Power-on transient current control circuit and control method thereof

Abstract

The invention relates to a power-on transient current control circuit and a control method thereof. The control circuit comprises an MOS tube, a current-limiting resistor, a first diode, a capacitor group, a first capacitor and a resistor group. One end of the current-limiting resistor is electrically connected to a power supply input end, the other end of the current-limiting resistor is electrically connected to one end of a load, a first end of the MOS tube is electrically connected to one end of the current-limiting resistor, and a second end of the MOS tube is electrically connected to one end of the current-limiting resistor; one end of the resistor group is electrically connected to the power supply output end, one end of the resistor group is electrically connected to the other end of the load, and the other end is electrically connected to one end of the capacitor group; one end of the capacitor group is electrically connected to the cathode of the first diode, and the other end of the resistor group is electrically connected to one end of the first capacitor; one end of the first capacitor is electrically connected to the first end of the MOS tube, the other end of the first capacitor is electrically connected to the positive electrode of the first diode, the other end of the first capacitor is electrically connected to the third end of the MOS tube, the opening time of the MOS tube is controlled, and the control duration of the transient current is adjusted.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a power-on transient current control circuit and method thereof. Background Art

[0002] In key devices and system chassis cards with high power requirements, the power supply will stably provide power to the entire system under ideal conditions. However, in actual applications, due to the complexity of system design and the influence of various factors, especially the presence of capacitive loads such as energy storage capacitors, the system will face some challenges when powered on.

[0003] First, when the energy storage capacitor is initially powered on, its charging process has not yet been completed. At this time, the impedance of the capacitor is very low, close to a short-circuit state. In this state, the capacitor behaves like a momentary current absorber, causing the system to generate a transient surge current much higher than that during normal operation at the moment of power-on. This transient surge current may not only exceed the rated output capacity of the power supply, but may also cause great load pressure on the entire power supply system.

[0004] The negative impact of this transient impact current is multifaceted. First, excessive current may cause the output voltage of the power supply to be unstable or even exceed its safety range, thereby damaging the power supply equipment. Second, the power supply system may fall into an overload state due to transient impact current, resulting in abnormal startup, hiccups (i.e., the system works briefly and then stops immediately after startup), or even complete paralysis. In addition, excessive current may also damage other sensitive electronic components in the system, affecting the overall performance and reliability of the system. Summary of the invention

[0005] In view of this, the present application proposes a power-on transient current control circuit and a control method thereof to solve the above problems.

[0006] According to one aspect of the present application, a power-on transient current control circuit is provided, comprising: a MOS tube, a current limiting resistor, a first diode, a first resistor, a first capacitor and a resistor group;

[0007] One end of the current limiting resistor is suitable for being electrically connected to the power input terminal, and the other end of the current limiting resistor is suitable for being electrically connected to one end of the load, so as to reduce the transient impact current of the power supply system;

[0008] The first end of the MOS tube is electrically connected to one end of the current limiting resistor, and the second end of the MOS tube is electrically connected to one end of the current limiting resistor;

[0009] One end of the resistor group is suitable for being electrically connected to the output end of the power supply, and one end of the resistor group is suitable for being electrically connected to the other end of the load, and the other end is electrically connected to one end of the capacitor group;

[0010] One end of the capacitor group is electrically connected to the cathode of the first diode, and the other end of the resistor group is electrically connected to one end of the first capacitor, so as to control the voltage across the first capacitor;

[0011] One end of the first capacitor is electrically connected to the first end of the MOS tube, the other end of the first capacitor is electrically connected to the positive electrode of the first diode, and the other end of the first capacitor is electrically connected to the third end of the MOS tube, controlling the turn-on time of the MOS tube and adjusting the control duration of the transient current.

[0012] In a possible implementation, the resistor group includes: a first resistor and a second resistor, one end of the first resistor is electrically connected to the current limiting resistor, the other end of the first resistor is electrically connected to one end of the second resistor, and the other end of the second resistor is electrically connected to the first diode.

