CHARGE AND DISCHARGE CONTROL CIRCUIT AND BATTERY DEVICE
First Claim
1. A charge and discharge control circuit, comprising:
- a control circuit configured to detect a voltage and abnormality of a secondary battery; and
a short-circuit and overcurrent detecting circuit configured to detect an overcurrent and a short circuit based on a voltage of an overcurrent detecting terminal,the short-circuit and overcurrent detecting circuit comprising;
a reference voltage circuit comprising a constant current circuit, a first impedance element, and a transistor having a resistance value that is changed depending on the voltage of the secondary battery, the reference voltage circuit being configured to output a voltage generated when a current of the constant current circuit flows through the first impedance element and the transistor;
a first comparator circuit configured to compare the voltage of the overcurrent detecting terminal with the voltage of the reference voltage circuit;
a second impedance element including one terminal connected to the overcurrent detecting terminal;
a third impedance element including one terminal connected to another terminal of the second impedance element; and
a second comparator circuit configured to compare a voltage generated at a node of the second impedance element and the third impedance element with the voltage of the reference voltage circuit.
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Accused Products
Abstract
Provided is a highly safe battery device in which the accuracy of an overcurrent detection current value and a short-circuit current value is improved and current consumption is reduced. A short-circuit and overcurrent detecting circuit includes: a reference voltage circuit configured to output a reference voltage generated when a constant current flows through an impedance element and a transistor having a resistance value that is changed depending on a voltage of a secondary battery; a first comparator circuit configured to compare a voltage of an overcurrent detecting terminal with the reference voltage; and a second comparator circuit configured to compare a voltage based on the voltage of the overcurrent detecting terminal with the reference voltage.
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Citations
8 Claims
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1. A charge and discharge control circuit, comprising:
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a control circuit configured to detect a voltage and abnormality of a secondary battery; and a short-circuit and overcurrent detecting circuit configured to detect an overcurrent and a short circuit based on a voltage of an overcurrent detecting terminal, the short-circuit and overcurrent detecting circuit comprising; a reference voltage circuit comprising a constant current circuit, a first impedance element, and a transistor having a resistance value that is changed depending on the voltage of the secondary battery, the reference voltage circuit being configured to output a voltage generated when a current of the constant current circuit flows through the first impedance element and the transistor; a first comparator circuit configured to compare the voltage of the overcurrent detecting terminal with the voltage of the reference voltage circuit; a second impedance element including one terminal connected to the overcurrent detecting terminal; a third impedance element including one terminal connected to another terminal of the second impedance element; and a second comparator circuit configured to compare a voltage generated at a node of the second impedance element and the third impedance element with the voltage of the reference voltage circuit. - View Dependent Claims (2, 3, 4, 6, 7)
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5. A battery device, comprising:
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a charge and discharge control circuit comprising; a control circuit configured to detect a voltage and abnormality of a secondary battery; and a short-circuit and overcurrent detecting circuit configured to detect an overcurrent and a short circuit based on a voltage of an overcurrent detecting terminal; and a first charge and discharge control switch and a second charge and discharge control switch that are connected in a charge and discharge path of the secondary battery, the short-circuit and overcurrent detecting circuit comprising; a reference voltage circuit comprising a constant current circuit, a first impedance element, and a transistor having a resistance value that is changed depending on the voltage of the secondary battery, the reference voltage circuit being configured to output a voltage generated when a current of the constant current circuit flows through the first impedance element and the transistor; a first comparator circuit configured to compare the voltage of the overcurrent detecting terminal with the voltage of the reference voltage circuit; and a second comparator circuit configured to compare a voltage generated at a node of the first charge and discharge control switch and the second charge and discharge control switch with the voltage of the reference voltage circuit. - View Dependent Claims (8)
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Specification