Server power supply and sampling circuit thereof

Abstract

The invention discloses a server power supply and a sampling circuit thereof. The sampling circuit comprises a voltage conversion module, a first bias voltage module, a second bias voltage module, a first amplification module, a sampling module and a second amplification module, wherein the first bias voltage module outputs first bias voltage; the second bias voltage module outputs a second bias voltage; the first amplification module amplifies the output voltage and the first bias voltage to obtain a first amplified voltage; the sampling module collects and outputs a first amplified voltage; the second amplification module eliminates the first bias voltage in the first amplification voltage, amplifies the first bias voltage and then outputs a second amplification voltage. According to the technical scheme, by optimizing bias voltage processing and amplifier design, the precision problem in a current sampling circuit is effectively solved, and particularly, accurate current sampling and data reporting can be guaranteed under the conditions of large current and low current.

Description

Technical Field

[0001] The present invention relates to the technical field of server power supplies, and in particular to a server power supply and a sampling circuit thereof. Background Art

[0002] With the rapid development of the Internet industry and artificial intelligence technology, users' demand for data storage and processing capabilities continues to increase, resulting in higher and higher power requirements for server power supplies. Under the limitation of the standard size of 175×73×40mm of the CRPS (Common Redundant Power Supply) server power supply, the power density requirement of the server power supply has exceeded 100W / in3, and its power level needs to reach 3200W. The mainstream output voltage of existing server power supplies is 12V. If a power output of 3200W is to be achieved, an output current of up to 265A needs to be provided. In addition, considering that the server power supply needs to meet the requirement of 1.5 times the peak power in some scenarios, that is, the maximum output current of 397A, it is particularly important to ensure the normal operation of the server and the accurate monitoring of the current output.

[0003] The server power supply system uses DSP (digital signal processor) for digital control. The supply voltage of DSP is usually 3.3V, and the server power supply needs to have a high-precision current reporting function, requiring the ability to report the output current to the BMC (Baseboard Management Controller) system in real time with an accuracy of 3%. Therefore, how to accurately sample the output current under high current conditions and perform precise conversion and reporting has become one of the key challenges in power supply design.

[0004] The output current is usually sampled by combining a low-resistance sampling resistor with a high-precision operational amplifier to convert the output current into a voltage signal and input it into the DSP. However, due to the large output current range, the sampling voltage corresponds to 3.3V at 397A, while at a smaller current such as 5A, the sampling voltage is only 40mV. This makes the sampling accuracy at low voltage easily affected by the PCB line impedance and the operational amplifier offset voltage (OFFSET), resulting in the sampling signal accuracy within 100mV unable to meet the design requirements. Therefore, how to optimize the current sampling circuit to eliminate noise interference and improve the accuracy of small current sampling is the key to achieving high-precision current reporting function. Summary of the invention

[0005] The embodiment of the present invention provides a server power supply and a sampling circuit thereof to solve the above technical problems.

[0006] A first aspect of an embodiment of the present invention provides a sampling circuit for a server power supply, including:

[0007] A voltage conversion module, used for converting an input voltage into an output voltage;

[0008] A first bias voltage module, used for outputting a first bias voltage;

[0009] A second bias voltage module, used for outputting a second bias voltage;

[0010] A first amplifying module, whose input end is respectively connected to the output end of the voltage conversion module and the output end of the first bias voltage module, and is used to amplify the output voltage and the first bias voltage to obtain a first amplified voltage;

[0011] a sampling module, whose input end is connected to the output end of the first amplifying module, and is used to collect and output the first amplified voltage;

[0012] The second amplifying module has a first input end connected to the output end of the first amplifying module and a second input end connected to the output end of the second bias voltage module, and is used to eliminate the first bias voltage in the first amplified voltage and output a second amplified voltage after amplification.

[0013] Optionally, the voltage conversion module includes a first capacitor, a second capacitor, a first MOS transistor, a second MOS transistor, a first resistor, a second resistor, a first inductor, a second inductor, a first diode, a second diode and a transformer;

[0014] One end of the first capacitor and the drain of the first MOS tube are connected in common and receive an input voltage, the source of the first MOS tube is respectively connected to one end of the first inductor and the drain of the second MOS tube, the second end of the first inductor is respectively connected to one end of the second inductor and the first end of the primary coil of the transformer, the other end of the first capacitor, the source of the second MOS tube, the other end of the second inductor and the second end of the primary coil of the transformer are connected in common to the ground, the first end of the secondary coil of the transformer is connected to the cathode of the first diode, the center tap of the secondary coil of the transformer is respectively connected to one end of the second capacitor and one end of the first resistor, the second end of the secondary coil of the transformer is connected to the cathode of the second diode, the anode of the first diode, the anode of the second diode and one end of the second resistor are connected in common as the first output end of the voltage conversion module, and the other end of the second capacitor, the other end of the first resistor and the other end of the second resistor are connected in common as the second output end of the voltage conversion module.

