CN112231866B

CN112231866B - Capacitance selection method, device, server and medium of power distribution network

Info

Publication number: CN112231866B
Application number: CN201910582701.3A
Authority: CN
Inventors: 蔡步森; 陈欢洋
Original assignee: Zhejiang Uniview Technologies Co Ltd
Current assignee: Zhejiang Uniview Technologies Co Ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2024-02-02
Anticipated expiration: 2039-06-28
Also published as: CN112231866A

Abstract

The embodiment of the invention discloses a capacitance selection method, a device, a server and a medium of a power distribution network, wherein the method comprises the following steps: determining preset parameters including target impedance, lowest cut-off frequency and highest cut-off frequency of a power distribution network; selecting a plurality of different types of decoupling capacitors according to the lowest cutoff frequency and the highest cutoff frequency; determining the capacitance action frequency range of each type of decoupling capacitor according to the working frequency range of each type of decoupling capacitor; determining the number of each type of decoupling capacitors in the plurality of different types of decoupling capacitors according to the target impedance, and determining an actual impedance curve of the power distribution network; determining an antiresonant point in the minimum cutoff frequency and the maximum cutoff frequency ranges; judging whether the actual impedance of the antiresonant point is larger than the target impedance; if yes, the number of decoupling capacitors of the capacitor action frequency band where the anti-resonance point is located is increased. The technical scheme provided by the embodiment of the invention can rapidly determine the quantity of the decoupling capacitors, thereby improving the selection efficiency of the decoupling capacitors and shortening the time consumption of the decoupling capacitors.

Description

Capacitance selection method, device, server and medium of power distribution network

Technical Field

The embodiment of the invention relates to the technical field of circuit design, in particular to a capacitor selection method, a device, a server and a medium of a power distribution network.

Background

With the increasing use of high-speed signals (> 10G), electronic systems are evolving towards high speeds, high densities, low voltages and high currents, with increasingly significant power integrity issues. The fluctuation of the power supply voltage can influence the normal operation of the chip, and the whole system can be hung up in severe cases. Therefore, in the design of the power distribution network (power delivery network, PDN) system, not only is a clean power supply provided for the circuit, but it also serves to provide a low noise loop for high speed signals, multi-chip noise isolation, and to ensure electromagnetic integrity. Therefore, the rationality of the PDN system is particularly important.

In general, the design of a PDN system, generally from the frequency domain, uses a target impedance as a reference standard, and different types of decoupling capacitors are added so that the impedance of the PDN system is lower than the target impedance in a target frequency range, and the core of the process is to determine the type and the number of the decoupling capacitors. However, in the existing PDN system design scheme, the selection process of the decoupling capacitor is less efficient and takes a long time, and an optimal combination scheme of the decoupling capacitor cannot be obtained.

Disclosure of Invention

The embodiment of the invention provides a capacitor selection method, a device, a server and a medium of a power distribution network, which are used for improving the selection effectiveness of decoupling capacitors, shortening the time used in the process and being beneficial to obtaining an optimal combination scheme of the decoupling capacitors.

In a first aspect, an embodiment of the present invention provides a method for selecting a capacitance of a power distribution network, where the method includes:

determining preset parameters; the preset parameters comprise target impedance, lowest cut-off frequency and highest cut-off frequency of the power distribution network;

selecting a plurality of different types of decoupling capacitors according to the lowest cut-off frequency and the highest cut-off frequency; wherein the operating frequency band of the plurality of different types of decoupling capacitors covers a frequency band range between the lowest cut-off frequency and the highest cut-off frequency;

determining the capacitance action frequency range of each type of decoupling capacitor according to the working frequency range of each type of decoupling capacitor; the capacitance action frequency bands of each type of decoupling capacitor are not overlapped with each other, and the capacitance action frequency bands of a plurality of different types of decoupling capacitors cover the frequency band range between the lowest cut-off frequency and the highest cut-off frequency;

Determining the number of each type of decoupling capacitors in the plurality of different types of decoupling capacitors according to the target impedance, and determining an actual impedance curve of the power distribution network;

determining an antiresonant point within the lowest cut-off frequency and the highest cut-off frequency ranges;

judging whether the actual impedance of the antiresonant point is larger than the target impedance;

if yes, the number of decoupling capacitors of the capacitor action frequency band where the anti-resonance point is located is increased.

In a second aspect, an embodiment of the present invention further provides a capacitance selection device of a power distribution network, where the device includes:

a preset parameter determining unit for determining preset parameters; the preset parameters comprise target impedance, lowest cut-off frequency and highest cut-off frequency of the power distribution network;

a decoupling capacitor selection unit for selecting a plurality of different types of decoupling capacitors according to the lowest cutoff frequency and the highest cutoff frequency; wherein the operating frequency band of the plurality of different types of decoupling capacitors covers a frequency band range between the lowest cut-off frequency and the highest cut-off frequency;

the action frequency band determining unit is used for determining the capacitance action frequency band of each type of decoupling capacitor according to the working frequency band of each type of decoupling capacitor;

A capacitance number determining unit configured to determine the number of decoupling capacitances of each of the plurality of different types of decoupling capacitances according to the target impedance, and determine an actual impedance curve of the power distribution network;

an antiresonant point determining unit, configured to determine an antiresonant point within the lowest cutoff frequency and the highest cutoff frequency range;

an impedance magnitude judging unit for judging whether the actual impedance of each antiresonant point is larger than the target impedance;

and the capacitance quantity increasing unit is used for increasing the decoupling capacitance of the capacitance action frequency band where the anti-resonance point is located when the judgment result is yes.

In a third aspect, an embodiment of the present invention further provides a server, including:

one or more processors;

storage means for storing one or more programs,

the one or more programs, when executed by the one or more processors, cause the one or more processors to implement a method of capacitance selection for a power distribution network according to any of the embodiments of the present invention.

In a fourth aspect, embodiments of the present invention further provide a computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements a method for capacitance selection of a power distribution network according to any of the embodiments of the present invention.

According to the selection method of the power distribution network, which is provided by the embodiment of the invention, the capacitance action frequency range of each type of decoupling capacitor is determined according to the working frequency range of each type of decoupling capacitor; and after determining the number of various decoupling capacitors to obtain an actual impedance curve of the power distribution network, searching an anti-resonance point, determining a capacitor action frequency band where the anti-resonance point is located when the actual impedance of the anti-resonance point is larger than the target impedance, and increasing the number of decoupling capacitors of the capacitor action frequency band. Therefore, the actual impedance of the anti-resonance point can be effectively reduced, thereby being beneficial to quickly determining the quantity of the decoupling capacitors, improving the selection efficiency of the decoupling capacitors, shortening the time consumption of the process and being beneficial to obtaining the optimal combination scheme of the decoupling capacitors. The method solves the problems that the time consumption is long and the optimal combination scheme of the decoupling capacitor cannot be obtained due to the low efficiency of the selection process of the decoupling capacitor in the prior art.

