EEVblog Electronics Community Forum
EEVblog => Other Blogs => Topic started by: palpurul on June 25, 2018, 09:19:30 am
-
Hello,
I investigated opamp input capacitance and my findings were somewhat interesting and unexpected to me and I decided to write about it my blog.
I found out that in some cases differential input resistance appears as capacitance to ground and contributes to the total input capacitance along with opamp's common-mode input capacitance.
In Part 1 (https://dctodaylight.wordpress.com/2018/07/04/opamp-input-capacitance-part-1//) I explained the theory and calculations. I also verified my calculations in SPICE.
In Part 2 (https://dctodaylight.wordpress.com/2018/07/04/opamp-input-capacitance-part-2-results/) calculated, simulated and measured results are shown for different types opamps.
The measured results were larger than expected for opamps with lower differential resistance. I don't exactly know what was causing that, but I concluded that it was because of variation in open loop gain and differential resistance. I am open to hear your opinions about this.
I hope you find it interesting and useful.
Check out my blog and other stuff that I posted. So fat my content was mostly about analog stuff, but I might post about anything related to electronics.
Blog : https://dctodaylight.wordpress.com (https://dctodaylight.wordpress.com)
Suggestions and comments are appreciated.
Thanks! ;)
EDIT:
I had to move blog to wordpress from wix because wix site was causing a lot of problems for me.
Enjoy my new new site. :D