<https://www.dropbox.com/s/gv2ta7zik7weyxt/IMG_20200427_235520731.jpg?dl=0> Test rig for the mighty ADuM4120. 30 volts to the right power supply line and 3.3/5 volt logic level to the left. A very nice isolated gate driver. And at over $4 a piece in singles a real bummer when someone who isn't me wrecks one up by accident connecting the MOSFET source/drains wrong on the high-side/low-side switching circuit. or a couple. I can write that off as a business loss, right?
A gate driver circuit
Started by ●April 28, 2020
Reply by ●April 28, 20202020-04-28
On 4/28/2020 12:08 AM, bitrex wrote:> <https://www.dropbox.com/s/gv2ta7zik7weyxt/IMG_20200427_235520731.jpg?dl=0> > > Test rig for the mighty ADuM4120. 30 volts to the right power supply > line and 3.3/5 volt logic level to the left. A very nice isolated gate > driver. And at over $4 a piece in singles a real bummer when someone who > isn't me wrecks one up by accident connecting the MOSFET source/drains > wrong on the high-side/low-side switching circuit. or a couple. > > I can write that off as a business loss, right?At 30 volts into a 220 ohm load at 1 MHz she get a lil warm to the touch. Don't run it up much higher than that with that load or you're going to burn your fingertip and I'm fresh out of ice cream sammies.
Reply by ●April 28, 20202020-04-28
On Tue, 28 Apr 2020 00:08:53 -0400, bitrex <user@example.net> wrote:><https://www.dropbox.com/s/gv2ta7zik7weyxt/IMG_20200427_235520731.jpg?dl=0> > >Test rig for the mighty ADuM4120. 30 volts to the right power supply >line and 3.3/5 volt logic level to the left. A very nice isolated gate >driver. And at over $4 a piece in singles a real bummer when someone who >isn't me wrecks one up by accident connecting the MOSFET source/drains >wrong on the high-side/low-side switching circuit. or a couple. > >I can write that off as a business loss, right?The bummer about most integrated gate drivers is the high prop delay. But is $4 really an issue? -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●April 28, 20202020-04-28
On 4/28/2020 12:42 AM, jlarkin@highlandsniptechnology.com wrote:> On Tue, 28 Apr 2020 00:08:53 -0400, bitrex <user@example.net> wrote: > >> <https://www.dropbox.com/s/gv2ta7zik7weyxt/IMG_20200427_235520731.jpg?dl=0> >> >> Test rig for the mighty ADuM4120. 30 volts to the right power supply >> line and 3.3/5 volt logic level to the left. A very nice isolated gate >> driver. And at over $4 a piece in singles a real bummer when someone who >> isn't me wrecks one up by accident connecting the MOSFET source/drains >> wrong on the high-side/low-side switching circuit. or a couple. >> >> I can write that off as a business loss, right? > > The bummer about most integrated gate drivers is the high prop delay. > > But is $4 really an issue? > > >That's the most expensive part i've ever blown! I guess the guys in the auto repair biz have it worse, though
Reply by ●April 28, 20202020-04-28
On 4/28/2020 12:42 AM, jlarkin@highlandsniptechnology.com wrote:> On Tue, 28 Apr 2020 00:08:53 -0400, bitrex <user@example.net> wrote: > >> <https://www.dropbox.com/s/gv2ta7zik7weyxt/IMG_20200427_235520731.jpg?dl=0> >> >> Test rig for the mighty ADuM4120. 30 volts to the right power supply >> line and 3.3/5 volt logic level to the left. A very nice isolated gate >> driver. And at over $4 a piece in singles a real bummer when someone who >> isn't me wrecks one up by accident connecting the MOSFET source/drains >> wrong on the high-side/low-side switching circuit. or a couple. >> >> I can write that off as a business loss, right? > > The bummer about most integrated gate drivers is the high prop delay. > > But is $4 really an issue? > > >The total prop delay on this is 79 ns, falling edge. That seems better than most. Oh hey, it looks like you can get 'em for $2.16 in quantities of 100 direct from Analog. Mouser's discount is only $3.47. way to undercut your distributors
Reply by ●April 28, 20202020-04-28
bitrex wrote...> > At 30 volts into a 220 ohm load at 1 MHz she get a > lil warm to the touch.What about 5 or 10MHz into a modest capacitance- only load? Test temp with wetted fingertip, is OK if it doesn't sizzle, or sizzles slowly. -- Thanks, - Win
