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How to power an opamp(with -5v) form USB? Answered

I`m making a dac+amp with usb input and headphone out. I`m powering it from USB. The USB controller and the DAC uses 5v and 3.3V, but the opamp(LM4562) uses +-5v. How could I get this differential voltage form the 5V of the USB, even if i get less current.
If you can give me a good IC, it would be great, but if you can give me even a schematic (+IC) would be awesome.


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8 years ago

Look at single-supply circuits, you probably don't need to go bipolar supply.

Here, you are dealing with AC signals, which means that you can capacitively couple your signals in and out of the amp. Bias the +ve input with a resistive divider, or better, a resistive divider followed by a voltage follower.

Bear in mind, this amp is not rail to rail inputs OR outputs, so design accordingly.

If, at the end of the day, you really HAVE to go to bipolar supplies, you can readily buy DC-DC converters for the job. They TEND to be noisy for analogue work, and you'll realy need to filter them well.