[0015] Optionally, the first bias voltage module includes a fourth resistor, one end of the fourth resistor is the input end of the first bias voltage module and receives the first voltage, and the other end of the fourth resistor is the output end of the first bias voltage module.

[0016] Optionally, the first amplification module includes a third resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a fourth capacitor, a fifth capacitor and a first operational amplifier;

[0017] The non-inverting input terminal of the first operational amplifier is respectively connected to one end of the third resistor, one end of the fourth resistor, one end of the fifth resistor, one end of the third capacitor and one end of the fourth capacitor; the inverting input terminal of the first operational amplifier is respectively connected to one end of the sixth resistor, one end of the seventh resistor, one end of the eighth resistor, one end of the fourth capacitor and one end of the fifth capacitor; the other end of the fifth resistor is the first input terminal of the first amplification module; the other end of the sixth resistor is the second input terminal of the first amplification module; the output terminal of the first operational amplifier, the other end of the seventh resistor, the other end of the eighth resistor, the other end of the ninth resistor and the other end of the fifth capacitor are commonly connected to the output terminal of the first amplification module; the other end of the third resistor, the other end of the fourth resistor and the other end of the ninth resistor are commonly connected to the ground.

[0018] Optionally, the sampling module includes a tenth resistor, one end of the tenth resistor is the input end of the sampling module, and the other end of the tenth resistor is the output end of the sampling module.

[0019] Optionally, the second bias voltage module includes an eleventh resistor, a twelfth resistor, an eleventh capacitor, a twelfth capacitor and a second operational amplifier, the non-inverting input terminal of the second operational amplifier is respectively connected to one end of the eleventh resistor, one end of the twelfth resistor and one end of the eleventh capacitor, the other end of the eleventh resistor receives a second voltage, the non-inverting input terminal of the second operational amplifier, the output terminal of the second operational amplifier and one end of the twelfth capacitor are connected in common as the output terminal of the second bias voltage module, and the other end of the eleventh capacitor, the other end of the twelfth resistor and the other end of the twelfth capacitor are connected in common to ground.

[0020] Optionally, the first bias voltage and the second bias voltage are the same.

[0021] Optionally, the second amplification module includes a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-first capacitor, a twenty-second capacitor and a third operational amplifier;

[0022] The non-inverting input terminal of the third operational amplifier is connected to one end of the twenty-first resistor, the other end of the twenty-first resistor is the first input terminal of the second amplifying module, the inverting input terminal of the third operational amplifier is respectively connected to one end of the twenty-second resistor, one end of the twenty-third resistor and one end of the twenty-first capacitor, the other end of the twenty-second resistor is the second input terminal of the second amplifying module, the output terminal of the third operational amplifier, the other end of the twenty-third resistor, the other end of the twenty-first capacitor and one end of the twenty-second capacitor are connected together as the output terminal of the second amplifying module, and the other end of the twenty-second capacitor is grounded.

[0023] A second aspect of an embodiment of the present invention provides a server power supply, comprising: the sampling circuit described in the first aspect.

[0024] Optionally, the server power supply further includes a control module, and an input end of the control module is connected to an output end of the sampling module.

[0025] The technical effects of the embodiments of the present invention are as follows: by introducing and eliminating the bias voltage, the problem of insufficient sampling accuracy at low current is solved, ensuring that the sampling accuracy can meet the design requirements even under low voltage signals. The cascade amplification design of the first module amplification and the second amplification module ensures that the current can be accurately sampled and amplified under high current conditions, solving the conversion problem of large current sampling signals. Through multi-stage amplification and precise adjustment, it is ensured that the current output can be reported to the control system with high accuracy, improving the real-time and accuracy of current monitoring. The technical solution effectively solves the accuracy problem in the current sampling circuit by optimizing the bias voltage processing and amplifier design, especially ensuring accurate current sampling and data reporting under both high current and low current conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0027] Figure 1 It is a structural schematic diagram of a sampling circuit of a server power supply provided in Embodiment 1 of the present invention;

[0028] Figure 2 It is a circuit diagram of a voltage conversion module in a sampling circuit of a server power supply provided by Embodiment 1 of the present invention;

[0029] Figure 3This is a circuit diagram of the connection between a first amplification module, a first bias voltage module and a sampling module in a sampling circuit of a server power supply provided by Embodiment 1 of the present invention;

