Single-stage and modular multi-stage clock-booster

A two-stage clock-booster for producing a second boosted clock voltage on a second output node that is a multiple of a supply voltage, the two-stage clock-booster comprising:

• a first stage clock booster for producing a first boosted clock voltage on a first output node that is a multiple of the supply voltage, said first stage clock booster comprising
• a pump capacitor having a first terminal being driven by a first control phase signal, and a second terminal,
• a first switch controlled by the first boosted clock voltage for connecting the second terminal of said pump capacitor to the supply voltage during a charge phase,
• a second switch for connecting the second terminal of said pump capacitor to the first output node during a boosted clock voltage output phase, said second switch having a control node,
• a switching circuit for alternately connecting the control node of said second switch to the supply voltage and to the first terminal of said pump capacitor, said switching circuit being driven by a second control phase signal, and
• a third switch controlled by a third control phase signal for connecting the first output node to a reference voltage during the charge phase;
• a second stage clock booster connected in cascade to said first stage clock booster for producing the second boosted clock voltage on the second output node that is a multiple of the supply voltage, said second stage clock booster comprising
• a pump capacitor having a first terminal connected to the first output node of said first stage clock booster and being driven by the first boosted clock voltage, and a second terminal,
• a first switch controlled by the second boosted clock voltage for connecting the second terminal of said pump capacitor to the second terminal of said pump capacitor of said first stage clock booster during the charge phase, said first switch being connected to a supply node coinciding with the second terminal of said pump capacitor of said first stage clock booster,
• a second switch for connecting the second terminal of said pump capacitor to the second output node during the boosted clock voltage output phase, said second switch having a control node,
• a switching circuit for alternately connecting the control node of said second switch to the supply voltage and to the first terminal of said pump capacitor, said switching circuit being driven by the second control phase signal,
• a third switch controlled by the third control phase signal for connecting the second output node to the reference voltage during the charge phase;
• and
• a generator for generating the first, second and third control phase signals for alternately connecting the respective second terminals of said pump capacitors to the supply voltage and to their respective output nodes, for connecting the first terminal of said pump capacitor to the reference voltage and to the supply voltage of said first stage clock booster, respectively, said generator also
• a) charging in parallel at the supply voltage said pump capacitors of both stages, and grounding the respective output node of each stage,
• b) isolating the respective output node of each stage, and connecting said pump capacitor in each stage to their respective output node so that said pump capacitors are in series,
• c) connecting the first terminal of said pump capacitor of said first stage to the supply voltage when the second boosted clock voltage is being produced on the second output node of said second stage, and
• d) performing in reverse order steps b) and a) for grounding the respective output nodes of each stage.

A multi-stage clock booster for producing on an output node a boosted clock voltage that is a multiple of a supply voltage, the multi-stage clock booster comprising:

• a first stage clock booster for producing a first boosted clock voltage on a first output node that is a multiple of the supply voltage, said first stage clock booster comprising
• a pump capacitor having a first terminal being driven by a first control phase signal, and a second terminal,
• a first switch controlled by the first boosted clock voltage for connecting the second terminal of said pump capacitor to the supply voltage during a charge phase,
• a second switch for connecting the second terminal of said pump capacitor to the first output node during a boosted clock voltage output phase, said second switch having a control node,
• a switching circuit for alternately connecting the control node of said second switch to the supply voltage and to the first terminal of said pump capacitor, said switching circuit being driven by a second control phase signal, and
• a third switch controlled by a third control phase signal for connecting the first output node to a reference voltage during the charge phase;
• a plurality of additional stage clock boosters connected in cascade to each other and to said first stage clock booster, each additional clock booster stage for producing a boosted clock voltage on a respective output node that is a multiple of the supply voltage, each additional stage clock booster comprising
• a pump capacitor having a first terminal connected to the output node of a previous stage clock booster and being driven by the boosted clock voltage produced by the previous stage, and a second terminal,
• a first switch controlled by the boosted clock voltage produced by the previous stage for connecting the second terminal of said pump capacitor to the second terminal of said pump capacitor of the previous stage during the charge phase, said first switch being connected to a supply node coinciding with the second terminal of said pump capacitor of the previous stage,
• a second switch for connecting the second terminal of said pump capacitor to the output node of its respective stage during the boosted clock voltage output phase, and having a control node,
• a switching circuit for alternately connecting the control node to the supply voltage and to the first terminal of said pump capacitor, said switching circuit being driven by the second control phase signal,
• a third switch controlled by the third control phase signal for connecting the output node of its respective stage to a reference voltage during the charge phase;
• and
• a generator for generating the first, second and third control phase signals for alternately connecting the respective second terminals of said pump capacitors to the supply voltage and to the respective output nodes, and for connecting the first terminal of said pump capacitor to the reference voltage and to the supply voltage of said first stage clock booster, respectively, said generator also
• a) charging in parallel at the supply voltage the pump capacitors of all stages and grounding the respective output node of each stage,
• b) isolating the respective output nodes and connecting said pump capacitors to the output node in its respective stage so that said pump capacitors are in series to each other,
• c) connecting the first terminal of said pump capacitor of said first stage to the supply voltage when the boosted voltage is being produced on the output node of a last stage, and
• d) performing in a reverse order steps b) and a) for grounding the respective output nodes.

A method for producing a boosted clock voltage on an output node of a single-stage clock booster, the boosted clock voltage being a multiple of a supply voltage, the method comprising:

• driving a first terminal of a pump capacitor with a first control phase signal;
• controlling a first switch with the boosted clock voltage for connecting a second terminal of the pump capacitor to the supply voltage during a charge phase;
• operating a second switch for connecting a second terminal of the pump capacitor to the output node during a boosted clock voltage output phase;
• operating a switching circuit for alternately connecting a control node of the second switch to the supply voltage and to the first terminal of the pump capacitor, the switching circuit being driven by a second control phase signal;
• operating a third switch controlled by a third control phase signal for connecting the output node to a reference voltage during the charge phase;
• and
• generating the first, second and third control phase signals for alternately connecting the second terminal of said pump capacitor to the supply voltage and to the output node, and for connecting the first terminal of the pump capacitor to the reference voltage and to the supply voltage, respectively.