Drawings

FIG. 1 is a schematic diagram of an equivalent model of a decoupling capacitor according to an embodiment of the present invention

Fig. 2 is an impedance curve of a decoupling capacitor provided by an embodiment of the present invention;

fig. 3 is an impedance curve of the same type of decoupling capacitors provided in an embodiment of the present invention in parallel;

Fig. 4 is an impedance curve of a parallel connection of decoupling capacitors of a class provided by an embodiment of the present invention;

FIG. 5 is a graph showing the impedance of a power distribution network including decoupling capacitors of different types and different numbers connected in parallel;

fig. 6 is an impedance curve of two types of decoupling capacitors provided by an embodiment of the present invention;

fig. 7 is an impedance plot of the decoupling capacitor of fig. 6 after application to a power distribution network;

FIG. 8 is an impedance plot of the power distribution network with the addition of a decoupling capacitor to the power distribution network of FIG. 7;

FIG. 9 is a graph of the impedance of the power distribution network after continuing to add a decoupling capacitor of the same type as that of FIG. 8;

FIG. 10 is an impedance curve of the power distribution network after adding a decoupling capacitor to the active frequency band of the capacitor with an anti-resonance point based on FIG. 7;

fig. 11 is a schematic diagram of a determination manner of a capacitance action frequency band of a decoupling capacitor according to an embodiment of the present invention;

FIG. 12 is a schematic view of a capacitive test fixture plate according to an embodiment of the present invention;

fig. 13 is a schematic structural diagram of a capacitance testing device according to an embodiment of the present invention;

FIG. 14 is a schematic diagram of a capacitive test interface provided by an embodiment of the present invention;

FIG. 15 is a schematic diagram of a power distribution network system according to an embodiment of the present invention;

fig. 16 is a flowchart of a capacitance selection method of a power distribution network according to an embodiment of the present invention;

FIG. 17 is a schematic diagram of the refinement flow of S110 in FIG. 16;

FIG. 18 is a schematic diagram of the refinement flow of S130 in FIG. 16;

FIG. 19 is a schematic diagram of the refinement flow of S140 in FIG. 16;

FIG. 20 is a flowchart of another capacitance selection method of a power distribution network according to an embodiment of the present invention;

FIG. 21 is a flow chart of a method for capacitance selection of a further power distribution network according to an embodiment of the present invention;

fig. 22 is a schematic structural diagram of a capacitance selecting device of a power distribution network according to an embodiment of the present invention;

fig. 23 is a schematic structural diagram of a server according to an embodiment of the present invention.

Detailed Description

The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.

Examples

Hereinafter, concepts and models involved in the embodiments of the present invention will be described first with reference to fig. 1 to 15; meanwhile, by comparing with the prior art, the beneficial effects of the capacitance (i.e. decoupling capacitance) selection method of the power distribution network provided by the embodiment of the invention are exemplified.

Referring to fig. 1, fig. 1 shows a first-order equivalent model of decoupling capacitance, also referred to as RLC model of decoupling capacitance. Wherein ESR represents the equivalent series resistance of the capacitor, ESL represents the equivalent series inductance of the capacitor, C represents the equivalent capacitance of the capacitor, and Lmnt is the mounting inductance (including the pad-to-via trace inductance and the via-induced inductance).

On this basis, the actual impedance curve of the decoupling capacitor is shown as L004 in fig. 2. With continued reference to fig. 2, the horizontal axis X represents frequency in hertz (Hz) and the vertical axis Y represents impedance in Ohms (Ohms, Ω); the coordinates of the impedance graphs are the same as those described below, and reference will be made to the description herein for understanding, and details are not repeated herein. L001 represents the trend of the equivalent capacitance C of the actual capacitance with frequency, L002 represents the trend of the equivalent inductance ESL of the actual capacitance with frequency, and L003 represents the equivalent series resistance ESR of the actual capacitance. The lowest point of L004 corresponds to the Self-resonant frequency (Self-resonant frequency, SRF) of the capacitor, the impedance of which point is equal to the equivalent series resistance ESR of the capacitor.

Fig. 2 shows the impedance profile of a single decoupling capacitor, on the basis of which fig. 3 shows the impedance profile after the same type of decoupling capacitor has been connected in parallel. Referring to fig. 3, L011 represents an impedance curve of one capacitor, L012 represents an impedance curve of two capacitors connected in parallel, L013 represents an impedance curve of three capacitors connected in parallel, L014 represents an impedance curve of four capacitors connected in parallel, and L015 represents an impedance curve of five capacitors connected in parallel. As can be seen from a comparison of the five impedance curves in fig. 3, adding one decoupling capacitor reduces the impedance at all frequencies. Therefore, the parallel capacitor can reduce the power supply impedance, which is the basic principle of PDN network impedance design.

Referring to fig. 4, fig. 4 shows an impedance curve after connecting two different types of capacitors in parallel. "different classes," i.e., "different types," are understood to mean that the SRFs are different. In fig. 4, L021 represents the equivalent capacitance of the first type capacitance, and L022 represents the equivalent capacitance of the second type capacitance; the equivalent series inductances of the first type of capacitance and the second type of capacitance are represented by L023, and L024 represents an actual impedance curve after the first type of capacitance and the second type of capacitance are connected in parallel. Wherein, two minimum points on L024 are the self-resonance points of the two capacitors respectively. In addition, there is a parallel resonance peak between the two self-resonance points, shown as D025, which is the parallel resonance frequency (Parallel resonance frequency, PRF) of the two capacitors. In PDN system design, it is necessary to suppress the impedance corresponding to the PRF point so that the actual impedance at that point is less than the target impedance.

On the basis of fig. 3 and 4, fig. 5 shows impedance curves for the parallel application of different types and numbers of decoupling capacitors to the power distribution network. Referring to fig. 5, L030 represents a target impedance curve, and L031, L032, L033, L034, and L035 represent actual impedance curves of different types of capacitances and numbers of capacitances applied to the PDN system, respectively. Where the actual impedance curve comprises several valleys (i.e. minima points), the PDN system comprises several types of capacitances correspondingly. The PDN system design also aims at showing that the actual impedance corresponding to each antiresonant point is smaller than the target impedance.

On the basis, in the design process of the PDN system, the actual utilization situation needs to be considered. For example, excessive selection of capacitor types can affect the processing efficiency and material management of the production link; for another example, too many capacitors are selected, which increases hardware cost and layout space and routing difficulty of the printed circuit board (printed circuit board, PCB). Thus, in designing a PDN system, a proper type and amount of decoupling capacitance is required to build a reasonable PDN system.

The main principle of PDN system design is: firstly, calculating target impedance of a corresponding frequency band according to power supply voltage, maximum current and load noise margin; secondly, selecting a proper type and number of capacitors according to the target impedance, so that the impedance of the PDN system is smaller than the target impedance in a corresponding frequency band. The basis for capacitance selection is: the smaller capacitance impedance can better reduce the PDN impedance, so that the PDN impedance is better improved.

