Charge Pump Ic. Operating from input voltages ranging from 1 6v to 5 5v the max1759 generates an output either fixed 3 3v or adjustable 2 5v to 5 5v and delivers output currents up to 100ma. Charge pump ic design is an excellent book which not only covers all the aspects of the on chip charge pump design but also illustrates how to approach circuit design.
This configuration makes the boot capacitor a storage capacitor that smooths out the square wave and provides the current to the high sidemosfet. Building a charge pump circuit the circuit shown here is for a simple three stage charge pump that uses the evergreen 555 timer ic. The vt cancellation through parallel structure demonstrates the need based design approach.
Instead they use mosfet switches with low on resistance r ds on.
By eliminating the inductor these switched capacitor converters provide a small solution footprint and a simpler design. In a sense this circuit is modular stages can be cascaded to increase the output voltage with limitation number two in mind. Unlike boost converters charge pump ics can operate without inductors and other external components and require just two capacitors for energy storage. However ic based charge pumps do not use diodes.
