Quote Originally Posted by mackrackit View Post
That is a difficult one to answer.
The VDIP requires 5 volts. Four re-chargeable "AA" batteries will give ~4.8 volts, close enough but for how long.
Be cautious with your battery types here... 4 NiCad AA's will give about 4.8v, but 4 rechargeable ALKALINE AA's can give over 5.6V +

For linear regulators, these aren't too bad...
http://ww1.microchip.com/downloads/e...Doc/21991c.pdf
Only a couple hundred mV dropout voltage, so they work OK on 5 v circuits from a 6v battery.

You may want to use a switching regulator. Could have one that works with a battery input from 3 to 6 volts, then four "AA" batteries of any type will work. Depending on the circuit the efficiency can be very good.
If you need to run off a wide supply range, including sucking batteries down "to the last drop" then a good switching supply is THE way to go....


steve