AnsweredAssumed Answered


Question asked by Nicola on Aug 8, 2011
Latest reply on Aug 10, 2011 by RobK
Hi all,
I am looking for a frequency to voltage converter, I am checking the AD650 chip. This is a VFC converter but it could be used like FVC, this application is well descripted in the application note AN-279.
I have a couple of doubts:
The first is in the (3) formula on page 2 of the AN279. In this formula 'I' parameter compares, in my opinion this is not a parameter and is a division symbol '/', only in this case the dimensional analysis is right.
The second doubt is relative to the response time of the FVC. In my system this time has to be in the order of milliseconds; it seems that this time is compatible only with high ripple value.
My system frequency range is 50-120KHz, I need 1ms response time. The ADC is 12 bit precision and using a 2.048V range it can appreciate 0.5mV of variation. I could try to work using 10 bit precision, in this case my system can work with a ripple <2mV.
Did someone use this component (or similar) for similar application?
Thank you in advance and regards.