ADS124S08: Schematic Review for ADS124S08IPBSR

Hi XJ,

Seem my responses below:

XJ said:

Part Number: ADS124S08

HI,

I do have customer would like to to use  ADS124S08IPBSR into thier project and possible help to review the schematic ? [BB} We can help with schematic reviews.

Meantime ,possible help to advise for the below?

1.         All Sensors input are analog Single-End

2.         Do we need to "Buffer" the analog signal before coming to ADS124S08? [BB]  This is difficult to say without knowing more specific information regarding the sensors.  The ADS124S08 does have a pre-charge buffer that will be a sufficient buffer for most applications when bypassing the PGA.

3.         How do we design "Full-Scale" 24-bit with  Single-End signal input and uni-polar AVDD?  [BB]  This may not be the right question to ask as due to noise you most likely will not be able to achieve all 24 bits.  Full-scale range relates specifically to the reference voltage  used (+/-Vref).  If the measurement is made relative to AGND, than you will only see a maximum of 23-bits (+ full-scale) as you would not be able to make a measurement in a negative direction.  If due to noise the best resolution is 22 bits, then capturing that extra bit is inconsequential.  You could also make the measurement pseudo-differential by comparing to a voltage not AGND.  See section 10.1.4 on page 88 of the ADS124S08 datasheet.

4.         Is there any note for code programming? only by-pass PGA?  [BB] We do not have a specific application note for use while bypassing the PGA.  Information in the ADS124S08 datasheet should be sufficient, or you can ask specific questions here.  Configuration for single-ended operation with the PGA bypassed is the default setting in the Gain Setting Register (0x03).