Hi All,
I am a beginner and my first time on this forum.
I have a question on a particular phase detector (mC 4o44). I have a project that deals with PLL. The phase detector used is the one stated above. I am haveing trouble with the whole ckt so I tried to check out each block. First is the phase detect.

some how I can't get the a pulse at the output. I feed in a reference freq from an oscillator and another frequency from a function geneator. Both inputs at same freq and same amplitude. I wired 13,4 together and 11,2 together. I also fed 10,5 to pin 9 with resistor in between.

Please help.
Frank

 

Welcome to the forum.
Can you post the schematic of your circuit?

 

Hi Alec,
Thanks for the reply. The schematic is only that what is on the datasheet as I am trying to get the MC 4o44 to work.

Here is the datasheet.
http://www.alldatasheet.com/datasheet-pdf/pdf/86788/MOTOROLA/MC4044.html

 

How are you conditioning the two signals from the RF generators before applying them to the pins on the 4044? Those inputs will not tolerate a signal that swings below ground.

 

Hi MikeML,
The pin R is from an oscillator on the bread board. As far as the generator I don't know the answer to that. Maybe that is the culprit? I have the FG connected to a BNC cable and the other end are clips. The black clip connected to ground and the positive clip connected to pin V of the 40 44.
Is this the correct way for the FG to send a signal. Also, I have the FG set to send square waves.

Thanks,
Frank

 

I know this sounds like a dumb question but, do you really have an MC4044?

When Motorola first started making 4000 series CMOS they already had a 4000 series including the MC4044. Their solution was to create the MC14000 series for their CMOS parts. This was a very painful period for purchasing agents and production personal since many CMOS circuits got built with the phase comparator instead.

 

... Also, I have the FG set to send square waves.

Ok if you crank in a DC offset to center the square wave on 1/2Vcc, meaning that the bottom is at or near 0V, and the top of the square wave is equal to Vcc (5V?)