Other Parts Discussed in Thread: OPA4188,
Dears
We need 4-20mA output, and designed this schematic. The solution is OPA4188+DAC8565. Can you kindly help me review it?
Looking forward to your reply.
Thanks
Elsa Duan
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Dears
We need 4-20mA output, and designed this schematic. The solution is OPA4188+DAC8565. Can you kindly help me review it?
Looking forward to your reply.
Thanks
Elsa Duan
Hi,
In DAC section, you can ground Vref_L if you are not intended to drive the Vref_L input.
As I understand from the post, you want to generate 4-20mA output corresponding to what range of DAC output voltage?
I assume100 ohms acting as the sense resistor here. if that's the case the voltage across the sense will be a replica of input itself.
Current through 100ohms will be Vinput/100.
You may need to add offset to get 4mA when your DAC input is at 0V. If your intention is to design a loop powered transmitter, we have lot of reference designs available to help, or you can have a look at XTR devices.
https://www.ti.com/product/XTR117?keyMatch=XTR117&tisearch=Search-EN-everything&usecase=GPN
Regards,
AK