Question
A board we are producing that uses the ADuM4160 fails during production test.
When comparing the design with an article in Analog Dialog 43-06, june 2009 I noticed that the design of our customer uses10K pull ups for pulling SPU to VDD1 and SPD to VDD2 while in the examplesshown in the article this is a shorted. Could this be the cause of our problems?
Answer
The option is there to connect to gnd or Vddx, as you can see in the ADuM4160eval board schematic, no resistors are used.
Most customers simply tie the lines high. VDD1 to PDEN, and SPU and VDD2to SPD, and PIN and the USB works fine.