"high voltage" MOSFET

[bitrex]

Looking for a MOSFET with a 100 or 150-200 (would be better), Vds
N-channel that can switch a couple amps at a couple MHz, preferably in
D-pak or something for ease of compact Manhattan-prototyping.

MOSFET-selection is always problematic for me there are so many and the
parameters like temperature de-rating and how fast you can switch it at
a given temperature all interact so it's hard to know where to start. A
master list of a few favorite devices to run the numbers on/check in the
sim/blow up by accident, for a set of applications/speeds/voltages that
are people's favorites to use in their own work would be helpful, if
anyone's got a physical or mental list or somethin'.

 

[sea moss]

since you are hand soldering, I would go for a TO-220 part. lots of parts to choose from, many probably fine. Look at the tradeoff between Rds_on and Ciss. You might need small Ciss since you are switching pretty fast; then keep an eye on temperature if you choose a part with higher Rds_on. It goes without saying if you are switching at 2MHz keep the leads short.

 

[mpm]

On Friday, March 20, 2020 at 10:19:05 PM UTC-4, bitrex wrote:

Looking for a MOSFET with a 100 or 150-200 (would be better), Vds
N-channel that can switch a couple amps at a couple MHz, preferably in
D-pak or something for ease of compact Manhattan-prototyping.

If you can keep it cool, IRFP4668 (in TO-247AC package).
One of my favorites, but influenced by the fact I have plenty on-hand.

Note that it sports a rather hefty gate-charge, so be prepared to drive it hard to get that low Rds(on) quickly. Typically .008 to .010 Ohms.

 

[bitrex]

On 3/20/2020 11:13 PM, mpm wrote:

On Friday, March 20, 2020 at 10:19:05 PM UTC-4, bitrex wrote:
Looking for a MOSFET with a 100 or 150-200 (would be better), Vds
N-channel that can switch a couple amps at a couple MHz, preferably in
D-pak or something for ease of compact Manhattan-prototyping.

If you can keep it cool, IRFP4668 (in TO-247AC package).
One of my favorites, but influenced by the fact I have plenty on-hand.

Note that it sports a rather hefty gate-charge, so be prepared to drive it hard to get that low Rds(on) quickly. Typically .008 to .010 Ohms.

So to hopefully helpfully clarify my needs further the application is
like an interleaved synchronous-buck-type converter but I'm using it to
generate a power sine wave at a couple MHz. There is a goodly amount of
dead-time for the switches. The gate driver is an Analog Devices ADuM4120.

Just testing a few MOSFETs from the LTSpice library with fairly high
Vds. IRFH5207, Vds 75 volts - blah! Way too slow, these will shoot-thru
and smoke themselves instantly. no good for these speeds.

Infineon BSZ900N15NS3G, Vds 150 volts - yes, this is my ballpark. Looks
like will drive my load and stay cool under a couple 100mW dissipation
no problem. That laptop-motherboard style package seems a bit
inconvenient for a copper-clad-board test item, though.

<https://www.mouser.com/Search/Refine?Keyword=BSZ900N15NS3G>

 

[bitrex]

On 3/20/2020 11:32 PM, bitrex wrote:

On 3/20/2020 11:13 PM, mpm wrote:
On Friday, March 20, 2020 at 10:19:05 PM UTC-4, bitrex wrote:
Looking for a MOSFET with a 100 or 150-200 (would be better), Vds
N-channel that can switch a couple amps at a couple MHz, preferably in
D-pak or something for ease of compact Manhattan-prototyping.

If you can keep it cool, IRFP4668 (in TO-247AC package).
One of my favorites, but influenced by the fact I have plenty
on-hand. 

Note that it sports a rather hefty gate-charge, so be prepared to
drive it hard to get that low Rds(on) quickly.  Typically .008 to .010
Ohms.


So to hopefully helpfully clarify my needs further the application is
like an interleaved synchronous-buck-type converter but I'm using it to
generate a power sine wave at a couple MHz. There is a goodly amount of
dead-time for the switches. The gate driver is an Analog Devices ADuM4120.

