Charge Pumping via CMOS?

[idlefaction]

Hi all

I have a box with a 5V regulated supply, I want to pump it up to 12V or more to run an AD633 in the same box.

Normally I'd just use a MAX1044 but I happen to have two spare inverters on a 4069UBE in the same box...  is there some way of using those?  I had a look at the PAIA stack-in-a-box 4049 charge pump but it uses five inverters and I only have two :-)

Any help appreciated!

[toneman]

Using a 4049, like the PAIA SIAB, is not a "charge pump".
A ChargePump shuffels the charges on capacitors.
Can Either 1/2 a voltage or double it.
Main point bout chips like the MAX1944---NO inductors!!
The Inverter "pump", 4 lack of better name,
"could" work with just 2 inverters in parallel.
Depends on how much current U need.
That's why the SIAB uses 5 in parallel.
Try same technique with 2.  Why not??
There always the 555doubler.
google 4 it.
Or just use the left over inverters to blink some LEDs

[Paul Perry (Frostwave)]

True, you can't make a true charge pump from that.
You could make a square wave oscillator, feed the output to a voltage multiplier rectifier stack.. but I doubt you would get an output that had low enough impedance, and that was smooth enough. I think the AD633 is a bit thirsty. Well, 6ma, I see on the sheet, not that much!

[Zero the hero]

Check the "Super Octaver" project at Mark Hammer site: there's a DC/DC CMOS converter. Don't know if it will be useful, but his could be a starting point.

[Peter Snowberg]

The term for this inverter circuit is a "voltage multiplier".