On Sun, 29 Jun 2014 13:08:03 -0700, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>On Sun, 29 Jun 2014 11:48:52 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Sun, 29 Jun 2014 11:24:05 -0700, John Larkin >><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>>On Sun, 29 Jun 2014 07:29:40 -0700, John Larkin >>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>> >>>>>On Sun, 29 Jun 2014 01:15:08 -0700 (PDT), whit3rd <whit3rd@gmail.com> wrote: >>>>> >>>>>>On Friday, June 27, 2014 4:20:18 PM UTC-7, John Larkin wrote: >>>>>>> What's an easy way to plot the C-V curve of a back-biased diode? >>>>>> >>>>>>Easy, is to buy the source/meter Keithley solution. They'd love >>>>>>to explain it all to you... >>>>>><http://www.keithley.com/promo/lp/semiconductor> >>>>> >>>>>I bought an expensive Keithley source-meter. Crap. Sent it back. >>>>> >>>>>But I meant in LT Spice, which is why I titled the post "LT Spice..." >>>>> >>>>>I can read the C-V curve off the data sheet. What I want to do is make sure (or >>>>>force) my Spice sim to behave like the actual diode, so I want to do a >>>>>simulation of the diode c-v curve, to make sure I have everything right. >>>> >>>>I don't know how to post-process data in LTspice, but here's how I do >>>>it in PSpice... >>>> >>>><http://www.analog-innovations.com/SED/C-V_Plot%20-%20PSpice%20AD.png> >>>> >>>>An alternative is to do it like the Keithley does, superimpose a small >>>>sinusoidal signal on the DC, and measure the co-sinusoidal current. >>>> >>>> ...Jim Thompson >>> >>>The voltage ramp thing that I did seems OK. >>> >>>It does report the initial capacitance of a 1N914 as 4 pF, which is high, but >>>that's the value in the LT Spice model. >> >>The PSpice model has the same CJ0. >> >> ...Jim Thompson > >Various data sheets have typs from 4 to 0.85. Not the thing you'd want to use as >a varicap. > >I do need a "power varicap" for a weird thing I'm considering. I figured I'd >fudge up some standard LT library parts, series and parallel or whatever, to see >if my circuit might work. If it does, then I can try to find real diodes with >the required CV curves.What's your maximum voltage? You might want to try some zeners. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
LT Spice diode C-V graph
Started by ●June 27, 2014
Reply by ●June 29, 20142014-06-29
Reply by ●June 29, 20142014-06-29
On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@on-my-web-site.com> wrote:>> ...snip... > I don't know how to post-process data in LTspice, but here's how I do > it in PSpice... > > ...snip...Jim, I sent you all that stuff! simply EXPORT the variable you want to work with. If you can live with uneven steps it's fast. if you cannot... easiest way for me...after a .tran run ltsputil.exe in a batch file to make the steps uniform use N+1, like 10001, or 20001, or 100001 etc. after running the uniform step conversion, open the new example_eq.raw file and EXPORT something from that! like V(out), which comes out as a text file in columnar form t, V(out) You can scoop if you want and put in Excel I use a text editor and strip off the text header, rename, and save as vo.txt and load into octave then I pull out the t, separate from the v and you're up and running doing anything you want. You get a lot more power that way and avoid all the artifacts that LTspice puts into the FFT. Plus you can also do things not possible in LTspice [I think]
Reply by ●June 29, 20142014-06-29
