schematic eval board-ad7982 -pmdz, schematic error ' EVAL-AD7982-PMDZ schematic.pdf)

Question

Good morning, 
I have just received my evaluation board AD7982-pmdz but the schematic (eval-AD7982-pmdz schematic) on the analog device website is not correct, the VIO (pin10 U3) of the converter is not connected to the VCC_PMOD , therefore the ADC interface digital SPI is not compatible (digital SPI) with the HOST.
I don't understand this difference between the AD board and the AD schematic (picture bellow). Could you send me the good schematic, Regards,

NathanT · Accepted Answer

Hi bbertrand , 
 Based on your feedback from the evaluation board, we have checked the layout for EVAL-AD7982PMDZ and we saw that the capacitors, C17 and C29, from U3 (that is connected to VIO PIN) is connected to the pins for the VCC_PMOD, which is from the connector for SPI PMOD INTERFACE, TSW-106-25F-D-RA. Thus, the VIO pin from U3 has a connection to VCC_PMOD. You can use the images attached below as your reference. 
 The Violet box highlights the U3, AD7982. Green box signifies the common ground for capacitors, C17 and C29. Lastly, the blue box signifies that C17 and C29 has connections to the VIO pin of U3; also, the blue line from the highlighted pins of the capacitors signifies that it has connections to VCC_PMOD, Pins 6 and 12. So aside from the layout given, here are some ways to check if the VIO pin from U3 is connected to the VCC_PMOD: 
 
 You can do a continuity test from the pins of capacitors C17 and C29 to the pins 6 and 12 of the SPI PMOD INTERFACE. 
 You can check the voltage across C17 and C29, to the voltage across pins 6 and 12 of the SPI PMOD INTERFACE, with respect to ground. The voltage across these pins will be depending on the voltage supply from the host interface. Please see the attached image below. 
 
 Let me know if the following feedback will be a help to you, so that I could further assist you. Regards, Jo

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schematic eval board-ad7982 -pmdz, schematic error ' EVAL-AD7982-PMDZ schematic.pdf)

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