[0030] Figure 4 It is a circuit diagram of a second bias voltage module in a sampling circuit of a server power supply provided in Embodiment 1 of the present invention;

[0031] Figure 5 It is a circuit diagram of a second amplification module in a sampling circuit of a server power supply provided in Embodiment 1 of the present invention;

[0032] Figure 6 It is a structural schematic diagram of a server power supply provided by Embodiment 2 of the present invention;

[0033] In the figure: 101, voltage conversion module; 102, first bias voltage module; 103, second bias voltage module; 104, first amplification module; 105, sampling module; 106, second amplification module; 201, control module. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be understood that the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0036] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there may be no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0037] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0038] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0039] In order to fully understand the present invention, detailed structures and steps will be presented in the following description to illustrate the technical solutions proposed by the present invention. The preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0040] Embodiment 1

[0041] This embodiment 1 provides a sampling circuit of a server power supply, such as Figure 1 As shown, including:

[0042] A voltage conversion module 101, used to convert an input voltage into an output voltage;

[0043] A first bias voltage module 102, configured to output a first bias voltage;

[0044] A second bias voltage module 103, configured to output a second bias voltage;

[0045] A first amplifying module 104, whose input end is respectively connected to the output end of the voltage conversion module 101 and the output end of the first bias voltage module 102, and is used to amplify the output voltage and the first bias voltage to obtain a first amplified voltage;

[0046] A sampling module 105, whose input end is connected to the output end of the first amplifying module 104, is used to collect and output the first amplified voltage;

[0047] The second amplifying module 106 has a first input end connected to the output end of the first amplifying module 104 and a second input end connected to the output end of the second bias voltage module 103, and is used to eliminate the first bias voltage in the first amplified voltage and output the second amplified voltage after amplification.

[0048] Among them, the sampling circuit of the server power supply provided in the first embodiment ensures high-precision current sampling and eliminates the influence of bias voltage through the collaborative work of multiple modules. The functions and working processes of each module are described in detail below. The voltage conversion module 101 converts the input voltage in the power supply system into an output voltage signal suitable for subsequent processing. The input voltage is provided by an internal power supply. The voltage conversion module 101 transmits the voltage signal to the first amplification module 104 for further processing. The first bias voltage module 102 generates a first bias voltage for compensating the voltage signal. The first bias voltage module 102 adds a fixed reference voltage to the output voltage signal to improve the accuracy of the amplified signal, especially when processing low voltage (low current) signals. The second bias voltage module 103 generates a second bias voltage for canceling with the first bias voltage to eliminate the influence on the voltage signal. The second bias voltage module 103 generates a bias voltage that is the same as or similar to the first bias voltage, which is used to offset the first bias voltage introduced in the first amplified voltage. The first amplification module 104 amplifies the output voltage from the voltage conversion module 101 and the first bias voltage of the first bias voltage module 102, and obtains the amplified first voltage signal by amplifying the voltage superimposed by the two. The sampling module 105 collects the amplified voltage signal output by the first amplification module 104, and outputs it for subsequent processing, collects the amplified voltage signal, and transmits it to the digital signal processor (DSP) or control module in the system for calculation and processing. The second amplification module 106 performs secondary amplification on the processed signal after eliminating the first bias voltage in the first amplified voltage to ensure the accuracy of the output signal. The module receives the signal from the second bias voltage module 103, and performs calculation with the output voltage signal of the first amplification module 104. After eliminating the influence of the first bias voltage, the processed signal is amplified again to output the final second amplified voltage.

[0049] The technical effect of the technical solution provided in the first embodiment is that: by introducing and eliminating the bias voltage, the problem of insufficient sampling accuracy at low current is solved, ensuring that the sampling accuracy can meet the design requirements even under low voltage signals (such as 40mV). The cascade amplification design of the first module amplification and the second amplification module ensures that the current can be accurately sampled and amplified under high current conditions (such as 397A), solving the conversion problem of large current sampling signals. The technical solution ensures that the current output can be reported to the control system with an accuracy of 3% through multi-stage amplification and precise adjustment, thereby improving the real-time and accuracy of current monitoring. The technical solution effectively solves the accuracy problem in the current sampling circuit by optimizing the processing of the bias voltage and the amplifier design, especially ensuring the current sampling and data reporting under both high current and low current conditions.

