First of all - sorry for my grammar, English is not my native language.
I'm in the middle of component choosing for my new DAC project and I need help with voltage regulators.
My project will have 3 separate voltage sections - one for digital part 3.3V ( I'm thinking about ADM7155), one for powering TCXO (ADM7155 again, 3.3V) and last one for analog side of a DAC (5V, better option is 5.5V) - here I would like to use ADM7150 but I'm worried about its stability. Each section will be powered from separate battery.
I have done little research on the web and supposedly there is a stability issue with ADM7150, also I have negative opinions from my friend who said to me, that it's hard to implement this IC correctly.
My question is - if I use similar board layout to that from the datasheet recommendation, should I run into possible problems with powering a DAC?
There are 4 power pins on analog side of a DAC, decoupling is done with 0.1uF NP0 + 10uF tantalum each, then after that there is 100uF electrolytic capacitor. Is this environment suited for ADM7150 or should I use different voltage regulator (if so - which one)?
Thank You kindly for Your help.
Thank for your questions.
ADM715x are world class ultralow noise LDO family for RF signal devices. Stability is guaranteed by 10uF output ceramic capacitor. Please refer the data sheet in detail. If the input voltage is from a switching regulator, adding some ferrite bead will help to attenuate the noise at times of switching frequency.
Please see the attached image. As long as the equivalent ESR of the output capacitive network does not exceed the datasheet recommendations, you can use tantalum capacitor. Let me know if you have more questions.