Reply by ●April 28, 20202020-04-28
On Tue, 28 Apr 2020 00:48:33 -0400, bitrex <user@example.net> wrote:>On 4/28/2020 12:42 AM, jlarkin@highlandsniptechnology.com wrote: >> On Tue, 28 Apr 2020 00:08:53 -0400, bitrex <user@example.net> wrote: >> >>> <https://www.dropbox.com/s/gv2ta7zik7weyxt/IMG_20200427_235520731.jpg?dl=0> >>> >>> Test rig for the mighty ADuM4120. 30 volts to the right power supply >>> line and 3.3/5 volt logic level to the left. A very nice isolated gate >>> driver. And at over $4 a piece in singles a real bummer when someone who >>> isn't me wrecks one up by accident connecting the MOSFET source/drains >>> wrong on the high-side/low-side switching circuit. or a couple. >>> >>> I can write that off as a business loss, right? >> >> The bummer about most integrated gate drivers is the high prop delay. >> >> But is $4 really an issue? >> >> >> > >That's the most expensive part i've ever blown! > >I guess the guys in the auto repair biz have it worse, thoughWe recently fried a couple of $200 distributed amplifier chips. I've done better at the system level. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●April 28, 20202020-04-28
On 28 Apr 2020 08:03:13 -0700, Winfield Hill <winfieldhill@yahoo.com> wrote:>bitrex wrote... >> >> At 30 volts into a 220 ohm load at 1 MHz she get a >> lil warm to the touch. > > What about 5 or 10MHz into a modest capacitance- > only load? Test temp with wetted fingertip, > is OK if it doesn't sizzle, or sizzles slowly.I can touch a 50C surface for many seconds, 60C for about 1 second, and can interpolate reasonably well. That's easier than setting up a thermocouple or the FLIR. For a serious gate driver, like slamming a Cree SiC at 5 MHz, you've got to roll your own. DEI/IXYS used to makes some real beasts, but I think they are gone now. -- John Larkin Highland Technology, Inc Science teaches us to doubt. Claude Bernard
Reply by ●April 28, 20202020-04-28
On 4/28/2020 12:00 PM, jlarkin@highlandsniptechnology.com wrote:> On Tue, 28 Apr 2020 00:48:33 -0400, bitrex <user@example.net> wrote: > >> On 4/28/2020 12:42 AM, jlarkin@highlandsniptechnology.com wrote: >>> On Tue, 28 Apr 2020 00:08:53 -0400, bitrex <user@example.net> wrote: >>> >>>> <https://www.dropbox.com/s/gv2ta7zik7weyxt/IMG_20200427_235520731.jpg?dl=0> >>>> >>>> Test rig for the mighty ADuM4120. 30 volts to the right power supply >>>> line and 3.3/5 volt logic level to the left. A very nice isolated gate >>>> driver. And at over $4 a piece in singles a real bummer when someone who >>>> isn't me wrecks one up by accident connecting the MOSFET source/drains >>>> wrong on the high-side/low-side switching circuit. or a couple. >>>> >>>> I can write that off as a business loss, right? >>> >>> The bummer about most integrated gate drivers is the high prop delay. >>> >>> But is $4 really an issue? >>> >>> >>> >> >> That's the most expensive part i've ever blown! >> >> I guess the guys in the auto repair biz have it worse, though > > We recently fried a couple of $200 distributed amplifier chips. I've > done better at the system level. > >I learned at some point to bill the client for a few spares of all the pricey-bits due to "development mishaps" on a prototype upfront they seem more amenable to that at the beginning of a project than if you tell them late in the game "Yeah so I blew up the output stage please add $X to you bill"
Reply by ●April 28, 20202020-04-28
tirsdag den 28. april 2020 kl. 18.05.58 UTC+2 skrev jla...@highlandsniptechnology.com:> On 28 Apr 2020 08:03:13 -0700, Winfield Hill <winfieldhill@yahoo.com> > wrote: > > >bitrex wrote... > >> > >> At 30 volts into a 220 ohm load at 1 MHz she get a > >> lil warm to the touch. > > > > What about 5 or 10MHz into a modest capacitance- > > only load? Test temp with wetted fingertip, > > is OK if it doesn't sizzle, or sizzles slowly. > > I can touch a 50C surface for many seconds, 60C for about 1 second, > and can interpolate reasonably well. That's easier than setting up a > thermocouple or the FLIR.I seem remember that back in the day 50C was the safety limit for user touchable parts like exposed heatsinks and such