[0050] As an implementation of the voltage conversion module 101, Figure 2 As shown, the voltage conversion module 101 includes a first capacitor C1, a second capacitor C2, a first MOS transistor Q1, a second MOS transistor Q2, a first resistor R1, a second resistor R2, a first inductor L1, a second inductor L2, a first diode D1, a second diode D2 and a transformer T1; one end of the first capacitor C1 and the drain of the first MOS transistor Q1 are connected in common and receive an input voltage VIN, the source of the first MOS transistor Q1 is respectively connected to one end of the first inductor L1 and the drain of the second MOS transistor Q2, the second end of the first inductor L1 is respectively connected to one end of the second inductor L2 and the first end of the primary coil of the transformer T1, the other end of the first capacitor C1 and the source of the second MOS transistor Q2 are respectively connected to one end of the second inductor L2 and the first end of the primary coil of the transformer T1, and the other end of the first capacitor C1 and the source of the second MOS transistor Q2 are respectively connected to the first inductor L1 and the drain of the second MOS transistor Q2. , the other end of the second inductor L2 and the second end of the primary coil of the transformer T1 are connected to the ground, the first end of the secondary coil of the transformer T1 is connected to the cathode of the first diode D1, the center tap of the secondary coil of the transformer T1 is respectively connected to one end of the second capacitor C2 and one end of the first resistor R1, the second end of the secondary coil of the transformer T1 is connected to the cathode of the second diode D2, the anode of the first diode D1, the anode of the second diode D2 and one end of the second resistor R2 are connected to the first output end of the voltage conversion module 101, and the other end of the second capacitor C2, the other end of the first resistor R1 and the other end of the second resistor R2 are connected to the second output end of the voltage conversion module 101.

[0051] Among them, the first capacitor C1 and the second capacitor C2 are used for filtering and smoothing the ripple of the input voltage and the output voltage. The first capacitor C1 is connected to the input voltage in common, and plays a buffering role to reduce the fluctuation of the input voltage; the second capacitor C2 is located at the output end, and is used to filter out the high-frequency noise in the output voltage and provide a stable DC voltage. The first MOS tube Q1 and the second MOS tube Q2 are used as switching elements in the voltage conversion module 101, and voltage conversion is achieved by controlling the on and off. The first MOS tube Q1 and the second MOS tube Q2 are turned on and off in turn under the action of the PWM (pulse width modulation) control signal, and the energy transmission is controlled by adjusting the on time. When the first MOS tube Q1 is turned on, the input voltage is transmitted to the subsequent first inductor L1, the second inductor L2 and the transformer T1 through the first MOS tube Q1; the conduction of the second MOS tube Q2 forms a current loop, so that the subsequent inductor releases energy. The first inductor L1 and the second inductor L2 store and convert electrical energy, and convert the input voltage into a voltage suitable for the transformer T1 to process. The transformer T1 performs voltage conversion, and converts the voltage of the primary coil into the voltage of the secondary coil according to a certain ratio. The transformer T1 generates a magnetic field in its primary coil through the electric energy provided by the inductor, and the secondary coil generates a corresponding voltage according to the turns ratio. The center tap provides an additional voltage adjustment path, and the output voltage is divided into positive and negative paths. The first diode D1 and the second diode D2 act as rectifying elements to convert the AC voltage output by the secondary coil of the transformer T1 into a DC voltage, and together with the center tap voltage, form the output voltage of the voltage conversion module 101. The first resistor R1 and the second resistor R2 act as load voltage dividers to share the output voltage and ensure the balance of the voltage output end. The first resistor R1 and the second resistor R2 adjust the amplitude of the output voltage through the voltage divider to ensure that the output voltage of the voltage conversion module 101 is stable within the design range. The first output terminal and the second output terminal output the converted DC voltage for use in subsequent circuits. The DC voltage after rectification, filtering and voltage division is output through the first output terminal and the second output terminal, providing positive voltage and negative voltage respectively to meet the needs of different circuits.

[0052] The technical effect of this embodiment is that the voltage conversion module converts the input voltage into a stable output voltage through the coordinated action of multiple elements, and ensures efficient energy transmission and stable output voltage through the switch control of the MOS tube, the energy storage and release of the inductor, the voltage conversion of the transformer and the rectification process of the diode.

[0053] It should be noted that in addition to the above-mentioned structure, the voltage conversion module 101 includes but is not limited to the following structures: Buck (step-down) converter, Boost (step-up) converter, Buck-Boost converter, Flyback (flyback) converter, Forward (forward) converter, LLC resonant converter, etc.

[0054] As an implementation method, Figure 3 As shown, the first bias voltage module 102 includes a fourth resistor R4 , one end of the fourth resistor R4 is the input end of the first bias voltage module 102 and receives the first voltage S3V3 , and the other end of the fourth resistor R4 is the output end of the first bias voltage module 102 .

