Hi guys....GREAT THREAD! Thanks. I am into the same thing...IGBT and SiCMOS, 500...900V.>>See the IGBT as a several microIGBT in paralel.This is the exact issue: Cell paralleling in high current and/or low R semiconductores!>>Use in linear mode at 1/4 of rated current or less.1/4? I am trying to get a GO from a manufacturer....trying to use a SiCMOS in linear mode at 0.1% of rated current: NO approval. @Mark: "IOW, they didn't think it'd work so they didn't try it." That's exactly it. NO manufacturer actually gives you any data for continuous operation. Even for us, who are one of the bigger customers. We are even doing common development with the biggest manufacturers but regarding linear mode, they just did not test and don´t have the guts to give you ANY hint. Lately there are too many requests from customers like us who are big players in electromobility (500...800V) so they are just starting to test. But this is still no part of the normal semicondictor certification process. Will change drastically in about two years time! Meanwhile just think logically and do an accelerated life time test! Then release the parts on your own. Regards Michael --------------------------------------- Posted through http://www.Electronics-Related.com
IGBT in Linear Mode
Started by ●May 31, 2011
Reply by ●June 4, 20182018-06-04
Reply by ●June 4, 20182018-06-04
On Mon, 04 Jun 2018 10:48:02 -0500, "mexman" <129087@Electronics-Related> wrote:>Hi guys....GREAT THREAD! Thanks. >I am into the same thing...IGBT and SiCMOS, 500...900V. > >>>See the IGBT as a several microIGBT in paralel. > >This is the exact issue: Cell paralleling in high current and/or low R >semiconductores! > >>>Use in linear mode at 1/4 of rated current or less. > >1/4? I am trying to get a GO from a manufacturer....trying to use a SiCMOS >in linear mode at 0.1% of rated current: NO approval. > >@Mark: "IOW, they didn't think it'd work so they didn't try it." > >That's exactly it. >NO manufacturer actually gives you any data for continuous operation. Even >for us, who are one of the bigger customers. We are even doing common >development with the biggest manufacturers but regarding linear mode, they >just did not test and don´t have the guts to give you ANY hint. >Lately there are too many requests from customers like us who are big >players in electromobility (500...800V) so they are just starting to test. >But this is still no part of the normal semicondictor certification >process. Will change drastically in about two years time! >Meanwhile just think logically and do an accelerated life time test! >Then release the parts on your own. > >Regards >Michael >So gather some solid data and report back. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Thinking outside the box... producing elegant solutions, by understanding what nature is hiding. "It is not in doing what you like, but in liking what you do that is the secret of happiness." -James Barrie
Reply by ●June 5, 20182018-06-05
On 2018-04-10 13:52, Tim Williams wrote:> Well, the bigger problem is that transconductance, and therefore power > density, is so many times higher than MOSFETs. > > As it is, many MOSFETs suffer from 2nd breakdown. RTFDS, find one that > behaves. > > IGBTs simply aren't intended to be used in linear mode, at all. On the > rare occasion that an SOA is provided, they rarely plot durations over > 100us, and the SOA is quite narrow by then already. I've never seen a > DC SOA on one. >Many have to do that for milliseconds. An example are ignition coil drivers. If the voltage after opening gets too high there is (at least there is supposed to be) some circuitry that then begins to pull the gate up again and dissipate the energy. That feature is to prevent overvoltage breakdown of the IGBT or the coil in case a spark plug has failed, the distributor has let go or a cable has come off. Or when Gomer Pyle forgot to put it back on. https://vignette.wikia.nocookie.net/mayberry/images/5/57/GillyandGoober.png/revision/latest?cb=20110730152008 Why they use IGBT in ignition, beats me. It doesn't make much sense.> A fixed current derating is meaningless, and misses everything about the > problem. >? -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●June 5, 20182018-06-05
tirsdag den 5. juni 2018 kl. 16.44.49 UTC+2 skrev Joerg:> On 2018-04-10 13:52, Tim Williams wrote: > > Well, the bigger problem is that transconductance, and therefore power > > density, is so many times higher than MOSFETs. > > > > As it is, many MOSFETs suffer from 2nd breakdown. RTFDS, find one that > > behaves. > > > > IGBTs simply aren't intended to be used in linear mode, at all. On the > > rare occasion that an SOA is provided, they rarely plot durations over > > 100us, and the SOA is quite narrow by then already. I've never seen a > > DC SOA on one. > > > > Many have to do that for milliseconds. An example are ignition coil > drivers. If the voltage after opening gets too high there is (at least > there is supposed to be) some circuitry that then begins to pull the > gate up again and dissipate the energy. That feature is to prevent > overvoltage breakdown of the IGBT or the coil in case a spark plug has > failed, the distributor has let go or a cable has come off. Or when > Gomer Pyle forgot to put it back on. >I've seen some driver for ignition IGBTs that also seems have a feature to "abort" an ignition by slowly turning off the IGBT
