A server power board current slow start device and a server power board

Abstract

The application relates to the technical field of power supply, and discloses a server power board current slow-start device and a server power board. The slow-start device comprises a voltage monitor, a control circuit, a switching circuit and a current limiting circuit. After the power board is powered on, the control circuit sends a conduction signal to the switching circuit, and the voltage monitor monitors the voltage of a server load end and feeds back to the control circuit. When the voltage of the server load end reaches a preset voltage, the control circuit sends an off signal to the switching circuit, so that the current slowly flows to the load through the current limiting circuit, the problem of excessive impact current in the power-on process is inhibited, and the rear-end load and nonlinear components are protected.

Description

A server power board current soft-start device and server power board Technical Field

[0001] This invention relates to the field of power supply technology, specifically to a server power board current soft-start device and a server power board. Background Technology

[0002] Servers provide computing or application services to other clients on a network (such as PCs, smartphones, ATMs, and even large equipment like train systems). Servers have high-speed CPU computing power, long-term reliable operation, powerful I / O external data throughput, and better scalability. Depending on the services provided, servers generally have the ability to respond to service requests, provide services, and ensure service availability. As electronic devices, servers have a very complex internal structure, but it is not much different from the internal structure of ordinary computers, such as: CPU, hard drive, memory, system, system bus, etc.

[0003] However, with the increasingly widespread application of big data and AI computing in various internet, banking, and service systems, higher demands are being placed on server performance and requirements. Server operating current is also increasing, and due to the increased load, the capacity of nonlinear loads in the overall server chain is also increasing. This increased capacity of nonlinear loads leads to a larger inrush current during server startup, resulting in significant transient currents on the nonlinear loads downstream of the memory. When the nonlinear load current is large, it can cause false triggering of overvoltage and overcurrent protection devices in the input memory, or even thermal damage to the memory. In severe cases, it can lead to server crashes and restarts, adversely affecting the overall stability of the server. Summary of the Invention

[0004] In view of this, the present invention provides a server power board current soft start device and a server power board to solve the problem of how to achieve server power board soft start.

[0005] In a first aspect, the present invention provides a server power board current soft-start device, comprising: a voltage monitor, a control circuit, a switching circuit, and a current limiting circuit, wherein a first terminal of the voltage monitor is connected to the output terminal of the main power supply circuit of the server load, and a second terminal of the voltage monitor is connected to the first terminal of the control circuit; the second terminal of the control circuit is connected to the control terminal of the switching circuit; a first terminal of the switching circuit is connected to the input terminal of the main power supply circuit of the server load, and a second terminal of the switching circuit is connected to the first terminal of the current limiting circuit; the second terminal of the current limiting circuit is connected to the output terminal of the main power supply circuit of the server load; the input terminal of the main power supply circuit of the server load is connected to the output terminal of the power board, and the output terminal of the main power supply circuit of the server load is connected to the load; when the power board is powered on, the control circuit sends a conduction signal to the switching circuit, the voltage monitor monitors the voltage at the server load terminal and feeds it back to the control circuit; when the voltage at the server load terminal reaches a preset voltage, the control circuit sends a shutdown signal to the switching circuit.

[0006] In this invention, when the switching circuit is on and the main power supply circuit is off, the server power board output voltage is delivered to the current limiting circuit through the switching circuit. The current limiting circuit limits the voltage before delivering it to the server load to prevent current overshoot. When the switching circuit is off and the main power supply circuit is on, the server power board output voltage is delivered to the server load through the main power supply circuit, so that the current slowly flows to the load through the current limiting circuit to suppress the problem of excessive inrush current during power-on and protect the downstream load and nonlinear components.

[0007] In one optional embodiment, the voltage monitor includes a voltage conversion circuit and a voltage conditioning circuit, wherein a first terminal of the voltage conversion circuit is connected to the output terminal of the main power supply circuit of the server load, and a second terminal of the voltage conversion circuit is connected to the first terminal of the voltage conditioning circuit; the second terminal of the voltage conditioning circuit is connected to the first terminal of the control circuit; when the power board is powered on, the control circuit sends a conduction signal to the switching circuit, the voltage conversion circuit monitors the voltage at the server load terminal, and the voltage conversion circuit performs voltage reduction and voltage conversion on the voltage at the server load terminal to obtain a differential voltage signal; the voltage conditioning circuit performs differential amplification and voltage tracking on the differential voltage signal and feeds it back to the control circuit.

