we use DAC8564, DAC8562 and DAC7564 in several configuration:
- with external Reference LM41440 1.024 V or internal reference and Vref_L to GND
- IOVDD and AVDD 3,3 V with recommended filter
There is no way to output voltages below approx. 1 mV when input is 0x0000h. The specific value depends on measured channel and DAC. Same happens after power-on without any connection to microcontroller or additional components. For example with DAC8564IBPW there is no useful output below 0x51h.These value seems much higher than given in datasheets.
For ongoing projects, we search for DAC with similar performance but "more rail-to-rail" functionality (e.g. 0.1 mV when using internal reference)..
Any idea will help.