David, I'm pretty sure that Hspice has an element called a voltage controlled switch that will do this. It takes ON and OFF resistances as parameters. Later, Weston -----Original Message----- From: David Kaiser [mailto:david.kaiser@xxxxxxxxxx] Sent: Tuesday, October 14, 2003 3:55 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] How to build a variable resistor in HSPICE Can anyone show me how to build a resistor in HSPICE that varys in value= from 1000 Ohms to 1 ohm in about 1ns and visa-versa? I suppose I could use a FET, but I don't have enough experience with= transistors in HSPICE to do this myself. Thanks in advance. David Kaiser 4 McDATA Pkwy. Broomfield, CO 80021 (720) 558-4431 david.kaiser@xxxxxxxxxx ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu