24 Apr 2008 05:19:17

Mook Johnson

800+V MOSFET with fast Antiparellel diode

I'm looking for some other choices in the 800-1200V MOSFET with a fast antiparallel diode (trr less than 300nS) The application is a 150Khz full bridge SMPS running off 300 - 600VDC at ~150Watts. I can live with highish RDS (1 - 8 ohms) as long as the part is fast switching (lowish ciss) and fast trr. I'm trying to aviod external antiparallel diodes across each fet. I'm familiar with the fets from the following sources and am looking for more options. Vishay IR IR/Omniel APT ST Fairchild Infinion IXYS Onsemi (nothingover 600V) Are there any other manufacturers I should be looking into for fast switching high voltage mosfets? Any IGBTs that can have good efficiency at 150KHz could be considered as well.

24 Apr 2008 16:41:51

legg

Re: 800+V MOSFET with fast Antiparellel diode

On Thu, 24 Apr 2008 05:19:17 -0500, "Mook Johnson" <mook@mook.net > wrote: >I'm looking for some other choices in the 800-1200V MOSFET with a fast >antiparallel diode (trr less than 300nS) > >The application is a 150Khz full bridge SMPS running off 300 - 600VDC at >~150Watts. > Why would you use a full bridge at that power level? Is this a typo? RL

24 Apr 2008 18:23:27

Mook Johnson

Re: 800+V MOSFET with fast Antiparellel diode

"legg" <legg@nospam.magma.ca > wrote in message news:l2s114pbrj0afase9smn9troe0p8n5q1f6@4ax.com... > On Thu, 24 Apr 2008 05:19:17 -0500, "Mook Johnson" <mook@mook.net> > wrote: > >>I'm looking for some other choices in the 800-1200V MOSFET with a fast >>antiparallel diode (trr less than 300nS) >> >>The application is a 150Khz full bridge SMPS running off 300 - 600VDC at >>~150Watts. >> > Why would you use a full bridge at that power level? > Is this a typo? > > RL Yes we are using a full bridge at this power level because that is how the design was originally made. The MOSFETs used in the original design are hard to get (long lead time) and I'm looking for suitable replacements. Is there anything wrong with using full bridge for lower power levels with high voltage?

25 Apr 2008 04:52:41

dBc

Re: 800+V MOSFET with fast Antiparellel diode

Greetings MJ.. A side note. Reference: "The application is a 150Khz ..." Megahertz is defined as MHz, kilohertz as kHz and hertz as Hz. It is, in fact, ALWAYS a capital "H" to pay homage to Mr. Heinrich Hertz. The first letter of that last name is always capitalized. Consider: http://www.ideafinder.com/history/inventors/hertz.htm or, http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214263,00.html or, http://tf.nist.gov/timefreq/general/glossary.htm(click on "M" or "J-K" - these folks should know the difference) Further proof? Take a look at www.fcc.gov and note their frequency references. In addition, simply take a look at a stereo dial, clock radio or even your transistor radio and notice how the manufacturers abbreviate frequency. Cheers, Mr. Mentor "Mook Johnson" <mook@mook.net > wrote in message news:AsmdnRLeHNVT_43VnZ2dnUVZ_qWtnZ2d@comcast.com... | I'm looking for some other choices in the 800-1200V MOSFET with a fast | antiparallel diode (trr less than 300nS) | | The application is a 150Khz full bridge SMPS running off 300 - 600VDC at | ~150Watts. | | I can live with highish RDS (1 - 8 ohms) as long as the part is fast | switching (lowish ciss) and fast trr. | I'm trying to aviod external antiparallel diodes across each fet. | | I'm familiar with the fets from the following sources and am looking for | more options. | | Vishay IR | IR/Omniel | APT | ST | Fairchild | Infinion | IXYS | Onsemi (nothingover 600V) | | Are there any other manufacturers I should be looking into for fast | switching high voltage mosfets? | | Any IGBTs that can have good efficiency at 150KHz could be considered as | well. | | |

25 Apr 2008 11:35:59

legg

Re: 800+V MOSFET with fast Antiparellel diode

On Thu, 24 Apr 2008 18:23:27 -0500, "Mook Johnson" <mook@mook.net > wrote: > >"legg" <legg@nospam.magma.ca> wrote in message >news:l2s114pbrj0afase9smn9troe0p8n5q1f6@4ax.com... >> On Thu, 24 Apr 2008 05:19:17 -0500, "Mook Johnson" <mook@mook.net> >> wrote: >> >>>I'm looking for some other choices in the 800-1200V MOSFET with a fast >>>antiparallel diode (trr less than 300nS) >>> >>>The application is a 150Khz full bridge SMPS running off 300 - 600VDC at >>>~150Watts. >>> >> Why would you use a full bridge at that power level? >> Is this a typo? >> >> RL > >Yes we are using a full bridge at this power level because that is how the >design was originally made. >The MOSFETs used in the original design are hard to get (long lead time) and >I'm looking for suitable replacements. > >Is there anything wrong with using full bridge for lower power levels with >high voltage? Well, you can cut complexity and many other factors in half simply by converting to a half bridge, for a start, ( particularly if the output voltage is appreciably lower than the input - which I suspect is the case ). Reverse recovery problems and leakage energy recovery can be simplified or avoided entirely by using a two-transistor forward ( or even two-transistor flyback ) converter. Justification for the original design is really more in order here, particularly if it's producing problems that seem to require redesign, now. RL email by removing 'nospam.' . http://www.magma.ca/~legg/

25 Apr 2008 19:11:02

Joerg

Re: 800+V MOSFET with fast Antiparellel diode

Mook Johnson wrote: > I'm looking for some other choices in the 800-1200V MOSFET with a fast > antiparallel diode (trr less than 300nS) > > The application is a 150Khz full bridge SMPS running off 300 - 600VDC at > ~150Watts. > > I can live with highish RDS (1 - 8 ohms) as long as the part is fast > switching (lowish ciss) and fast trr. > I'm trying to aviod external antiparallel diodes across each fet. > > I'm familiar with the fets from the following sources and am looking for > more options. > > Vishay IR > IR/Omniel > APT > ST > Fairchild > Infinion > IXYS > Onsemi (nothingover 600V) > > Are there any other manufacturers I should be looking into for fast > switching high voltage mosfets? > > Any IGBTs that can have good efficiency at 150KHz could be considered as > well. > I guess you looked at it already but just in case, the SPD02N80C3 comes to mind: http://www.infineon.com/dgdl/SPD02N80C3_Rev.2.4.pdf?folderId=db3a304412b407950112b408e8c90004&fileId=db3a304412b407950112b42cd2e347b1 No idea if anyone makes FETs with diode at this voltage level but I doubt it. As RL mentioned a full bridge is kind of unusual in this situation. So maybe the old design could be improved. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

25 Apr 2008 16:58:27

Mook Johnson

Re: 800+V MOSFET with fast Antiparellel diode

<snip > >> >>Yes we are using a full bridge at this power level because that is how the >>design was originally made. >>The MOSFETs used in the original design are hard to get (long lead time) >>and >>I'm looking for suitable replacements. >> >>Is there anything wrong with using full bridge for lower power levels with >>high voltage? > > Well, you can cut complexity and many other factors in half simply by > converting to a half bridge, for a start, ( particularly if the output > voltage is appreciably lower than the input - which I suspect is the > case ). > > Reverse recovery problems and leakage energy recovery can be > simplified or avoided entirely by using a two-transistor forward ( or > even two-transistor flyback ) converter. > > Justification for the original design is really more in order here, > particularly if it's producing problems that seem to require redesign, > now. > > RL I'd love nothing more than to chnage the design (design is the fun stage) but this is one of those fire that poped up and they want a replacement component pronto. The FET in question is an APT1003RKLLG. nonstock te digikey and all microsemi parts are on do not design in status due to delivery problems.

25 Apr 2008 22:12:54

legg

Re: 800+V MOSFET with fast Antiparellel diode

On Fri, 25 Apr 2008 16:58:27 -0500, "Mook Johnson" <mook@mook.net > wrote: > ><snip> > >>> >>>Yes we are using a full bridge at this power level because that is how the >>>design was originally made. >>>The MOSFETs used in the original design are hard to get (long lead time) >>>and >>>I'm looking for suitable replacements. >>> >>>Is there anything wrong with using full bridge for lower power levels with >>>high voltage? >> >> Well, you can cut complexity and many other factors in half simply by >> converting to a half bridge, for a start, ( particularly if the output >> voltage is appreciably lower than the input - which I suspect is the >> case ). >> >> Reverse recovery problems and leakage energy recovery can be >> simplified or avoided entirely by using a two-transistor forward ( or >> even two-transistor flyback ) converter. >> >> Justification for the original design is really more in order here, >> particularly if it's producing problems that seem to require redesign, >> now. >> >> RL > >I'd love nothing more than to chnage the design (design is the fun stage) >but this is one of those fire that poped up and they want a replacement >component pronto. The FET in question is an APT1003RKLLG. nonstock te >digikey and all microsemi parts are on do not design in status due to >delivery problems. > There's no reason to use parts higher than 800V fets in a full bridge with 600V rails, but TO-220 STP3NK80Z STP4NK80Z STP9NK80Z STP11NM80 STP8NK85Z STP2NK90Z STP5NK90Z STP6NK90Z STP9NK90Z STP5NK100Z STP8NK100Z STP3N150 STP4N150 TO-220 insulated STP8NK80ZFP STP10NK80ZFP STP3NK90ZFP are all in stock at Digikey RL

