I tried to use the following schematic to set AD5420 working in daisy-chain mode.
When the print circuit board was produced, I wrote driver code to make it work. It seems that the dirver can work properly, because the content of Control Register, readed from the readback operation, is equal to what I set before. At runtime the software sends data to Data Register to Change the output current regularly. However, after the system run some hours, the output currents jump to Zero and the Voltage of the underneath AD5420 chip‘s Pin 2(DVCC) is measured about 1.18V.
Is my design error or else?