Supply voltage generating circuit and semiconductor memory device using same
AssigneeFujitsu Limited
InventorsHiroyoshi Tomita, Shinnosuke Kamata
Life of this patent
Estimating the term…
Abstract
A semiconductor memory device with a supply voltage generating circuit which can fine-tune its output voltages according to the frequency of a given clock signal. A reference voltage generator produces a plurality of different reference voltages. A clock signal receiver accepts a clock signal and supplies it to a period measurement unit for measurement of the cycle period of the given clock signal. A selector selects one of the produced reference voltages according to the clock period measured by the period measurement unit. A supply voltage generator produces a supply voltage corresponding to the selected reference voltage.
Claims11
A supply voltage generating circuit, comprising:
- a reference voltage generator which generates a plurality of reference voltages having different voltage levels;
- a period measurement unit which measures the period of a given clock signal;
- a selector which selects one of the generated reference voltages according to the measured clock period;
- and
- a supply voltage generator which produces a supply voltage having a voltage level that corresponds to the selected reference voltage.
A supply voltage generating circuit, comprising:
- a reference voltage generator which generates a plurality of reference voltages having different voltage levels;
- a selector which selects one of the generated reference voltages according to a given control parameter;
- and
- a supply voltage generator which produces a supply voltage having a voltage level that corresponds to the selected reference voltage.
A semiconductor memory device, comprising:
- a memory unit which stores given data, comprising an input/output interface;
- a reference voltage generator which generates a plurality of reference voltages having different voltage levels;
- a period measurement unit which measures the period of a given clock signal;
- a selector which selects one of the generated reference voltages according to the measured clock period;
- a supply voltage generator which produces a supply voltage having a voltage level that corresponds to the selected reference voltage for use in said memory unit;
- and
- a constant supply voltage source which provides the input/output interface of said memory unit with a constant supply voltage that does not vary with the period of the clock signal.
A semiconductor memory device, comprising:
- a memory unit which stores given data;
- a reference voltage generator which generates a plurality of reference voltages having different voltage levels;
- a selector which selects one of the generated reference voltages according to a given control parameter;
- and
- a supply voltage generator which produces a supply voltage having a voltage level that corresponds to the selected reference voltage for use in said memory unit.
Dependencies are inferred from the claim text.