[time-nuts] DAC resistors

Hal Murray hmurray at megapathdsl.net
Tue Oct 6 23:02:49 UTC 2009

> I am constructing a phase meter to monitor the phase creep of clocks.
> It consists of a BCD counter counting say microseconds that has its
> count strobed into a latch by a pulse from the clock. The Latch drives
> a DAC which drives a pen recorder and an analogue data logger. Now I
> am familiar with R - 2R networks, and that method is used on each
> decade but the resistors that combine the decades in a 10:1 ratio are
> the problem. ...

Why are you using a BCD counter?

If you want it to drive a display, consider adding a binary counter in 
parallel with the BCD counter.

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