US 4,731,552 AGranted

Boost signal generator with bootstrap means

AssigneeMitsubishi Denki Kabushiki Kaisha

InventorTakayuki Miyamoto

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Abstract

A boost signal generating circuit providing a higher boosted voltage in a shortened time period but with minimum power consumption. The boost signal generating circuit includes a boosting circuit including first and second MOS transistors, a capacitor and a charging device, a dynamic inverter circuit including third and fourth MOS transistors, a boost potential generator circuit, and a fifth MOS transistor having a source serving as a boost signal source. The fifth MOS transistor is turned on by a charging current supplied by the charging device to thus raise its source potential, while simultaneously the dynamic inverter circuit is actuated to actuate a boostrap circuit, thereby to raise its output voltage and hence reduce the on resistance of the fifth MOS transistor, resulting in a boosted signal at a potential near the output voltage of the boost potential generator circuit.

Claims5

Dependent claims

A semiconductor boost signal generator circuit, comprising:

boost potential generating means for providing at an output node thereof an output voltage V.sub.p higher than a source voltage;
an MOS transistor for producing a signal to be boosted, said MOS transistor having a gate electrode, a first main electrode connected to said output node of said boost potential generating means, and a second main electrode connected to a load capacitor;
bootstrap control means having at least one input node connected to said second main electrode of said MOS transistor and an output node whose potential varies from a first level to a second level when a potential of said second main electrode of said MOS transistor becomes equal to or greater than a predetermined level;
and bootstrap means having an input node connected to said output node of said bootstrap control means and a bootstrap output node connected to said gate electrode for producing at said bootstrap output node an unboosted signal at a potential enabling said MOS transistor to be turned on, and for boosting the potential of said signal when said output node of said bootstrap control means assumes said second level.

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Dependencies are inferred from the claim text.