Just testing a few MOSFETs from the LTSpice library with fairly high
Vds. IRFH5207, Vds 75 volts - blah! Way too slow, these will shoot-thru
and smoke themselves instantly. no good for these speeds.

Infineon BSZ900N15NS3G, Vds 150 volts - yes, this is my ballpark. Looks
like will drive my load and stay cool under a couple 100mW dissipation
no problem. That laptop-motherboard style package seems a bit
inconvenient for a copper-clad-board test item, though.

https://www.mouser.com/Search/Refine?Keyword=BSZ900N15NS3G

Obviously cuz the ~0.2 ish Rds looks ok we're not talking huge output
power requirements, here. Trading that off for lower gate charge seems
the right way to go.

 

[bitrex]

On 3/20/2020 11:02 PM, sea moss wrote:

since you are hand soldering, I would go for a TO-220 part. lots of parts to choose from, many probably fine. Look at the tradeoff between Rds_on and Ciss. You might need small Ciss since you are switching pretty fast; then keep an eye on temperature if you choose a part with higher Rds_on. It goes without saying if you are switching at 2MHz keep the leads short.

Looking thru the LTSpice lib it looks like there's a set of Infineon
parts that have Vds in the range of 100-200 volts, gate charges of about
5-20 nC and Rds-ons in the range of about 0.2-0.5 ohms that, at least in
the sim, look like they'll work great at this speed with my Analog
Devices 2A isolated gate driver. The package is "PG-TSDSON-8" or "laptop
motherboard" as I call it which is a bit inconvenient for hand soldering
I think.

 

[bitrex]

On 3/20/2020 11:45 PM, bitrex wrote:

On 3/20/2020 11:02 PM, sea moss wrote:
since you are hand soldering, I would go for a TO-220 part.  lots of
parts to choose from, many probably fine.  Look at the tradeoff
between Rds_on and Ciss.  You might need small Ciss since you are
switching pretty fast; then keep an eye on temperature if you choose a
part with higher Rds_on. It goes without saying if you are switching
at 2MHz keep the leads short.


Looking thru the LTSpice lib it looks like there's a set of Infineon
parts that have Vds in the range of 100-200 volts, gate charges of about
5-20 nC and Rds-ons in the range of about 0.2-0.5 ohms that, at least in
the sim, look like they'll work great at this speed with my Analog
Devices 2A isolated gate driver. The package is "PG-TSDSON-8" or "laptop
motherboard" as I call it which is a bit inconvenient for hand soldering
I think.

Even with a hot-air station once you slap it down to a sheet of
copper-clad they're pretty hard to get off I expect if you blow it.
Maybe tack their drain pad to risers of copper-clad and let the source
and gate pins hang off the side.

 

[Uwe Bonnes]

bitrex <user@example.net> wrote:

Looking for a MOSFET with a 100 or 150-200 (would be better), Vds
N-channel that can switch a couple amps at a couple MHz, preferably in
D-pak or something for ease of compact Manhattan-prototyping.

I think "serveral MHzand Ampere" contradicts and easy to handle
package. Did you have a look at the bare die GAN mosfets, like those
from EPC?
--
Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------

 

[Uwe Bonnes]

bitrex <user@example.net> wrote:

Looking for a MOSFET with a 100 or 150-200 (would be better), Vds
N-channel that can switch a couple amps at a couple MHz, preferably in
D-pak or something for ease of compact Manhattan-prototyping.

I think "serveral MHz and Ampere" and easy to handle package contradict.
Did you have a look at the bare die GAN mosfets, like those
from EPC?
--
Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------

 

[Winfield Hill]

bitrex wrote...

Looking for a MOSFET with a 100 or 150-200 Vds
N-channel - switch a couple amps at a couple MHz,
preferably in D-pak ...

You should avoid the temptation to go big, with
low Rds(on). Instead go for low Qg and low Coss.
Power dissipation terms are f Qg Vg, f Coss Vd^2,
and i^2 Rds(on). It'd be good to keep Coss under
50pF. Looking in my giant MOSFET spreadsheet, an
FQD5N20L looks good, Qg = 5nC with 5V gate drive,
Coss = 40pF, and Rds = 1-ohm, oops, a little high.
Or maybe FDD7N20TM, Rds = 0.58 ohms, Coss = 45pF.


