AD74413 internal voltage reference.

Question

AD74413 internal voltage reference.

Is it possible to use an internal voltage reference or is it desirable to use an external one?
And what are the disadvantages of an internal voltage reference?

Best regards, Dmitry

APavlik · Accepted Answer

Hi Dmitry, 
 thank you for your question. 
 Yes, it is possible to use internal reference, the REFIN pin must be tied to the REFOUT pin. Decoupling is also recommended due to noise. (See datasheet for more details www.analog.com/.../AD74413R.pdf) 
 Please know, any error in reference used will correspond to gain error in various analog IO function. If you want to use internal reference, you have to consider accuracy specification of internal reference and take into account the effects it will have on IO. 
 For example, our Evaluation board (EVAL-AD74413R) uses companion product 2.5 V ADR4525 reference, which gives better accuracy to final solution, than internal reference only. 
 I hope this answers your questions, if not feel free to get back to us. 
 Best regards, 
 Arnost)