On Sun, 29 Jun 2014 14:01:34 -0700, RobertMacy <robert.a.macy@gmail.com> wrote:>On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@on-my-web-site.com> wrote: > >>> ...snip... >> I don't know how to post-process data in LTspice, but here's how I do >> it in PSpice... >> >> ...snip... > >Jim, I sent you all that stuff! > >simply EXPORT the variable you want to work with. If you can live with >uneven steps it's fast. if you cannot...I'm talking a direct graphical display, called "Performance Analysis" built into Probe, the PSpice post-processor.> >easiest way for me...after a .tran >run ltsputil.exe in a batch file to make the steps uniform use N+1, like >10001, or 20001, or 100001 etc.I have the opposite problem... actually the math is solved and I await my programmer son to be in-need to get him to write an executable for me: take _evenly_ spaced data and "sparse" it into as few points as necessary to meet an RMS error criterion.> >after running the uniform step conversion, open the new example_eq.raw >file and EXPORT something from that! > >like V(out), which comes out as a text file in columnar form t, V(out) You >can scoop if you want and put in Excel > >I use a text editor and strip off the text header, rename, and save as >vo.txt and load into octave > >then I pull out the t, separate from the v and you're up and running doing >anything you want. > >You get a lot more power that way and avoid all the artifacts that LTspice >puts into the FFT. Plus you can also do things not possible in LTspice [I >think]...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●June 29, 20142014-06-29
Den s=F8ndag den 29. juni 2014 23.08.05 UTC+2 skrev Jim Thompson:> On Sun, 29 Jun 2014 14:01:34 -0700, RobertMacy >=20 > <robert.a.macy@gmail.com> wrote: >=20 >=20 >=20 > >On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson =20 >=20 > ><To-Email-Use-The-Envelope-Icon@on-my-web-site.com> wrote: >=20 > > >=20 > >>> ...snip... >=20 > >> I don't know how to post-process data in LTspice, but here's how I do >=20 > >> it in PSpice... >=20 > >> >=20 > >> ...snip... >=20 > > >=20 > >Jim, I sent you all that stuff! >=20 > > >=20 > >simply EXPORT the variable you want to work with. If you can live with ==20>=20 > >uneven steps it's fast. if you cannot... >=20 >=20 >=20 > I'm talking a direct graphical display, called "Performance Analysis" >=20 > built into Probe, the PSpice post-processor. >=20 >=20 >=20 > > >=20 > >easiest way for me...after a .tran >=20 > >run ltsputil.exe in a batch file to make the steps uniform use N+1, like==20>=20 > >10001, or 20001, or 100001 etc. >=20 >=20 >=20 > I have the opposite problem... actually the math is solved and I await >=20 > my programmer son to be in-need to get him to write an executable for >=20 > me: take _evenly_ spaced data and "sparse" it into as few points as >=20 > necessary to meet an RMS error criterion. >=20just install something like octave or scilab, simple scripting of every fil= e handling, plotting and curve fitting function you can imagine=20 -Lasse
Reply by ●June 29, 20142014-06-29
On Sun, 29 Jun 2014 13:19:31 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Sun, 29 Jun 2014 13:08:03 -0700, John Larkin ><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: > >>On Sun, 29 Jun 2014 11:48:52 -0700, Jim Thompson >><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >> >>>On Sun, 29 Jun 2014 11:24:05 -0700, John Larkin >>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>> >>>>On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson >>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>> >>>>>On Sun, 29 Jun 2014 07:29:40 -0700, John Larkin >>>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>>> >>>>>>On Sun, 29 Jun 2014 01:15:08 -0700 (PDT), whit3rd <whit3rd@gmail.com> wrote: >>>>>> >>>>>>>On Friday, June 27, 2014 4:20:18 PM UTC-7, John Larkin wrote: >>>>>>>> What's an easy way to plot the C-V curve of a back-biased diode? >>>>>>> >>>>>>>Easy, is to buy the source/meter Keithley solution. They'd love >>>>>>>to explain it all to you... >>>>>>><http://www.keithley.com/promo/lp/semiconductor> >>>>>> >>>>>>I bought an expensive Keithley source-meter. Crap. Sent it back. >>>>>> >>>>>>But I meant in LT Spice, which is why I titled the post "LT Spice..." >>>>>> >>>>>>I can read the C-V curve off the data sheet. What I want