[0008] In one optional embodiment, the voltage conversion circuit includes a step-down circuit and a differential voltage circuit, wherein the first terminal of the step-down circuit is connected to the output terminal of the main power supply circuit of the server load, the second terminal of the step-down circuit is connected to the first terminal of the differential voltage circuit; the second terminal of the differential voltage circuit is connected to the output terminal of the main power supply circuit of the server load, and the third terminal of the differential voltage circuit is connected to the first terminal of the voltage conditioning circuit; when the power board is powered on, the control circuit sends a conduction signal to the switching circuit, the step-down circuit steps down the voltage at the server load terminal, and the differential voltage circuit performs voltage conversion on the stepped-down voltage at the server load terminal to obtain a differential voltage signal.

[0009] In one alternative implementation, the step-down circuit includes a plurality of step-down resistors, wherein the plurality of step-down resistors are connected in series, or in parallel, or in a series-parallel configuration.

[0010] In one optional embodiment, the differential voltage circuit includes a filter circuit and a voltage conversion chip. The first terminal of the filter circuit is connected to the second terminal of the step-down circuit and the input terminal of the voltage conversion chip. The second terminal of the filter circuit is connected to the output terminal of the main power supply circuit of the server load and the input terminal of the voltage conversion chip. The output terminal of the voltage conversion chip is connected to the first terminal of the voltage conditioning circuit. The filter circuit filters the voltage at the server load and then sends it to the voltage conversion chip, which converts the voltage at the server load into a differential voltage signal.

[0011] In one optional embodiment, the voltage conditioning circuit includes a differential amplifier circuit and a voltage follower circuit, wherein a first terminal of the differential amplifier circuit is connected to a second terminal of the voltage conditioning circuit, and a second terminal of the differential amplifier circuit is connected to a first terminal of the voltage follower circuit; the second terminal of the voltage follower circuit is connected to a first terminal of the control circuit; the differential amplifier circuit differentially amplifies the differential voltage signal, and the voltage follower circuit voltage-follows the amplified differential voltage signal and feeds it back to the control circuit.

[0012] In one optional embodiment, the differential amplifier circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, a second capacitor, a third capacitor, and a first operational amplifier. The first terminal of the first resistor is connected to the second terminal of the voltage conditioning circuit, and the second terminal of the first resistor is connected to the first terminal of the second resistor. The second terminal of the second resistor is connected to the first terminal of the first capacitor, the first terminal of the third resistor, and the inverting input terminal of the first operational amplifier. The first terminal of the fourth resistor is connected to the second terminal of the voltage conditioning circuit, and the second terminal of the fourth resistor is connected to the first terminal of the fifth resistor. The second terminal of the fifth resistor is connected to the first terminal of the sixth resistor, the first terminal of the second capacitor, and the non-inverting input terminal of the first operational amplifier. The second terminal of the sixth resistor is connected to the second terminal of the second capacitor and then grounded. The positive power supply terminal of the first operational amplifier is connected to the power supply voltage and is also connected to the first terminal of the third capacitor. The negative power supply terminal of the first operational amplifier is grounded. The second terminal of the third capacitor is grounded.

[0013] In one optional embodiment, the voltage follower circuit includes: a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, and a second operational amplifier. The first terminal of the seventh resistor is connected to the second terminal of the differential amplifier circuit. The second terminal of the seventh resistor is connected to the first terminal of the fourth capacitor and the non-inverting input terminal of the second operational amplifier. The inverting input terminal of the second operational amplifier, its output terminal, and the first terminal of the eighth resistor are connected. The second terminal of the eighth resistor is connected to the first terminal of the fifth capacitor and the first terminal of the control circuit. The second terminal of the fourth capacitor is grounded. The second terminal of the fifth capacitor is grounded.

