The WEBENCH Electrical Simulator is an online electrical simulation tool that provides immediate access to accurate performance information of National components via the Internet. The WEBENCH Electrical Simulator utilizes an industry standard SPICE simulation engine combined with component models based on the latest National Semiconductor device information. These tools are web enabled with an interactive schematic and waveform viewer so that you can have access to high speed sophisticated simulation from any platform having Web access and a browser.source

WEBENCH online design and prototyping tools deliver results faster than ever. Now you have the world’s most powerful and award-winning online design environment right at your fingertips. Design, optimize, generate your prototype, and download your test vectors—all online.And do it all for free, anywhere, anytime.The WEBENCH environment provides the end-to-end design and prototyping tools you need to create power supplies that meet your design’s requirements.WEBENCH tools let designers solve design problems before prototyping—alleviating the time and trouble associated with traditional design methods.source