Analyzing Your Power Networks in Altium Designer

The practical performance of a PCB design layout depends on a multitude of factors, many of which can be predicted, to a reasonable degree, through a range of PCB design analysis tools such as post-layout Signal Integrity analysis. What's often neglected, however, or simply relegated to a 'rule of thumb' methodology, is developing the most effective layout design for board's DC Power Delivery systems. This is the judgment applied to the design of a board's copper areas that provide both the DC supply rails to the circuitry and their ground or common return path to the DC supply source. The desired outcome is an efficient design that maintains the integrity of the design's DC power layout.

With modern digital designs featuring high-speed circuitry, multiple devices, densely populated boards, and multiple supply rails, the demands placed on a design's DC power distribution network warrant a more analytical approach to its design. The DC analysis of a Power Delivery Network (PDN), or the results of its DC Power Integrity (PI-DC), is basically aimed at ensuring that adequate copper has been provided in the path from the voltage sources to the loads – in other words, that the planes, traces, and vias on the board are of sufficient size (and characteristics) to meet the power consumption requirements of the devices on the board.

Fortunately, the guesswork can be removed from the assessment of a PCB's power delivery network through the use of a DC Power Integrity (PI-DC) simulation tool, which analyzes a board design's DC performance based on its electrical and physical properties and helps the engineer answer 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 a report of the analysis simulation results.

To perform a DC Power Integrity analysis right in the Altium Designer PCB design environment, the go-to solution is the Power Analyzer by Keysight.

Provided as a downloadable Altium Extension application, the Power Analyzer by Keysight, enabled by Keysight Technologies, integrates directly with Altium Designer to allow PI-DC simulation and analysis of the current PCB project. 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.