[0014] In one optional embodiment, the switching circuit includes: a driving circuit and a controllable switching device, wherein a first terminal of the driving circuit is connected to a second terminal of the control circuit, and the second terminal of the driving circuit is connected to a control terminal of the controllable switching device; a first terminal of the controllable switching device is connected to the input terminal of the main power supply circuit of the server load, and a second terminal of the controllable switching device is connected to a first terminal of the current limiting circuit; when the power board is powered on, the control circuit sends a conduction signal to the driving circuit, and the driving circuit drives the controllable switching device to conduct; when the voltage at the server load reaches a preset voltage, the control circuit sends a shutdown signal to the driving circuit, and the driving circuit drives the controllable switching device to shut down.

[0015] In this invention, when the controllable switching device is turned on, the voltage drop is small, the temperature is low, and the power board efficiency is high.

[0016] In one alternative implementation, the current limiting circuit includes at least one current limiting resistor.

[0017] In a second aspect, the present invention provides a server power board, including the server power board current soft-start device of the first aspect and any optional embodiment thereof. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 is a schematic diagram of a power supply board providing power to a server load in related technologies;

[0020] Figure 2 is a composition diagram of a server power board current soft-start device according to an embodiment of the present invention;

[0021] Figure 3 is a composition diagram of another server power board current soft-start device according to an embodiment of the present invention;

[0022] Figure 4 is a specific circuit structure diagram of the voltage conversion circuit according to an embodiment of the present invention;

[0023] Figure 5 is a detailed circuit structure diagram of the voltage conditioning circuit according to an embodiment of the present invention;

[0024] Figure 6 is a composition diagram of another server power board current soft-start device according to an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] As shown in Figure 1, the server power supply unit (PSU) is a crucial component of a server system, primarily responsible for providing stable and reliable power during server operation. The most critical components in a server system are the CPU and memory, which require a stable current supply to ensure normal and efficient server operation. Therefore, the server's PSU plays a vital role in the server's stability, reliability, and performance. When the P12V power board is powered on, the numerous downstream loads and inductive loads such as capacitors can cause a large instantaneous inrush current. This can easily lead to uneven current distribution in the memory (EFUSE) and exceed the EFUSE's overcurrent protection threshold, severely impacting the server's operational stability.

[0030] Therefore, in order to solve the above problems, this embodiment provides a server power board current soft start device, as shown in Figure 2, including: a voltage monitor, a control circuit, a switching circuit and a current limiting circuit.

[0031] As shown in Figure 2, the first terminal of the voltage monitor is connected to the output terminal of the main power supply circuit of the server load, and the second terminal of the voltage monitor is connected to the first terminal of the control circuit. The input terminal of the main power supply circuit of the server load is connected to the output terminal of the power supply board, and the output terminal of the main power supply circuit of the server load is connected to the load.

[0032] Specifically, the voltage monitor has the function of monitoring the server load voltage and can condition the load voltage and feed it back to the control circuit. The conditioning content is not limited to step-down, differential amplification, filtering, voltage matching, voltage following, etc., so as to obtain a voltage signal that the control circuit can recognize and process.

[0033] As shown in Figure 2, the second terminal of the control circuit is connected to the control terminal of the switching circuit.

[0034] Specifically, the control circuit can determine whether the voltage of the server load has reached the preset voltage threshold, and based on the determination result, control the on / off state of the switch circuit to enable the server power board to directly supply power to the load through the main power supply circuit, or to supply power to the load after current limiting by the current limiting circuit.

[0035] Optionally, the control circuit can be an analog circuit or a digital circuit. When the control circuit is an analog circuit, it has a built-in comparator that compares the server load voltage with a reference voltage and outputs a high-level or low-level signal to control the switching circuit. When the control circuit is a digital circuit, it can be a CPLD control module in the server. The CPLD chip controls the state of the control loop, providing timely response and simple logic. The CPLD control module converts the server voltage into a digital voltage signal, compares the digital voltage signal with a preset voltage threshold, and outputs a control signal to control the switching circuit.