[0013] In one possible implementation, the capacitor group includes: a second capacitor and a third capacitor, one end of the second capacitor is electrically connected to the cathode of the first diode, the other end of the second capacitor is electrically connected to the other end of the first capacitor, one end of the third capacitor is electrically connected to one end of the second capacitor, and the other end of the third capacitor is electrically connected to the other end of the second capacitor.

[0014] In a possible implementation, the device further includes: a third resistor, one end of the third resistor is electrically connected to one end of the first capacitor, and the other end of the third resistor is electrically connected to the other end of the first capacitor.

[0015] In a possible implementation, the device further includes: a second diode, wherein a cathode of the second diode is electrically connected to a cathode of the first diode, and an anode of the second diode is electrically connected to one end of the first capacitor.

[0016] In a possible implementation, the device further includes: a fourth resistor, one end of which is electrically connected to the cathode of the first diode, and the other end of which is electrically connected to one end of the first capacitor.

[0017] In a possible implementation, the MOS tube is an N-channel MOS field effect tube, the source of the MOS tube is electrically connected to one end of the first capacitor, the gate of the MOS tube is electrically connected to the other end of the first capacitor, and the drain of the MOS tube is electrically connected to the other end of the current limiting resistor.

[0018] In a possible implementation, the model of the MOS tube is FQB34N20.

[0019] According to one aspect of the present application, a power-on transient current control method is provided, which uses the above-mentioned circuit to control the power-on transient current of a system power board, including:

[0020] Determining the resistance value of the current limiting resistor according to the current limiting control current;

[0021] Determine the capacitance value of the first capacitor, the capacitance value of the capacitor group, and the resistance value of the resistor group according to the control duration of the transient upper current;

[0022] After the power is turned on, the current limiting resistor is connected to the resistor group, the resistor group is connected to the capacitor group, and the capacitor group is connected to the first capacitor;

[0023] When the control time is reached, the base and gate of the MOS tube are connected to the two ends of the first capacitor, and the drain of the MOS tube is connected to the resistor group to transmit power to the load.

[0024] In a possible implementation, the control time is calculated as follows: t=N*RC, where N is a coefficient of the control time, R is a resistance value of the control circuit, and C is a capacitance value of the control circuit.

[0025] Beneficial effects of this application:

[0026] The power-on transient current control circuit and control method proposed in the present application have a simple connection mode, and can extend the control time of the transient impact current to protect the power supply equipment. Specifically, a MOS tube is connected in series on the power supply card, and the voltage at both ends of the first capacitor is controlled by a first resistor, a first diode and a resistor group. Since the two ends of the first capacitor are electrically connected to the source and gate of the MOS tube, and when the voltage between the source and the gate reaches the set voltage, the MOS tube starts to work. Since the capacitor group is continuously charged, and the capacitor group and the first capacitor are in a parallel state, the voltage at both ends of the first capacitor can be indirectly controlled, so that the MOS tube is turned on. At this time, the time of the power-on transient current is extended. When the capacitor group continues to charge to a certain voltage, it exceeds the breakdown voltage of the first diode. At this time, the first capacitor is charged so that the voltage at both ends of the first capacitor can reach the range of the conduction voltage of the MOS tube, further extending the power-on transient current. And when the MOS tube is turned on, the current limiting resistor can be bypassed to reduce the power consumption and heat generation of the system operation.

[0027] Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the present application and, together with the description, serve to explain the principles of the present application.

[0029] Figure 1 A circuit diagram of a power-on transient current control circuit according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0030] Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0031] Among them, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application or simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0034] In addition, in order to better illustrate the present application, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present application.

