Memory cell power scavenging apparatus and method
First Claim
1. A system for efficiently using standby current in a system, comprising:
- a single power supply having first and second voltage level outputs;
a memory circuit coupled to one of said voltage level outputs to receive standby power in a deaddressed state;
a common bias supply bus connected to receive standby current from said memory circuit, said common bias supply bus having a voltage level between said first and second voltage level outputs; and
at least one second circuit connected to said common bias supply bus such that at least some of the standby current of said memory circuit may flow through said second circuit to provide a portion of the current required to operate said second circuit.
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Accused Products
Abstract
The present invention utilizes the power available for application to a static RAM cell in a manner which provides efficient use of the power so that greater standby power may be applied to the static RAM to increase the memory speed. The current required to maintain the memory cell in a preset state flows from the Ucc source through a row of parallel memory cells and through a common bias supply and various peripheral circuits, such as decoders. A shunt voltage regulator controls the dependence of the common bias supply voltage on current fluctuations caused by addressing and deaddressing the memory cells. The invention includes an isolation device for isolating a particular row of memory cells when it is addressed without disturbing the bias on other memory cell rows. Similarly, the reference voltages of each of the peripheral circuits can be made independent of the common bias supply voltage and independent of the other peripheral circuits by the use of a local voltage regulator on each peripheral.
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Citations
22 Claims
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1. A system for efficiently using standby current in a system, comprising:
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a single power supply having first and second voltage level outputs; a memory circuit coupled to one of said voltage level outputs to receive standby power in a deaddressed state; a common bias supply bus connected to receive standby current from said memory circuit, said common bias supply bus having a voltage level between said first and second voltage level outputs; and at least one second circuit connected to said common bias supply bus such that at least some of the standby current of said memory circuit may flow through said second circuit to provide a portion of the current required to operate said second circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. An apparatus for more efficiently utilizing the standby current in a system, comprising:
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a single power supply for providing a single voltage level output relative to a reference voltage level; a first subsystem coupled to draw operating current from said power supply and operating over a first voltage range within the range of voltage between said single voltage level output and said reference voltage level; a common bias supply bus coupled to said first subsystem to receive said operating current; and a second subsystem operating over a second voltage range within the range defined by said single voltage level output and said reference voltage level, said second subsystem being coupled to said common bias supply bus to draw operating current therefrom. - View Dependent Claims (17, 18, 22)
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19. A method for supplying standby current from a power source to a static random access memory, comprising the steps of:
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passing standby current through a deaddressed memory circuit to a common bias supply bus; and passing at least part of said standby current from said memory circuit through a circuit coupled to said common bias supply bus. - View Dependent Claims (20, 21)
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Specification