CD4046 Question

Its about the 4046 or equivalent here not your high performance stuff and who says PD2 in a 4046 is an XOR?

ciao Ban

Ban,

What's your beef exactly? You're the one quoting the PD labels. I've been using 4046s for 30 years.

Cheers

Phil Hobbs

So it's not instantaneous?

"Thought is required." ???

Crikey! You trying to out snot Larkin ?:-)

I haven't used a PLL for signal detection since the '60's... just synthesizers since.

Knowing that a synthesizer is truly locked and still not "wobbling" is critical to know prior to turning on a transmitter. ...Jim Thompson

It's shown that way on the data sheet ?? ...Jim Thompson

There isn't much sense in a lock detector that's faster than the loop filter. If you're interested in the phase variance, the phase pulses output can be useful, or you can use an auxiliary PD in quadrature.

Nah, I'm nowhere near as big a wildman as he is, and besides, I can't make Cajun red beans and rice.

I didn't mean anything by it. Just quit leading with your chin. ;)

Sure, but a phase variance meter isn't the same as a lock detector, in my language at least. Once the loop is in lock, you can do all sorts of tricks, which you know at least as well as I do.

Cheers

Phil Hobbs

Trivial. I just tell my wife, who is truly French/Cajun/Dutch blend (and related to every Carter in Kentucky), what I'd like for dinner ;-)

I never lead with my chin. Butt of a rifle maybe ;-)

TACAN (couldn't remember the other day)...

What Gardner himself said couldn't work, when I demonstrated it at a company (name I can't remember) in El Monte, CA, ~1968-69 :-)

Indeed. ...Jim Thompson

The datasheet says: Phase comparator 2 is an edge-controlled digital memory

network. It consists of four flip-flops, control gating and a

having a common output node. When the p-type or n-type

drivers are ON, they pull the output up to VDD or down to

VSS respectively. This type of phase comparator only acts

on the positive-going edges of the signals at SIGNIN and

COMPIN. Therefore, the duty factors of these signals are

not of importance.

Funny how you avoid mentioning PD1.

Gerhard

phase detector one can not give you a lock indication.and there will be always a phase angle exept at the center frequency, it's an XOR after all. The OP wanted to detect a "locked" condition. ciao Ban

I was planning on using comparator II, and after looking a little more carefully it looks like the phase pulses of pin one could be fed to an inverter, and in turn to a buffer that would control power to a LED. The led would be dim when there were many phase pulses, but when the thing smooths out, the LED would go to full brightness. Just a thought.

Thanks, Chris

After more careful inspection, I see that the references to the "ancient" text were for the loop filter. Is there an on-line reference so that I can find values for the loop filter?

Thanks, Chris Maness