[0035] like Figure 1As shown, the power-on transient current control circuit includes: a MOS tube Q11, a current limiting resistor R169, a first diode D34, a first resistor R168, a first capacitor C175 and a resistor group; one end of the current limiting resistor R169 is suitable for being electrically connected to a power input end, and the other end of the current limiting resistor R169 is suitable for being electrically connected to one end of a load, so as to reduce the transient impact current of the power supply system; the first end of the MOS tube Q11 is electrically connected to one end of the current limiting resistor, and the second end of the MOS tube Q11 is electrically connected to one end of the current limiting resistor; one end of the resistor group is suitable for being electrically connected to the power output end, and the resistor group One end of the resistor is suitable for being electrically connected to the other end of the load, and the other end is electrically connected to one end of the capacitor group; one end of the capacitor group is electrically connected to the cathode of the first diode D34, and the other end of the resistor group is electrically connected to one end of the first capacitor C175 to control the voltage across the first capacitor; one end of the first capacitor C175 is electrically connected to the first end of the MOS tube Q11, the other end of the first capacitor C175 is electrically connected to the anode of the first diode D34, and the other end of the first capacitor C175 is electrically connected to the third end of the MOS tube Q11 to control the turn-on time of the MOS tube Q11 and adjust the control duration of the transient upper current.

[0036] The power-on transient current control circuit proposed in this embodiment has a simple connection method. The MOS tube Q11 is connected in series on the power board, and the voltage across the first capacitor C175 is controlled by the first resistor R168, the first diode D34 and the resistor group. Since the two ends of the first capacitor C175 are electrically connected to the source and gate of the MOS tube Q11, and when the voltage between the source and the gate reaches the set voltage, the MOS tube Q11 starts to work. Since the capacitor group is continuously charged, and the capacitor group and the first capacitor C175 are in a parallel state, the voltage across the first capacitor C175 can be indirectly controlled, so that the MOS tube Q11 is turned on. At this time, the time of the power-on transient current is extended. When the capacitor group continues to charge to a certain voltage, it exceeds the breakdown voltage of the first diode D34. At this time, the first capacitor C175 is charged so that the voltage across the first capacitor can reach the range of the conduction voltage of the MOS tube Q11, further extending the power-on transient current. And when the MOS tube Q11 is turned on, the current limiting resistor R169 can be bypassed to reduce the power consumption and heat generation of the system operation. Furthermore, by controlling the values ​​of the resistor and the capacitor, the turn-on time of the MOS tube Q11 can be controlled, and the control time of the transient current can be further adjusted.

[0037] In one specific embodiment, the resistor group includes: a first resistor C165 and a second resistor C167, one end of the first resistor C165 is electrically connected to a current limiting resistor R169, the other end of the first resistor C165 is electrically connected to one end of the second resistor C167, and the other end of the second resistor C167 is electrically connected to a first diode D34. In this embodiment, it should be noted that after the supply voltage is divided and limited by the first resistor C165 and the second resistor C167, the first capacitor C175 is charged by the first diode D34. It should also be noted that the resistance values ​​of the first resistor C165 and the second resistor C167 are the same. It should be noted that the first resistor C165 and the second resistor C167 need to be selected according to the actual situation, and it should be noted that the number of resistors in the resistor group is not limited to two, as long as the supply voltage is divided and limited.

[0038] In one specific embodiment, the resistance of the first resistor C165 and the resistance of the second resistor C167 are both 47K.

[0039] In one specific embodiment, the capacitor group includes: a second capacitor C173 and a third capacitor C174, one end of the second capacitor C173 is electrically connected to the cathode of the first diode D34, and the other end of the second capacitor C173 is electrically connected to the other end of the first capacitor C175. One end of the third capacitor C174 is electrically connected to the cathode of the first diode, and the other end is electrically connected to the other end of the first capacitor C175. That is, the second capacitor C173 and the third capacitor C174 are arranged in parallel.

