Multi-stage charge pump voltage generator with protection of the devices of the charge pump

A method of protecting low-voltage transistors of a positive voltage multi-stage charge pump from abrupt variations of the output voltage upon coupling a load to the charge pump, the method comprising:

• connecting an output high-voltage PMOS transistor between an output node of the positive voltage multi-stage charge pump and the load;
• and
• controlling the output high-voltage PMOS transistor based upon a voltage present on a connection node between two stages of said positive voltage multi-stage charge pump.

A boosted voltage generator for connection to a load, comprising:

• a negative voltage multi-stage charge pump including at least two stages with a connection node therebetween, and generating a boosted negative voltage on an output node;
• and
• an output high-voltage NMOS transistor having conduction terminals connected between the output node of said negative voltage multi-stage charge pump and the load, and having a control terminal connected to the connection node between the at least two stages of said negative voltage multi-stage charge pump.

A method of protecting low-voltage transistors of a negative voltage multi-stage charge pump from abrupt variations of the output voltage upon coupling a load to the charge pump, the method comprising:

• connecting an output high-voltage NMOS transistor between an output node of the negative voltage multi-stage charge pump and the load;
• and
• controlling the output high-voltage NMOS transistor based upon a voltage present on a connection node between two stages of said negative voltage multi-stage charge pump.