We are executing full-custom designing on a CAD system in which detailed device information provided by semiconductor foundries (device characteristics, detailed design rules, etc.) has been implemented into the integrated analog IC design environment provided by Cadence Design Systems. IC designing is proceeded by using the database in which the latest practical achievement of fabrication processes on device has been reflected in an environment in which all the required design tools such as circuit diagram input, various circuit simulators, waveform display functions and layout design tools, etc. are working together in collaboration.