[0040] The first capacitor C175 is connected in series with the first diode D34 and in parallel with the second capacitor C173. By controlling the voltage of the second capacitor C173, the voltage of the first capacitor C175 is controlled. Since the voltage of the first capacitor C175 is equal to the V gs . Therefore, the second capacitor C173 and the third capacitor C174 indirectly control the connectivity state of the MOS tube Q11. Preferably, the capacitance of the second capacitor C173 is the same as that of the third capacitor C174. In this embodiment, it should be noted that the capacitor group and one end of the first diode D34 are both electrically connected to the resistor group, wherein power is supplied to the capacitor group first, and the capacitor group is charged. When the voltage of the capacitor group exceeds the breakdown voltage of the first diode D34, the first capacitor C175 is charged. As the voltage across the first capacitor C175 changes, the voltage between the source and the gate of the MOS tube Q11 meets the turn-on voltage of the MOS tube Q11, thereby turning on the MOS tube Q11, further limiting the control time of the power-on transient impact current while bypassing the high-power current limiting resistor R169 to reduce the power consumption and heat generation of the system operation.

[0041] In one specific embodiment, the capacitance of the second capacitor C173 and the capacitance of the third capacitor C174 are 4.7 μF, and the rated voltage is 50V.

[0042] It should be noted that the number of capacitors in the capacitor group in this embodiment is not limited to two, and the capacitance of the capacitors in the capacitor group can also be adjusted according to actual conditions.

[0043] In a possible implementation, the device further includes: a third resistor R168, one end of the third resistor R168 is electrically connected to one end of the first capacitor C175, and the other end of the third resistor R168 is electrically connected to the other end of the first capacitor C175.

[0044] In one specific embodiment, the second diode D33 is further included, wherein the cathode of the second diode D33 is electrically connected to the cathode of the first diode D34, and the anode of the second diode D33 is electrically connected to one end of the first capacitor C175. In this embodiment, it should be noted that the second diode D33 is arranged in parallel with the capacitor group to limit the voltage of the capacitor group to not exceed the breakdown voltage of the second diode D33.

[0045] In one specific embodiment, the second diode D33 is a voltage regulator diode, and the model of the second diode D33 is BZV55-C18, and the voltage regulation parameter of the second diode D33 is 18V.

[0046] In one specific embodiment, the fourth resistor C166 is further included, one end of the fourth resistor C166 is electrically connected to the cathode of the first diode D34, and the other end of the fourth resistor C166 is electrically connected to one end of the first capacitor C175. In this embodiment, it should be noted that the fourth resistor C166 is connected in parallel with the second diode D33 and the capacitor group to further protect the circuit.

[0047] In one specific embodiment, the voltage between the power input terminal and the power output terminal is 110V.

[0048] In one specific embodiment, the resistance of the fourth resistor C166 is 200K.

[0049] In one specific embodiment, the MOS transistor Q11 is an N-channel MOS field effect transistor, the source of the MOS transistor Q11 is electrically connected to one end of the first capacitor C175, the gate of the MOS transistor Q11 is electrically connected to the other end of the first capacitor C175, and the drain of the MOS transistor Q11 is electrically connected to the other end of the current limiting resistor R169. It should be noted that the gate of the MOS transistor Q11 is the G pin of the MOS transistor Q11, the source of the MOS transistor Q11 is the S pin of the MOS transistor Q11, and the drain of the MOS transistor Q11 is the D pin of the MOS transistor Q11.

[0050] In one specific embodiment, the model of the MOS tube Q11 is FQB34N20. In this embodiment, it should be noted that the turn-on parameter of the MOS tube Q11 is 3V <V gs <5V.

[0051] In one specific embodiment, the current limiting resistor R169 is a high-power limiting resistor, the resistance of the current limiting resistor R169 is 100 ohm, and the rated power of the current limiting resistor R169 is 3W.

[0052] In one specific embodiment, the voltage regulation parameter of the first diode D34 is 6.2V.

[0053] In one specific embodiment, the resistance of the first resistor R168 is 100K.

[0054] In one specific embodiment, the capacitance of the first capacitor C175 is 0.1 μF, and the rated voltage of the first capacitor C175 is 50V.

[0055] In one of the specific embodiments, it also includes: an electrolytic capacitor C7, the negative electrode of the electrolytic capacitor C7 is electrically connected to the other end of the current limiting resistor R169, and the positive electrode of the electrolytic capacitor C7 is electrically connected to the resistor group. It should be noted that the electrolytic capacitor is set to further buffer the control duration of the transient current. In addition, it should be noted that it also includes: a fourth capacitor C205, the fourth capacitor C205 and the electrolytic capacitor C7 are set in parallel to provide a stable current for the load. Further, in one of the specific embodiments, the capacitance of the electrolytic capacitor C7 is 330μF, and the rated voltage is 200V.

