Oh, in that case it will draw pretty much no current. You could do the same thing with a smaller, cheaper device, but the 2n2222a will be fine. I don't know if there's a MUX that can run from 2.7V signals but it would be worth a look to reduce parts count.Edit: Actually, I am looking at the datasheet for the 74HC4051, and you can power this IC from 2.7V and use just the MCU to drive the input selector pins. Otherwise, you can use the 74HCT4051 and power it from 5V and still drive with your 2.7V outputs. A high level is over 2.0V max (1.6V typ), and a low level is below 0.8V min (1.2V typ). So, you wouldn't need your 2n2222a afterall.**broken link removed**