I would like to use a charge pump to step up a 1.5V AAA battery to >7V. The charge pump itself is already constructed and works fine when I test it with a 5V input. At this point I'm providing the clock signals using a microcontroller. However, the microcontroller can't operate at 1.5V, and eventually I'd like to power the microcontroller from the output of the pump. I am not sure what would be the best way to provide the two out of phase clock signals that the pump requires. I've had some success constructing a multivibrator using capacitors, resistors and MOSFETs, as shown on p. 16, Fig 1-26 here:
This works fine from a 5V source, but getting it to run successfully from a battery is proving more difficult. I can see that there are various low-voltage multivibrator ICs available, but these are pretty big and seem like overkill for such a simple application.
So, how would one usually go about providing the clock signals for a low input voltage charge pump?