A few months back I designed and tested a DAC based around the PCM5102A by TI. Ever since I've been using it with my JDS Labs CmoyBB amp and it sounds quite wonderful, but I'm not a fan of carrying both DAC and AMP around constantly. Thus I've been working on expanding the DAC PCB to also include a cmoy amp section. The actual amp is complete, I just need to find a way to power it. I could go with the classic 9V battery and TLE rail splitter, but since this will always be used with a desktop computer, having a battery on-board would be an inconvenience. What is a nice way to get roughly +-4.5 V for use with an OPA2227 or similar amp off of the 5V USB VCC? Here is what I had in mind:
1) Inverting charge pump followed by a LDO reg for the (-) rail and then just an LDO reg for the (+) rail.
2) This part (LTC3260) http://www.linear.com/product/LTC3260