Re: S-52 tunnel diode

Don Black <donald_black@...>

No, it's got a gain of about 40 db, the switching range is less than 10 mV and it can have up to 2 volts input. It's only the time to cross the input threshold of 10 mV (actually about 6 V so that even with a 2 volt input pulse of 1 ns or more the switching time is only less that 0.5%, i.e. it will reach the 25 ps. Here is a link to the data for the DS800 sampling oscilloscope with sample displays. The relevant one is the 1 GHz sine wave to one channel and the square wave from a ONET8501 to the other channel with full switching speed. I wrote to them asking how they connected from the ONET8501 and the just used a short 50 ohm line track on the PCB to a coax into the oscilloscope. Note the rise time is the combination of the pulse and oscilloscope response (8 GHz), the display is 75 ps per division.

Don Black.

Don Black.

On 09-Aug-13 11:24 PM, Craig Sawyers wrote:

Impressive – but you only get 25ps out if you shove 25ps in.




From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Don Black
Sent: 09 August 2013 13:16
To: TekScopes@...
Subject: Re: [TekScopes] Re: S-52 tunnel diode


Look at the ONET8501; 25 pS rise and fall and selectable output up to 900 mV.

Don Black.

On 09-Aug-13 9:56 PM, Alex wrote:


You know, these types of risetimes are in the domain of logic chips these days like the SY58601UMG. Even comparators like the ADCMP572. Not quite 25ps, but maybe close enough.

Of course you have to deal with fine pitch QFN packages.

--- In TekScopes@..., "sander.slang" wrote:
> Has somebody experience with the tunnel diode CR69 inside a S-52 pulse generator head?
> I know they can be easily damaged and I would like to buy a spare part in case it dies. After some study on this forum I discovered that somebody mentoined that they are very difficult to buy and for some tunnel diodes (maybe other brand) can have a low lifetime. Any experience with this?
> And now almost 40 years later are there no good replacement parts or even faster tunnel diodes? It would be nice if I can experiment with this and make my own tunnel diodes enclosures on a lathe.

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