74HC4046 chip question

Hello,
I found this application of a HC4046 PLL chip

Pin 14 signal input
Pin 2 signal output

Pins 3, 16 B+
Pin 8 B-


No other pins are used
Phase Comarartor 1 seems to be the only item hooked up
with useful frequencies to 30 Mhz

A total of 3 HC4046 are used for this and a mux into a PIC processor

Any other ideas to reduce the chip count?

Regards,
Charlie

Good joke. The schematic is showing a completely meaningless circuit. You get the same function by placing an inverting gate
between pin14 and pin2. Consult the 4046 datasheet.

Hi,
I was not playing any type of joke.

This is an actual circuit on a commerical product.

I have looked at the 4046 spec sheets and thought someone else might know why someone would waste so much real estate using the 4046 in this way.


To me it seems odd to use this just for a inv erter with a high Z input--- do you agree?

Regards,
Charlie

I remember AM transistor radios with an advertising text "9 Transistors", but two or three transistors had all pins soldered to ground...

I tell you why. CD4046 cost is 50 cents, when a simple transistor as 2N2222 could cost 90 cents.

http://search.digikey.com/scripts/Dk...eywords=cd4046

http://search.digikey.com/scripts/Dk...eywords=2n2222

You would use one CD4069 normally. The price comparison isn't really representative in my opinion.