Bruce wrote:
The essentials of a Wikinson TDC can be simplified to the attached
circuit which only requires the addition of a zero crossing
comparator to monitor the voltage across the capacitor C1.
A few refinements to improve the capacitor charging current
switching transitions and the addition of an upper voltage clamp
together with the use of faster transistors may be useful.
The HFA3096 transistor array (3 NPN + 2 PNP) should do nicely. My
simulations show a small but definite improvement in the current
switching transitions.
BTW, the PNPs in an HFA3096/3128 also pretty much solve the Cb-e
feedthrough in a Wenzel-style squaring circuit, giving pretty flat
tops on the high output pulses without resorting to diode isolation
or other secondary techniques.
Best regards,
Charles
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