[0055] Among them, the role of the fourth resistor R4 is to generate a fixed bias voltage in the circuit and limit the size of the current to prevent excessive current from affecting subsequent circuits. The input end of the fourth resistor R4 receives a stable input voltage (first voltage), and the first voltage usually comes from a regulated power supply or a reference voltage source. Under the action of the fourth resistor R4, according to the resistance value and the input voltage, through the voltage divider relationship, a relatively low and stable voltage is generated at the other end of the fourth resistor R4, and this voltage is output as the first bias voltage. The first bias voltage module 102 generates a stable bias voltage for compensating for the error caused by the low voltage signal in the sampling circuit, so that the sampling signal is more accurate.

[0056] The technical effect of this embodiment is that through the voltage dividing effect of the fourth resistor, the first bias voltage module provides a stable bias voltage for the sampling circuit, and the voltage is used to eliminate errors caused by line errors or operational amplifier offset voltages, thereby ensuring that the sampling signal can maintain a high degree of accuracy under different current conditions.

[0057] It should be noted that, in addition to the above structure, the first bias voltage module 102 also includes but is not limited to the following structures: a reference voltage source structure, a constant current source plus a resistor structure, a Zener diode voltage stabilization structure, and the like.

[0058] As an implementation method, Figure 3As shown, the first amplification module 104 includes a third resistor R3, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5 and a first operational amplifier U1; the non-inverting input terminal of the first operational amplifier U1 is respectively connected to one end of the third resistor R3, one end of the fourth resistor R4, one end of the fifth resistor R5, one end of the third capacitor C3 and one end of the fourth capacitor C4, and the inverting input terminal of the first operational amplifier U1 is respectively connected to one end of the sixth resistor R6, one end of the seventh resistor R7, One end of the eighth resistor R8, the other end of the fourth capacitor C4 and one end of the fifth capacitor C5, the other end of the fifth resistor R5 is the first input end of the first amplifying module 104, the other end of the sixth resistor R6 is the second input end of the first amplifying module 104, the output end of the first operational amplifier U1, the other end of the seventh resistor R7, the other end of the eighth resistor R8, one end of the ninth resistor R9 and the other end of the fifth capacitor C5 are connected together as the output end of the first amplifying module 104, and the other end of the third capacitor C3, the other end of the third resistor R3 and the other end of the ninth resistor R9 are connected together to the ground.

[0059] Among them, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the third capacitor C3, and the fourth capacitor C4 are mainly used for the in-phase input terminal of the first operational amplifier U1 to form a filtering and gain adjustment circuit for the input signal. The resistor is used to set the voltage distribution of the input signal, and the capacitor is used to filter out high-frequency noise. The fourth resistor R4 and the fifth resistor R5 respectively introduce the external voltage signal into the in-phase input terminal of the operational amplifier, and the signal gain of the in-phase input terminal is determined by selecting the resistance value. The fourth resistor R4 forms a voltage divider with the previous stage signal to adjust the input voltage. The third capacitor C3 and the fourth capacitor C4 are used to filter out high-frequency noise and reduce interference. The fifth capacitor C5, the seventh resistor R7, and the eighth resistor R8 are mainly used for the inverting input terminal of the operational amplifier to form a negative feedback loop for controlling the gain of the operational amplifier. The seventh resistor R7 and the eighth resistor R8 determine the gain of the feedback loop, and the fifth capacitor C5 is used to stabilize the feedback loop to prevent high-frequency oscillation. The ninth resistor R9 acts as a load resistor to ensure that the voltage at the output terminal can be stably transmitted to the next stage circuit and to fine-tune the output voltage. The first operational amplifier U1 is a core component used to differentially amplify the input signal and generate an output voltage proportional to the input signal. The amplification is performed by the difference between the in-phase and inverting input terminals. The in-phase input terminal receives the signal regulated by the resistor network, while the inverting input terminal receives the negative feedback signal. The first operational amplifier U1 amplifies according to the voltage difference between the input terminals, and adjusts the accuracy of the output signal through the feedback of the inverting input terminal. The output terminal provides an amplified voltage signal proportional to the input signal, which is transmitted to the next stage circuit.

[0060] The technical effect of this implementation is that the first amplification module ensures the differential amplification of the input signal through the coordination between multiple resistors and capacitors. After the input signal is adjusted, it enters the operational amplifier through the in-phase and inverting input terminals respectively. The operational amplifier controls the gain through the feedback network and outputs a high-precision amplified signal, ensuring the accuracy and stability of the output signal when processing low voltage or low current signals.

[0061] As an implementation method, Figure 3 As shown, the sampling module 105 includes a tenth resistor R10 , one end of the tenth resistor R10 is an input end of the sampling module 105 , and the other end of the tenth resistor R10 is an output end of the sampling module 105 .

