TO220--thin leads--high current--How?
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From: Archimedes' Lever on 3 May 2010 16:53 On Mon, 03 May 2010 15:33:57 -0500, John Fields <jfields(a)austininstruments.com> wrote: >On Mon, 03 May 2010 12:28:19 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > > >>Here's a 100 volt pulse into 50 ohms, transformer coupled. >> >>http://www.highlandtechnology.com/DSS/T760DS.html > >--- >8nm prop delay? > >JF Yeah... they transpose units of measure to keep folks on their toes.
From: John Larkin on 3 May 2010 17:12 On Mon, 03 May 2010 15:33:57 -0500, John Fields <jfields(a)austininstruments.com> wrote: >On Mon, 03 May 2010 12:28:19 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > > >>Here's a 100 volt pulse into 50 ohms, transformer coupled. >> >>http://www.highlandtechnology.com/DSS/T760DS.html > >--- >8nm prop delay? > >JF Good catch. I'll have it fixed. John
From: John Larkin on 3 May 2010 17:24 On Mon, 03 May 2010 13:53:14 -0700, Archimedes' Lever <OneBigLever(a)InfiniteSeries.Org> wrote: >On Mon, 03 May 2010 15:33:57 -0500, John Fields ><jfields(a)austininstruments.com> wrote: > >>On Mon, 03 May 2010 12:28:19 -0700, John Larkin >><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >> >>>Here's a 100 volt pulse into 50 ohms, transformer coupled. >>> >>>http://www.highlandtechnology.com/DSS/T760DS.html >> >>--- >>8nm prop delay? >> >>JF > > Yeah... they transpose units of measure to keep folks on their toes. But aren't those pulses pretty? John
From: tm on 3 May 2010 18:30 "John Larkin" <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote in message news:6nfut5lb86d4qtev90f9lt4nacg304shas(a)4ax.com... >>> >>> >>>>Here's a 100 volt pulse into 50 ohms, transformer coupled. >>>> >>>>http://www.highlandtechnology.com/DSS/T760DS.html >>> >>>--- >>>8nm prop delay? >>> >>>JF >> >> Yeah... they transpose units of measure to keep folks on their toes. > > But aren't those pulses pretty? > > John > How did you do it? It does look nice. Tom
From: MooseFET on 3 May 2010 21:09
On May 3, 10:24 am, "Tim Williams" <tmoran...(a)charter.net> wrote: > "MooseFET" <kensm...(a)rahul.net> wrote in message > > news:a255d645-99e3-4207-8aad-dbe3d49c2988(a)h20g2000prn.googlegroups.com... > > > There is some poorly documented impedance between the gate leg > > and the actual controlling gate element. > > In other words, gate spreading resistance. And maybe some inductance, and > other squirrelies, depending on how detailed you want to get. More > important also is the source lead inductance (which is sometimes specified > at 5nH or so). > > I get the impression that spreading resistance has dropped over the years.. > Back in the day, you didn't see FETs spec'd for very impressive rise/fall > times. But they also used fairly large Rg's, so is it just that they didn't > try? Way back when there was little point in going below a 20 Ohm gate driver. Today that is very much no longer the case. The funny thing is that the Siliconix parts of the past had low gate resistance can worked as very nice class D RF stages at 16MHz. I could get a couple of watts out of a VN88 with good efficiency. > > > The reverse transfer capacitance is not a constant with voltage or > > time. It conspires to stop the gate electrode from moving just at > > exactly the time when the conditions are the worst from a power > > point of view. > > Cgd is fun. > > http://myweb.msoe.edu/williamstm/Images/PFC_Gate1.png I've had it eat a driver stage for lunch |