power supply battery 9V to output +9V Gnd -9V

The MAX1044 is a charge pump converter - it uses a capacitor as a “bucket” to pump charge from one place to another. In this case, the 1044 connects the + terminal of C1 to +9V from the battery and its negative terminal to ground. C1 charges up to 9V from the battery. The 1044 then connects the + terminal of C1 to ground, and the - terminal to pin 5. This lets C1 dump the charge into C2. The - terminal of C2 is tied to pin 5, so it gets a negative voltage equal to the voltage across C1.

This charge pumping is a very efficient way to convert voltages. The only power lost is that power dissipated in the resistances of the switches inside the 1044 and the series resistance of the capacitors, as well as the power to run the internal oscillator that flips the switches when needed.

Read More Source : http://www.geofex.com/circuits/+9_to_-9.htm

This entry was posted on Sunday, July 29th, 2007 at 2:53 pm and is filed under Power supply, switching power supply. You can follow any responses to this entry through the RSS 2.0 feed.