[0036] As shown in Figure 2, the first terminal of the switching circuit is connected to the input terminal of the main power supply circuit of the server load, and the second terminal of the switching circuit is connected to the first terminal of the current limiting circuit. The second terminal of the current limiting circuit is connected to the output terminal of the main power supply circuit of the server load.

[0037] Specifically, when the switching circuit is on and the main power supply circuit is off, the server power board output voltage is sent to the current limiting circuit through the switching circuit. The current limiting circuit limits the voltage before sending it to the server load to prevent current overshoot. When the switching circuit is off and the main power supply circuit is on, the server power board output voltage is sent to the server load through the main power supply circuit.

[0038] Optionally, the switching circuit has a built-in controllable switch, which can be an IGBT, MOSFET, etc., and there are no restrictions on this.

[0039] Optionally, the current limiting circuit can be composed of linear components, such as at least one current limiting resistor, the value of which is determined according to a preset voltage threshold and the capacity of the nonlinear load at the back end of the memory.

[0040] Specifically, referring to Figure 2, the server power supply board has two power supply paths, and different power supply situations are involved after the server power supply board is turned on, as follows:

[0041] (1) When the power board is powered on, the control circuit sends a conduction signal to the switching circuit, and the voltage monitor monitors the voltage at the server load end and feeds it back to the control circuit.

[0042] When the power board is powered on, in order to avoid current overshoot, the main power supply circuit does not start, and the control circuit controls the switching circuit to conduct, so that the power board supplies power to the load through the auxiliary circuit composed of the switching circuit and the current limiting circuit.

[0043] Alternatively, the control circuit may not continuously control the switching circuit to be on, but may periodically control the switching circuit to be on or off, for example, controlling the switching circuit to be on every 5µs interval.

[0044] (2) When the voltage at the server load reaches the preset voltage, the control circuit sends a shutdown signal to the switching circuit.

[0045] During the process of the power board supplying power to the server load through the auxiliary circuit, the voltage monitor monitors the voltage of the server load in real time. The control circuit determines whether the voltage of the server load has reached the preset voltage threshold. When the preset voltage threshold is reached, it means that the voltage of the server nonlinear load has reached the preset voltage threshold. At this time, the power board can directly supply power to the server load, so the control circuit controls the switch circuit to turn off.

[0046] Optionally, when the power board supplies power to the server load through the main power supply circuit, the voltage monitor can also monitor the voltage of the server load in real time and feed it back to the control circuit. When the voltage of the server load exceeds the limit, the control circuit can turn on the switching circuit again to limit the current of the power board voltage. Alternatively, when the power board voltage is too high and may burn out the server load, the control circuit can directly cut off the main power supply circuit to disconnect the power board from the server load.

[0047] In some alternative implementations, as shown in Figure 3, the voltage monitor includes a voltage conversion circuit and a voltage conditioning circuit.

[0048] As shown in Figure 3, the first terminal of the voltage conversion circuit is connected to the output terminal of the main power supply circuit of the server load, the second terminal of the voltage conversion circuit is connected to the first terminal of the voltage conditioning circuit, and the second terminal of the voltage conditioning circuit is connected to the first terminal of the control circuit.

[0049] Specifically, when the power board is powered on, the control circuit sends a conduction signal to the switching circuit. The voltage conversion circuit monitors the voltage at the server load end. After the voltage at the server load end is stepped down and converted, a differential voltage signal is obtained. The voltage conditioning circuit performs differential amplification and voltage tracking on the differential voltage signal and feeds it back to the control circuit.

[0050] Specifically, in order to match the control parameters of the control circuit, a voltage conversion circuit and a voltage conditioning circuit need to be added before the control circuit. The voltage conversion circuit mainly functions to obtain differential signals, while the voltage conditioning circuit mainly amplifies and voltage follows the differential signals. Since differential signals have a strong ability to suppress common-mode input signals but have little effect on differential-mode signals, differential signals are used as the input stage and intermediate stage of integrated operations to suppress the influence of changes in external conditions on the circuit, such as temperature noise.

