Voltage detection circuit

Abstract

The invention discloses a voltage detection circuit which comprises a voltage divider circuit and a comparator. The voltage divider circuit includes a first capacitor and a second capacitor. A first end of the first capacitor is connected with a reference voltage, and a second end of the first capacitor is connected with a supply voltage through a first switch. A first end of the second capacitor is connected with the reference voltage through a second switch and connected with a ground potential through a third switch, and a second end of the second capacitor is the output end of the voltage divider circuit, connected with a first end of the comparator, and connected with the reference voltage through a forth switch. The second end of the first capacitor is connected with the second end of the second capacitor through a fifth switch. The voltage detection circuit can reduce the occupation space of the circuit on a chip, completely cancel the static power consumption of the circuit, thereby reducing the power consumption of the circuit, and guarantee that the high voltage dividing precision of the circuit.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit, in particular to a voltage detection circuit (VD). Background technique [0002] Such as figure 1 Shown is a schematic structural diagram of the existing voltage detection circuit, the existing voltage detection circuit includes a voltage divider circuit and a comparator 12, the voltage divider circuit is composed of a plurality of resistors 11 connected in series, and a divided voltage is taken out between the resistors 11 connected in series value V1, the divided voltage value V1 is connected to one input of the comparator 12. The other input terminal of the comparator 12 is connected to the reference voltage Vref. The comparator 12 compares the divided voltage V1 with the reference voltage Vref and outputs an output value out at the output terminal. [0003] The disadvantages of the existing voltage detection circuit are: [0004] 1. Since the series resistors of the voltage divider ci...

AI Technical Summary

Problems solved by technology

[0004] 1. Since the series resistors of the voltage divider circuit are connected in series between the power supply voltage and the ground, there will always be current in this path, which will cause excessive power consumption of the circuit

[0005] 2. In integrated circuits, resistors take up too much device area

Therefore, the area with too large resistance will also increase the manufacturing cost

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