phase lock loop problem

[f1kr1]

i'm built a circuit using mm74hc4046.
i'm connected 4.5 vdd.
r1=330k,r2=330k,c1=3.3nF for the VCO.
i got 15kHz for the VCO center frequency.
but when i change the input signal to what ever frequency.
the output still showing the same thing.
pls some one help me.

 

[betwixt]

I think you need to use at least five negative resistors. Arrange them so they face north, east, south and west with the last one pointing upwards. It doesn't matter which way around you connect them as that only applies to resistors with positive values. Atmospheric turbulence and solar magnetic flux with then alter the frequency according to my cat's mood and all will be well.

Alternatively, give us a schematic so we can see what on Earth you are talking about.


Brian.

 

[LvW]

I think you need to use at least five negative resistors. Arrange them so they face north, east, south and west with the last one pointing upwards. It doesn't matter which way around you connect them as that only applies to resistors with positive values. Atmospheric turbulence and solar magnetic flux with then alter the frequency according to my cat's mood and all will be well.
........

Brian, you have a good sense of humour. Compliment!
LvW

 

[f1kr1]

pin 10 i leave it open
pin5 to ground
pin 8 to ground

 

[rudane]

The datasheet for this component isn't very helpful. Did you find any application notes?

 

[f1kr1]

i have read some application note on this.
but still the circuit does not work.

Added after 2 minutes:

the phase comparator output should be a dc straught line right?
but i get some pulse on it.

 

[betwixt]

Having looked at the 'circuit', I stick to my original answer.

Brian.

 

[LvW]

Hi f1kr1,

is the figure with your "circuit" a joke? If yes, it wasn't a good one.

 

[rudane]

Please post the schematic of your design. Not a picture.

 

[f1kr1]

here's the schematic
Help me please.

 

[fishbrook02]

fmin for the vco is set by R2 and fmax is set by R1. Both resistors are 330k in your schematic.