Method for selecting decoupling capacitors from power supply distribution network on basis of maximum anti-resonance point

Abstract

The invention discloses a method for selecting decoupling capacitors from a power supply distribution network on the basis of the maximum anti-resonance point in order to solve the problems that the number of capacitors is large and computation time is long when decoupling capacitors are selected from a power supply distribution network in the prior art. The method includes the implementation steps that (1) circuit board parameters are input, and the self-resonance frequency and quality factor of capacitors are calculated; (2) cut-off target frequency is determined, and actual impedance and target impedance of the power supply distribution network are worked out; (3) within the cut-off target frequency, frequency corresponding to the maximum anti-resonance point is determined, and decoupling capacitors and the number of decoupling capacitors to be used are selected according to the determined frequency; (4) the number of all the selected capacitors is optimized, and the number of decoupling capacitors is reduced; (5) the optimized number of the capacitors is recorded and a final power supply distribution network actual impedance curve is drawn. According to the method, the number of decoupling capacitors selected from the power supply distribution network can be reduced, computation time for selection of the decoupling capacitors is shortened, and the method can be used for high-speed circuit design.

Description

technical field [0001] The invention belongs to the technical field of electronic circuits, and further relates to a method for selecting a decoupling capacitor, which can be applied to high-speed circuit design. Background technique [0002] With the development of electronic systems towards high speed, high density, low voltage and high current, the power integrity problem is becoming more and more prominent. At this time, the power distribution network PDN not only needs to provide pure power for the circuit, but also provides low noise for high-speed signals. circuit, noise isolation between multiple chips, and the role of ensuring electromagnetic integrity, so the rationality of the power distribution network design plays a key role in the success or failure of the system. [0003] For the design of the power distribution network, generally starting from the frequency domain, the target impedance is used as a reference standard, and different types of decoupling capacit...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that only one decoupling capacitor is used in the whole design process. Although it is easy to implement, it generally requires a large number of capacitors to complete the design, and because the impedance curve of the power distribution network obtained by the design is a deep "V" type, so the redundancy is greater

[0008] The disadvantage of the Decade Methods method and the Flat response method is that the number and type of capacitors used in each order of magnitude are limited, but the actual design may not always be able to meet their requirements.

The disadvantage of this method is that although the parameters affecting the impedance of the power distribution network are analyzed and designed, the specific design scheme of the decoupling network is not given from a global perspective, and the designer needs to establish the relationship between the parameters of the power distribution network. Correlation between, according to determine the required decoupling capacitor capacitance and number

However, since this method does not consider the influence of the quality factor of the capacitor on the scheme, nor does it consider the influence of the selection order of the decoupling frequency points on the scheme, so the scheme given by this method uses more types and numbers of capacitors, and it is also difficult to directly affects the computing speed

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