XTR105 with 8 RTD

Atul Bhakay

We are using this in 3 wire rtd circuit. We are using 4 or 8 rtd using XTR105U ic. Since instead of using 8 XTR we will use only one XTR and multiplex 8 rts sensor through analog switch.

This is done to reduce the price.

Please give solution

Regards

Atul Bhakay

over 11 years ago

0 John Griffith over 11 years ago

TI__Mastermind 21962 points

Hi Atul,

I am going to move your question to the Precision Amplifiers forum so that it can get the proper support and visibility. They should be able to address you question.

Thanks!

John

0 Collin Wells over 11 years ago in reply to John Griffith

TI__Guru 64495 points

Hi Atul,

Multi-plexing RTD sensors can be difficult because any resistance in the multiplexor will appear as a measurement in the error. Also, any mismatch in the resitances of the switches will affect the 3-wire cancellation (if you're using 3-wire RTDs).

What type of RTD sensors are you using? (2-wire, 3-wire)

What multiplexor are you going to use and how are you going to control the multiplexor settings?

0 Atul Bhakay over 11 years ago in reply to Collin Wells

Genius 3205 points

Hi, Thanks for your reply. However,

We are using 3 wire RTD. In 3 wire RTD is used to cancel the effect of wire resistance even though it is not equal still there is no difference on the reading.

Same principle can be used for MUX.

Now, kindly advise

Regards

Atul Bhakay

0 Collin Wells over 11 years ago in reply to Atul Bhakay

TI__Guru 64495 points

Hi Atul,

Please provide us a basic block diagram of your circuit showing the multiplexor you plan on using and how you plan on controlling it and we will comment on the connections.