We are using DAC161S997RGHR in our 4-20mA converter application. We have designed the schematic as per datasheet but we are not getting current output. We have used 51 ohm resistor across DAC output to measure current. As per ohms law we should get 1V across this resistor when current is 20mA and 200mV when current is 4mA. But We are constantly getting 0.85V across this resistor irrespective of any data on SPI bus.
Attached is our schematic. Can you please review and let us know if we are doing it correct.
VP_3.3_A and VP_3.3_D are locally supplied (self powered) and only the current loop is loop powered. Do we need to send GND_D to loop receiver?