[0056] The power-on transient current control method uses the above circuit to control the power-on transient current of the system power board, including:

[0057] Determining the resistance value of the current limiting resistor according to the current limiting control current;

[0058] Determine the capacitance value of the first capacitor, the capacitance value of the capacitor group, and the resistance value of the resistor group according to the control duration of the transient upper current;

[0059] After the power is turned on, the current limiting resistor is connected to the resistor group, the resistor group is connected to the capacitor group, and the capacitor group is connected to the first capacitor;

[0060] When the control time is reached, the base and gate of the MOS tube are connected to the two ends of the first capacitor, and the drain of the MOS tube is connected to the resistor group to transmit power to the load.

[0061] The power-on transient current control method proposed in this embodiment is flexible and adjustable. By adjusting the parameters of the current limiting resistor, the resistor group, the capacitor group and the first capacitor, the transient current size and duration during the power-on process can be flexibly controlled to meet the needs of different application scenarios. Compared with the traditional current limiting method with fixed resistance, the present invention reduces unnecessary energy loss and improves power utilization efficiency while controlling transient current. At the same time, it effectively limits the current impact at the initial stage of power-on, protecting the safe and stable operation of the power module, board components and the entire system.

[0062] It should be noted that, firstly, according to the expected current limiting control current size, the resistance value of the current limiting resistor is calculated by Ohm's law to ensure that the current does not exceed the set threshold value when the power is turned on.

[0063] Secondly, according to the control duration requirement of transient current, the parameters of the resistor group and capacitor group are designed. By adjusting the resistance value and the capacitance value, the time constant of the RC delay circuit can be accurately controlled, thereby realizing the control of the duration of transient current.

[0064] Specifically, after the power is turned on, the current limiting resistor is first connected to the resistor group, the resistor group is then connected to the capacitor group, and finally the capacitor group is connected to the first capacitor. At this time, the current enters the circuit through the current limiting resistor, and at the same time begins to charge the capacitor group, forming an RC delay effect. When the preset control time is reached, the control signal connects the base and gate of the MOS tube to the two ends of the first capacitor, the MOS tube is turned on, and its drain is connected to the resistor group to transmit power to the load. At this time, since the charging of the capacitor group has been completed, the transient current is effectively controlled, and the system enters a stable working state.

[0065] In one specific embodiment, the control time is calculated as follows: t=N*RC, where N is a coefficient of the control time, R is a resistance value of the circuit, and C is a capacitance value of the circuit.

[0066] In a specific solution, when the power supply voltage of the power board is 110VDC, the average current of the operation is set to I p When the power is first turned on, the power board supplies 110V voltage, which is limited by the current limiting resistor R169 before charging the electrolytic capacitor C7, thereby slowing down the charging speed of the electrolytic capacitor C7. Among them, the transient impact current I=U / R+I within the control time of limiting the transient impact current of power on p =110V / 10ohm+Ip=11A+Ip. It should be noted that U is the supply voltage of the power board, and R is the resistance of the current limiting resistor. Therefore, the larger the resistance of the current limiting resistor R169, the further the transient impact current can be reduced, thereby reducing the transient power-on current of the system.

[0067] The design calculation for limiting the transient impact current during power-on is as follows: The selection value of electrolytic capacitor C7 is 330uF, and the theoretical value of charging time is t=5*RC. It should be noted here that R refers to the resistance of the current limiting resistor in series with the electrolytic capacitor. C refers to the capacity of the electrolytic capacitor. After substituting the actual value, the theoretical charging time of electrolytic capacitor C7 is calculated as t=5*10ohm*330uF=16.5ms. t is used to describe the time required for the capacitor voltage to reach 63.2% of its final value (here is the voltage of the charging power supply). In practical applications, in order to ensure that the capacitor is fully charged and reaches a stable voltage value, a 5-fold time constant (i.e. 5*RC) is usually selected to ensure that the capacitor voltage reaches most of its final value (close to 100%), thereby meeting the needs of most applications.