Reply by ●June 5, 20182018-06-05
On 2018-06-05 08:08, Lasse Langwadt Christensen wrote:> tirsdag den 5. juni 2018 kl. 16.44.49 UTC+2 skrev Joerg: >> On 2018-04-10 13:52, Tim Williams wrote: >>> Well, the bigger problem is that transconductance, and therefore >>> power density, is so many times higher than MOSFETs. >>> >>> As it is, many MOSFETs suffer from 2nd breakdown. RTFDS, find >>> one that behaves. >>> >>> IGBTs simply aren't intended to be used in linear mode, at all. >>> On the rare occasion that an SOA is provided, they rarely plot >>> durations over 100us, and the SOA is quite narrow by then >>> already. I've never seen a DC SOA on one. >>> >> >> Many have to do that for milliseconds. An example are ignition >> coil drivers. If the voltage after opening gets too high there is >> (at least there is supposed to be) some circuitry that then begins >> to pull the gate up again and dissipate the energy. That feature is >> to prevent overvoltage breakdown of the IGBT or the coil in case a >> spark plug has failed, the distributor has let go or a cable has >> come off. Or when Gomer Pyle forgot to put it back on. >> > > I've seen some driver for ignition IGBTs that also seems have a > feature to "abort" an ignition by slowly turning off the IGBT >Same thing, that is the way it's typically done. The primary voltage reaches a certain threshold and the IGBT is held in a linear range until that voltage starts to drop down. Then the conductive path slowly opens. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●June 6, 20182018-06-06
On Tuesday, April 10, 2018 at 1:14:32 PM UTC-5, DecadentLinux...@decadence.org wrote:> alfredogabrielmendez@gmail.com wrote in > news:1bab319f-de35-4801-abed-12010777f151@googlegroups.com: > > > Since the most sensible will carry the major current and become an hot > > spot who will dest5ory te junction. > > They attach them all to the same die base so there is no thermal runaway of > any one element.From what I've gleaned about these things that won't work. This is because even as cells , in thermal equilibrium, each cell does not have the same thermal characteristics except for near saturation or cutoff. The gain has gamma.
Reply by ●June 6, 20182018-06-06
>Regards >Michael >So gather some solid data and report back. " Must be nice to think that is so easy. (I am not being sarcastic) The way I see it first you have to get a bunch of these things, disposable. Then you match them well tot heir on and off stats just to be sure of that. Then comes the fun part, finding he real linear SOA. Since we don't know where to start, if we got 10 amp jobs then start with 50 mA. Keep doubling it until the failures happen. Then we do a couple of more tests with other batches of the SAME IGBT. Note their discrepancy level and then test. I don't want to do it. Go to an electronics school and pay some kid that knows something. (hey, that could pay off)
Reply by ●June 11, 20182018-06-11
On Mon, 04 Jun 2018 10:48:02 -0500, "mexman" <129087@Electronics-Related> wrote:>Hi guys....GREAT THREAD! Thanks. >I am into the same thing...IGBT and SiCMOS, 500...900V. > >>>See the IGBT as a several microIGBT in paralel. > >This is the exact issue: Cell paralleling in high current and/or low R >semiconductores! > >>>Use in linear mode at 1/4 of rated current or less. > >1/4? I am trying to get a GO from a manufacturer....trying to use a SiCMOS >in linear mode at 0.1% of rated current: NO approval. > >@Mark: "IOW, they didn't think it'd work so they didn't try it." > >That's exactly it. >NO manufacturer actually gives you any data for continuous operation. Even >for us, who are one of the bigger customers. We are even doing common >development with the biggest manufacturers but regarding linear mode, they >just did not test and don´t have the guts to give you ANY hint. >Lately there are too many requests from customers like us who are big >players in electromobility (500...800V) so they are just starting to test. >But this is still no part of the normal semicondictor certification >process. Will change drastically in about two years time! >Meanwhile just think logically and do an accelerated life time test! >Then release the parts on your own. > >Regards >Michael >I've got some GREAT IGBT _amplifier_ schematics, along with some seaport property in Yuma to show you >:-} Doesn't anyone here stop and think, for at least a microsecond, before they plunge into such idiocy? ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Thinking outside the box... producing elegant solutions, by understanding what nature is hiding. "It is not in doing what you like, but in liking what you do that is the secret of happiness." -James Barrie
