Hey, I have to do a PCB for the acquisition of the ECG signal and later I'll have to stack it on a PCB for a independent power supply (other than the digital lab). I wanted to know if someone can give me an ideia about how to do the power supply since I need a +5V and -5V and i'm especially intrigued about the -5V. I was wondering about doing one circuit that would involve a voltage regulator that needs 12,5V and gives 5V like the L7805, but it only works for the positive voltage. Sorry if you don't understand anything, english is not my main language, feel free to ask more things if you need. I'm really not sure what would be a good solution.