[0062] The tenth resistor R10 collects the amplified voltage signal output by the first amplifying module 104 and outputs it for subsequent processing, collects the amplified voltage signal, and transmits it to a digital signal processor (DSP) or a control module in the system for calculation and processing.

[0063] As an implementation method, Figure 4 As shown, the second bias voltage module 103 includes an eleventh resistor R11, a twelfth resistor R12, an eleventh capacitor C11, a twelfth capacitor C12 and a second operational amplifier U2, the non-inverting input terminal of the second operational amplifier U2 is respectively connected to one end of the eleventh resistor R11, one end of the twelfth resistor R12 and one end of the eleventh capacitor C11, the other end of the eleventh resistor R11 receives the second voltage, the inverting input terminal of the second operational amplifier U2, the output terminal of the second operational amplifier U2 and one end of the twelfth capacitor C12 are commonly connected as the output terminal of the second bias voltage module 103, and the other end of the eleventh capacitor C11, the other end of the twelfth resistor R12 and the other end of the twelfth capacitor C12 are commonly connected to the ground.

[0064] Among them, the eleventh resistor R11 is used to limit the input current and form a voltage divider with the subsequent circuit to adjust the voltage input to the in-phase end of the second operational amplifier U2. One end of the eleventh resistor R11 receives the second voltage, and through the voltage divider effect of the eleventh resistor R11 and the twelfth resistor R12, the input voltage is reduced to a level suitable for subsequent circuit processing. The choice of resistance value determines the voltage amplitude of the input signal. The output end of the second operational amplifier U2 is connected to the inverting end to form a feedback loop. The eleventh capacitor C11 is mainly used to filter out high-frequency noise in the input signal to ensure the purity of the input signal. The twelfth capacitor C12 is located at the output end of the second operational amplifier U2, mainly used to stabilize the output voltage and filter out high-frequency noise in the output signal. The second operational amplifier U2 is the core component of the bias voltage module, which is responsible for amplifying the input signal and generating a stable bias voltage. The in-phase input end receives the input voltage adjusted by the eleventh resistor R11 and the eleventh capacitor C11 as a reference voltage signal, and the inverting input end is connected to the output end through a feedback circuit to help regulate and stabilize the output voltage of the second operational amplifier U2. The output terminal generates a stable bias voltage according to the input signal and the feedback signal.

[0065] The technical effect of this implementation is that the second bias voltage module forms a stable bias voltage generating circuit with the operational amplifier through a combination of resistors and capacitors, the eleventh resistor and the twelfth resistor set the voltage amplitude of the input signal and control the gain of the operational amplifier to ensure voltage stability, the eleventh capacitor and the twelfth capacitor are respectively used to filter out high-frequency noise at the input and output ends to maintain signal purity, and the second operational amplifier generates a stable bias voltage by amplifying the input signal and using negative feedback technology.

[0066] As an implementation method, Figure 5 As shown, the second amplifying module 106 includes a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-first capacitor C21, a twenty-second capacitor C22 and a third operational amplifier U3; the non-inverting input terminal of the third operational amplifier U3 is connected to one end of the twenty-first resistor R21, and the other end of the twenty-first resistor R21 is the first input terminal of the second amplifying module 106, the inverting input terminal of the third operational amplifier U3 is respectively connected to one end of the twenty-second resistor R22, one end of the twenty-third resistor R23 and one end of the twenty-first capacitor C21, the other end of the twenty-second resistor R22 is the second input terminal of the second amplifying module 106, the output terminal of the third operational amplifier U3, the other end of the twenty-third resistor R23, the other end of the twenty-first capacitor C21 and one end of the twenty-second capacitor C22 are connected together as the output terminal of the second amplifying module 106, and the other end of the twenty-second capacitor C22 is grounded.

