I am using AD5445 to generate output voltage 0-1.25V from a single 5V supply.
I literally implemented circuit from the figure 51.
Vin is supplied from ADR391 (2.5V voltage reference), the bias voltage is exactly 1/2 of the Vref.
My output buffer is designed with LTC6078.
I expected to have 1.25V on the output if the code written into dac is 0x0000, and I expect to have 0V if 0x0FFF is written into the DAC.
If nothing is written I expect to have 1.25V. I am able to read what I wrote into DAC.
The problem is that I always have 11mV on the output of the circuitry.
I checked CCA few times, all voltages are at the correct level,
The design is done correctly on 6 layers board and assembled and tested by the board house.
Is the problem caused with my usage of LTC6078? Should I switch to AD8066 since the package is the same?
I found and resolved the problem,
It wasn't AD5445
It wasn't LTC6078
It wasn't OP2177
Assembly house rotate two resistors and effectively short two grounds, but it wasn't completely short, it was just enough to mess-up things,
THANK YOU FOR HELP AND SUPPORT