Hello
I have a VCCS based on AD8130. After many googling and studying.. now I'm frustrated!
for checking the output capacitance usually I put a 1Kohm resistor on the output and check the 3-dB corner frequency. so the output capacitance is C=1/(2*pi*R*f3dB)
But I really I don't know how I should calculate the output impedance of the VCCS.
Regards
Hi Ali,
Few things.
1. The CMRR is dependent on how tightly matched the resistors are (RF/RG with RF'/RG'). For discrete components, the highest we can get is 66 dB CMRR for 0.1% tolerance. The external…
The best example or reference for your application is the CN0151. See figure 3.
The first AD8510 is a TIA to convert the current out of AD5443. So if you are in voltage mode, disregard the…
Thank's for your attention and recommendation
I've studied many papers about VCCS. (almost all papers )
it is one of the first application notes that I had studied before
one of the worst drawback of such circuit is the mismatch between resistors.
if you want a good accuracy it's better to use very accurate resistors (0.005% or better)
it's a good paper to talk about it:
http://ieeexplore.ieee.org/document/6221965/
I think AMP03 or INA105 are good choices for such application.
so you need a unity gain feedback (I'd like to call it a moderate version)
if you want very accurate VCCS it's better to use a DC stabilized feedback. (I'd like to call it a advanced version)
and ...