to do is make sure (or >>>>>>force) my Spice sim to behave like the actual diode, so I want to do a >>>>>>simulation of the diode c-v curve, to make sure I have everything right. >>>>> >>>>>I don't know how to post-process data in LTspice, but here's how I do >>>>>it in PSpice... >>>>> >>>>><http://www.analog-innovations.com/SED/C-V_Plot%20-%20PSpice%20AD.png> >>>>> >>>>>An alternative is to do it like the Keithley does, superimpose a small >>>>>sinusoidal signal on the DC, and measure the co-sinusoidal current. >>>>> >>>>> ...Jim Thompson >>>> >>>>The voltage ramp thing that I did seems OK. >>>> >>>>It does report the initial capacitance of a 1N914 as 4 pF, which is high, but >>>>that's the value in the LT Spice model. >>> >>>The PSpice model has the same CJ0. >>> >>> ...Jim Thompson >> >>Various data sheets have typs from 4 to 0.85. Not the thing you'd want to use as >>a varicap. >> >>I do need a "power varicap" for a weird thing I'm considering. I figured I'd >>fudge up some standard LT library parts, series and parallel or whatever, to see >>if my circuit might work. If it does, then I can try to find real diodes with >>the required CV curves. > >What's your maximum voltage? You might want to try some zeners. > > ...Jim ThompsonOh, 4KV or so. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
Reply by ●June 29, 20142014-06-29
On Sun, 29 Jun 2014 14:01:34 -0700, RobertMacy <robert.a.macy@gmail.com> wrote:>On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@on-my-web-site.com> wrote: > >>> ...snip... >> I don't know how to post-process data in LTspice, but here's how I do >> it in PSpice... >> >> ...snip... >[snip]> >easiest way for me...after a .tran >run ltsputil.exe in a batch file to make the steps uniform use N+1, like >10001, or 20001, or 100001 etc. > >after running the uniform step conversion, open the new example_eq.raw >file and EXPORT something from that! >[snip] PSpice supports the Berkeley (dot)PRINT statement, so I can generate columnized data simply by adding, in LTspice lingo, a "Spice directive" .PRINT V(N_27) I(VDC:+) etc. It's really odd that LTspice doesn't support that :-( ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●June 29, 20142014-06-29
On Sun, 29 Jun 2014 14:16:29 -0700, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>On Sun, 29 Jun 2014 13:19:31 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Sun, 29 Jun 2014 13:08:03 -0700, John Larkin >><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Sun, 29 Jun 2014 11:48:52 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>>On Sun, 29 Jun 2014 11:24:05 -0700, John Larkin >>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>> >>>>>On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson >>>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>> >>>>>>On Sun, 29 Jun 2014 07:29:40 -0700, John Larkin >>>>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>>>> >>>>>>>On Sun, 29 Jun 2014 01:15:08 -0700 (PDT), whit3rd <whit3rd@gmail.com> wrote: >>>>>>> >>>>>>>>On Friday, June 27, 2014 4:20:18 PM UTC-7, John Larkin wrote: >>>>>>>>> What's an easy way to plot the C-V curve of a back-biased diode? >>>>>>>> >>>>>>>>Easy, is to buy the source/meter Keithley solution. They'd love >>>>>>>>to explain it all to you... >>>>>>>><http://www.keithley.com/promo/lp/semiconductor> >>>>>>> >>>>>>>I bought an expensive Keithley source-meter. Crap. Sent it back. >>>>>>> >>>>>>>But I meant in LT Spice, which is why I titled the post "LT Spice..." >>>>>>> >>>>>>>I can read the C-V curve off the data sheet. What I want to do is make sure (or >>>>>>>force) my Spice sim to behave like the actual diode, so I want to do a >>>>>>>simulation of the diode c-v curve, to make sure I have everything right. >>>>>> >>>>>>I don't know how to post-process data in LTspice, but here's how I do >>>>>>it in PSpice... >>>>>> >>>>>><http://www.analog-innovations.com/SED/C-V_Plot%20-%20PSpice%20AD.png> >>>>>> >>>>>>An