The PDN design method can comprise a table look-up method, specifically, according to target impedance, working frequency bands and an existing capacitor bank model, simulation software is used for manually selecting the types and the amounts of the capacitors, so that the impedance of the PDN system meets the requirements of the target impedance in the corresponding frequency bands, and the obtained types and amounts of the capacitors are stored in a database. In the PDN system design, a group of proper capacitance types and quantity are selected from a database according to target impedance and working frequency band. However, the method has large workload of inputting the database in the early period, and the determined capacitance types and the determined capacitance numbers are selected through manual judgment and possibly are not optimal schemes; when the capacitance model changes, the database needs to be updated from new.

Optimizing based on the table look-up method, and realizing the selection of the capacitor through programming. Specifically, the self-resonant frequency of the capacitor is used as a capacitor selection basis to obtain a decoupling capacitor required by the PDN system, so that the actual impedance of the PDN system meets the system requirement. Fig. 6-9 exemplify two capacitances, illustrating the selection process. On this basis, fig. 10 shows a PDN system impedance curve obtained by applying the capacitance selection method provided by the embodiment of the present invention.

Referring to fig. 6, L051 represents the impedance curve of the 0402 package 10uF capacitor with its self-resonance point at 1.2MHz, and L052 represents the impedance curve of the 0402 package 1uF capacitor with its self-resonance point at 4.0MHz; the frequency corresponding to the intersection of L051 and L052 is 3.0MHz, which is related to the definition of the capacitive frequency band, which will be described in detail later. The frequency range from the resonance point of the 10uF capacitor to the intersection point of the two curves is 1.2MHz-3.0MHz, the frequency range is 1.8MHz, and the impedance of the 10uF capacitor in the frequency range is smaller than that of the 1uF capacitor; the frequency range from the resonance point of the 1uF capacitor to the intersection point of the two curves is 3.0MHz-4.0MHz, the frequency range is 1.0MHz, and the impedance of the 1uF capacitor in the frequency range is smaller than that of the 10uF capacitor. It can be seen that the frequency range of the 10uF capacitor is larger than that of the 1uF capacitor in the self-resonance frequency range of 1.2MHz-4.0 MHz.

For example, for a PDN system, its actual impedance is greater than the target impedance at a location corresponding to an anti-resonance point, as shown in fig. 7. Where L060 represents a target impedance curve, L061 represents an actual impedance curve, at the position D061, the frequency is 2.801MHz, the target impedance is 0.1 Ω, and the actual impedance is 0.187 Ω, i.e. the actual impedance is greater than the target impedance, whereby it is necessary to add a decoupling capacitor to reduce the impedance value at this position.

As can be seen from FIG. 6, the 0402 package 1uF capacitor has a self-resonance point frequency of 4.0MHz, and the 0402 package 10uF capacitor has a self-resonance point frequency of 1.2MHz. Thus, the self-resonance point of the 1uF capacitor is closer to the antiresonance point. Then, a 1uF capacitor is connected in parallel in the power network of the PDN system, the impedance curve of which is shown as L062 in fig. 8, at this time, the impedance at the location D061 decreases, shown as D062 in fig. 8, where the actual impedance is 0.039Ω, which is smaller than the target impedance, but there is still a location in the vicinity where the actual impedance is larger than the target impedance.

On the basis of fig. 7, one 1uF capacitor is changed into two 1uF capacitors, the impedance curves of the two 1uF capacitors are shown as L063 in fig. 9, at this time, the impedance at the position of D061 is reduced, shown by D063 in fig. 9, the actual impedance at the position is 0.020 Ω, which is smaller than the target impedance, and no position where the actual impedance is larger than the target impedance exists near the target impedance, i.e., the actual impedance of each frequency point is suppressed below the target impedance in the frequency band range shown in fig. 9.

In the capacitance selection process shown in fig. 7-9, only the self-resonance point frequency of the decoupling capacitor is used as the basis for selecting the capacitance. Specifically, near a frequency point D061 where the actual impedance is greater than the target impedance, a capacitor with a frequency closest to the frequency of the point from the resonance point is selected, and the impedance of the PDN system is reduced by increasing the number of capacitors. However, the equivalent series resistance ESR and the equivalent series inductance ESL of the capacitors with different capacitance values are different, and the range of the operating frequency band (i.e., the capacitance operating frequency band) and the operating effect of the impedance curve corresponding to the decoupling capacitor are different due to the influence of the two parameters. In the frequency range that the actual impedance of the PDN system is larger than the target impedance, the impedance of the PDN system can be better improved by the capacitor which is not closest to the frequency of the self-resonance point. The capacitance of the capacitance action frequency band of the PDN system can be effectively reduced, so that the type and the number of decoupling capacitors can be rapidly selected, the capacitance selection efficiency of the PDN system is further improved, the time required by the selection process is shortened, and an optimal combination scheme of the decoupling capacitors cannot be obtained.

Illustratively, fig. 10 is an impedance curve of the PDN system obtained after selecting a decoupling capacitor based on the concept of the capacitive frequency band of action. Referring to fig. 6, FD051 represents the capacitance operating band of the 10uF capacitor, and FD052 represents the capacitance operating band of the 1uF capacitor, bounded by the intersection of the two curves. And in combination with fig. 7, the frequency at the corresponding position of D061 is 2.8Hz, and falls within the range of the capacitance action frequency band of the 10uF capacitor. On the basis, a 10uF capacitor is added on the basis of fig. 7, the impedance curve of the capacitor is shown as L064 in fig. 10, at this time, the impedance at the position of D061 is reduced, shown as D064 in fig. 10, the actual impedance at the position is 0.024uF and is smaller than the target impedance, and no position where the actual impedance is larger than the target impedance exists nearby, namely, the actual impedance of each frequency point is suppressed to be lower than the target impedance in the frequency range shown in fig. 10.

With reference to fig. 7-10, on the premise of selecting the same number of decoupling capacitors, the suppression of the impedance of the antiresonant point and the suppression of the impedance of the majority of the frequency points in the operating frequency range by the capacitor of 10uF are more significant than the capacitor of 1 uF. Therefore, the decoupling capacitor of the capacitor action frequency band where the anti-resonance point is positioned is selected, so that the efficiency of capacitor selection is improved, and the optimal combination scheme of the decoupling capacitor is obtained.

Definition of capacitive frequency bands: and sequencing the self-resonance point frequency of the decoupling capacitor from low to high, and searching the intersection point frequency of the impedance curves of the adjacent capacitors, wherein the frequency range between the two intersection point frequencies is the capacitance action frequency range of the decoupling capacitor.

The definition of the capacitive frequency bands is illustrated in the following in connection with fig. 11.

