Is there any remediational way if I used a wrong I/O for PLL

[Analog_starter]

Re: Is there any remediational way if I used a wrong I/O for

Hi all,

I'v used a wrong I/O for PLL output, and its output driver capability is very limited.
My target maximal output is 500Mhz, but there is only 500mv(P-P) for the output signal swing as show in the oscillograph when the output is just about 50Mhz, say nothing of 500Mhz.
Now it is fabricated and packaged. Is there any remediational way? Can I simply add the buffer between this IC and oscillograph?

Thanks, thanks, thanks a lot !!

Best Regards
Analog_starter

Added after 5 minutes:

By the way, what is the lowest output signal swing that the buffer can detect? I used 0.18um 1.8V process.

Thanks!

 

[Teddy]

Re: Is there any remediational way if I used a wrong I/O for

Well I gues it sounds bad.
Do you have cap load on the output - if yes remove it.
Buffer will not help - you are limited with the frequency... internaly
Try not to put any load and ac couple it to the scope. Or be sure to use HIZ probe.

By the "wrong buffer" you mean excatly what? If the buffer is just small but predrivers are ok you could try to probe to the OB input and evaluate it there.
Obviously you can learn something then. In any casy next pass...

 

[Analog_starter]

Re: Is there any remediational way if I used a wrong I/O for

Thank you, Teddy.

What is 'HIZ probe'? And what the 'OB' stand for?

Best Regards
Analog_starter

 

[Teddy]

Re: Is there any remediational way if I used a wrong I/O for

high impedance probe and output buffer.
Honestly it sounds like no vcc connected to you IO