Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

ad5933

Status
Not open for further replies.
Been busy. Not sure if I will be able to do a full-fledged design. The app note with the 4627 is basically what you need for the voltage to current converter. The main issue is figuring out what the resistor should be. You do know it's 350 uA and you need to know, or can find, the max p-p or RMS voltage that the cihip allows and size the resistor accordingly. That should not be hard. You just have to sift through the data.

With the offset voltage so low, I doubt that offset compensation is required. If it is, it means an extra 4627, a reference and a few resistors.

When laying something like this out, you have to include bypass resistors and guards/grounds around the input pins. They are a ground plane that doesn't touch the + and - pins, but surround the pin. Better yet, is a voltage at the same potential as the pin surrounding the pin.

I'm wondering if a 4-layer board would make life a lot easier. gnd(top), +5, -5, traces for the most part. You can have traces at every layer. It's best to have vias not attached to a through hole pin if possible.
 
Hi thanks again. Is it possible whenever you have time to send me a design?
The voltage to current do I need it for the electrodes?
Thanks
 
Back in post #16, PDF page 7, The I-V converter is basically the App note with the 4627. Somewhere is all of AD's data there should be the numbers necessary to design it. e.g. Pick RG. The 350 uA comes from recommended limits. That should be straightforward.
 
I think the use of 4 electrodes is complicated. What about the use of 2 electrodes, can be easier?
 
Two electrodes have way too much contact resistance and 2 electrodes use DC+AC. The DC is bad too.
 
Last edited:
I wish you quick recovery! I don't mind waiting. Please whenever you can post here a message or send me a pm.Thanks
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top