Steve, I am trying to use the gpmos model that you have suggested for SSO simulations and it is very useful, but I would like veifying some issues: 1) implementing this model I noticed a mismatching beetwen pmos spice and gpmos model: is this caused by pmos threshold voltage (Vt) approximation? 2) what is exactly the flow that you use to extract the (x, y) data which are inserted in the gpmos list? 3) how you extimate the pgain value? The flow that I put in act is the following: I simulate the pmos lieing the sorce pin to Vdd=3V, the drain pin to GND and I apply a dc sweep on the gate pin over the range [0, 3V]. I extract the (Vg,Isd) data and calculate the (x, y) values for Gpmos model putting x=Vg and y= Vsg=(Vdd-Vg)/Isd. Is this flow correct or I am doing some errors? Thanks and best regards, Antonio swldstn@xxxxxxxxxxxx wrote: >David, > >Below is a Voltage Controlled Resistor (Gxxx) that I use to >emulate a simple Pmos Pullup to speed up some SSO work. >This is from Hspice. > >This one has piece wise linear control to emulate the IV curve >but you can simplify it to a simple linear equation > >Gpmos psource drain VCR NPWL(1) pgate die_vss LEVEL=1 >0.25v,'150g/(pgain*psso)' >+ 0.5v,'10meg/(pgain*psso)' 1v,'50k/(pgain*psso)' 2v,'4k/(pgain*psso)', >3v,'2k/(pgain*psso)' > >This is the gate voltage control used to turn on the VCR. > >Vpgate pgate die_vss PWL 0n 0V 7.5ns 0V 8.0nS 3V 15.0ns 3V >15.5ns 0V > >Hope this helps. The pgain and psso are just parameters I use >to set the drive strength and number of Pmos in parallel. > > >Steve Waldstein >swldstn@xxxxxxxxxxxx > > >-----Original Message----- >From: si-list-bounce@xxxxxxxxxxxxx >[mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Beal, Weston >Sent: Tuesday, October 14, 2003 7:38 PM >To: 'david.kaiser@xxxxxxxxxx'; si-list@xxxxxxxxxxxxx >Subject: [SI-LIST] Re: How to build a variable resistor in HSPICE > > >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 > > > > >------------------------------------------------------------------ >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 > > > > > ------------------------------------------------------------------ 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