[0051] In some alternative implementations, the voltage conversion circuit includes a buck circuit and a differential voltage circuit.

[0052] Specifically, the first terminal of the step-down circuit is connected to the output terminal of the main power supply circuit of the server load, and the second terminal of the step-down circuit is connected to the first terminal of the differential voltage circuit. A step-down circuit is added before the differential voltage circuit to reduce the voltage of the server load.

[0053] Optionally, the step-down circuit includes multiple step-down resistors, wherein the multiple step-down resistors are connected in series, parallel, or series-parallel configurations. For example, as shown in Figure 4, the step-down circuit includes four resistors, R9 to R12, connected in series, and the resistance values ​​of the four resistors are set as needed.

[0054] Specifically, the second terminal of the differential voltage circuit is connected to the output terminal of the main power supply circuit of the server load, and the third terminal of the differential voltage circuit is connected to the first terminal of the voltage conditioning circuit.

[0055] Specifically, when the power board is powered on, the control circuit sends a conduction signal to the switching circuit, the step-down circuit steps down the voltage at the server load end, and the differential voltage circuit converts the stepped-down voltage at the server load end to obtain a differential voltage signal.

[0056] In some optional implementations, the differential voltage circuit includes a filter circuit and a voltage conversion chip, wherein the first terminal of the filter circuit is connected to the second terminal of the step-down circuit and the input terminal of the voltage conversion chip, the second terminal of the filter circuit is connected to the output terminal of the main power supply circuit of the server load and the input terminal of the voltage conversion chip; the output terminal of the voltage conversion chip is connected to the first terminal of the voltage conditioning circuit; the filter circuit filters the voltage at the server load and then sends it to the voltage conversion chip, and the voltage conversion chip converts the voltage at the server load into a differential voltage signal.

[0057] Optionally, to further prevent interference from noise or other signals, a filter circuit is provided before the voltage conversion chip. This filter circuit can be composed of a capacitor and a resistor connected in parallel, or other filter circuit structures can be used, without limitation. For example, referring to Figure 4, JX1 is connected to the output terminal of the main power supply circuit, and the filter circuit is composed of resistors R13 and R14 and capacitor C6 connected in parallel.

[0058] Optionally, the voltage conversion chip has a built-in differential circuit that can convert the voltage of the server load into a differential signal to resist interference from the common-mode input signal.

[0059] Optionally, referring to Figure 4, the voltage conversion chip is U1, which can be HCPL7840. Pin 1 of HCPL7840 is connected to VDD and grounded after being connected in series with capacitor C7. Pin 2 is connected to the step-down resistor (R12). Pins 3 and 4 are shorted. Pin 5 is grounded. Pins 6 and 7 are connected to the differential amplifier circuit in the voltage conditioning circuit.

[0060] In some alternative implementations, the voltage conditioning circuit includes a differential amplifier circuit and a voltage follower circuit.

[0061] Specifically, the first terminal of the differential amplifier circuit is connected to the second terminal of the voltage conditioning circuit, and the second terminal of the differential amplifier circuit is connected to the first terminal of the voltage follower circuit; the second terminal of the voltage follower circuit is connected to the first terminal of the control circuit; the differential amplifier circuit performs differential amplification on the differential voltage signal, and the voltage follower circuit performs voltage following on the amplified differential voltage signal and feeds it back to the control circuit.

[0062] Specifically, differential amplifier circuits utilize the symmetry of circuit parameters and negative feedback to effectively stabilize the quiescent operating point. They are characterized by amplifying differential signals and suppressing common-mode signals, and are widely used in the input stages of directly coupled circuits and measurement circuits. Differential amplifier circuits are classified into four types according to their input / output method: dual-ended input dual-ended output, dual-ended input single-ended output, single-ended input dual-ended output, and single-ended input single-ended output.

[0063] Optionally, the differential amplifier circuit in this embodiment mainly adopts a dual-input single-output structure, as shown in Figure 5. The differential amplifier circuit specifically includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a first operational amplifier A1.

