UNDER-VOLTAGE AND OVER-VOLTAGE DETECTION CIRCUIT AND DRIVING METHOD THEREOF
First Claim
1. A low-voltage and over-voltage detection circuit comprising:
- a level shifter receiving a power source voltage and shifting an input voltage to a predetermined level to generate a shift voltage;
a voltage clamper maintaining the shift voltage at a clamping voltage when the shift voltage is higher than a predetermined clamping voltage;
a voltage regulator generating a regulator voltage that varies according to the power source voltage; and
a voltage detector receiving the shift voltage and the regulator voltage, including first and second transistors, and determining whether the power source voltage is a low-voltage or an over-voltage by using a drain voltage generated according to currents flowing to the first and second transistors, the first transistor performing a switching operation according to the two input voltages and the second transistor connected to the first transistor in parallel and generating hysteresis.
4 Assignments
0 Petitions
Accused Products
Abstract
The present invention relates to a low-voltage and over-voltage detection circuit and a driving method thereof.
The low-voltage and over-voltage detection circuit according to the present invention receives a power source voltage, generates a shift voltage by shifting the received voltage to a predetermined level, and fixes the shift voltage as a clamping voltage when the shift voltage is higher than a predetermined clamping voltage. The low-voltage and over-voltage detection circuit according to the present invention includes a first transistor and a second transistor. The first transistor generates a regulator voltage that varies according to the power source voltage and performs a switching operation according to the shift voltage and the regulator voltage, and the second transistor is connected in parallel with the first transistor and generates hysteresis. The low-voltage and over-voltage detection circuit according to the present invention determines whether the power source voltage is a low-voltage or an over-voltage by using a drain voltage generated according to currents flowing to the first and second transistors.
16 Citations
16 Claims
-
1. A low-voltage and over-voltage detection circuit comprising:
-
a level shifter receiving a power source voltage and shifting an input voltage to a predetermined level to generate a shift voltage; a voltage clamper maintaining the shift voltage at a clamping voltage when the shift voltage is higher than a predetermined clamping voltage; a voltage regulator generating a regulator voltage that varies according to the power source voltage; and a voltage detector receiving the shift voltage and the regulator voltage, including first and second transistors, and determining whether the power source voltage is a low-voltage or an over-voltage by using a drain voltage generated according to currents flowing to the first and second transistors, the first transistor performing a switching operation according to the two input voltages and the second transistor connected to the first transistor in parallel and generating hysteresis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
-
12. A driving method of a low-voltage and over-voltage detection circuit including a first transistor and a second transistor connected in parallel with the first transistor, comprising:
-
receiving a power source voltage and generating a shift voltage by shifting the power source voltage to a predetermined level; when the shift voltage is higher than a predetermined clamping voltage, fixing the shift voltage as a clamping voltage; generating a regulator voltage that varies according to the power source voltage; switching the first transistor according to the shift voltage and the regulator voltage; determining the power source voltage to be included in a normal range when drain voltages of the first and second transistors are close to the regulator voltage and generating a first-level detection signal, and determining the power source voltage to be a low-voltage or an over-voltage when the drain voltages are close to the power source voltage and generating a second-level detection signal; and switching the second transistor according to a reverse detection signal that is opposite to the detection signal. - View Dependent Claims (13, 14, 15, 16)
-
Specification