BlackBishop
Newbie level 3
![Newbie level 3](/styles/images/ranks/alevel3.gif)
Hi - this is my first question posted on this forum - and I have more to go later ![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I saw some docs and pages on the web about using cheap PIN diodes instead hard to get and expensive SRDs but they were quite general.
You may already guessed it is to be used as pulse generator with very short rise / fall times.
I don't know how fast PIN diodes could be in such application. Is it possible to go 50ps or lower or is that SRD only region?
Assuming that I have spec for SRD - there are junction capacitance, carrier life time, rise time and breakdown voltage.
For example: 0.15pF, 4ns, 30ps, 14V.
Quick analisis of SRDs show those with lower capacitance and lower carrier life time have shorter rise times.
Is it enough to pick those PINs with the lowest junction capacitance and carrier life time and expect decent rise times?
I saw some docs and pages on the web about using cheap PIN diodes instead hard to get and expensive SRDs but they were quite general.
You may already guessed it is to be used as pulse generator with very short rise / fall times.
I don't know how fast PIN diodes could be in such application. Is it possible to go 50ps or lower or is that SRD only region?
Assuming that I have spec for SRD - there are junction capacitance, carrier life time, rise time and breakdown voltage.
For example: 0.15pF, 4ns, 30ps, 14V.
Quick analisis of SRDs show those with lower capacitance and lower carrier life time have shorter rise times.
Is it enough to pick those PINs with the lowest junction capacitance and carrier life time and expect decent rise times?