[0064] In Figure 5, the first terminal of the first resistor R1 is connected to the second terminal of the voltage conditioning circuit, and the second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2; the second terminal of the second resistor R2 is connected to the first terminal of the first capacitor C1, the first terminal of the third resistor R3, and the inverting input terminal of the first operational amplifier A1, respectively; the first terminal of the fourth resistor R4 is connected to the second terminal of the voltage conditioning circuit, and the second terminal of the fourth resistor R4 is connected to the first terminal of the fifth resistor R5; the second terminal of the fifth resistor R5 is connected to the first terminal of the sixth resistor R6, the first terminal of the second capacitor C2, and the non-inverting input terminal of the first operational amplifier A1, respectively; the second terminal of the sixth resistor R6 is connected to the second terminal of the second capacitor C2 and then grounded; the positive power supply terminal of the first operational amplifier A1 is connected to the power supply voltage, and the positive power supply terminal of the first operational amplifier A1 is also connected to the first terminal of the third capacitor C3, and the negative power supply terminal of the first operational amplifier A1 is grounded; the second terminal of the third capacitor C3 is grounded.

[0065] Specifically, in Figure 5, ADC4 is connected to the control circuit. The first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 step down the two differential voltage signals and input them into the first operational amplifier A1. The sixth resistor R6 and the second capacitor C2 form an RC filter circuit. The first operational amplifier amplifies the differential voltage signal and sends it to the voltage follower circuit.

[0066] Specifically, this embodiment incorporates a voltage follower circuit. This circuit features high input impedance and low output impedance. When the input impedance is very high, it's equivalent to an open circuit to the preceding stage. When the output impedance is very low, it's equivalent to a low internal resistance of the power supply. Therefore, when the power supply output current changes, the voltage difference across this internal resistance changes little. This acts as a constant voltage source for the following stage, meaning the output voltage is unaffected by the impedance of the following stage. A circuit that is essentially an open circuit to the preceding stage and whose output voltage is unaffected by the impedance of the following stage naturally provides isolation, ensuring that the preceding and following stages do not interfere with each other.

[0067] Optionally, as shown in Figure 5, the voltage follower circuit includes: a seventh resistor R7, an eighth resistor R8, a fourth capacitor C4, a fifth capacitor C5, and a second operational amplifier A2. The first terminal of the seventh resistor R7 is connected to the second terminal of the differential amplifier circuit. The second terminal of the seventh resistor R7 is connected to the first terminal of the fourth capacitor C4 and the non-inverting input terminal of the second operational amplifier A2. The inverting input terminal of the second operational amplifier A2 is connected to its output terminal and the first terminal of the eighth resistor R8. The second terminal of the eighth resistor R8 is connected to the first terminal of the fifth capacitor C5 and the first terminal of the control circuit. The second terminal of the fourth capacitor C4 is grounded. The second terminal of the fifth capacitor C5 is grounded.

[0068] In Figure 5, the second operational amplifier A2 is a unity-gain buffer, which generates an output signal with an amplitude equal to the input signal. Since the input signal is applied to the non-inverting input, inversion does not occur. Therefore, the second operational amplifier A2 is a non-inverting buffer with excellent tracking capability.

[0069] In some alternative implementations, as shown in FIG6, the switching circuit includes: a driving circuit and a controllable switching device.

[0070] As shown in Figure 6, the first end of the drive circuit is connected to the second end of the control circuit, and the second end of the drive circuit is connected to the control end of the controllable switching device; the first end of the controllable switching device is connected to the input end of the main power supply circuit of the server load, and the second end of the controllable switching device is connected to the first end of the current limiting circuit.

[0071] Optionally, the controllable switching device can be an IGBT, MOSFET, etc., and is not limited thereto. The drive circuit can convert the control signal output by the control circuit into a control voltage that can drive the controllable switching device.

[0072] Specifically, when the power board is powered on, the control circuit sends a conduction signal to the drive circuit, which in turn drives the controllable switching device to conduct; when the voltage at the server load reaches the preset voltage, the control circuit sends a shutdown signal to the drive circuit, which in turn drives the controllable switching device to shut down.

