Sigrity SPEED2000 Power Ground Noise Simulation模式如何进行电源阻抗仿真分析操作指导(二)-有电容

Sigrity SPEED2000 Power Ground Noise Simulation模式如何进行电源阻抗仿真分析操作指导(二)-有电容

Sigrity SPEED2000 Power Ground Noise Simulation模式如何进行电源阻抗仿真分析操作指导(一)-无电容详细介绍了如何在该模式查看电源的自阻抗，它是没有电容参与的模式，接下来将电容模型加载到仿真中进行仿真分析，以下图为例

2D 视图

3D view

本例中cap1-6参与仿真

具体操作如下

1. 这些步骤和参数设置和Sigrity SPEED2000 Power Ground Noise Simulation模式如何进行电源阻抗仿真分析操作指导(一)-无电容完全一致，不再重复

1. 点击Setup VRAM& Decaps,设置电容参数

1. 跳转到component Manager界面，选中cap1，点击edit，设置RLC参数如下，为非理想电容模型

C   2   0   0.47u

L   2   3   1n

R   3   1   0.01

1. 点击ok

1. 另外cap2-5使用的都是相同的电容模型，所以都被自动更改了，点击确定

1. 以下选项设置和参数和Sigrity Speed2000 如何使用Power Ground Noise Simulation模式进行电源阻抗仿真分析操作指导(一)-无电容完全一致

1. 仿真结束后，结果如下

1. 在Load Curves空白处鼠标右击选择Load

1. 同时选中没有电容参与的电压和电流的时域曲线，加载进来

1. 点击打开

1. 弹出界面，点击ok，首先加载进来的是电流曲线

1. 之后继续会弹出界面，点击ok，加载电压曲线

1. 加载进来的曲线如下

1. 将加载进来的曲线设置成其它颜色以示区分，以加载进来的电压曲线为例，选中它，右击选择Property

1. 弹出界面，首先点击颜色框，选择蓝色，点击确定

1. 点击ok

1. 同时打开两个电压曲线，进行比较，可以看到有电容参与的电压噪声幅度会更小一些

1. 同样地，使用V1/C1的公式计算阻抗，结果如下

1. 使用同样的方法，将Sigrity Speed2000 如何使用Power Ground Noise Simulation模式进行电源阻抗仿真分析操作指导(一)-无电容保存的curve-no decap.cur加载进来

通过比较，可以发现，因为电容的加入，电源阻抗被大幅度的减低了

 Along with accuracy and efficiency, SPEED2000 provides an analysis flow that is particularly
valuable for design simulations that benefit from direct time domain observation. SPEED2000
can read databases from popular package and board design tools.
Chip data can also be incorporated into the same file for co-simulation. This provides an
environment for accessing the impact of noise propagation throughout the entire structure.
Circuits in the combined design are linked with SPICE circuit files.
Simulation parameters and excitation are added by the user; however, the user does not need
to create special purpose models. SPEED2000 directly provides voltage and current
waveforms.
SPEED2000 is particularly effective to be used for, but it is not limited to, the following
applications:
■ Computation of power and ground noise.
■ Determination of decoupling capacitor placement, including the number, values, and
locations of decoupling capacitors
■ Determination of frequency-dependent port parameters of packages, such as port input
impedances, S parameters, and transfer functions between different ports
■ Evaluation and design of power and ground distribution systems, including power and
ground plane arrangement, and power and ground via / pin assignment
■ Evaluation of electromagnetic coupling between different components
■ Evaluation of electromagnetic radiation from packages and printed circuit boards
■ Evaluation of signal and noise spectrum at various locations
■ Evaluation of signal and noise waveforms at various locations
■ Identification of package resonance.
SPDGEN and SPDSIM
SPEED2000 is composed of two executable modules: SPDGEN and SPDSIM.
■ SPDGEN — Provides a graphical user interface so the user can conveniently build and
modify package components and establish simulation parameters
■ SPDSIM — Provides the transient simulation engine that processes and displays the
package components. SPDSIM also provides a post processing interface so the user can
analyze, compare and print the results of package simulation
The SPDSIM simulations are entirely controlled by what the user establishes and sets up in
the SPDGEN package editor.
SPEED2000 provides powerful 3D editing functions using the SPDGEN module. Before
the.spd file (representing your package) is loaded into the SPDSIM module, the viewing and
simulation parameters need to be specified within the.spd file using the SPDGEN module.
In addition to simulation, the SPDSIM module provides a post processing interface so the
user can analyze, compare, save, export and print the results of package simulation.
■ The SPDGEN module provides the GUI-based package geometry editor and file builder,
it is used to create and edit the SPEED file (.spd) which contains package geometry and
simulation parameters
■ The SPDGEN Graphical User Interface (GUI) makes convenient “what if” analysis of a
package design possible; that is, a user can conveniently engineer a possible solution to
a problem (made apparent during the simulation) then simulate the new model to see the
results of changes made
■ The SPDSIM module loads and executes a transient simulation of the .spd file created
by SPDGEN. It should be noted that SPDSIM does not change the .spd file contents.
Use SPDGEN to select which components of a package design will be simulated