Backup power system for dynamic memory
First Claim
1. Apparatus for continuously supplying DC power to a dynamic memory said apparatus comprising:
- a DC/DC converter connected to said dynamic memory, wherein said DC/DC converter supplies regulated DC power to said dynamic memory to maintain a bit pattern stored in said dynamic memory;
a main DC power supply connected to said DC/DC converter, wherein said main DC power supply supplies input power to said DC/DC converter;
a backup DC power supply to backup the power supplied to said DC/DC converter by said main DC power supply;
a power down detector circuit for detecting when input power to said DC/DC converter is below a predetermined level, wherein an input power level for said DC/DC converter that is below said predetermined level prevents said DC/DC converter from supplying sufficient DC power to said dynamic memory to maintain said bit pattern stored in said dynamic memory;
means coupled to said power down detector circuit for immediately supplying backup power from said backup DC power supply when said input power from said main DC power supply is interrupted; and
means for automatically disconnecting said backup DC power supply when the input power for said DC/DC converter falls below said predetermined level.
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Accused Products
Abstract
A power supply system for a dynamic memory includes a main power supply, a backup power supply and a power down detection circuit which are all connected in parallel across the input of a DC/DC converter. In turn the DC/DC converter supplies regulated power to the dynamic memory. On interruption of the main power supply, the backup supply provides input power to the DC/DC converter only as long as the power sensed by the power down detection circuit is adequate for the DC/DC converter to maintain a bit pattern stored in the dynamic memory. On sensing inadequate input power to the DC/DC converter the backup supply is automatically disconnected.
52 Citations
13 Claims
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1. Apparatus for continuously supplying DC power to a dynamic memory said apparatus comprising:
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a DC/DC converter connected to said dynamic memory, wherein said DC/DC converter supplies regulated DC power to said dynamic memory to maintain a bit pattern stored in said dynamic memory; a main DC power supply connected to said DC/DC converter, wherein said main DC power supply supplies input power to said DC/DC converter; a backup DC power supply to backup the power supplied to said DC/DC converter by said main DC power supply; a power down detector circuit for detecting when input power to said DC/DC converter is below a predetermined level, wherein an input power level for said DC/DC converter that is below said predetermined level prevents said DC/DC converter from supplying sufficient DC power to said dynamic memory to maintain said bit pattern stored in said dynamic memory; means coupled to said power down detector circuit for immediately supplying backup power from said backup DC power supply when said input power from said main DC power supply is interrupted; and means for automatically disconnecting said backup DC power supply when the input power for said DC/DC converter falls below said predetermined level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for continuously supplying DC power to a memory, said method comprising the steps of:
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supplying regulated power to said memory from a main DC/DC converter; supplying DC input power to said DC/DC converter from a main DC power supply; supplying backup power from a backup DC power supply when said input power from said main DC power supply is interrupted; detecting when the input power to said DC/DC converter is below a predetermined power level, wherein an input power level for said DC/DC converter that is below said predetermined level prevents said DC/DC converter from supplying sufficient DC power to said memory to maintain a bit pattern stored in said memory; terminating said backup DC power supplied from said backup DC power supply when the input power to said DC/DC converter falls below said predetermined level. - View Dependent Claims (10, 11, 12, 13)
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Specification