[0073] This embodiment provides a server power supply board, including the server power supply board current soft-start device of the above embodiments and any optional embodiments thereof.

[0074] Specifically, the server power supply may include rectifier circuits, DC-DC circuits, etc., which can convert AC power to DC power, or convert DC power to DC power of another amplitude. A soft-start device is connected to the power supply stage so that when the switching circuit is on and the main power supply circuit is off, the output voltage of the server power supply board is sent to the current limiting circuit through the switching circuit. The current limiting circuit limits the voltage before sending it to the server load to prevent current overshoot. When the switching circuit is off and the main power supply circuit is on, the output voltage of the server power supply board is sent to the server load through the main power supply circuit, so that the current slowly passes through the auxiliary circuit, thereby suppressing the problem of excessive inrush current during the power-on process.

[0075] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A server power board current soft-start device, characterized in that, include: The system includes a voltage monitor, a control circuit, a switching circuit, and a current limiting circuit. The first terminal of the voltage monitor is connected to the output terminal of the main power supply circuit of the server load; the second terminal of the voltage monitor is connected to the first terminal of the control circuit; the second terminal of the control circuit is connected to the control terminal of the switching circuit; the first terminal of the switching circuit is connected to the input terminal of the main power supply circuit of the server load; the second terminal of the switching circuit is connected to the first terminal of the current limiting circuit; the second terminal of the current limiting circuit is connected to the output terminal of the main power supply circuit of the server load; the input terminal of the main power supply circuit of the server load is connected to the output terminal of the power supply board; and the output terminal of the main power supply circuit of the server load is connected to the load. When the power supply board is powered on, the control circuit sends a conduction signal to the switching circuit, and the voltage monitor monitors the voltage at the server load terminal and feeds it back to the control circuit. When the voltage at the server load reaches a preset voltage, the control circuit sends a shutdown signal to the switching circuit. When the switching circuit is on and the main power supply circuit is off, the server power board output voltage is sent to the current limiting circuit through the switching circuit. The current limiting circuit limits the voltage before sending it to the server load to prevent current overshoot. When the switching circuit is off and the main power supply circuit is on, the server power board output voltage is sent to the server load through the main power supply circuit. When the power board supplies power to the server load through the main power supply circuit, the voltage monitor monitors the voltage of the server load in real time and feeds it back to the control circuit. When the voltage of the server load exceeds the limit, the control circuit turns the switching circuit on again to limit the current of the power board voltage. Alternatively, when the power board voltage is too high and may burn out the server load, the control circuit directly cuts off the main power supply circuit to disconnect the power board from the server load.

2. The server power board current soft-start device according to claim 1, characterized in that, The voltage monitor includes a voltage conversion circuit and a voltage conditioning circuit. The first terminal of the voltage conversion circuit is connected to the output terminal of the main power supply circuit of the server load, and the second terminal of the voltage conversion circuit is connected to the first terminal of the voltage conditioning circuit. The second terminal of the voltage conditioning circuit is connected to the first terminal of the control circuit. When the power board is powered on, the control circuit sends a conduction signal to the switching circuit. The voltage conversion circuit monitors the voltage at the server load end. After stepping down and converting the voltage at the server load end, the voltage conversion circuit obtains a differential voltage signal. The voltage conditioning circuit differentially amplifies and voltage-follows the differential voltage signal before feeding it back to the control circuit.

3. The server power board current soft-start device according to claim 2, characterized in that, The voltage conversion circuit includes a step-down circuit and a differential voltage circuit. The first terminal of the step-down circuit is connected to the output terminal of the main power supply circuit of the server load, and the second terminal of the step-down circuit is connected to the first terminal of the differential voltage circuit. The second terminal of the differential voltage circuit is connected to the output terminal of the main power supply circuit of the server load, and the third terminal of the differential voltage circuit is connected to the first terminal of the voltage conditioning circuit. When the power board is powered on, the control circuit sends a conduction signal to the switching circuit. The step-down circuit reduces the voltage at the server load terminal, and the differential voltage circuit converts the reduced voltage at the server load terminal to obtain a differential voltage signal.

