LTspice IV is Linear Technology’s high performance SPICE simulator, schematic capture and waveform viewer with enhancements and models for simulating switching regulators. LTspice IV provides all SPICE analysis types within the time and the frequency domain. To make these functionalities available for your schematic created with EAGLE you can download the LTspice IV-EAGLE ULP (User Language Program) from the CadSoft website. This ULP enables the export of EAGLE data into LTspice IV and vice versa. Complete schematic sheets and single schematic groups can be transferred. Schematic changes are synchronized between both tools.