--
Thanks,
- Win

 

On 21 Mar 2020 09:02:35 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

bitrex wrote...

Looking for a MOSFET with a 100 or 150-200 Vds
N-channel - switch a couple amps at a couple MHz,
preferably in D-pak ...

You should avoid the temptation to go big, with
low Rds(on). Instead go for low Qg and low Coss.
Power dissipation terms are f Qg Vg, f Coss Vd^2,
and i^2 Rds(on). It'd be good to keep Coss under
50pF. Looking in my giant MOSFET spreadsheet, an
FQD5N20L looks good, Qg = 5nC with 5V gate drive,
Coss = 40pF, and Rds = 1-ohm, oops, a little high.
Or maybe FDD7N20TM, Rds = 0.58 ohms, Coss = 45pF.

Or maybe GaN. Many times better numbers. Easy to drive.





--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Winfield Hill]

jlarkin@highlandsniptechnology.com wrote...

Winfield Hill wrote:

bitrex wrote...

Looking for a MOSFET with a 100 or 150-200 Vds
N-channel - switch a couple amps at a couple MHz,
preferably in D-pak ...

You should avoid the temptation to go big, with
low Rds(on). Instead go for low Qg and low Coss.
Power dissipation terms are f Qg Vg, f Coss Vd^2,
and i^2 Rds(on). It'd be good to keep Coss under
50pF. Looking in my giant MOSFET spreadsheet, an
FQD5N20L looks good, Qg = 5nC with 5V gate drive,
Coss = 40pF, and Rds = 1-ohm, oops, a little high.
Or maybe FDD7N20TM, Rds = 0.58 ohms, Coss = 45pF.

Or maybe GaN. Many times better numbers. Easy to drive.

Most of the GaN and SiC parts in my spreadsheet are
aimed at higher-power applications. They start with
higher voltage ratings (600 or 1200V), and actually
have higher Qg and Coss values than conventional low-
voltage FETs. But then, my spreadsheet is certainly
incomplete.


--
Thanks,
- Win

 

On 21 Mar 2020 09:56:03 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

jlarkin@highlandsniptechnology.com wrote...

Winfield Hill wrote:

bitrex wrote...

Looking for a MOSFET with a 100 or 150-200 Vds
N-channel - switch a couple amps at a couple MHz,
preferably in D-pak ...

You should avoid the temptation to go big, with
low Rds(on). Instead go for low Qg and low Coss.
Power dissipation terms are f Qg Vg, f Coss Vd^2,
and i^2 Rds(on). It'd be good to keep Coss under
50pF. Looking in my giant MOSFET spreadsheet, an
FQD5N20L looks good, Qg = 5nC with 5V gate drive,
Coss = 40pF, and Rds = 1-ohm, oops, a little high.
Or maybe FDD7N20TM, Rds = 0.58 ohms, Coss = 45pF.

Or maybe GaN. Many times better numbers. Easy to drive.

Most of the GaN and SiC parts in my spreadsheet are
aimed at higher-power applications. They start with
higher voltage ratings (600 or 1200V), and actually
have higher Qg and Coss values than conventional low-
voltage FETs. But then, my spreadsheet is certainly
incomplete.

EPC has some dynamite 100 and 200 volt parts in that current range.
They are cheap and have amazing performance, the downside being the
horrible BGA packages.

https://www.dropbox.com/s/7247chxsr5iqi5s/T577B_30-volt_pulse.jpg?raw=1



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[bitrex]

On 3/21/2020 12:02 PM, Winfield Hill wrote:

bitrex wrote...

Looking for a MOSFET with a 100 or 150-200 Vds
N-channel - switch a couple amps at a couple MHz,
preferably in D-pak ...

You should avoid the temptation to go big, with
low Rds(on). Instead go for low Qg and low Coss.
Power dissipation terms are f Qg Vg, f Coss Vd^2,
and i^2 Rds(on). It'd be good to keep Coss under
50pF. Looking in my giant MOSFET spreadsheet, an
FQD5N20L looks good, Qg = 5nC with 5V gate drive,
Coss = 40pF, and Rds = 1-ohm, oops, a little high.
Or maybe FDD7N20TM, Rds = 0.58 ohms, Coss = 45pF.

