Hello,
My customer used DAC8775 and in system one more device are connected to same SPI interface of processor. Now customer found during SYNC=1 of DAC8775, which shall disable SPI of DAC8775 and SDO of DAC8775(pin24) shall be high-impedance(as datasheet), the SDO is actually not high-impedance and influenced the SPI network level.
As below circuit, DAC8775's SDO(SPI_MISO_DA) is connected to ISO7241's P11(and another SPI line SPI_MISO_AD) through R100. During SPI disable of DAC8775, the SPI_MISO_AD level was forced to 2.8V(it shall be 5V in theory). If removed this R100, then the level change to normal 5V.