Referring to fig. 11, a set of capacitors is selected, and the set of capacitors is composed of capacitor 1, capacitor 2 and capacitor 3, and the impedance curves of the capacitors are respectively represented by L055, L056 and L057, and the lowest point of each impedance curve is the self-resonance point of the decoupling capacitor. The decoupling capacitors corresponding to the self-resonance point from low to high are respectively a capacitor 1, a capacitor 2 and a capacitor 3. The impedance curves of decoupling capacitors of adjacent self-resonance points have a crossing point, for example, the capacitor 1 is adjacent to the capacitor 2 self-resonance point, the impedance curves of the two capacitors have a crossing point A, the capacitor 2 is adjacent to the capacitor 3 self-resonance point, and the impedance curves of the two capacitors have a crossing point B. On the basis, the capacitance action frequency band of the capacitor 2 is the frequency band (i.e. frequency range) between the points A and B. For the capacitor with the lowest self-resonance frequency, for example, the capacitor 1, the capacitor action frequency band is from the lowest cutoff frequency to the A point frequency; for the capacitor with the highest self-resonance frequency, for example, the capacitor 3, the capacitor action frequency band is from the point B frequency to the highest cut-off frequency. The "lowest cut-off frequency" and "highest cut-off frequency" in this paragraph are understood to be the lowest cut-off frequency and the highest cut-off frequency of the operating frequency band of the PDN system.

In fig. 11, only 3 capacitors are exemplified as an example, and the capacitive frequency bands are illustrated. In other embodiments, the number of decoupling capacitors may be set according to the requirements of the capacitor selection method of the power distribution network, which is not limited by the embodiment of the present invention.

Optionally, the decoupling capacitor can be tested through the capacitor testing device to obtain an accurate RLC model of the decoupling capacitor, so that proper capacitor types and number can be selected according to the impedance characteristic of the decoupling capacitor, the capacitor selection process of the PDN system can be optimized, and the design difficulty of the PDN system can be simplified.

Illustratively, referring to fig. 12, the capacitive test fixture plate 09 may include: two coaxial connectors SMA092 and an annular transmission line 091; wherein the capacitance 090 to be measured is fixed to the capacitance test fixture plate 09 by means of soldering.

As shown in fig. 13, the capacitance measuring instrument is a network analyzer 082, the capacitance measuring clamp plate 09 is connected to the network analyzer 082 through a measuring cable 081, and then the network analyzer 082 scans and obtains the impedance curve of the decoupling capacitance in the target frequency range. The target frequency band range may be, for example, 100kHz-500MHz. Then, the impedance curve obtained by the network analyzer 082 is fitted by simulation software, so that the parameters of the RLC model of the decoupling capacitor can be accurately obtained.

Illustratively, referring to fig. 14, fig. 14 shows the test and fit results for a decoupling capacitor. Wherein, L041 represents the impedance curve of the decoupling capacitor obtained by the network analyzer, L042 is the impedance curve drawn by the RLC parameter of the decoupling capacitor, the fitting degree of the quantity curve is very high, and the RLC parameter accuracy of the decoupling capacitor obtained by the network analyzer is also very high.

It should be noted that, fig. 14 only illustrates parameters of an RLC model of a decoupling capacitor. In other embodiments, the ESR, ESL, and ESC values displayed by the test interface may be different according to the type of decoupling capacitor selected, which is not limited in the embodiments of the present invention.

Optionally, a PDN system model may also be determined prior to the capacitance selection.

A schematic diagram of a PDN system model is exemplarily described below with reference to fig. 15, so as to illustrate a connection relationship between the decoupling capacitor and other components in the PDN system.

Illustratively, referring to fig. 15, the power distribution network system model 07 includes the following components: a power supply module 071, a decoupling capacitor module 072, a power supply plane 073, a diffusion impedance 074, a via impedance 075, a capacitor mounting inductor module 076 and a load 077; a first end of the power module 071 is electrically connected to the first end of the decoupling capacitor module 072, the first end of the power plane 073 and the first end of the load 077, a second end of the power module 071 is electrically connected to the second end of the capacitor mounting inductor module 076, the second end of the power plane 073 and the first end of the diffusion impedance 074, and the second end of the diffusion impedance 074 is electrically connected to the second end of the load 077 through the via impedance 075; the decoupling capacitor module 072 includes a plurality of different types of decoupling capacitors connected in parallel, and the capacitor mounting inductor module 076 includes a plurality of capacitor mounting inductors, each of which is electrically connected to the first end of the power module 071 through a capacitor mounting inductor.

The corresponding parameters of each component element in the PDN system model 07 need to be obtained before the capacitance selection is made, as detailed in the method section below.

On the basis of the above description, a capacitance selection method of the power distribution network according to an embodiment of the present invention is described below with reference to fig. 16 to 21.

Fig. 16 is a flow chart of a capacitance selection method of a power distribution network according to an embodiment of the present invention. Referring to fig. 16, the method includes:

s110, determining preset parameters.

The preset parameters comprise target impedance of the power distribution network, the lowest cut-off frequency and the highest cut-off frequency. The frequency range between the lowest cut-off frequency and the highest cut-off frequency is the working frequency band of the power distribution network, and the target impedance is the reference basis for selecting the type and the number of the capacitors. This step provides for the subsequent selection of the capacitor. In this embodiment, the preset parameters may be manually input by the user or may be automatically obtained by software, which is not limited in the embodiment of the present invention.

S120, selecting a plurality of different decoupling capacitors according to the lowest cutoff frequency and the highest cutoff frequency.

Wherein the frequency range between the lowest cut-off frequency and the highest cut-off frequency is covered by the working frequency range of the decoupling capacitors of a plurality of different classes. Specifically, each type of decoupling capacitor can cover a frequency range in the working frequency range of the power distribution network, and the working frequency ranges of a plurality of different types of decoupling capacitors are overlapped, so that the complete working frequency range of the power distribution network can be covered. Therefore, in the power distribution network, no matter where the actual impedance is larger than the frequency point corresponding to the target impedance position in the working frequency band, the actual impedance of the PDN system at the position can be reduced by increasing the number of decoupling capacitors. In this embodiment, the selection of the decoupling capacitor may be manually selected by a user, or may be automatically selected by software from a plurality of decoupling capacitors of different types or different groups, which is not limited in the embodiment of the present invention.

S130, determining the capacitance action frequency range of each type of decoupling capacitor according to the working frequency range of each type of decoupling capacitor.

The capacitance action frequency bands of each type of decoupling capacitor are not overlapped with each other, and the capacitance action frequency bands of a plurality of different types of decoupling capacitors cover the frequency band range between the lowest cut-off frequency and the highest cut-off frequency.

Illustratively, this step may be performed with reference to the explanation of FIG. 11 above, which is not repeated herein.

And S140, determining the number of each type of decoupling capacitor in the plurality of different types of decoupling capacitors according to the target impedance, and determining an actual impedance curve of the power distribution network.

