Low power consumption electronic circuit
First Claim
1. An electronic circuit comprising:
- a first node adapted to be supplied with a power supply voltage;
a second node;
a step down circuit including a plurality of capacitors and a plurality of switching elements for connecting said capacitors in series during a first time period and in parallel during a second time period, said step down circuit being made receptive of the power supply voltage supplied to said first node thereby to feed out a step down voltage to said second node, said step down circuit including;
a first switching element connected between said first node and a third node and adapted to be periodically turned on;
a first capacitor connected between said third node and a fourth node;
a second switching element connected between said fourth node and the reference potential point of said circuit and adapted to be turned on when said first switching element is not turned on;
a third switching element connected between said fourth node and said second node and adapted to be turned on substantially simultaneously with said first switching element;
a fourth switching element connected between said third node and said second node and adapted to be turned on substantially simultaneously with said first switching element;
a fourth switching element connected between said third node and second node and adapted to be turned on substantially simultaneously with said second switching element; and
a second capacitor adapted to be charged by the voltage which is supplied to said second node;
a voltage detector for detecting that said power supply voltage has dropped to a predetermined value; and
a control circuit made receptive of a detection signal, which is fed out from said voltage detector, for supplying the voltage, which is supplied to said first node, to said second node, said control circuit simultaneously turning on at least said first and fourth switching elements on the basis of the output signal of said voltage detector.
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Accused Products
Abstract
According to the present invention, the voltage of a battery is supplied to an electronic circuit such as a watch circuit through a step down circuit which is constructed of capacitors and switching MIDFETs. The step down circuit performs a current converting operation as well as a voltage converting operation. The operating current of the electronic circuit is reduced by the reduction in the operating voltage of the same. As a result that the operating current level of the electronic circuit is dropped and that the current conversion is performed by the step down circuit, the battery current is relatively largely dropped. The construction thus far described elongates the lifetime of the battery. According to the present invention, therefore, there is provided a circuit which is proper for driving the step down circuit.
23 Citations
31 Claims
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1. An electronic circuit comprising:
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a first node adapted to be supplied with a power supply voltage; a second node; a step down circuit including a plurality of capacitors and a plurality of switching elements for connecting said capacitors in series during a first time period and in parallel during a second time period, said step down circuit being made receptive of the power supply voltage supplied to said first node thereby to feed out a step down voltage to said second node, said step down circuit including;
a first switching element connected between said first node and a third node and adapted to be periodically turned on;
a first capacitor connected between said third node and a fourth node;
a second switching element connected between said fourth node and the reference potential point of said circuit and adapted to be turned on when said first switching element is not turned on;
a third switching element connected between said fourth node and said second node and adapted to be turned on substantially simultaneously with said first switching element;
a fourth switching element connected between said third node and said second node and adapted to be turned on substantially simultaneously with said first switching element;
a fourth switching element connected between said third node and second node and adapted to be turned on substantially simultaneously with said second switching element; and
a second capacitor adapted to be charged by the voltage which is supplied to said second node;a voltage detector for detecting that said power supply voltage has dropped to a predetermined value; and a control circuit made receptive of a detection signal, which is fed out from said voltage detector, for supplying the voltage, which is supplied to said first node, to said second node, said control circuit simultaneously turning on at least said first and fourth switching elements on the basis of the output signal of said voltage detector. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An electronic circuit comprising:
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a first node adapted to be supplied with a power supply voltage; a second node; a first switching element connected between said first node and a third and adapted to be periodically turned on; a first capacitor connected between said third node and a fourth node; a second switching element connected between said fourth node and the reference potential point of said circuit and adapted to be turned on when said first switching element is not turned on; a third switching element connected between said fourth node and a fifth node and adapted to be turned on in synchronism with said first switching element; a fourth switching element connected between said third node and said fifth node and adapted to be turned on in synchronism with said second switching element; a voltage regulator for supplying a predetermined voltage to said second node in accordance with the voltage which is supplied to said fifth node; and a second capacitor connected between said second node and the reference potential point of said circuit. - View Dependent Claims (9, 10, 11)
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12. An electronic circuit comprising:
