Power supply circuit for a data processor
First Claim
1. A power supply circuit for a data processor to which a data input circuit is connected, operation of the data input circuit providing an input to the data processor, the power supply circuit including a power up circuit that is latched on responsive to the operation of the data input circuit and when latched on supplies power from a power source to the processor, the power up circuit comprising a single pair of complementary transistors arranged so that an output electrode of each transistor is connected to an input electrode of the other transistor, a first of the transistors having its third electrode adapted to be connected to the power source, and the second transistor having its third electrode connected to the power input of the data processor, the operation of the data input circuit completing a path from the input electrode of the first transistor to a point that is essentially at a common reference potential to latch the power up circuit on.
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Accused Products
Abstract
In order to extend battery life when batteries are used and to conserve energy when commercial power is used, it is highly desirable that power not be applied to a data processor when it is not operating. A power supply in accordance with the present invention includes a power-up and supply subcircuit (100) that applies power to an associated data processor (500) when a data input circuit (700) is operated to select a particular operation of the processor. When the processor completes its operation, it provides an output signal to a power-down subcircuit (200) of the power supply which then removes power from the processor.
134 Citations
12 Claims
- 1. A power supply circuit for a data processor to which a data input circuit is connected, operation of the data input circuit providing an input to the data processor, the power supply circuit including a power up circuit that is latched on responsive to the operation of the data input circuit and when latched on supplies power from a power source to the processor, the power up circuit comprising a single pair of complementary transistors arranged so that an output electrode of each transistor is connected to an input electrode of the other transistor, a first of the transistors having its third electrode adapted to be connected to the power source, and the second transistor having its third electrode connected to the power input of the data processor, the operation of the data input circuit completing a path from the input electrode of the first transistor to a point that is essentially at a common reference potential to latch the power up circuit on.
- 11. A power supply circuit having a data processor and volatile memory, the power supply circuit including a subcircuit for supplying power to the memory, the memory supply subcircuit providing sufficient power to sustain the memory but not enough power to operate the memory when the processor is not in operation, and a subcircuit for supplying power to the processor, the processor supply subcircuit providing no power to the processor when the processor is not in operation, the processor supply subcircuit being responsive to an input to the processor for providing power to the processor and for increasing the power supplied by the memory supply subcircuit to a level sufficient to operate the memory.
Specification