Sequence circuit and semiconductor device using sequence circuit
AssigneeFujitsu Limited and Kabushiki Kaisha Toshiba
InventorsAtsushi Takeuchi, Masaharu Wada
Life of this patent
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Abstract
A semiconductor device includes a word line that is reset to a negative voltage when the word line is unselected. The semiconductor device further includes a sequence circuit that clamps the word line to a first fixed voltage, until a fixed power-supply voltage that is supplied to a memory cell connected to the word line reaches a second fixed voltage, at a time of starting power supply. Thus, the semiconductor device can prevent a negative power-supply voltage used for resetting the word line from rising, and can reduce consumed energy.
Claims7
A sequence circuit that controls a start-up order of a power-supply circuit, comprising:
- a first circuit that detects a first power-supply voltage charging a capacitor of a memory cell or a bit line;
- a second circuit that clamps a second power-supply voltage resetting a word line, to a first fixed voltage, until said first power-supply voltage reaches a second fixed voltage;
- and
- a third circuit that cancels clamping said second power-supply voltage after said first powersupply voltage reaches said second fixed voltage, and, then, generates said second power-supply voltage.
A semiconductor device, comprising:
- a word line that is reset to a negative voltage when said word line is unselected;
- and
- a sequence circuit that clamps said word line to a first fixed voltage until a fixed power-supply voltage supplied to a memory cell reaches a second fixed voltage, at a time of starting up power supply.
Dependencies are inferred from the claim text.