Based on the selection of the decoupling capacitor type in S120 and the determination of the capacitor acting frequency band of the decoupling capacitor in S130, in this step, the actual impedance of the decoupling capacitor can be determined according to the capacitance and the number of the self-resonance points of the decoupling capacitors. Specifically, by setting the actual impedance to be less than or equal to the target impedance, the number of decoupling capacitors of each type can be determined by rounding up.

Illustratively, when the capacitive active frequency band of a decoupling capacitor of a certain type does not overlap with the operating frequency band of the power distribution network, the decoupling capacitor of that type does not contribute to reducing the actual impedance of the power distribution network, and the amount may be 0.

When a plurality of selected different types of capacitors are connected in parallel and applied to the power distribution network, an actual impedance curve of the power distribution network can be obtained.

S150, determining an anti-resonance point in the range of the lowest cut-off frequency and the highest cut-off frequency.

In S140, the actual impedance at the self-resonance point frequency position of each decoupling capacitor is ensured to be less than or equal to the target impedance. As can be seen from fig. 4 above, the actual impedance at the anti-resonance point location is likely to be greater than the target impedance between two adjacent self-resonance point frequencies. Therefore, the antiresonant points are determined in preparation for the comparison of the actual impedance with the target impedance in the next step. In this embodiment, the positions of the maxima in the actual impedance curve of the power distribution network may be determined to correspond to the determined anti-resonance points.

S160, judging whether the actual impedance of the antiresonant point is larger than the target impedance.

If the actual impedance corresponding to the antiresonant point is greater than the target impedance, the number of decoupling capacitors needs to be optimized. If the determination result of this step is yes, S170 is executed.

S170, increasing the number of decoupling capacitors of a capacitor action frequency band where the antiresonant point is located.

The step can effectively reduce the actual impedance corresponding to each frequency point in the working frequency band of the power distribution network, thereby effectively inhibiting the actual impedance of the anti-resonance point and the range near the anti-resonance point. The method is beneficial to improving the selection efficiency of the decoupling capacitor, shortening the consumed time and obtaining the optimal combination scheme of the decoupling capacitor.

After S170, S160 is executed again until the actual impedance of each antiresonant point is smaller than the target impedance, and the process of selecting the decoupling capacitor is completed.

Optionally, before S110, the method may further include: a system model of the power distribution network is determined.

By way of example, a system model of a power distribution network may be as shown in fig. 15.

On this basis, referring to fig. 17, S110 may include:

s211, determining initial preset parameters.

The initial preset parameters are parameters representing the characteristics of each component of the power distribution network system model; it is also understood that parameters must be set in order for the power distribution network system model to operate. Referring to fig. 15, the initial preset parameters may include a voltage V of the load 077, a maximum operating current Imax, a ripple coefficient AR allowed by the operating voltage, a ratio TP of the transient current to Imax, a type of the power module 071, a value of each capacitor mounting inductance in the capacitor mounting inductance module 076, a size of the power plane 073, a value of the diffusion impedance 074, and a value of the via impedance 075; PDN impedance cut-off frequencies may also be included.

In this embodiment, the initial preset parameters may be set through a human-machine interface.

In this embodiment, the voltage ripple coefficient AR may take 1% -5%, and the ratio TP of the transient current to Imax ratio may take 30% -50%; a power supply module, also called voltage regulation module (Voltage Regulator Module, VRM), of the type which can be classified as a switching power supply or a linear power supply (corresponding to different Rvrm and Lvrm); the capacitor mounting inductances (Lmntl, lmnt2, … …, lmntn) are different according to the distribution of decoupling capacitance or the form of output (fanout), the sizes of the capacitor mounting inductances are also different, and the values can be about 0.5nH-2 nH; the power plane can be divided into three situations of large, medium and small according to the area score, and equivalent parameters Rp and Cp can be obtained in advance through simulation software; the value of the cut-off frequency of the PDN impedance can be divided into 20MHz and 100MHz, and the value of the diffusion impedance 074 is generally small and can be ignored in the embodiment.

S212, determining preset parameters according to the initial preset parameters.

This step mainly includes the determination of the target impedance and the operating frequency band of the power distribution network.

Optionally, S212 may include: calculating target impedance according to a target impedance calculation formula, and determining a lowest cut-off frequency and a highest cut-off frequency according to the type of the power supply module and the size of the power supply plane; the target impedance calculation formula is as follows:

wherein, in the impedance calculation formula, V is the voltage of the load chip, AR is the ripple coefficient allowed by the working voltage, imax is the maximum working current, TP is the ratio of transient current to Imax, Z _T Is the target impedance. Since each parameter on the right side of the equal sign is determined in S211 in the calculation formula, the target impedance of the power distribution network can be calculated and determined using the formula.

For example, a 1 volt power plane (v=1v), the allowable ripple factor of the operating voltage is 5%, the maximum operating current Imax is 10 amperes (imax=10a), and the transient current to Imax ratio TP is 50%; the determination may be made by calculation,target impedance Z _T Is 10 milliohms (Z _T =10mΩ). In other embodiments, the values of the preset parameters may be set according to the actual requirements of the capacitance selection method of the power distribution network, which is not limited by the embodiment of the present invention.

The type of the power module determines the frequency range in which the PDN system can provide power, and the size of the power plane includes the operating frequency range of the load, where the frequency range is generally within the frequency range in which the PDN system can provide power. Thus, the type of the power module and the size of the power plane can determine the working frequency band of the PDN system.

Optionally, the process of selecting the type of decoupling capacitor, i.e. S120 in fig. 1, may include: selecting a decoupling capacitor group from a preset capacitor bank; the decoupling capacitor bank includes a plurality of different types of decoupling capacitors.

The preset capacitor bank can comprise a plurality of decoupling capacitor groups, and each decoupling capacitor group can be suitable for PDN systems with one or a plurality of different working frequency bands. The "application" in this section can be understood as that in the decoupling capacitor group, the working frequency bands of various decoupling capacitors are overlapped to cover the working frequency band of the PDN system.

On this basis, referring to fig. 18, S130 may include:

s231, in the decoupling capacitor group, the decoupling capacitors of different types are ordered according to the self-resonance point frequency of each type of decoupling capacitor from low to high.

S232, determining the intersection point of impedance curves of decoupling capacitors adjacent to the self-resonance point in frequency.

S233, determining the capacitance action frequency band of the first type decoupling capacitor as a frequency band range between two intersection points on the impedance curve, and determining the capacitance action frequency band of the second type decoupling capacitor as a frequency band range between the intersection point on the impedance curve and the boundary cut-off frequency.

