The LTpowerCAD® design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design with µModule regulators and many other products, mostly monolithic buck step-down regulators. Unlike conventional simulation tools, this LTpowerCAD tool guides users throughout the whole supply design process: it searches suitable parts according to user’s supply specifications; then it guides the user to select and optimize circuit component values with suggestions and warnings. The tool shows real-time results of feedback loop bode plot, as well as the power stage performance. The design can be exported to LTspice simulation circuit for users to further verify their designs. The tool also provides PCB layout examples. Currently, this design tool works on Microsoft Windows based PC with Excel 2000, 2003, 2007, 2010 and 2013. With internet connection, the user can make real time update of the program and its component library.