Jim Thompson wrote:
On Fri, 03 Aug 2007 15:46:32 -0700, Joerg
wrote:


Jim Thompson wrote:


On Fri, 03 Aug 2007 22:20:53 GMT, Joerg
wrote:



Hello Folks,

See the scope plot and excerpt from the ON Semi datasheet for the
CD4060. The blue trace is at the node RS/Rtc/Ctc, the yellow trace is at
pin 9 which is an output.

Why is there sag at the end of each phase? Rs is 500K and Rtc is 100K. I
mean, that shouldn't be any load to write home about even for a CD
series part.


Joerg!!

Out1 looks normal to me. Think about it.


Normal? Well, maybe they put an inverter with really lousy gain in
there. In an RC oscillator that can cause lots of wasted power (which is
what I am seeing). Oh do I wish I had two more CD40106 inverter, but not
this time.



Out 2 looks like it's AC-coupled, or you're not looking where you
think.


The yellow trace is OUT2, the blue one is the left node of the cap. Both
DC-coupled.



Or maybe because it's not English ?:-)


Oops. Got to get into Margarita mode for tonight ;-)


Blue trace is normal, yellow trace indicates that OUT2 can't support
the current. Increase the resistance value.


Had to dip into the pool, it's 100F out here.

John's post got me thinking, it's probably a wimpy 1-stage inverter and
crossing over slowly. The sag is the same with 100K as it is with 33.2K
on the next timer.

I wonder why they didn't put a real inverter in there because this one
isn't part of the oscillator for crystal operation (that only uses the
first one).

--
Regards, Joerg

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