How to keep galvanic isolation with in the system. LTC2984

Question

PDF PDF 
 As per File: without spi isolator.pdf 
 1) Use one DC-DC to generate 3.3V_AGND with ground labeled as AGND. 
 2) Use second DC-DC to generate 3.3V_DGND with ground labeled as D GND. 
 3) This configuration is simple and my component count is also less. 
 Now my question is that Is galvanic isolation present between Micro_controller and LTC2984? 
 As per File: with spi isolator.pdf 
 1) Use one DC-DC to generate 3.3V_AGND with ground labeled as AGND. 
 2) Use second DC-DC to generate 3.3V_DGND with ground labeled as D GND. 
 3) In this place another component spi isolator for galvanic isolation 
 Now my question ..is first configuration ok? or I have to use second one ? My priority is galvanic isolation.

LoganC · Accepted Answer

Hi Syed Abbas 
 The LTC2984 does not provide any isolation from the analog inputs to the digital. Therefore your first proposal does not provide galvanic isolation. Further, you will need to make sure you are using an isolating DC-DC converter topology. 
 Take a look at the LTM2883 SPI isolator, it can isolate SPI from the microcontroller and also provide enough power to supply the LTC2984 on the isolated side. 
 -Logan)

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How to keep galvanic isolation with in the system. LTC2984