Is there any kind of IC/ circuit that can output a changing voltage proportional to a changing input frequency?

 

Yes. It's called a Frequency to Voltage converter and they are generally also Voltage to Frequency converters.
SG

 

Yes. It's called a Frequency to Voltage converter.
SG

Thanks I will check it out

 

F to V and V to F as mentioned. You can either roll your own or buy a plug and play turn key solution depending on your application(s).

Ron

 

Check out the LM2907/LM2917 and see if it'll do what you need.

 

hi,
This is one example.
E

 

hi,
This is one example.
E

Thanks, it helped a lot.

 

Check out the LM2907/LM2917 and see if it'll do what you need.

Thanks for the help, appreciated.

 

F to V and V to F as mentioned. You can either roll your own or buy a plug and play turn key solution depending on your application(s).

Ron

Thank you, the lm331 has caught my interest

 

Yes. It's called a Frequency to Voltage converter and they are generally also Voltage to Frequency converters.
SG

Thanks, that helped a lot.

 

as others have said, yes
but it would be good to know what sort of frequency range and voltage range in you need.

After all, frequency to voltage is what an FM radio does,
( ok the change in frequency gives the change in voltage ) ,,,

Alternatively, hard limiting a sine wave of variable frequency to a square wave, and then low pass filtering the output will give you a varying output voltage as the input frequency changes.

 

as others have said, yes
but it would be good to know what sort of frequency range and voltage range in you need.

After all, frequency to voltage is what an FM radio does,
( ok the change in frequency gives the change in voltage ) ,,,

Alternatively, hard limiting a sine wave of variable frequency to a square wave, and then low pass filtering the output will give you a varying output voltage as the input frequency changes.

Well if you could help me it would be awesome, the lowest frequency can be as low as 5 hertz... And the highest frequency can be 5kHz.. and the voltage varies from 0 to 5 volt.. do you think it is possible? Because as far as I know it's practically impossible

 

Alternatively, hard limiting a sine wave of variable frequency to a square wave, and then low pass filtering the output will give you a varying output voltage as the input frequency changes.

By itself, that won't give you a frequency-dependent output voltage. But if you take the square wave and use it to trigger a monostable multivibrator, and then low-pass filter the multivibrator's output, that would do the trick.

EDIT: Lots of frequency to voltage converter circuits, here.

 

the lowest frequency can be as low as 5 hertz... And the highest frequency can be 5kHz

I doubt you'd find anything to cover a 1000:1 ratio in a single range accurately. You'll likely need several switched ranges.

 

By itself, that won't give you a frequency-dependent output voltage. But if you take the square wave and use it to trigger a monostable multivibrator, and then low-pass filter the multivibrator's output, that would do the trick.

EDIT: Lots of frequency to voltage converter circuits, here.

OOPs ,

your right, put it down to snr moment,
yep dont just hard limit and get the DC !!!