Yes that sounds the ballpark of what I need. It's driving about a 100
ohm load thru an LC with the N-fets sources hooked to four different
rails like an interleaved buck, with bootstrapping on the top FET driver
to drive the gate of that one high enough. one node switches e.g.
+25/-25 and the other e.g. +12/-12 gates driven in sequence with some
dead-time.

Need to go fairly fast but not ridiculously fast; the 2A ADuM4120 seems
up to the task with FETs with gate charges in that range. with the
standard MOSFET gate-circuit of diode, small resistor in parallel in
line and pull-down at the gate the waveforms look very clean in the sim.

 

[Winfield Hill]

bitrex wrote...

Need to go fairly fast but not ridiculously fast; the
2A ADuM4120 seems up to the task with FETs with gate
charges in that range ...

Yes, the ADuM4120 is an amazing part. It's 150kV/us
slew rating is one of the best specs out there. That
would be 150V/ns, or a 4ns risetime with a 600V pulse.
But its 2pF in-to-out capacitance implies i = C dV/dt
= 300mA i/o current during the 4ns swing. Worrisome.
Better stick to slower edges.


--
Thanks,
- Win

 

[Winfield Hill]

jlarkin@highlandsniptechnology.com wrote...

EPC has some dynamite 100 and 200 volt parts in that
current range. (2A) They are cheap and have amazing
performance, the downside being the horrible BGA packages.

https://www.dropbox.com/s/7247chxsr5iqi5s/T577B_30-volt_pulse.jpg?raw=1

Yes, good to far beyond 2 MHz. For example, EPC2012 has
gate charge < 2nC at 5V, so P_drive = f Q Vgs = 0.1W at
10MHz, and with Coss = 73pF, P_loss = f Coss V^2 = 7W.


--
Thanks,
- Win

 

On 22 Mar 2020 10:19:12 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

jlarkin@highlandsniptechnology.com wrote...

EPC has some dynamite 100 and 200 volt parts in that
current range. (2A) They are cheap and have amazing
performance, the downside being the horrible BGA packages.

https://www.dropbox.com/s/7247chxsr5iqi5s/T577B_30-volt_pulse.jpg?raw=1

Yes, good to far beyond 2 MHz. For example, EPC2012 has
gate charge < 2nC at 5V, so P_drive = f Q Vgs = 0.1W at
10MHz, and with Coss = 73pF, P_loss = f Coss V^2 = 7W.

What's stunning is the Crss of 0.4 pF. That makes all sorts of
dumb-looking circuits work.

I've got a GaN totem-pole making 10 volt pulses with rise/fall below
250 ps. From dirt-cheap parts. The circuit works to at least 80 volts,
but slows down a bit. The pulses do look a little ratty at that speed,
so I'll lowpass them to make prettier edges around 1 ns.

I've tested the EPC GaN parts. They die at just about 2x rated
voltage.

I kinda miss the Avago phemts, but the EPC GaNs are really better.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

Switching that fast at 100V then I hope you are doing ZVS and ZCS swithing

Otherwise you need super junction part or GAN

Cheers

Klaus

 

klaus.kragelund@gmail.com wrote in
news:8dffc872-f146-4255-a01e-297af46eef4c@googlegroups.com:

Switching that fast at 100V then I hope you are doing ZVS and ZCS
swithing

Otherwise you need super junction part or GAN

Cheers

Klaus

Isn't anything at those levels GAN nowadays?

 

On Sun, 22 Mar 2020 16:40:19 -0700 (PDT), klaus.kragelund@gmail.com
wrote:

>Switching that fast at 100V then I hope you are doing ZVS and ZCS swithing

It's a pulse generator. Totem pole, 50 ohm DPAK resistor, output
connector. And maybe the cosmetics lowpass filter.

Otherwise you need super junction part or GAN

I'm using the EPC GaN fets.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"