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a first node adapted to be supplied with a power supply voltage; a second node; a first switching element connected between said first node and a third node and adapted to be periodically turned on; a first capacitor having its one terminal connected with said third node and its other terminal connected with a fourth node; a second switching element connected between said fourth node and the reference potential point of said circuit and adapted to be turned on when said first switching element is not turned on; a third switching element connected between said fourth node and a fifth node and adapted to be turned on in synchronism with said first switching element; a fourth switching element connected between said third node and said fifth node and adapted to be turned on in synchronism with said second switching element; a voltage regulator for supplying a predetermined voltage to said second node in accordance with the voltage which is supplied to said fifth node; a second capacitor connected between said second node and the reference potential point of said circuit; and a charging circuit for charging said first capacitor with such a voltage during a predetermined time period after the power supply is made as is substantially equal to the output voltage of said voltage regulator. - View Dependent Claims (13, 14, 15, 16)
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17. An electronic circuit comprising:
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a first node adapted to be supplied with a power supply voltage; a second node; a step down circuit including a plurality of capacitors and a plurality of switching elements for connecting said capacitors in series during a first time period and in parallel during a second time period, said step down circuit being made receptive of the power supply voltage supplied to said second node;
said step down circuit including a first switching element connected between said first node and a third node;
a first capacitor connected between said third node and a fourth node;
a second switching element connected between said fourth node and the reference potential point of said circuit;
a third switching element connected between said fourth node and said second node;
a fourth switching element connected between said third node and said second node; and
a second capacitor adapted to be charged in accordance with the voltage which is supplied to said second node;a clock generator adapted to be operated by the voltage, which is supplied to said second node, thereby to feed out clock pulses for switching said switching elements, said clock generator being made operative to generate at least both a clock pulse for simultaneously turning on said first and third switching elements and a clock pulse for simultaneously turning on said second and fourth switching element and; a level shifting circuit made receptive of the clock pulses, which are fed out of said clock generator, thereby to feed out a clock pulse at the level of said power supply voltage, which is supplied to said first node, said first to fourth switching elements being adapted to be switched by the output signal of said level shifting circuit. - View Dependent Claims (18, 19, 20, 21, 22)
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23. An electronic circuit comprising:
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a first node adapted to be supplied with a power supply voltage; a second node; a first switching element connected between said first node and a third node; a first capacitor connected between said third node and a fourth node; a second switching element connected between said fourth node and the reference potential point of said circuit; a third switching element connected between said fourth node and said second node; a fourth switching element connected between said third node and said second node; a second capacitor adapted to be charged in accordance with the voltage which is supplied to said second node; a clock generator made operative by the voltage, which is supplied from said second capacitor, to generate clock pulses partly for substantially simultaneously turning on said first and third switching elements and partly for substantially turning on said second and fourth switching elements during the time period which is different from the "ON" time period of said first and third switching elements; and a starter for supplying the voltage, which is supplied to said first node, to said fourth node during a predetermined time period when the power supply is made. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
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31. An electric circuit comprising:
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a first node adapted to be supplied with a power supply voltage; a second node; a first switching insulated gate field effect transistor connected between said first node and a third node; a first capacitor connected between said third node and fourth node; a second switching insulated gate field effect transistor connected between said fourth node and the reference potential point of said circuit; a third switching insulated gate field effect transistor connected between said third node and second node; a second capacitor adapted to be charged in accordance with the voltage which is supplied to said second node; a clock generator for generating a first clock pulse, which is supplied to gates of said second and third switching insulated gate field effect transistors for complementally turning on and off the second and third switching insulated gate field effect transistors, a second clock pulse, which is supplied to a gate of said first switching insulated gate field effect transistor for turning on the first switching insulated gate field effect transistor duuring a first time period, the turning on of the first insulated gate field effect transistor being delayed a predetermined time period from the turning on of said third switching insulated gate field effect transistor and the turning off of the first insulated gate field effect transistor being advanced a predetermined time period compared to the turning off of said third switching insulated gate field effect transistor, and a third clock pulse, which is supplied to a gate of said fourth switching insulated gate field effect transistor for turning on the fourth insulated gate field effect transistor during a second time period, the turning on of the fourth field effect transistor being delayed a predetermined time period from the turning off of said third switching insulated gate field effect transistor and the turning off of the fourth insulated gate field effect transistor being advanced a predetermined time period compared to the turning on of said fourth switching insulated gate field effect transistor; and a load circuit made receptive of at least the voltage, which is supplied to said second node, as the power supply voltage.
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Specification