AD6676 : Getting error message as unrecognized chip

Hello,

Seems that problem may be related to SPI readback.  Make sure that you have configured the device for 4-wire (default) or 3-wire readback.

One should verify that a particular register like 0x0106 can be written and readback from properly.  If required. I probe CS, SCLK, SDIO, and SDO (if used) with o'scope to see that proper instruction is being written to AD6676 and also readback.

Hi,

We have two boards. In that, we are observing this issue in only one board. In other board we are getting proper CHIP_ID = 0xBB. Our doubt is that at what scenarios we will get the 0xff from AD6676

Hello,

Good to know that one of the boards is working hence issue is likely not related to the software instruction/data cycle when communicating to the AD6676 device.   Considering the package is WLCSP with 0.5 mm ball pitch, perhaps the issue is related to poor solder connection to the SPI related pins or even the VDDIO supply that powers the CMOS I/O's. To debug...........try measuring the resistance of these pins for the working and non-working board (board unpowered) to see if a difference exists.  This may help indicate what pin may have poor connection.