4. The server power board current soft-start device according to claim 3, characterized in that, The step-down circuit includes a plurality of step-down resistors, wherein the plurality of step-down resistors are connected in series, or in parallel, or in a series-parallel configuration.

5. The server power board current soft-start device according to claim 3, characterized in that, The differential voltage circuit includes a filter circuit and a voltage conversion chip. The first terminal of the filter circuit is connected to the second terminal of the step-down circuit and the input terminal of the voltage conversion chip. The second terminal of the filter circuit is connected to the output terminal of the main power supply circuit of the server load and the input terminal of the voltage conversion chip. The output terminal of the voltage conversion chip is connected to the first terminal of the voltage conditioning circuit. The filter circuit filters the voltage at the server load and then sends it to the voltage conversion chip, which converts the voltage at the server load into a differential voltage signal.

6. The server power board current soft-start device according to claim 2, characterized in that, The voltage conditioning circuit includes a differential amplifier circuit and a voltage follower circuit, wherein a first terminal of the differential amplifier circuit is connected to a second terminal of the voltage conditioning circuit, and a second terminal of the differential amplifier circuit is connected to a first terminal of the voltage follower circuit; the second terminal of the voltage follower circuit is connected to a first terminal of the control circuit; the differential amplifier circuit differentially amplifies the differential voltage signal, and the voltage follower circuit voltage-follows the amplified differential voltage signal and feeds it back to the control circuit.

7. The server power board current soft-start device according to claim 6, characterized in that, The differential amplifier circuit includes: a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, a second capacitor, a third capacitor, and a first operational amplifier. The first terminal of the first resistor is connected to the second terminal of the voltage conditioning circuit, and the second terminal of the first resistor is connected to the first terminal of the second resistor. The second terminal of the second resistor is connected to the first terminal of the first capacitor, the first terminal of the third resistor, and the inverting input terminal of the first operational amplifier. The first terminal of the fourth resistor is connected to the second terminal of the voltage conditioning circuit, and the second terminal of the fourth resistor is connected to the first terminal of the fifth resistor. The second terminal of the fifth resistor is connected to the first terminal of the sixth resistor, the first terminal of the second capacitor, and the non-inverting input terminal of the first operational amplifier. The second terminal of the sixth resistor is connected to the second terminal of the second capacitor and then grounded. The positive power supply terminal of the first operational amplifier is connected to the power supply voltage and is also connected to the first terminal of the third capacitor. The negative power supply terminal of the first operational amplifier is grounded. The second terminal of the third capacitor is grounded.

8. The server power board current soft-start device according to claim 6, characterized in that, The voltage follower circuit includes a seventh resistor, an eighth resistor, a fourth capacitor, a fifth capacitor, and a second operational amplifier. The first terminal of the seventh resistor is connected to the second terminal of the differential amplifier circuit. The second terminal of the seventh resistor is connected to the first terminal of the fourth capacitor and the non-inverting input terminal of the second operational amplifier. The inverting input terminal of the second operational amplifier is connected to its output terminal and the first terminal of the eighth resistor. The second terminal of the eighth resistor is connected to the first terminal of the fifth capacitor and the first terminal of the control circuit. The second terminal of the fourth capacitor is grounded. The second terminal of the fifth capacitor is grounded.

9. The server power board current soft-start device according to claim 1, characterized in that, The switching circuit includes a driving circuit and a controllable switching device. A first terminal of the driving circuit is connected to a second terminal of the control circuit, and the second terminal of the driving circuit is connected to a control terminal of the controllable switching device. A first terminal of the controllable switching device is connected to the input terminal of the main power supply circuit of the server load, and a second terminal of the controllable switching device is connected to a first terminal of the current limiting circuit. When the power board is powered on, the control circuit sends a turn-on signal to the driving circuit, which drives the controllable switching device to turn on. When the voltage at the server load reaches a preset voltage, the control circuit sends a turn-off signal to the driving circuit, which drives the controllable switching device to turn off.

10. A server power supply board, characterized in that, Includes the server power board current soft-start device as described in any one of claims 1-9.

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