25 Apr 2008 22:54:35

legg

Re: 800+V MOSFET with fast Antiparellel diode

On Fri, 25 Apr 2008 16:58:27 -0500, "Mook Johnson" <mook@mook.net > wrote: >I'd love nothing more than to chnage the design (design is the fun stage) >but this is one of those fire that poped up and they want a replacement >component pronto. The FET in question is an APT1003RKLLG. nonstock te >digikey and all microsemi parts are on do not design in status due to >delivery problems. > The original part was 500nS/3.2uC Placing external antiparallel diodes may not be effective without series drain diodes to stop parasitic diodes from functioning. I'm surprised that you are running into this problem at such low current levels.... should be a few hundred milliamps.....unless you're really flogging the mag current. It may not be such a big deal converting a full bridge to a half bridge or two-transistor forward - its possible that the foil patern would not have to change - just the magnetics and parts stuffed in present locations. Full bridge to half bridge - replace one side of the bridge with film capacitors, halve the primary turns and lay off current mode in favor of voltage mode. You can still use current mode influence for ripple and transient rejection. A little goes a long way. Same 'reverse recovery' in the fets, though. Full bridge to two-transistor forward. Replace one phase of fets (opposite quadrants) with ultrafast rectifiers, reroute secondary center-tap to antiphase end of secondary, increase secondary rectifier voltages, and output choke inductance increases by ~3. Reverse recovery is all in real rectifiers. The old control circuit will limit switching duty cycle to <50% RL

26 Apr 2008 06:41:03

Mook Johnson

Re: 800+V MOSFET with fast Antiparellel diode

"legg" <legg@nospam.magma.ca > wrote in message news:v8451452lfeokqks2fmcb2t2u1domu1jnl@4ax.com... > On Fri, 25 Apr 2008 16:58:27 -0500, "Mook Johnson" <mook@mook.net> > wrote: > > > >>I'd love nothing more than to chnage the design (design is the fun stage) >>but this is one of those fire that poped up and they want a replacement >>component pronto. The FET in question is an APT1003RKLLG. nonstock te >>digikey and all microsemi parts are on do not design in status due to >>delivery problems. >> > > The original part was 500nS/3.2uC > > Placing external antiparallel diodes may not be effective without > series drain diodes to stop parasitic diodes from functioning. I'm > surprised that you are running into this problem at such low current > levels.... should be a few hundred milliamps.....unless you're really > flogging the mag current. > > It may not be such a big deal converting a full bridge to a half > bridge or two-transistor forward - its possible that the foil patern > would not have to change - just the magnetics and parts stuffed in > present locations. > > Full bridge to half bridge - replace one side of the bridge with film > capacitors, halve the primary turns and lay off current mode in favor > of voltage mode. You can still use current mode influence for ripple > and transient rejection. A little goes a long way. Same 'reverse > recovery' in the fets, though. > > Full bridge to two-transistor forward. Replace one phase of fets > (opposite quadrants) with ultrafast rectifiers, reroute secondary > center-tap to antiphase end of secondary, increase secondary rectifier > voltages, and output choke inductance increases by ~3. Reverse > recovery is all in real rectifiers. The old control circuit will limit > switching duty cycle to <50% > > RL > Thanks, I'll look into it but I'm pretty sure the changes are more than "they" want. :( I was hoping to find some that were slightly better thant the APT parts for reverse recovery but it seams like ~400nS is about as good as it gets. The design dies work with the APT parts but I was looking for some gains in noise and efficiency by selecting better mosfets that originally designed in. Oh well.

30 Apr 2008 11:21:47

Joerg

Re: 800+V MOSFET with fast Antiparellel diode

dBc wrote: > Greetings MJ.. > > A side note. > > Reference: > "The application is a 150Khz ..." > > Megahertz is defined as MHz, kilohertz as kHz and hertz as Hz. It > is, in fact, ALWAYS a capital "H" to pay homage to Mr. Heinrich > Hertz. The first letter of that last name is always capitalized. > Consider: http://www.ideafinder.com/history/inventors/hertz.htm > or, > http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci214263,00.html > or, http://tf.nist.gov/timefreq/general/glossary.htm(click on > "M" or "J-K" - these folks should know the difference) > > Further proof? Take a look at www.fcc.gov and note their > frequency references. In addition, simply take a look at a stereo > dial, clock radio or even your transistor radio and notice how > the manufacturers abbreviate frequency. > > Cheers, > Mr. Mentor > > > > > "Mook Johnson" <mook@mook.net> wrote in message > news:AsmdnRLeHNVT_43VnZ2dnUVZ_qWtnZ2d@comcast.com... > | I'm looking for some other choices in the 800-1200V MOSFET with > a fast > | antiparallel diode (trr less than 300nS) > | > | The application is a 150Khz full bridge SMPS running off 300 - > 600VDC at > | ~150Watts. > | > | I can live with highish RDS (1 - 8 ohms) as long as the part is > fast > | switching (lowish ciss) and fast trr. > | I'm trying to aviod external antiparallel diodes across each > fet. > | > | I'm familiar with the fets from the following sources and am > looking for > | more options. > | > | Vishay IR > | IR/Omniel > | APT > | ST > | Fairchild > | Infinion > | IXYS > | Onsemi (nothingover 600V) > | > | Are there any other manufacturers I should be looking into for > fast > | switching high voltage mosfets? > | > | Any IGBTs that can have good efficiency at 150KHz could be > considered as > | well. > | Uhm, I thought he founded some kind of car rental business. <ducking for cover > -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.