Semiconductor booster circuit having cascaded MOS transistors

A semiconductor booster circuit having MOS transistors connected in cascade, comprising:

• a plurality of stages each having a first MOS transistor, a second MOS transistor, a first capacitor having one terminal that is connected to a drain of said first MOS transistor, and a second capacitor having one terminal that is connected to a drain of said second MOS transistor;
• wherein
• in each of said stages, said first and second MOS transistors are connected in series to constitute a plurality of series circuits;
• said series circuit that are constituted in said plurality of stages, respectively, are connected in series between input and output sides of said plurality of stages;
• a voltage is directly applied to the drain of said first MOS transistor in the stage closest to said input side so that said voltage is boosted by said first and second MOS transistors in each of said stages thereby generating a boosted voltage, which is higher than said voltage, at the source of said second MOS transistor in a stage closest to said output side;
• said plurality of stages are divided into at least two groups;
• said first and second MOS transistors included in the stages of each group are formed in wells respective that are formed in a semiconductor substrate;
• and
• electrical potentials respectively applied to said wells in said groups are distinct from one another;
• a third capacitor having one terminal connected to a gate of said first MOS transistor;
• a fourth capacitor having one terminal connected to a gate of said second MOS transistor;
• a third MOS transistor connected between the gate and a source of said first MOS transistor, and having a gate connected to the one terminal of said first capacitor;
• and
• a fourth MOS transistor connected between the gate and source of said second MOS transistor, and having a gate connected to the one terminal of said second capacitor.

A semiconductor booster circuit, comprising:

• a plurality of stages each having a MOS transistor and a capacitor, said MOS transistor being formed in a well and having a drain, a source and a gate, and said capacitor having one terminal connected to the source of said MOS transistor;
• wherein said plurality of stages are connected in series by connecting said MOS transistor of said plurality of stages in cascade;
• a voltage is directly applied to the source of said MOS transistor in a stage closest to an input terminal so that said voltage is boosted by said MOS transistor in each of said plurality of stages thereby generating a boosted voltage, which is higher than said voltage, at the drain of said MOS transistor in a stage closest to an output terminal;
• wherein in each of said plurality of stages, the source of said MOS transistor is directly connected to the gate of said MOS transistor and the well in which said MOS transistor is formed;
• and
• wells of said plurality of stages are electrically insulated from each other.