Baroque BJT Digital Driver Stage

Had been meaning to finish this drawing for, hmm, guess it's about 8 years or so. Anyway, here it is:

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Not too useful to me at board level, just for how many parts it takes. Should be good for some speed and current though. (Note, resistor values are initial guesses and subject to optimization.)

Tim

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Seven Transistor Labs, LLC 
Electrical Engineering Consultation and Design 
Website: https://www.seventransistorlabs.com/
Reply to
Tim Williams
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Time to upgrade to GaN fets!

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I'm just finishing up the rev B layout. The rev A has sub-ns edges, but there's some ringing (around 700 MHz) so I added an absorptive output lowpass filter to beautify the pulse, but that cost me rise/fall time. I'm optimistic that rev B will ring less, or at least at a higher frequency.

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John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

Pleasingly symmetric, and exactly 7 PNP and 7 NPN.

piglet

Reply to
piglet

I like the Xerox Alto-like vertical screen of that scope, is there an advantage to using those early digital scopes in 2019? The built in delay-lines probably make it more useful

Reply to
bitrex

The display is magnetically deflected, vertical raster scan. The video generator is a couple square feet of TTL. There's a color version, shadow mask tube, but I like my b+w, which is a lot sharper.

They are cheap and work very well. We have at least a dozen 1180x scopes and maybe 50 sampling heads, up to 40 GHz, and TDR, all for about the cost of our one 7 GHz LeCroy (which hardly anyone can remember how to use.)

A non-sampling (realtime ADC) version of my scope might cost a megabuck.

I rarely use the delay-line "internal" trigger. I generally use one of our digital delay generators to manage an experiment, and give the scope a pre-trigger. Or sometimes give the scope a delayed trigger. Our DDGs have much less jitter for longish delays than those scopes do.

A hobbyist or startup could get into the picosecond business with one of these and a few other bits of gear for under $2K.

An interesting box would host a few SD-series Tek sampling heads, with a timebase and a USB interface. Tek showed such a box once at a trade show, but never offered it for sale.

--

John Larkin         Highland Technology, Inc 

lunatic fringe electronics
Reply to
John Larkin

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