The 12V level shifter saga

On Mon, 10 Feb 2020 17:37:27 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-02-10 16:21, John Larkin wrote:
On Mon, 10 Feb 2020 14:26:20 -0500, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-02-09 21:33, jlarkin@highlandsniptechnology.com wrote:
On 9 Feb 2020 18:10:05 -0800, Winfield Hill <winfieldhill@yahoo.com
wrote:

jlarkin@highlandsniptechnology.com wrote...

https://www.dropbox.com/s/v23ns59k8ke1h54/LVDS_GaN_Driver.JPG?raw=1
work surprisingly well.

What low-Vgs, low Ciss parts do you like to use?

The EPC bga parts. They are hard to handle, hard to rework, physically
fragile, and wonderful.

What's really low is the Crss. EPC2037 is good for 100 volts, 1.7
amps, and drain-gate capacitance is 0.1 pF. As Phil has noted,
terminal inductances are picohenries.



I'll have to get a few and measure their noise. I could bootstrap a
solar panel with one of those.

Have to ask Simon to do some breakouts in his abundant spare time.

Cheers

Phil Hobbs

We did a bunch of EPC breakouts. I could send you a few, or the
Gerbers.

https://www.dropbox.com/s/iwsfcm5jryuoxev/GaN_Boards.JPG?raw=1

It's hard to solder the BGAs to the boards. These little boards were
OK, but we are now doing better "solder mask defined pads."

Sort of like the SchmartBoard idea?

I now know some things now that aren't on the data sheets.

Any and all of the above would be very welcome!

Thanks

Phil Hobbs

I can send you a few boards with some fets mounted, at least the ones
I haven't blown up yet. I'll see what parts are available.

Anyone is welcome to the PADS files and Gerbers, but you'd have to
make boards and solder the critters down.

https://www.dropbox.com/s/tho7up7klfeeisi/Z426A.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"

 

On Mon, 10 Feb 2020 16:09:04 -0800 (PST), dagmargoodboat@yahoo.com
wrote:

On Saturday, February 8, 2020 at 7:30:19 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Sat, 8 Feb 2020 15:38:59 -0800 (PST), klaus.kragelund@gmail.com
wrote:

The LVDS driver idea is good, but a little expensive

It may also have trouble when the switch node is moving with 50V/ns

Could be fun to try it out

Cheers

Klaus


Things like this

https://www.dropbox.com/s/v23ns59k8ke1h54/LVDS_GaN_Driver.JPG?raw=1

work surprisingly well.

Cute circuit. TI has some boot-strapped gate drivers that
essentially integrate that for Si MOSFETs, cap-coupled.

Cheers,
James Arthur

All the commercial gate drivers that I've seen have a lot of prop
delay. A home-brew LVDS+GaN can come in at a few ns.

My little Pockels Cell driver (1200v 7 ns pulses, 4 MHz) has Tiny
logic driving GaN driving water-cooled SiC. Lotta gain-bandwidth
there.



--

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]

James Arthur wrote...

On February 8, 2020, John Larkin wrote:
On 8 Feb 2020, Klaus Kragelund wrote:

The LVDS driver idea is good, but a little expensive
It may also have trouble when the switch node is moving
with 50V/ns. Could be fun to try it out

Things like this

https://www.dropbox.com/s/v23ns59k8ke1h54/LVDS_GaN_Driver.JPG?raw=1

work surprisingly well.

Cute circuit. TI has some boot-strapped gate drivers that
essentially integrate that for Si MOSFETs, cap-coupled.

The TI parts are nice, work to higher voltages,
and can drive higher Ciss, but John's LVDS scheme
with the 100V, 1A EPC mosfets is much faster!


--
Thanks,
- Win

 

On 11 Feb 2020 05:27:03 -0800, Winfield Hill <winfieldhill@yahoo.com>
wrote:

James Arthur wrote...

On February 8, 2020, John Larkin wrote:
On 8 Feb 2020, Klaus Kragelund wrote:

The LVDS driver idea is good, but a little expensive
It may also have trouble when the switch node is moving
with 50V/ns. Could be fun to try it out

Things like this

https://www.dropbox.com/s/v23ns59k8ke1h54/LVDS_GaN_Driver.JPG?raw=1

work surprisingly well.

Cute circuit. TI has some boot-strapped gate drivers that
essentially integrate that for Si MOSFETs, cap-coupled.

The TI parts are nice, work to higher voltages,
and can drive higher Ciss, but John's LVDS scheme
with the 100V, 1A EPC mosfets is much faster!

Three or six sections of Tiny logic triple buffers can drive the
bigger EPC parts. Run them at abs max Vcc or so.

https://www.digikey.com/product-detail/en/epc/EPC2053/917-1204-2-ND/9356646


Then parallel a bunch of those, each with its own gate drivers. Crazy
fast and 20 KW peak pulse power *each*



--

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"