Hi，I'm using cy68013-56pvxc on my circuit  board with a MAXIM1316 analog-digital chip.I separate the AGND and DGND net and connect them together with a 0 ohm resisitor.recently i have received my circuit board and have check it that everything is ok.But After I welded cy68013-56pvxc on board (no other component on board)i found that the AGND and DGND was connected.I check the single chip and the board carefully and nothing is wrong except that pin 13 and pin 17 were not internally connected(the datasheet declares that these two pins are all AGND pins).My circuit is attached below.Please help me.

 Hi,

  Yep, these two pins are AGND pins but it doesn't mean they are internally connected(they are not internally connected).The designation "AGND" on these pins indicates that they should be connected  to ground with as short a path as possible.

Thanks

Prajith

 Hi,

  Yep, these two pins are AGND pins but it doesn't mean they are internally connected(they are not internally connected).The designation "AGND" on these pins indicates that they should be connected  to ground with as short a path as possible.

Thanks

Prajith

 thank you for the answer!and could you explain why agnd net and dgnd net are connected after the chip is welded onto the board?I have check the single board and single chip and everything is ok.I'm really confused.

 Hi,

   In mixed signal designs we physically seperate sensitive analog components from noisy digital componets. This is achieved by keeping AGND and DGND planes seperate and connecting them directly to Ground reference point. We treat AGND and DGND seperately, however, ultimately they are connected to a single GND reference point.

Thanks

Prajith