The first type of decoupling capacitor is a decoupling capacitor with a self-resonant point frequency in a decoupling capacitor group in a middle range, for example, a capacitor 2 corresponding to L056 in fig. 11; the second type of decoupling capacitor is the decoupling capacitor with the lowest or highest frequency of the self-resonance point in the decoupling capacitor group, such as the capacitor 1 and the capacitor 3 corresponding to L055 and L057 in fig. 11; the boundary cut-off frequency is the lowest operating frequency of the decoupling capacitor with the lowest self-resonance point frequency or the highest operating frequency of the decoupling capacitor with the highest self-resonance point frequency.

It should be noted that, when one decoupling capacitor group includes only two decoupling capacitors, the two decoupling capacitors are both the second type of decoupling capacitors.

Thus, the division of the capacitance action frequency band of the decoupling capacitor is completed by S231-S233.

On this basis, to simplify the execution complexity of the subsequent steps, after S130, the method may further include:

decoupling capacitors in the decoupling capacitor bank are removed, wherein the capacitance action frequency range is not in the frequency range between the lowest cutoff frequency and the highest cutoff frequency.

Wherein, the "the capacitance action frequency range is not in the frequency range between the lowest cut-off frequency and the highest cut-off frequency" means that the capacitance action frequency range of the decoupling capacitor is not overlapped with the operation frequency range of the PDN system, i.e. the number of the decoupling capacitors does not affect the actual impedance curve of the PDN, or the number of the decoupling capacitors has little effect on the actual impedance curve of the PDN. Thus, to increase the efficiency of capacitance selection, the decoupling capacitance can be eliminated; and only selecting decoupling capacitors of the capacitive operating frequency band within the operating frequency band of the PDN system, and selecting decoupling capacitors of the power near the lowest cut-off frequency and near the highest cut-off frequency of the operating frequency band of the PDN system, wherein the capacitive operating frequency band overlaps the operating frequency band of the PDN system.

Alternatively, referring to fig. 19, S140 may include:

s241, determining the minimum number of decoupling capacitors of each type when the impedance of the decoupling capacitors at the self-resonance point position is smaller than the target impedance as the number of the decoupling capacitors according to the impedance parallel connection mode.

In this way, on the premise of following the PDN design principle, a smaller number of decoupling capacitors can be adopted, so that the hardware cost is saved, and the PCB layout space and wiring difficulty are simplified.

S242, determining an actual impedance curve of the power distribution network according to the system model of the power distribution network and the types and the quantity of decoupling capacitors of each type.

Wherein, the system model of the power distribution network can refer to fig. 15, the type and the number of decoupling capacitors of each type are determined in the preamble step, and other parameters in the system model of the power distribution network are also determined in the preamble step, so that the actual impedance curve of the PDN can be determined.

It should be noted that, in the impedance curve, the actual impedance at the position where part of the antiresonant point may exist is larger than the target impedance, and the number of decoupling capacitors needs to be further optimized through the subsequent steps.

Optionally, after S160 in fig. 1, if the determination result is no, it is indicated that the actual impedance at the anti-resonant point position is less than or equal to the target impedance, that is, the actual impedance at the anti-resonant point position meets the PDN design rule. At this time, the method may further include: and determining the number of decoupling capacitors corresponding to the capacitor action frequency band where the antiresonance point is positioned as the number of the decoupling capacitors.

So far, in the capacitance selection process, the number of decoupling capacitors corresponding to the capacitance action frequency band where the anti-resonance point is located can be determined.

Optionally, if the number of antiresonant points is multiple, after determining the number of decoupling capacitors corresponding to the capacitor operating frequency bands where each antiresonant point is located, the method further includes further optimizing the number of decoupling capacitors, and referring to fig. 20, the method may include:

s310, determining preset parameters.

S320, selecting a plurality of different decoupling capacitors according to the lowest cutoff frequency and the highest cutoff frequency.

S330, determining the capacitance action frequency range of each type of decoupling capacitor according to the working frequency range of each type of decoupling capacitor.

S340, determining the number of decoupling capacitors of each type in the plurality of different types of decoupling capacitors according to the target impedance, and determining an actual impedance curve of the power distribution network.

S350, determining an anti-resonance point in the minimum cutoff frequency and the maximum cutoff frequency.

S360, judging whether the actual impedance of the antiresonant point is larger than the target impedance.

And S370, if the actual impedance of each anti-resonance point is not larger than the target impedance, determining the number of decoupling capacitors corresponding to the capacitor action frequency band where each anti-resonance point is located as the number of the decoupling capacitors.

Thus, the determination of the type of decoupling capacitor and the number thereof is completed. Since the impedance values corresponding to the frequency points in the actual impedance curve of the PDN system are reduced to different extents when the decoupling capacitance of the capacitance operating frequency band of each antiresonant point is added, after S370, an attempt may be made to reduce the decoupling capacitance added in the preceding step corresponding to a portion of the antiresonant points, or the decoupling capacitance initially determined in S340, so as to achieve the purpose of further optimizing the number of decoupling capacitances. Further optimization of the number of decoupling capacitors is described in exemplary fashion below in connection with S380, S390, and S392.

S380, reducing decoupling capacitance of a capacitance action frequency band where an anti-resonance point is located.

Wherein, this step causes an increase in the actual impedance corresponding to each frequency point in the actual impedance curve of the PDN system. Therefore, the selection of the anti-resonance point can be based on the anti-resonance point of the actual impedance closest to the target impedance, and the anti-resonance point at a position far from the anti-resonance point is selected; or, after S370, the actual impedance values corresponding to the anti-resonance points may be compared, and the anti-resonance point corresponding to the smaller actual impedance value is selected; the selection may be performed according to the actual requirement of the capacitance selection method of the power distribution network, which is not limited in the embodiment of the present invention.

S390, judging whether the actual impedance corresponding to each frequency point in the actual impedance curve of the power distribution network is smaller than or equal to the target impedance.

I.e. after S380, it is determined whether the PDN system still meets the design principles (or principles).

If yes, S380 is continuously executed, that is, the decoupling capacitance of the capacitive action frequency band where an anti-resonance point is located is continuously reduced. The anti-resonance point selected in this step may be the same as or different from the anti-resonance point selected in the previous execution of S380, which is not limited in the embodiment of the present invention.

If not, then S392 is performed.

S392, adding a decoupling capacitor of the capacitor action frequency band where the anti-resonance point is located.

So far, the optimization is ended.

The type of decoupling capacitor and its corresponding number may also be included, and a PDN impedance curve (which may include an actual impedance curve and a target impedance curve) may be displayed at the display interface.

For example, referring to fig. 21, the method may include:

starting.

S410, acquiring preset parameters.

I.e. the initial preset parameters are determined.

S420, calculating target impedance.

I.e. the target impedance of the PDN system is calculated.

S430, calculating the action frequency range of each capacitance impedance.

I.e. the capacitive band of action of each decoupling capacitor is calculated.

S440, selecting the capacitance in the cut-off frequency range.

Namely, only decoupling capacitors with capacitance action frequency ranges within the working frequency range of the PDN system are selected, and decoupling capacitors with capacitance action frequency ranges overlapping with the working frequency range of the PDN system are selected.