alternative is to do it like the Keithley does, superimpose a small >>>>>>sinusoidal signal on the DC, and measure the co-sinusoidal current. >>>>>> >>>>>> ...Jim Thompson >>>>> >>>>>The voltage ramp thing that I did seems OK. >>>>> >>>>>It does report the initial capacitance of a 1N914 as 4 pF, which is high, but >>>>>that's the value in the LT Spice model. >>>> >>>>The PSpice model has the same CJ0. >>>> >>>> ...Jim Thompson >>> >>>Various data sheets have typs from 4 to 0.85. Not the thing you'd want to use as >>>a varicap. >>> >>>I do need a "power varicap" for a weird thing I'm considering. I figured I'd >>>fudge up some standard LT library parts, series and parallel or whatever, to see >>>if my circuit might work. If it does, then I can try to find real diodes with >>>the required CV curves. >> >>What's your maximum voltage? You might want to try some zeners. >> >> ...Jim Thompson > >Oh, 4KV or so.Oooooh! And probably need 10:1 capacitance also ?:-) ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●June 29, 20142014-06-29
On Sun, 29 Jun 2014 14:15:30 -0700 (PDT), Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:>Den s�ndag den 29. juni 2014 23.08.05 UTC+2 skrev Jim Thompson: >> On Sun, 29 Jun 2014 14:01:34 -0700, RobertMacy >> >> <robert.a.macy@gmail.com> wrote: >> >> >> >> >On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson >> >> ><To-Email-Use-The-Envelope-Icon@on-my-web-site.com> wrote: >> >> > >> >> >>> ...snip... >> >> >> I don't know how to post-process data in LTspice, but here's how I do >> >> >> it in PSpice... >> >> >> >> >> >> ...snip... >> >> > >> >> >Jim, I sent you all that stuff! >> >> > >> >> >simply EXPORT the variable you want to work with. If you can live with >> >> >uneven steps it's fast. if you cannot... >> >> >> >> I'm talking a direct graphical display, called "Performance Analysis" >> >> built into Probe, the PSpice post-processor. >> >> >> >> > >> >> >easiest way for me...after a .tran >> >> >run ltsputil.exe in a batch file to make the steps uniform use N+1, like >> >> >10001, or 20001, or 100001 etc. >> >> >> >> I have the opposite problem... actually the math is solved and I await >> >> my programmer son to be in-need to get him to write an executable for >> >> me: take _evenly_ spaced data and "sparse" it into as few points as >> >> necessary to meet an RMS error criterion. >> > >just install something like octave or scilab, simple scripting of every file handling, plotting and curve fitting function you can imagine > > >-LasseWhich is better? ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●June 29, 20142014-06-29
Den s=C3=B8ndag den 29. juni 2014 23.21.11 UTC+2 skrev Jim Thompson:> On Sun, 29 Jun 2014 14:15:30 -0700 (PDT), Lasse Langwadt Christensen >=20 > <langwadt@fonz.dk> wrote: >=20 >=20 >=20 > >Den s=EF=BF=BDndag den 29. juni 2014 23.08.05 UTC+2 skrev Jim Thompson: >=20 > >> On Sun, 29 Jun 2014 14:01:34 -0700, RobertMacy >=20 > >>=20 >=20 > >> <robert.a.macy@gmail.com> wrote: >=20 > >>=20 >=20 > >>=20 >=20 > >>=20 >=20 > >> >On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson =20 >=20 > >>=20 >=20 > >> ><To-Email-Use-The-Envelope-Icon@on-my-web-site.com> wrote: >=20 > >>=20 >=20 > >> > >=20 > >>=20 >=20 > >> >>> ...snip... >=20 > >>=20 >=20 > >> >> I don't know how to post-process data in LTspice, but here's how I =do>=20 > >>=20 >=20 > >> >> it in PSpice... >=20 > >>=20 >=20 > >> >> >=20 > >>=20 >=20 > >> >> ...snip... >=20 > >>=20 >=20 > >> > >=20 > >>=20 >=20 > >> >Jim, I sent you all that stuff! >=20 > >>=20 >=20 > >> > >=20 > >>=20 >=20 > >> >simply EXPORT the variable you want to work with. If you can live wit=h =20>=20 > >>=20 >=20 > >> >uneven steps it's fast. if you cannot... >=20 > >>=20 >=20 > >>=20 >=20 > >>=20 >=20 > >> I'm talking a direct graphical display, called "Performance Analysis" >=20 > >>=20 >=20 > >> built into Probe, the PSpice post-processor. >=20 > >>=20 >=20 > >>=20 >=20 > >>=20 >=20 > >> > >=20 > >>=20 >=20 > >> >easiest way for me...after a .tran >=20 > >>=20 >=20 > >> >run ltsputil.exe in a batch file to make the steps uniform use N+1, l=ike =20>=20 > >>=20 >=20 > >> >10001, or 20001, or 100001 etc. >=20 > >>=20 >=20 > >>=20 >=20 > >>=20 >=20 > >> I have the opposite problem... actually the math is solved and I await >=20 > >>=20 >=20 > >> my programmer son to be in-need to get him to write an executable for >=20 > >>=20 >=20 > >> me: take _evenly_ spaced data and "sparse" it into as few points as >=20 > >>=20 >=20 > >> necessary to meet an RMS error criterion. >=20 > >>=20 >=20 > > >=20 > >just install something like octave or scilab, simple scripting of every =file handling, plotting and curve fitting function you can imagine=20>=20 > > >=20 > > >=20 > >-Lasse >=20 >=20 >=20 > Which is better? >=20on windows probably scilab Octave is much more Matlab compatible but to get a gui you need to get vers= ion 3.8+ but that's "experimental" for windows http://mxeoctave.osuv.de/ Matlab is the Rolls-Royce, but it comes at a Rolls-Royce price=20 -Lasse
Reply by ●June 29, 20142014-06-29
On Sun, 29 Jun 2014 14:16:29 -0700, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>On Sun, 29 Jun 2014 13:19:31 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Sun, 29 Jun 2014 13:08:03 -0700, John Larkin >><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Sun, 29 Jun 2014 11:48:52 -0700, Jim Thompson >>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>> >>>>On Sun, 29 Jun 2014 11:24:05 -0700, John Larkin >>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>> >>>>>On Sun, 29 Jun 2014 09:58:04 -0700, Jim Thompson >>>>><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: >>>>> >>>>>>On Sun, 29 Jun 2014 07:29:40 -0700, John Larkin >>>>>><jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: >>>>>> >>>>>>>On Sun, 29 Jun 2014 01:15:08 -0700 (PDT), whit3rd <whit3rd@gmail.com> wrote: >>>>>>> >>>>>>>>On Friday, June 27, 2014 4:20:18 PM UTC-7, John Larkin wrote: >>>>>>>>> What's an easy way to plot the C-V curve of a back-biased diode? >>>>>>>> >>>>>>>>Easy, is to buy the source/meter Keithley solution. They'd love >>>>>>>>to explain it all to you... >>>>>>>><http://www.keithley.com/promo/lp/semiconductor> >>>>>>> >>>>>>>I bought an expensive Keithley source-meter. Crap. Sent it back. >>>>>>> >>>>>>>But I meant in LT Spice, which is why I titled the post "LT Spice..." >>>>>>> >>>>>>>I can read the C-V curve off the data sheet. What I want to do is make sure (or >>>>>>>force) my Spice sim to behave like the actual diode, so I want to do a >>>>>>>simulation of the diode c-v curve, to make sure I have everything right. >>>>>> >>>>>>I don't know how to post-process data in LTspice, but here's how I do >>>>>>it in PSpice... >>>>>> >>>>>><http://www.analog-innovations.com/SED/C-V_Plot%20-%20PSpice%20AD.png> >>>>>> >>>>>>An alternative is to do it like the Keithley does, superimpose a small >>>>>>sinusoidal signal on the DC, and measure the co-sinusoidal current. >>>>>> >>>>>> ...Jim Thompson >>>>> >>>>>The voltage ramp thing that I did seems OK. >>>>> >>>>>It does report the initial capacitance of a 1N914 as 4 pF, which is high, but >>>>>that's the value in the LT Spice model. >>>> >>>>The PSpice model has the same CJ0. >>>> >>>> ...Jim Thompson >>> >>>Various data sheets have typs from 4 to 0.85. Not the thing you'd want to use as >>>a varicap. >>> >>>I do need a "power varicap" for a weird thing I'm considering. I figured I'd >>>fudge up some standard LT library parts, series and parallel or whatever, to see >>>if my circuit might work. If it does, then I can try to find real diodes with >>>the required CV curves. >> >>What's your maximum voltage? You might want to try some zeners. >> >> ...Jim Thompson > >Oh, 4KV or so.Y5V capacitor?
