Online electronics design and simulation tool

Paul Boughton

Fairchild Semiconductor has enhanced its Power Supply WebDesigner (PSW) online design and simulation tool to include power train discrete (MOSFET/IGBT/Rectifier) device power loss and efficiency analysis tools.

Intended for 100W to 3kW designs as a function of input and output conditions, these new modules provide designers with power factor correction (PFC), phase-shifted full-bridge plus secondary side synchronous rectification (PSFB+SR) power train discrete device analysis and the matrix of device combinations associated with these topologies.

From user-specified electrical and mechanical specifications, the new modules provide an optimum combination of discrete power semiconductors, transformer and inductor design values, as well as a bill of material (BOM). It also provides a dashboard view of the converter’s system and device power loss, device junction temperature, and further component fine-tuning over the operating conditions.

As with other PSW modules, designers using the tools can accept default recommended values, or spend time optimizing the important details to their unique design needs. They can get quick, accurate estimates on design performance, and refine design choices as they go. The tools also allow them to spend the time to perform detailed simulation analysis and learn the insights of how their design and its hardware prototype will work with higher degree of confidence.

The Power Train Discrete Module consists of a phase-shifted full bridge with secondary side synchronous rectification (PSFB+SR) module and power factor correction (PFC) module.

The online simulation tools provide designers with an optimised tool that works with the most popular PSFB+SR control ICs on the market (UCC28950 and UCC3895) as well as a complete power train design including selection of the optimum Fairchild MOSFET, IGBT, and rectifier.

Users can select the optimum bridge rectifier, MOSFET/IGBT, and power rectifier part numbers (PNs), or let the tools recommend from user-specified system design inputs.

An optimised power train discrete design targets power supplies that need PFC and/or PSFB+SR while the discrete component losses can be correlated against hardware for high levels of relative accuracy unmatched by equation-based calculation alone.

The tool includes the ability to compare different sets of power train discrete combinations within one analysis and can recommend or fine-tune the power train discrete components, automating a tedious, high-iteration, manual trial-and-error/test-design step, and saving valuable time.

It also provides visual representation of system and major component power loss and efficiency over different line and load conditions, allowing designer to go back into the online design steps to re-balance the system and component loss before prototyping.

These new modules save designer’s time when evaluating various combinations. Rather than spending the typical one-week-per-combination bench testing time, PSW can simulate each combination quickly and accurately – typically 2 percent difference over line and load conditions between tool and hardware measurement results.

When a design is complete, PSW creates a BOM which can be sent to their procurement department or instantly procure the components online, saving time on documentation or sourcing parts elsewhere. Additionally, they can save their design for future reference or pass the design on to other team members.

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