Groups > sci.electronics.design > #430124

Re: Gate resistor for lateral power MOSFET?

From	Frank Miles <fpm@u.washington.edu>
Newsgroups	sci.electronics.design
Subject	Re: Gate resistor for lateral power MOSFET?
Date	2016-10-02 02:59 +0000
Organization	A noiseless patient Spider
Message-ID	<nspt5p$3p0$1@dont-email.me> (permalink)
References	<nsgvlp$i4p$1@dont-email.me> <nsmgft$f4q$1@dont-email.me> <nsorq5$71o$1@dont-email.me> <nsp28701ud@drn.newsguy.com>

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On Sat, 01 Oct 2016 12:19:35 -0700, Winfield Hill wrote:

> Frank Miles wrote...
>> Winfield Hill wrote:
>>> Frank Miles wrote...
>>>> Frank Miles wrote:
>>>>>   [ snip ]
>>>>> The breakpoint is around 1MHz, so distortion may be tolerable.
>>>>
>>>>Early testing looks very good!  Stability seems fine with a few
>>>>different loads, distortion (at least as viewed on the 'scope) is
>>>>negligible, and BW and slew rates are at least twice as fast as I
>>>>need.
>>>>This is with gate resistors around 240 ohms (no beads, at least not
>>>>yet).   [snip]
>>> 
>>> I wasn't in the discussion, but would like to point out / remind
>>> anyone interested, of my 200 W amplifier project of last fall.  This
>>> has a 1000 V/us slew rate and a DC to 10 MHz response (-3dB rolloff
>>> frequency).
>>> But ahem, it doesn't use lateral MOSFETs.
>>
>> I'm sorry, Win - I didn't recall that.  I have no vested interest in
>> the lateral MOSFETS.  Is there a web link or at least a title that I
>> might search for?
> 
>  I don't remember the s.e.d. subject, and just now I couldn't find the
>  folder I made on DropBox, for you s.e.d. blokes and a DIY-audio
>  discussion, so I created a new one, see AMP-70A under s.e.d.
> https://www.dropbox.com/sh/mkoqdo5y0b9fevm/AACBM7iDdTyRLFADqLgj7ljNa?
dl=0

That was so nice for you to post this, thanks!  I remember seeing it
now, though I'd forgotten it before I began the project with the power
amp requirement.

One prominent note in your schematic warns about using the 1-ohm output
apparently due to lack of protection.  You may not have needed the low-
resistance output (though that seems strange given the 5A - losing over
1kW is a lot of heat!) - but did you find that active shutdown schemes
were too slow to protect your amplifier?  (I haven't yet done this with
my amplifier)

Thread

Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-09-28 17:46 +0000
  Re: Gate resistor for lateral power MOSFET? John Larkin <jjlarkin@highlandtechnology.com> - 2016-09-28 11:35 -0700
    Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-09-28 22:22 +0000
      Re: Gate resistor for lateral power MOSFET? John Larkin <jjlarkin@highlandtechnology.com> - 2016-09-28 17:20 -0700
  Re: Gate resistor for lateral power MOSFET? Winfield Hill <hill@rowland.harvard.edu> - 2016-09-28 19:16 -0700
    Re: Gate resistor for lateral power MOSFET? Phil Allison <pallison49@gmail.com> - 2016-09-28 23:07 -0700
      Re: Gate resistor for lateral power MOSFET? Winfield Hill <hill@rowland.harvard.edu> - 2016-09-29 12:51 -0700
  Re: Gate resistor for lateral power MOSFET? Phil Allison <pallison49@gmail.com> - 2016-09-28 19:52 -0700
    Re: Gate resistor for lateral power MOSFET? Winfield Hill <hill@rowland.harvard.edu> - 2016-09-28 20:13 -0700
      Re: Gate resistor for lateral power MOSFET? Winfield Hill <hill@rowland.harvard.edu> - 2016-09-29 12:52 -0700
    Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-09-29 16:41 +0000
      Re: Gate resistor for lateral power MOSFET? Phil Allison <pallison49@gmail.com> - 2016-09-29 18:52 -0700
        Re: Gate resistor for lateral power MOSFET? boB <boB@theresnoplacelikehome.com> - 2016-09-30 00:54 -0700
          Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-09-30 15:57 +0000
        Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-09-30 15:53 +0000
          Re: Gate resistor for lateral power MOSFET? George Herold <gherold@teachspin.com> - 2016-09-30 09:19 -0700
          Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-09-30 20:04 +0000
            Re: Gate resistor for lateral power MOSFET? Winfield Hill <hill@rowland.harvard.edu> - 2016-09-30 14:07 -0700
              Re: Gate resistor for lateral power MOSFET? dplatt@coop.radagast.org (Dave Platt) - 2016-09-30 14:52 -0700
              Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-10-01 17:29 +0000
                Re: Gate resistor for lateral power MOSFET? Winfield Hill <hill@rowland.harvard.edu> - 2016-10-01 12:19 -0700
                Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-10-02 02:59 +0000
                Re: Gate resistor for lateral power MOSFET? Phil Allison <pallison49@gmail.com> - 2016-10-01 21:10 -0700
                Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-10-03 00:20 +0000
                Re: Gate resistor for lateral power MOSFET? Winfield Hill <hill@rowland.harvard.edu> - 2016-10-02 09:43 -0700
                Re: Gate resistor for lateral power MOSFET? Frank Miles <fpm@u.washington.edu> - 2016-10-03 00:33 +0000
          Re: Gate resistor for lateral power MOSFET? Phil Allison <pallison49@gmail.com> - 2016-09-30 22:40 -0700

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