S450, estimating a group of capacitors according to the target impedance.

That is, the number of the various decoupling capacitors selected in S440 is determined; also included is determining an actual impedance curve for the PDN system.

S460, searching an impedance curve antiresonant point.

That is, in the actual impedance curve of the PDN system, the anti-resonance points are determined. Thereafter, a judgment step is performed, i.e., S470 is performed.

S470, judging whether the antiresonant point impedance is larger than the target impedance.

That is, for each antiresonant point, it is determined whether the actual impedance at the antiresonant point position is greater than the target impedance.

If so, the number of decoupling capacitors needs to be increased, i.e., S472 is performed, and S470 is performed back.

And S472, increasing the capacitance of the frequency band where the antiresonant point is located.

Namely, the number of decoupling capacitors corresponding to the capacitance action frequency band where the antiresonance point is located is increased.

If not, the actual impedance of the antiresonant point is smaller than or equal to the target impedance, namely the PDN design principle is satisfied. At this time, S480 is performed.

S480, optimizing the quantity of the capacitors before and after the antiresonant point.

Namely, an attempt is made to reduce the number of decoupling capacitors corresponding to the capacitance action frequency band where part of the antiresonant points are located, so that the number of the decoupling capacitors is smaller on the premise that the actual impedance is smaller than the target impedance.

S490, determining the use quantity of the capacitors and outputting an impedance curve.

That is, the type of decoupling capacitor and the corresponding number thereof are determined, and the actual impedance curve of the PDN system is output, and the target impedance curve can also be synchronously output.

And (5) ending.

According to the selection method of the power distribution network, which is provided by the embodiment of the invention, the capacitance action frequency range of each type of decoupling capacitor is determined according to the working frequency range of each type of decoupling capacitor; and after determining the number of various decoupling capacitors to obtain an actual impedance curve of the power distribution network, searching an anti-resonance point, determining a capacitor action frequency band where the anti-resonance point is located when the actual impedance of the anti-resonance point is larger than the target impedance, and increasing the number of decoupling capacitors of the capacitor action frequency band. Therefore, the actual impedance of the anti-resonance point can be effectively reduced, thereby being beneficial to quickly determining the quantity of the decoupling capacitors, improving the selection efficiency of the decoupling capacitors, shortening the time consumption of the process and being beneficial to obtaining the optimal combination scheme of the decoupling capacitors.

Based on the same inventive concept, the embodiments of the present invention further provide a capacitance selection device of a power distribution network, which may be used to perform the capacitance selection method of the power distribution network in the foregoing embodiments, so that the device also has the technical effects of the method in the foregoing embodiments, and the same features are understood by referring to the foregoing description and are not repeated herein.

For example, referring to fig. 22, the apparatus 60 includes: a preset parameter determining unit 610, configured to determine preset parameters; the preset parameters comprise target impedance, lowest cut-off frequency and highest cut-off frequency of the power distribution network; a decoupling capacitor selection unit 620, configured to select a plurality of different types of decoupling capacitors according to the lowest cutoff frequency and the highest cutoff frequency; wherein the operating frequency band of the plurality of different types of decoupling capacitors covers a frequency band range between the lowest cut-off frequency and the highest cut-off frequency; an active frequency band determining unit 630, configured to determine a capacitive active frequency band of each type of the decoupling capacitor according to an active frequency band of each type of the decoupling capacitor; a capacitance number determining unit 640 for determining the number of decoupling capacitances of each of the plurality of different types of decoupling capacitances according to the target impedance, and determining an actual impedance curve of the power distribution network; an antiresonant point determining unit 650 configured to determine an antiresonant point within the lowest cutoff frequency and the highest cutoff frequency range; an impedance magnitude judging unit 660 for judging whether the actual impedance of each antiresonant point is greater than the target impedance; and a capacitance number increasing unit 670, configured to increase the decoupling capacitance of the capacitance action frequency band where the antiresonant point is located when the determination result is yes.

Note that, fig. 22 shows, by way of example only, the signal transmission relationship of each unit, but the signal transmission direction is not limited thereto. In addition, each unit corresponds to only a division of functionality, and in an actual device structure, some units may be integrated in the same component, which is not limited by the embodiment of the present invention.

On the basis of the above embodiment, the embodiment of the present invention further provides a server, including: one or more processors; and the storage device is used for storing one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors are enabled to realize the capacitance selection method of the power distribution network provided by any embodiment.

By way of example, and with reference to FIG. 23, FIG. 23 illustrates a block diagram of an exemplary server 512 suitable for use in implementing embodiments of the present invention. The server 512 shown in fig. 23 is only an example, and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

As shown in fig. 23, the server 512 is in the form of a general-purpose server. Components of server 512 may include, but are not limited to: one or more processors 516, a memory device 528, a bus 518 that connects the various system components (including the memory device 528 and the processor 516).

Bus 518 represents one or more of several types of bus structures, including a memory device bus or memory device controller, a peripheral bus, an accelerated graphics port, a processor, or a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include industry standard architecture (Industry Subversive Alliance, ISA) bus, micro channel architecture (Micro Channel Architecture, MAC) bus, enhanced ISA bus, video electronics standards association (Video Electronics Standards Association, VESA) local bus, and peripheral component interconnect (Peripheral Component Interconnect, PCI) bus.

Server 512 typically includes a variety of computer system readable media. Such media can be any available media that is accessible by server 512 and includes both volatile and nonvolatile media, removable and non-removable media.

The storage 528 may include computer system readable media in the form of volatile memory, such as random access memory (Random Access Memory, RAM) 530 and/or cache memory 532. The server 512 may further include other removable/non-removable, volatile/nonvolatile computer system storage media. By way of example only, storage system 534 may be used to read from or write to non-removable, nonvolatile magnetic media (not shown in FIG. 23, commonly referred to as a "hard disk drive"). Although not shown in fig. 23, a magnetic disk drive for reading from and writing to a removable nonvolatile magnetic disk (e.g., a "floppy disk"), and an optical disk drive for reading from or writing to a removable nonvolatile optical disk such as a Read Only Memory (CD-ROM), digital versatile disk (Digital Video Disc-Read Only Memory, DVD-ROM), or other optical media, may be provided. In such cases, each drive may be coupled to bus 518 through one or more data media interfaces. The storage 528 may include at least one program product having a set (e.g., at least one) of program modules configured to carry out the functions of the embodiments of the invention.

A program/utility 540 having a set (at least one) of program modules 542 may be stored in, for example, storage 528, such program modules 542 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each or some combination of which may include an implementation of a network environment. Program modules 542 generally perform the functions and/or methods in the described embodiments of the invention.

