Patent ID: 6448842
Filing Date: 2002-09-10
Classification: H02M

Abstract:
A voltage boosting device, comprising: a phase generator stage generating phase signals, and a charge pump circuit having an input and an output, and phase inputs receiving said phase signals, said charge-pump circuit comprising a plurality of voltage boosting stages cascade connected between said input and said output, each voltage boosting stage defining a first and a second transfer node, connected to a respective adjacent voltage boosting stage, each voltage boosting stage comprising:a storage capacitor with a first and a second terminal, said first terminal of said storage capacitor receiving a first one of said phase signals, and said second terminal of said storage capacitor being connected to said second transfer node; a switch element formed by an NMOS transistor having a first and a second conduction terminal and a control terminal, said first and second conduction terminals connected respectively to said first transfer node and to said second transfer node; a voltage boosting capacitor, having a first terminal receiving a second one of said phase signals, and a second terminal connected to said control terminal of said switch element; a first precharge circuit connected between said first transfer node and the control terminal of said switch element, so as to control charge transfer from said first transfer node to said second transfer node; said first precharge circuit comprising an activation terminal receiving a first activation signal, and said charge pump circuit additionally comprising a second precharge circuit, connected between said second transfer node and said control terminal of said switch element so as to control charge transfer from said second transfer node to said first transfer node, said second precharge circuit having an activation terminal receiving a second activation signal, said first and second activation signals never being active simultaneously.