[0067] Wherein, the 21st resistor R21 is used to introduce the input signal into the in-phase input terminal of the third operational amplifier U3, and set the voltage and current amplitude of the input signal. The function of the 21st resistor R21 is to protect the input terminal of the third operational amplifier U3 from the impact of excessive current by adjusting the input current, and pass the input signal to the third operational amplifier U3. The 22nd resistor R22 is connected between the second input terminal and the inverting input terminal of the third operational amplifier U3, and the 22nd resistor R22 introduces the bias voltage signal from the second bias voltage module 103 into the inverting input terminal of the third operational amplifier U3, and the 22nd resistor R22 and R21 jointly set the voltage difference between the input terminals. The 23rd resistor R23 is used as a negative feedback resistor for adjusting gain and stability. The 23rd resistor R23 is connected between the inverting input terminal and the output terminal of the third operational amplifier U3 to form a negative feedback network, adjust the gain of the amplifier, and stabilize the working state of the amplifier through the feedback signal. The 21st capacitor C21 is used to filter out high-frequency noise in the feedback loop. When a high-frequency signal appears, the capacitor will short-circuit these noise signals, thereby preventing them from outputting signals. The twenty-second capacitor C22 is used to filter out high-frequency noise in the input signal, maintain the stability of the signal, and improve the accuracy of the amplifier circuit. The third operational amplifier U3 is used to integrate and amplify the input signal, eliminate the influence of the bias voltage, and amplify the signal output. The in-phase input terminal of the third operational amplifier U3 receives the output voltage from the first amplifier module 104, and the inverting input terminal receives the output voltage from the second bias voltage module 103. The third operational amplifier U3 performs differential amplification according to the voltage difference between the two input signals, and eliminates the first bias voltage in the input signal while amplifying the signal.

[0068] The technical effect of this embodiment is that the core function of the second amplifying module is to amplify the signal output by the first amplifying module and eliminate the first bias voltage therein, and the output signal and the second bias voltage signal of the amplifying module are respectively introduced through the twenty-first resistor and the twenty-second resistor, and the purified amplified signal is obtained through the differential amplification processing of the third operational amplifier. The twenty-third resistor and the twenty-first capacitor jointly control the gain and feedback to ensure the stability of the input signal, and the twenty-second capacitor further reduces the noise at the output end to ensure the purity of the input signal.

[0069] It should be noted that, in addition to the above structures, the second amplification module 106 includes but is not limited to: a differential amplifier structure, an amplifier structure with servo control, an operational amplifier structure with feedback, and the like.

[0070] The first embodiment is described in detail below in conjunction with a specific circuit structure:

[0071] like Figure 3As shown in the figure, by adding a 0.1V bias voltage to the in-phase input of the first-stage amplifier module in the output current sampling circuit, the minimum detection voltage is increased to 0.11V, which can eliminate the influence of the PCB line impedance of the sampling circuit and the OFFSET voltage of the sampling operation, as shown in the following table:

[0072]

[0073]

[0074] However, increasing the bias will cause the 12VLS to be non-linear, resulting in the system flow being unable to pass, as shown in the following table:

[0075]

[0076] In order to overcome the above problems, Figure 5 As shown, a debiasing circuit is added to the second-stage amplifier module to subtract the 0.1V bias added in the first stage to ensure that the 12VLS voltage and output current are in a linear relationship, as shown in the following table:

[0077]

[0078]

[0079] Embodiment 2

[0080] The second embodiment provides a server power supply, including the sampling circuit provided by the first embodiment.

[0081] like Figure 6 As shown, the server power supply further includes a control module 201 , and an input end of the control module 201 is connected to an output end of the sampling module 105 .

[0082] A server power supply provided in the second embodiment of the present invention amplifies the small voltage signal of the output current sampling into a sampling signal of up to 3.3V through the first amplification module 104, and adds a bias voltage at the same time, and sends this signal to the control module 201 for output current reporting, so as to ensure that a signal greater than 0.1V can be collected when the current is small, and the sampling and reporting accuracy is ensured. The output current signal collected by the first stage is converted into a current-sharing bus signal through the second amplification module 106, and a Vbis signal is added at the same time, and the first-stage bias voltage and the second-stage Vbis are set to the same amplitude, and the bias voltage introduced by the first stage is eliminated, so that the 12VLS signal meets the requirements of the CRPS protocol. The signal is 8V when fully loaded and 4V when half loaded, and the output load and 12VLS are linearly related.

[0083] In the second embodiment, when the sampling resistance value of the output end of the CPRS server power supply with high power and large output current is very small (0.001 milliohms), the sampling accuracy of the output small current is guaranteed, and at the same time, the output current sharing bus signal of the single power supply is not affected by the introduced bias voltage.

[0084] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. A sampling circuit for a server power supply, characterized in that: include: A voltage conversion module, used for converting an input voltage into an output voltage; A first bias voltage module, used for outputting a first bias voltage; A second bias voltage module, used for outputting a second bias voltage; A first amplifying module, whose input end is respectively connected to the output end of the voltage conversion module and the output end of the first bias voltage module, and is used to amplify the output voltage and the first bias voltage to obtain a first amplified voltage; a sampling module, whose input end is connected to the output end of the first amplifying module, and is used to collect and output the first amplified voltage; The second amplifying module has a first input end connected to the output end of the first amplifying module and a second input end connected to the output end of the second bias voltage module, and is used to eliminate the first bias voltage in the first amplified voltage and output a second amplified voltage after amplification.

