The inductor in the T2-Mini is nothing special.
On Oct 4, 2017, 12:57 PM, at 12:57 PM, Attila Kinali <att...@kinali.ch> wrote: >On Wed, 4 Oct 2017 12:02:35 +1300 (NZDT) >Bruce Griffiths <bruce.griffi...@xtra.co.nz> wrote: > >> I could measure the PN of the TAPR variant of the Wenzel circuit >> as well as the PN of the comparator based circuit (with CMOS output >buffer). > > >BTW: one thing that has been bothering me with the TAPR variant of the >Wenzel circuit is the 100µH inductor in the tail of the diff-pair. >As it presents an impedance of approximately 6k at 10MHz it is cruical >to the working of the diff-pair (which would otherwise be just two >independent transistors). But I was unable to find a 100µH inductor >with a self-resonance frequency significantly higher than 10MHz. >Quite to the contrary, most seem to mingle around 1MHz. This poses >two questions: > >1) does the TADD2 mini use a special inductor? > >and > >2) Given the 100µH inductor has an SFR somewhere in the range of 1-5MHz >and is likely to have significant core losses around and/or above >10MHz, >doesn't this limit the performance of the circuit quite significantly? > >I have been thinking of replacing the inductor with a current source >(simple current mirror) and at least in the spice simulations it looks >decent. No idea of the noise performance, though. > > Attila Kinali >-- >It is upon moral qualities that a society is ultimately founded. All >the prosperity and technological sophistication in the world is of no >use without that foundation. > -- Miss Matheson, The Diamond Age, Neil Stephenson >_______________________________________________ >time-nuts mailing list -- time-nuts@febo.com >To unsubscribe, go to >https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.