[0068] From the circuit analysis, it can be seen that after the 110V power supply voltage is divided and limited by the first resistor R165 and the second resistor R167, the first capacitor C175 needs to be charged through the voltage regulator diode D34 (voltage regulator value is 6.2V). <V gs <5V, when the voltage across the first capacitor C175 reaches 5V, the N-MOS field effect transistor Q11 is turned on; at the same time, since the voltage zener diode parameter of the first diode D34 is 6.2V, when the voltage across the capacitor C175 reaches 5V, the sum of the voltages is 5V+6.2V=11.2V;

[0069] Continuing to analyze the circuit, it can be seen that after the electrolytic capacitor C7 is charged, the 110V power supply voltage is limited by the first resistor R165 and the second resistor R167, and then the second capacitor C173 and the third capacitor C174 (selected as 4.7uF) are charged. When the second capacitor C173 and the third capacitor C174 are charged to 11.2V, the first diode D34 reaches the breakdown voltage, and the first capacitor C175 starts charging.

[0070] The voltage Vt across the second capacitor C173 and the third capacitor C174 satisfies the formula: V t =V u *[1–exp(-t / RC)]. V t is the voltage across the second capacitor C173 and the third capacitor C174, and V t V changes with time t. u is the final charging voltage of the second capacitor C173 and the third capacitor C174, that is, the voltage value across the two ends of the capacitor when it is fully charged. t is time, indicating the time elapsed from the start of charging to a certain moment. RC is the time constant of the circuit.

[0071] Ideally, when V u=110V, it can be calculated that when V t =11.2V, the charging time t of the second capacitor C173 and the third capacitor C174 is u =110V, V t =11.2V is substituted into the calculation formula to solve the charging time t=0.1074*RC. It should be noted that since the electrolytic capacitor C7 is charged and is equivalent to a power supply, under ideal conditions, the voltage sum of the resistor group and the capacitor can be regarded as 110V. It should be noted here that R is the resistance sum of the resistor group, and C is the capacitance sum of the capacitor group. Therefore, substituting R=47kohm*2, C=4.7uF*2 into the calculation formula, it can be solved that the time t=0.1074*RC=0.1074*883.6ms=94.9ms for the second capacitor C173 and the third capacitor C174 to charge to 9.2V.

[0072] At this time, the 110V power supply voltage is limited by the first resistor R165 and the second resistor R167, and then the first capacitor C175 is charged by the first diode D34. At the same time, the circuit analysis shows that since the voltage regulation parameter of the first diode D33 is 18V and the voltage regulation parameter of the first diode D34 is 6.2V, after the first capacitor C175 is fully charged, the voltage across it is 18V-6.2V=11.8V; the voltage Vt across the first capacitor C175 satisfies the formula, Vt=V u *[1–exp(-t / RC)], ideally, at V u =11.8V, it is necessary to calculate when V t =3V charging time t, V u =11.8V, V t =3V is substituted into the calculation formula to solve the charging time t=0.293*RC. Here R is the resistance value of the resistor group, and here C is the capacitance of the first capacitor. Substituting R=47kohm*2 and C=0.1uF into the calculation formula, the charging time t=0.293*RC=0.293*9.4ms=2.75ms can be solved when the voltage across the first capacitor is 3V. In the above design analysis, the control time for limiting the transient impact current of power-on is: 16.5ms+94.9ms+2.75ms=114.15ms. Subsequently, when the capacitor C175 is charged to more than 3V, the MOS tube Q11 is fully turned on, and the current limiting resistor R169 will be bypassed at this time to complete the system power-on control.

[0073] It should be noted that although the power-on transient current control circuit and the control method thereof are introduced as an example in this application, those skilled in the art will understand that this application should not be limited thereto. In fact, the user can flexibly set the parameters according to personal preferences and / or actual application scenarios, as long as they are reasonable.