2. The sampling circuit according to claim 1, characterized in that: The voltage conversion module includes a first capacitor, a second capacitor, a first MOS transistor, a second MOS transistor, a first resistor, a second resistor, a first inductor, a second inductor, a first diode, a second diode and a transformer; One end of the first capacitor and the drain of the first MOS tube are connected in common and receive an input voltage, the source of the first MOS tube is respectively connected to one end of the first inductor and the drain of the second MOS tube, the second end of the first inductor is respectively connected to one end of the second inductor and the first end of the primary coil of the transformer, the other end of the first capacitor, the source of the second MOS tube, the other end of the second inductor and the second end of the primary coil of the transformer are connected in common to the ground, the first end of the secondary coil of the transformer is connected to the cathode of the first diode, the center tap of the secondary coil of the transformer is respectively connected to one end of the second capacitor and one end of the first resistor, the second end of the secondary coil of the transformer is connected to the cathode of the second diode, the anode of the first diode, the anode of the second diode and one end of the second resistor are connected in common as the first output end of the voltage conversion module, and the other end of the second capacitor, the other end of the first resistor and the other end of the second resistor are connected in common as the second output end of the voltage conversion module.

3. The sampling circuit according to claim 1, characterized in that: The first bias voltage module includes a fourth resistor, one end of the fourth resistor is an input end of the first bias voltage module and receives a first voltage, and the other end of the fourth resistor is an output end of the first bias voltage module.

4. The sampling circuit according to claim 3, characterized in that: The first amplification module includes a third resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a third capacitor, a fourth capacitor, a fifth capacitor and a first operational amplifier; The non-inverting input terminal of the first operational amplifier is respectively connected to one end of the third resistor, one end of the fourth resistor, one end of the fifth resistor, one end of the third capacitor and one end of the fourth capacitor; the inverting input terminal of the first operational amplifier is respectively connected to one end of the sixth resistor, one end of the seventh resistor, one end of the eighth resistor, one end of the fourth capacitor and one end of the fifth capacitor; the other end of the fifth resistor is the first input terminal of the first amplification module; the other end of the sixth resistor is the second input terminal of the first amplification module; the output terminal of the first operational amplifier, the other end of the seventh resistor, the other end of the eighth resistor, the other end of the ninth resistor and the other end of the fifth capacitor are commonly connected to the output terminal of the first amplification module; the other end of the third resistor, the other end of the fourth resistor and the other end of the ninth resistor are commonly connected to the ground.

5. The sampling circuit according to claim 1, characterized in that: The sampling module includes a tenth resistor, one end of the tenth resistor is an input end of the sampling module, and the other end of the tenth resistor is an output end of the sampling module.

6. The sampling circuit according to claim 1, characterized in that: The second bias voltage module includes an eleventh resistor, a twelfth resistor, an eleventh capacitor, a twelfth capacitor and a second operational amplifier, the in-phase input terminal of the second operational amplifier is respectively connected to one end of the eleventh resistor, one end of the twelfth resistor and one end of the eleventh capacitor, the other end of the eleventh resistor receives a second voltage, the in-phase input terminal of the second operational amplifier, the output terminal of the second operational amplifier and one end of the twelfth capacitor are commonly connected as the output terminal of the second bias voltage module, and the other end of the eleventh capacitor, the other end of the twelfth resistor and the other end of the twelfth capacitor are commonly connected to ground.

7. The sampling circuit according to claim 6, characterized in that: The first bias voltage and the second bias voltage are the same.

8. The sampling circuit according to claim 1, characterized in that: The second amplification module includes a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-first capacitor, a twenty-second capacitor and a third operational amplifier; The non-inverting input terminal of the third operational amplifier is connected to one end of the twenty-first resistor, the other end of the twenty-first resistor is the first input terminal of the second amplifying module, the inverting input terminal of the third operational amplifier is respectively connected to one end of the twenty-second resistor, one end of the twenty-third resistor and one end of the twenty-first capacitor, the other end of the twenty-second resistor is the second input terminal of the second amplifying module, the output terminal of the third operational amplifier, the other end of the twenty-third resistor, the other end of the twenty-first capacitor and one end of the twenty-second capacitor are connected together as the output terminal of the second amplifying module, and the other end of the twenty-second capacitor is grounded.

9. A server power supply, characterized in that: include: The sampling circuit according to any one of claims 1 to 8.

10. The server power supply according to claim 9, characterized in that: The server power supply further includes a control module, an input end of the control module is connected to an output end of the sampling module.

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