The server 512 may also communicate with one or more external devices 514 (e.g., keyboard, pointing terminal, display 524, etc.), with one or more terminals that enable a user to interact with the server 512, and/or with any terminals (e.g., network card, modem, etc.) that enable the server 512 to communicate with one or more other computing terminals. Such communication may occur through an input/output (I/O) interface 522. Also, the server 512 may communicate with one or more networks (e.g., local area network (Local Area Network, LAN), wide area network (Wide Area Network, WAN) and/or public network, such as the internet) via the network adapter 520. As shown in fig. 23, network adapter 520 communicates with the other modules of server 512 via bus 518. It should be appreciated that although not shown, other hardware and/or software modules may be used in connection with server 512, including, but not limited to: microcode, end drives, redundant processors, external disk drive arrays, disk array (Redundant Arrays of Independent Disks, RAID) systems, tape drives, data backup storage systems, and the like.

The processor 516 executes programs stored in the storage 528 to perform various functional applications and data processing, for example, to implement the method for selecting a power distribution network according to any embodiment of the present invention, and the specific method is referred to above and will not be described herein.

On the basis of the foregoing embodiments, the embodiments of the present invention further provide a computer readable storage medium, on which a computer program is stored, where the program when executed by a processor implements a method for selecting a capacitance of a power distribution network according to any one of the embodiments of the present invention, and the specific method is referred to above and will not be repeated herein.

The computer storage media of embodiments of the invention may take the form of any combination of one or more computer-readable media. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

The computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, either in baseband or as part of a carrier wave. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, smalltalk, C ++ and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or terminal. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer, for example, through the internet using an internet service provider.

Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.

Claims

1. A method for capacitance selection of a power distribution network, comprising:

2. The method of claim 1, wherein prior to determining the preset parameters, further comprises: determining a system model of the power distribution network;

wherein, the system model of the power distribution network includes: the power supply module, the decoupling capacitor module, the power supply plane, the diffusion impedance, the via impedance, the capacitor mounting inductance module and the load; the first end of the power supply module is electrically connected with the first end of the decoupling capacitor module, the first end of the power supply plane and the first end of the load, the second end of the power supply module is electrically connected with the second end of the capacitor mounting inductor module, the second end of the power supply plane and the first end of the diffusion impedance, and the second end of the diffusion impedance is electrically connected with the second end of the load through the via impedance; the decoupling capacitor module comprises a plurality of decoupling capacitors of different types connected in parallel, the capacitor mounting inductor module comprises a plurality of capacitor mounting inductors, and each decoupling capacitor is electrically connected with the second end of the power supply module through one capacitor mounting inductor.

3. The method of claim 2, wherein determining the preset parameters comprises:

determining initial preset parameters; the initial preset parameters comprise the voltage V of a load, the maximum working current Imax, the ripple coefficient AR allowed by the working voltage, the proportion TP of transient current and Imax, the type of a power supply module, the value of a capacitor mounting inductor, the size of a power supply plane, the value of diffusion impedance and the value of via impedance;

and determining the preset parameters according to the initial preset parameters.

4. A method according to claim 3, wherein determining the preset parameters from the initial preset parameters comprises:

calculating the target impedance according to a target impedance calculation formula, and determining the lowest cut-off frequency and the highest cut-off frequency according to the type of the power supply module and the size of a power supply plane;

the target impedance calculation formula is as follows:

5. the method of claim 1, wherein selecting a plurality of different types of decoupling capacitors based on the lowest cutoff frequency and the highest cutoff frequency comprises:

and selecting one decoupling capacitor group from the preset capacitor bank.

6. The method of claim 5, wherein determining the capacitance operating band for each type of decoupling capacitance based on the operating band for each type of decoupling capacitance comprises:

In the decoupling capacitor group, sequencing the decoupling capacitors of different types according to the self-resonance point frequency of each decoupling capacitor from low to high;

determining the intersection point of impedance curves of the decoupling capacitors adjacent to each other in frequency from the resonance point;

determining the capacitance action frequency range of the first type decoupling capacitor as the frequency range between the two intersection points on the impedance curve, and determining the capacitance action frequency range of the second type decoupling capacitor as the frequency range between the intersection points and the boundary cut-off frequency on the impedance curve;

the first type of decoupling capacitor is the decoupling capacitor with the self-resonance point frequency in the decoupling capacitor group in a middle range, and the second type of decoupling capacitor is the decoupling capacitor with the lowest or highest self-resonance point frequency in the decoupling capacitor group; the boundary cut-off frequency is the lowest working frequency of the decoupling capacitor with the lowest self-resonance point frequency or the highest working frequency of the decoupling capacitor with the highest self-resonance point frequency.

7. The method of claim 6, further comprising, after determining a capacitance action band of each type of the decoupling capacitance according to an operation band of each type of the decoupling capacitance:

And removing the decoupling capacitors in the decoupling capacitor group, wherein the capacitance action frequency range of the decoupling capacitors is not in the frequency range between the lowest cutoff frequency and the highest cutoff frequency.

8. The method of claim 1, wherein determining the number of each of the plurality of different types of decoupling capacitors based on the target impedance comprises:

and determining the minimum number of the decoupling capacitors when the impedance of each type of decoupling capacitors at the self-resonance point position is smaller than the target impedance as the number of the decoupling capacitors according to the mode of impedance parallel connection.

9. The method of claim 8, wherein determining an actual impedance curve of the power distribution network comprises:

and determining an actual impedance curve of the power distribution network according to a system model of the power distribution network and the types and the quantity of each type of decoupling capacitor.

10. The method of claim 1, further comprising, after determining whether the actual impedance of the antiresonant point is greater than the target impedance:

if not, determining the number of the decoupling capacitors corresponding to the capacitor action frequency band where the anti-resonance point is located as the number of the decoupling capacitors.

11. The method of claim 1, wherein the number of antiresonant points is plural, and wherein after determining whether the actual impedance of the antiresonant points is greater than the target impedance, further comprising:

if the actual impedance of each anti-resonance point is not greater than the target impedance, determining the number of decoupling capacitors corresponding to the capacitance action frequency band where each anti-resonance point is located as the number of the decoupling capacitors; also included thereafter is:

reducing the decoupling capacitor of the capacitor action frequency band where one anti-resonance point is located;

judging whether the actual impedance corresponding to each frequency point in the actual impedance curve of the power distribution network is smaller than or equal to the target impedance;

if yes, continuing to reduce the decoupling capacitor of the capacitor action frequency band where the anti-resonance point is located;

if not, the decoupling capacitor of the capacitor action frequency band where the anti-resonance point is positioned is increased again;

and the capacitance selection and optimization process is finished.

12. A capacitance selection device of a power distribution network, comprising:

13. A server, comprising:

one or more processors;

Storage means for storing one or more programs,

the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the capacitance selection method of a power distribution network as recited in any one of claims 1-11.

14. A computer readable storage medium having stored thereon a computer program, which when executed by a processor implements a method of capacitance selection of a power distribution network according to any of claims 1-11.