https://www.digikey.com/en/products/detail/ixys/IXTT02N450HV/3737633?s=N4IgTCBcDaIJYA8AuSAMYB2IC6BfIA Rds_on is < 625 ohms! More like a tube! It sure Spices nice. https://www.dropbox.com/s/wlpc73azpm0iyzn/T855_Totem_2.jpg?raw=1 -- John Larkin Highland Technology, Inc The best designs are necessarily accidental.
4500 volt mosfet
Started by ●July 15, 2021
Reply by ●July 15, 20212021-07-15
jlarkin@highlandsniptechnology.com wrote in news:8gdveg1188en4vg0bphd53vsicu588ce42@4ax.com:> > https://www.digikey.com/en/products/detail/ixys/IXTT02N450HV/373763 > 3?s=N4IgTCBcDaIJYA8AuSAMYB2IC6BfIA > > Rds_on is < 625 ohms! More like a tube! > > It sure Spices nice. > > https://www.dropbox.com/s/wlpc73azpm0iyzn/T855_Totem_2.jpg?raw=1 > > > >Ya saw how far apart them thar legs are. At those potentials everything would need to be potted. Incorporate at full potential very carefully (planning and engineering).
Reply by ●July 15, 20212021-07-15
On Wed, 14 Jul 2021 21:19:37 -0700, jlarkin wrote:> https://www.digikey.com/en/products/detail/ixys/IXTT02N450HV/3737633?s=N4IgTCBcDaIJYA8AuSAMYB2IC6BfIA> > Rds_on is < 625 ohms! More like a tube! > > It sure Spices nice. > > https://www.dropbox.com/s/wlpc73azpm0iyzn/T855_Totem_2.jpg?raw=1That data sheet is a bit sneaky. The DC specs (fig 13 and 14) are nowhere near as impressive as the headline figures. But, given that a lot of your designs are about making crazy-fast pulses, that might not matter.
Reply by ●July 15, 20212021-07-15
jla...@highlandsniptechnology.com wrote: ==============================> https://www.digikey.com/en/products/detail/ixys/IXTT02N450HV/3737633?s=N4IgTCBcDaIJYA8AuSAMYB2IC6BfIA > > Rds_on is < 625 ohms! More like a tube! >** OK - which tube then ?? How about the venerable 6BQ5 ?? With 100V on the plate, it will pass over 150mA = 600 ohms Rpk on. Max plate V is speced at 1100V - it will easily take double that without breakdown. Transconductance is about 12mA/V = well less than a MOSFET, but not bad thing with kV of output signal involved. Dissipation is 12W long term, 10 times that ( 150mA at 800V) for a few seconds without failure. That big lump of steel ( the plate ) takes some time to get red hot. OTOH the MOSFET chip will fail in sub 1 mS if abused like that. Tubes can actually arc over internally from extreme plate voltages without failure, particularly all glass types like the 6BQ5. AKA the EL84 to non Yanks ..... FYI: I have a test rig here that uses a pair in P-P, 650V on the plates and 325V on the screens. Operated in Class AB. Outputs 60W of clean, sine wave power without distress. ...... Phil
Reply by ●July 15, 20212021-07-15
On Thu, 15 Jul 2021 05:01:43 +0000 (UTC), DecadentLinuxUserNumeroUno@decadence.org wrote:>jlarkin@highlandsniptechnology.com wrote in >news:8gdveg1188en4vg0bphd53vsicu588ce42@4ax.com: > >> >> https://www.digikey.com/en/products/detail/ixys/IXTT02N450HV/373763 >> 3?s=N4IgTCBcDaIJYA8AuSAMYB2IC6BfIA >> >> Rds_on is < 625 ohms! More like a tube! >> >> It sure Spices nice. >> >> https://www.dropbox.com/s/wlpc73azpm0iyzn/T855_Totem_2.jpg?raw=1 >> >> >> >> > > Ya saw how far apart them thar legs are. > > At those potentials everything would need to be potted. > > Incorporate at full potential very carefully (planning and >engineering).At 40 volts/mil creepage, that fet is good for 8 KV or so. One could put a little slot in the board too. Or a dab of conformal coat around the pins. I'd expect the silicon to break down before the pcb insulation does. I'll have to test one and see what actually happens. I have an old Spellman 30 KV supply that might still work. -- John Larkin Highland Technology, Inc The best designs are necessarily accidental.
Reply by ●July 15, 20212021-07-15
On 7/14/21 9:19 PM, jlarkin@highlandsniptechnology.com wrote:> > https://www.digikey.com/en/products/detail/ixys/IXTT02N450HV/3737633?s=N4IgTCBcDaIJYA8AuSAMYB2IC6BfIA > > Rds_on is < 625 ohms! More like a tube! > > It sure Spices nice. > > https://www.dropbox.com/s/wlpc73azpm0iyzn/T855_Totem_2.jpg?raw=1 > >But a tube costs less and, if picking a Russian one, is more available right now :-) -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●July 15, 20212021-07-15
On Thu, 15 Jul 2021 09:57:54 -0700, Joerg <news@analogconsultants.com> wrote:>On 7/14/21 9:19 PM, jlarkin@highlandsniptechnology.com wrote: >> >> https://www.digikey.com/en/products/detail/ixys/IXTT02N450HV/3737633?s=N4IgTCBcDaIJYA8AuSAMYB2IC6BfIA >> >> Rds_on is < 625 ohms! More like a tube! >> >> It sure Spices nice. >> >> https://www.dropbox.com/s/wlpc73azpm0iyzn/T855_Totem_2.jpg?raw=1 >> >> > >But a tube costs less and, if picking a Russian one, is more available >right now :-)Just need the tube and a floating grid driver and a 4500 volt isolated filament transformer. All surface mount of course. I just got some Ixys mega-dpak parts to play with, so they seem to be available. I'll crank up the old Spellman and blow some up.
