I am doing a project on portable 12 lead portable ecg device. We have to use raspberry pi or arduino to implement the application. We are considering ADAS1000 to do so.
As a minimum, you will need to provide supplies for AVDD and IOVDD. As you know ADCVDD and DVCC can be supplied from on chip regulators.
The evaluation board was designed to operate primarily from a +5V incoming supply (to suit the wall adaptor that was supplied with the board), that +5V rail goes through the buck-boost ADP2503 to provide a regulated 5V rail that feeds 2x ADP151 LDOs which provide 3.3V for AVDD and 3.3V for IOVDD (note IOVDD can run lower supply, the minimum 1.65V). The ADP151 were chosen because of their low noise performance.
The ADP2503 can accept lower voltages, 2.3V min. What kind of battery are you planning to use? what range of voltage do you expect?
There may also be power solutions from the Analog Devices/Linear portfolio that could also be suitable here.