Irregular voltage detection and cutoff circuit using bandgap reference voltage generation circuit
First Claim
1. An irregular voltage detection and cutoff circuit, which monitors an operating voltage range of a power-supply voltage, the irregular voltage detection and cutoff circuit comprising:
- a bandgap reference voltage generation circuit, which generates a bandgap reference voltage from the power-supply voltage;
a reference voltage generator, which generates a first reference voltage at a same voltage level as the bandgap reference voltage, and a second reference voltage;
a voltage detector, which generates a detection voltage from the power supply voltage; and
a comparator, which generates a switching control signal that cuts off the power-supply voltage by comparing the first and second reference voltages with the detection voltage, wherein the reference voltage generator comprises;
an OP amp, wherein bandgap reference voltage is inputted to a non-inverting input terminal thereof and the first reference voltage is inputted to an inverting input terminal thereof;
a PMOS transistor, whose gate is connected to an output of the OP amp, whose source is connected to the power-supply voltage, and whose drain is connected to the first reference voltage;
a first resistor, which is connected between the first reference voltage and the second reference voltage; and
a second resistor, which is connected between the second reference voltage and a ground voltage.
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Accused Products
Abstract
An irregular voltage detection and cutoff circuit using a bandgap reference voltage generation circuit includes the bandgap reference voltage generation circuit, which generates a bandgap reference voltage from the power-supply voltage, a reference voltage generator, which generates a first reference voltage and a second reference voltage in the same voltage level as the bandgap reference voltage from the power-supply voltage, a voltage detector, which generates a detection voltage from the power-supply voltage, and a comparator, which generates a switching control signal that cuts off the power-supply voltage by comparing the first and second reference voltages with the detection voltage.
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Citations
9 Claims
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1. An irregular voltage detection and cutoff circuit, which monitors an operating voltage range of a power-supply voltage, the irregular voltage detection and cutoff circuit comprising:
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a bandgap reference voltage generation circuit, which generates a bandgap reference voltage from the power-supply voltage; a reference voltage generator, which generates a first reference voltage at a same voltage level as the bandgap reference voltage, and a second reference voltage; a voltage detector, which generates a detection voltage from the power supply voltage; and a comparator, which generates a switching control signal that cuts off the power-supply voltage by comparing the first and second reference voltages with the detection voltage, wherein the reference voltage generator comprises; an OP amp, wherein bandgap reference voltage is inputted to a non-inverting input terminal thereof and the first reference voltage is inputted to an inverting input terminal thereof; a PMOS transistor, whose gate is connected to an output of the OP amp, whose source is connected to the power-supply voltage, and whose drain is connected to the first reference voltage; a first resistor, which is connected between the first reference voltage and the second reference voltage; and a second resistor, which is connected between the second reference voltage and a ground voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification