other capacitor, and its resistance between the signal line and the Zener diode 1 is lower than a set value, and the capacitance of the first capacitor is much smaller than the parasitic capacitance of the Zener diode 1.

[0032] According to the capacitor parallel calculation formula Ct=C1*C2 / (C1+C2), C1 can be regarded as the capacitance of the first capacitor, and C2 is the parasitic capacitance of the Zener diode 1. It can be seen that when C1 is smaller than C2, the combined capacitance value of the two capacitors arranged in series is much smaller than the single capacitance value. Therefore, the parasitic capacitance of the Zener diode 1 in the voltage stabilizing circuit can reduce the excessive influence on the high-frequency signal in the signal line.

[0033] Preferably, Figure 1 As shown, in the embodiment of the present application, the first capacitor is configured as a first diode 2, and the first diode 2 is preferably a model with a body capacitance value lower than 1pF, which is connected in series in the forward direction between the signal line and the voltage stabilizing diode 1, and the parasitic capacitance value of the first diode 2 is much smaller than the voltage stabilizing diode 1. The above technical solution can reduce the capacitance value of the entire voltage stabilizing circuit by using the parasitic capacitance of the first diode 2 without affecting the conduction between the signal line and the voltage stabilizing diode 1, thereby ensuring the normal transmission of high-frequency signals in the signal line.

[0034] In the above scheme, the capacitance value of the first diode 2 is fixed, but as the frequency of the signal transmitted in the signal line increases, the body capacitance of the first diode 2 will also affect the signal transmission. For this reason, a capacitance-adjusting voltage source is connected between the first diode 2 and the voltage-stabilizing diode 1, and the capacitance-adjusting voltage source is connected to the cathode of the first diode 2 after a resistor. The working principle of the above-mentioned capacitance-adjusting voltage source is to use an external voltage to adjust the width between the PN nodes inside the diode, thereby achieving voltage regulation. The above-mentioned technical scheme can adjust the parasitic capacitance value of the first diode 2, and then adjust the capacitance value of the entire voltage-stabilizing circuit, so that it can be flexibly applied to signal transmission lines of different frequencies. At the same time, the first diode 2 itself is also reversely pressurized and non-conductive, which can cut off the direct influence of the capacitance-adjusting voltage source on the signal line.

[0035] like Figure 2As shown, in a specific application, the capacitance-adjusting voltage source is connected to the controller 3 control, configured as a program-controlled voltage source or directly electrically connected to the control data pin of the controller 3. In practice, the capacitance-adjusting voltage source should not be too large to avoid affecting the voltage-stabilizing effect of the voltage-stabilizing diode 1. A frequency acquisition module is also connected to the signal line to collect the signal transmission frequency in the signal line and output it to the controller 3. The controller 3 receives and responds to the signal transmission frequency detection value to control the voltage output value of the capacitance-adjusting voltage source. The controller 3 can be directly built using FPGA or other analog circuits. Similarly, the signal frequency in the acquisition signal line can be directly completed by the built-in program module of the controller 3. The above technical solution can use the controller 3 to accurately adjust the size of the capacitance-adjusting voltage source, so that the capacitance value of the entire voltage-stabilizing circuit can be accurately adjusted; at the same time, the controller 3 can also serve as the central node of feedback control, automatically adjusting the capacitance-adjusting voltage source according to the signal transmission frequency in the collected signal line, so as to realize the adaptive adjustment of the capacitance value of the entire voltage-stabilizing circuit, and has strong applicability.

[0036] In order to stabilize the voltage of the capacitance regulating voltage source when the voltage suddenly becomes too high and avoid reverse breakdown of the first diode 2, the output end of the capacitance regulating voltage source is grounded via a voltage regulator tube.

[0037] In order to ensure that the current does not exceed the forward current of the first diode 2 and that the power consumption generated on the voltage-limiting diode 1 does not damage the voltage-limiting diode 1, a current-limiting device 4 is connected in series on the signal line. The number of the current-limiting devices 4 is at least two, and the connection point between the first capacitor and the signal line is located between two adjacent current-limiting devices 4. The current-limiting device 4 can be implemented by a current-limiting fuse.

[0038] The above is only a preferred embodiment of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A voltage stabilizing circuit on a high-speed signal line, connected to the high-speed signal line, characterized in that: It comprises a grounded voltage-stabilizing diode (1), and a first capacitor arranged between the voltage-stabilizing diode (1) and a signal line, wherein the capacitance value of the first capacitor is smaller than the parasitic capacitance value of the voltage-stabilizing diode (1); The resistance of the first capacitor between the signal line and the voltage-stabilizing diode (1) is lower than a set value.

2. The voltage stabilizing circuit for a high-speed signal line according to claim 1, characterized in that: The first capacitor is configured as a first diode (2), the first diode (2) is connected in series in the forward direction between the signal line and the voltage-stabilizing diode (1), and the parasitic capacitance value of the first diode (2) is smaller than that of the voltage-stabilizing diode (1).

3. The voltage stabilizing circuit for a high-speed signal line according to claim 2, characterized in that: A capacitance-adjusting voltage source is connected between the first diode (2) and the voltage-stabilizing diode (1), and the capacitance-adjusting voltage source is connected to the cathode of the first diode (2) via a resistor.

4. The voltage stabilizing circuit for a high-speed signal line according to claim 3, characterized in that: The capacitance regulating voltage source is control-connected to the controller (3) and is configured as a program-controlled voltage source or is directly electrically connected to a control data pin of the controller (3); The signal line is also connected to a frequency acquisition module for acquiring the signal transmission frequency in the signal line and outputting it to the controller (3); The controller (3) receives and controls the voltage output value of the capacitance-adjusting voltage source in response to the signal transmission frequency detection value.

5. The voltage stabilizing circuit for a high-speed signal line according to claim 4, characterized in that: The output end of the capacitance regulating voltage source is grounded via a voltage regulator tube.

6. The voltage stabilizing circuit for a high-speed signal line according to claim 1, characterized in that: The signal line is connected in series with a current limiting device (4).

7. The voltage stabilizing circuit for a high-speed signal line according to claim 6, characterized in that: The number of the current limiting devices (4) is at least two, and the connection point between the first capacitor and the signal line is located between two adjacent current limiting devices (4).

8. The voltage stabilizing circuit for a high-speed signal line according to claim 1, characterized in that: The voltage stabilizing circuit is composed of multiple circuits, all of which are connected to the signal line.

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