[0074] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A power-on transient current control circuit, characterized in that: include: MOS tube, current limiting resistor, first diode, capacitor group, first capacitor and resistor group; One end of the current limiting resistor is suitable for being electrically connected to a power input terminal, and the other end of the current limiting resistor is suitable for being electrically connected to one end of the load; The first end of the MOS tube is electrically connected to one end of the current limiting resistor, and the second end of the MOS tube is electrically connected to one end of the current limiting resistor; One end of the resistor group is suitable for being electrically connected to the output end of the power supply, and one end of the resistor group is suitable for being electrically connected to the other end of the load, and the other end is electrically connected to one end of the capacitor group; One end of the capacitor group is electrically connected to the cathode of the first diode, and the other end of the resistor group is electrically connected to one end of the first capacitor, so as to control the voltage across the first capacitor; One end of the first capacitor is electrically connected to the first end of the MOS tube, the other end of the first capacitor is electrically connected to the positive electrode of the first diode, and the other end of the first capacitor is electrically connected to the third end of the MOS tube to control the turn-on time of the MOS tube and adjust the control duration of the transient current.

2. The power-on transient current control circuit according to claim 1, characterized in that: The resistor group includes: a first resistor and a second resistor, one end of the first resistor is electrically connected to the current limiting resistor, the other end of the first resistor is electrically connected to one end of the second resistor, and the other end of the second resistor is electrically connected to the first diode.

3. The power-on transient current control circuit according to claim 1, characterized in that: The capacitor group includes: a second capacitor and a third capacitor, one end of the second capacitor is electrically connected to the cathode of the first diode, the other end of the second capacitor is electrically connected to one end of the first capacitor, one end of the third capacitor is electrically connected to one end of the second capacitor, and the other end of the third capacitor is electrically connected to the other end of the second capacitor.

4. The power-on transient current control circuit according to claim 1, characterized in that: Also includes: a third resistor, one end of the third resistor being electrically connected to one end of the first capacitor, and the other end of the third resistor being electrically connected to the other end of the first capacitor.

5. The power-on transient current control circuit according to claim 1, characterized in that: Also includes: A second diode, wherein a cathode of the second diode is electrically connected to a cathode of the first diode, and an anode of the second diode is electrically connected to one end of the first capacitor.

6. The power-on transient current control circuit according to claim 5, characterized in that: Also includes: a fourth resistor, one end of the fourth resistor being electrically connected to the cathode of the first diode, and the other end of the fourth resistor being electrically connected to one end of the first capacitor.

7. The power-on transient current control circuit according to any one of claims 1 to 6, characterized in that: The MOS tube is an N-channel MOS field effect tube, the source of the MOS tube is electrically connected to one end of the first capacitor, the gate of the MOS tube is electrically connected to the other end of the first capacitor, and the drain of the MOS tube is electrically connected to the other end of the current limiting resistor.

8. The power-on transient current control circuit according to claim 7, characterized in that: The model of the MOS tube is FQB34N20.

9. A power-on transient current control method, characterized in that: Using the circuit described in any one of claims 1 to 8 to control the power-on transient current of a system power board, comprising: Determining the resistance value of the current limiting resistor according to the current limiting control current; Determine the capacitance value of the first capacitor, the capacitance value of the capacitor group, and the resistance value of the resistor group according to the control duration of the transient upper current; After the power is turned on, the current limiting resistor is connected to the resistor group, the resistor group is connected to the capacitor group, and the capacitor group is connected to the first capacitor; When the control time is reached, the base and gate of the MOS tube are connected to the two ends of the first capacitor, and the drain of the MOS tube is connected to the resistor group to transmit power to the load.

10. The power-on transient current control method according to claim 9, characterized in that: The control time length is calculated as follows: t=N*RC, where N is a coefficient of the control time length, R is a resistance value of the control circuit, and C is a capacitance value of the control circuit.

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