DAC8560 Liner Output Voltage

Hi Simon,

Please find below my comments on your schematics:

1. I don't think you need Q10 for the /SYNC signal. You can directly control the pin from a uC
2. Please use 1uF and 0.1uF for the decoupling instead of 100pF
3. R8 is not required as the output amplifier itself has the feedback resistor. However, if you want to keep it as an option to have a gain that is slightly more than 1, you can keep it
4. The PI controller at the output of the DAC looks fine from an architecture point of view. However, you need to simulate it in order to set the resistor and capacitor value correctly depending on the settling behavior you need
5. As you are sensing the voltage drop across the sense resistor R82, which can be very close to ground the opamp may not be operating in the linear region. You can refer the following TI Design for the right power supply configuration:

www.ti.com/.../tidu040b.pdf

6. In general, try to avoid the Meg Ohm resistors from the opamp circuits. They can be big contributors of thermal noise and offset errors due to bias current
7. You can generate the set-point from the DAC using the DXP software and MMB0 motherboard for your testing. I am assuming you would use another controller for the actual system

Hope this answers your questions. Please let me know if you need any further support.

Regards,
Uttam