Power Analyzer by Keysight

Created: August 18, 2022 | Updated: January 17, 2023

To deliver today's high-performance products, engineers must evaluate their designs to detect and resolve any potential signal integrity (SI) and power integrity (PI) issues during the design stage. 

Power Integrity analysis, also called Power Delivery Network (PDN) analysis, can be performed in both the DC and the AC domains. Altium Designer supports DC analysis of a power delivery network using the Power Analyzer by Keysight, enabled by Keysight Technologies.

DC Power Integrity analysis helps the engineer answers critical design questions, including:

  • Identify and resolve DC voltage and current density issues
  • Calculate multi-network and return path interactions
  • Visualize the voltage and current density distribution and identify hotspots in the PCB editor
  • Examine the voltage, current density, and via current at any location on the board
  • Generate an HTML report of the analysis simulation results

Rather than relying on simple cross-sectional area calculations to determine the current carrying capacity of the power network, the Power Analyzer first accurately models the copper structures, and then calculates the power delivery voltages and currents across the PCB. With results presented in both visual and tabular form, the engineer can use this feedback and quickly adjust the track widths, copper thicknesses, and via properties to ensure they achieve the integrity of DC power delivery required for their design. 

To perform a Power Integrity analysis in Altium, the engineer first creates a hierarchical network of the entire power delivery system, identifying each power and return net, the sources and loads, as well as any series elements present in each section of the power network. Once the network and configuration settings have been defined, the Power Analyzer can examine the entire network.

The Power Analyzer by Keysight extension is supported for use in Altium Designer 22.10 and later.

Configuring the Power Network

The Power Analyzer examines the flow of energy through the copper pathways in the power network. The power network is defined by identifying and configuring the various network elements, including the net, the source, any series components, and the loads. To configure the power network:

Add an Analysis document to the Project

Analysis is configured and run from a Power Analyzer by Keysight document (<ProjectName>.pdnaK).

Configure the Board Properties

The Power Analyzer needs to know the physical properties of the board, such as the allowable current density, the type of copper, the working temperature, and so on. Confirm that the default values defined in the Configuration section of the analyzer document are suitable for your design.

Automatic Power Net Identification

The Power Analyzer can attempt to identify the power nets automatically. To do this, it needs to know how to identify circuit elements such as voltage regulators, connectors, and series components. As well as using clues such as component designator prefixes, you can also add parameters to certain components to enhance the automatic detection process. Learn more about Configuring the Auto-Define Settings.

Choose the Power Net(s)

Click Button - Define Automatically for automatic power net identification, or click Button - Manage Nets to manually select the power net(s). Learn more about defining the Power Nets.

Extend the Net(s)

If the power net passes through a series component such as a fuse, extend the net and identify the series components and chained nets. Learn more about extending a net.

Identify and Configure the Source

Each power net starts from a Source, such as a connector. Enable the source in the Add Source dialog, then click the Gear icon to configure that source. Learn more about identifying and configuring the Source.

Identify the Loads

Start with the major current consumers, including the Voltage Regulator Modules (VRMs). Learn more about identifying the Loads.

Configure the Loads and VRMs

Click the gear icon to open the Load Properties dialog, and configure each load. When a device is configured as a Voltage Regulator Module (VRM), a child power network is automatically created in the hierarchy with that VRM as the source.

Identify the Loads in the Child Power Nets

Ensure that the major load components are included in every power net.

Confirm the Power Network

Click the Button - Show in Tree button to confirm that the power network is ready to test.

Ready for Analysis

Check the Tree to visually confirm that each power network is complete. To move from one power net to another, click on the Power Analyzer by Keysight link to return to the power net document, and select the Tree for each power net. When this is complete, you're ready to analyze the power network.

Analyzing the Power Network

Once the Power Networks have been defined, you're ready to analyze the DC power distribution across and through the board.

Analyze the Copper Structures

Based on the Configuration settings, when you click the Button - Analyze All Nets button, the copper structures present in the board are analyzed and simulated to determine the current flows and voltage drops.

Show on PCB

A Summary of the Voltage Drop, Current Density and Max Via Current analysis results are shown as part of the Power Net Definition in the *.pdnaK document. Click Button - Show on PCB to explore the current density and voltage drop heatmaps. The colored heatmap view will open in the PCB editor and the Power Analyzer by Keysight panel will also open, where you can configure the Heatmap, explore any Violations, and place measurement Probes. Learn more about Running an Analysis.

Examine the Heatmaps

The calculated current flow and voltage drops are displayed as Heatmaps, directly in the PCB editor. Use the PCB editor Layer tabs to examine the heatmap on each layer, switch between 2D and 3D PCB view modes with the standard 2 and 3 shortcuts, and click the Show Heatmap button in the Power Analyzer by Keysight panel to switch between the power analysis Heatmaps, and the standard PCB display modes.

Explore the Analysis Results

In the PCB editor, the results you are examining in the power network analysis are controlled via the Power Analyzer by Keysight panel. At the top of the panel, select the power network/net whose Heatmap you want to display. Note that if there are violations present in the design, the default is to include Only nets with violations in the dropdown, clear that option to include all power nets in the list. Learn more about the Power Analyzer by Keysight Panel.

Switch between Current Density and Voltage Drop

The Heatmap displays either the Current Density through the copper or the Voltage Drop across the copper, use the buttons at the top of the Heatmap tab of the panel to select the required mode. A scale for the Heatmap is displayed below the board, automatically scaled for current from Zero to Max Current Density, or for voltage drop from (Voltage - VDrop) to Voltage. Directional arrows indicating current flow can be displayed on the Heatmap, and the Current Density or Voltage Drop scale can be adjusted. Learn more about configuring and controlling the display of the Heatmap.

Exploring the Voltage Drop

The location of current density hotspots can be directly identified by their color on the heatmap. Because it is calculated as a difference between locations, understanding the voltage drops requires deeper interpretation. To assist in identifying critical locations, use the Enable Visual Slider for Voltage Contour option to display pre-defined contour lines, either as a voltage or as a percentage. Learn more about the Heatmap for Voltage Drop.

Probing the Results

To take a measurement directly from the Heatmap, place a Probe. Place a single Probe to display the absolute Current or Voltage at that location, or click at a second location to measure the difference between the two Probe points. The type of measurement (V or I) is determined by the current Heatmap mode (Current Density or Voltage Drop). Learn more about Probes.

Examine the Ground Net Results

By default, the Ground net is excluded from the Heatmap results. Disable the Skip Ground checkbox in the Configuration section of the *.pdnaK document to include it, then select the GND net in the Network / Net dropdown at the top of the Power Analysis by Keysight panel. Note that the Heatmap supports polygon structures on signal layers, but the behavior of a power plane layer cannot be simulated. Learn more about the Configuration options.


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