Analog

 

http://www.electropages.com/2017/08/texas-instruments-mcus-supported-extensive-ecosystem-reference-designs-code-examples/

Low Power

http://www.eetimes.com/document.asp?doc_id=1332131

http://www.ti.com/lit/an/scha004/scha004.pdf

http://www.linear.com/products/Voltage_Output_DACs

https://electronics.stackexchange.com/questions/28628/why-dont-microcontrollers-generally-have-on-chip-dacs

current-output DACs

http://www.analog.com/media/en/training-seminars/tutorials/MT-019.pdf

I2C/SPI interface to external DAC

https://www.maximintegrated.com/en/app-notes/index.mvp/id/3439

https://books.google.com/books?id=CB9GaAU1dwsC&pg=PA323&lpg=PA323&dq=pic+dacs&source=bl&ots=Hia7z5wybf&sig=jcu-4YYO7K09dnobm__T7C-atdg&hl=en&sa=X&ved=0ahUKEwjt05PosMrVAhVhHGMKHaPNAP8Q6AEIZzAJ#v=onepage&q=pic%20dacs&f=false