12MHz Sine to Square IC?

[jamesnguyen]

Hi everyone,

I have a 12MHz, 0.8Vpp clip sine wave coming from a VCO and I need to square up this signal to TTL-compatible logic. The TI's CDC3RL02 can do the conversion, but its output is only 1.8V. I will need another level converter to convert it to 3.3V.

Is there any IC out there that can convert 0.8V clip sine wave to 3.3V square wave?

Regards,
James

 

[ScottyUK]

What about an comparator with an open-collector output? The frequency isn't all that high, so there should be a few choices available.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[jamesnguyen]

Thank you for your advice.

How is the output jitter with a comparator? What's the advantage of an open collector output?

Regards,
James

 

[VEBill]

How about a 'zero crossing detector' IC? The function you describe is pretty much exactly what they're made for.

 

[ScottyUK]

Output jitter should be ok if you keep the pull-up fairly low in value. The open collector would get around your interfacing problem to the 3.3V system if you can't find a comparator to work from a 3.3V rail.

Nice idea VE1BLL.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[itsmoked]

I agree with Scotty. The comparator would be the easiest. The open collector allows you to run any voltage output, within reason.

Other possibilities:
An alternative would be an op-amp to increase the voltage followed by a Schmidt trigger.

Use a dual op-amp and use the first one as an amp and the second one as a comparator.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[automatic2]

I'd try a 74HC nand or similar.