Overvoltage comparison circuit

Abstract

The invention relates to an overvoltage comparison circuit, which comprises a reverser, a first branch circuit, a second branch circuit, a third branch circuit, a fourth branch circuit and a fifth branch circuit, wherein the first branch circuit, the second branch circuit, the third branch circuit, the fourth branch circuit and the fifth branch circuit are respectively connected in parallel between an external power supply and the ground, the first branch circuit comprises a first current source and a first low-voltage device which are in series connection, in addition, a grid electrode and adrain electrode of the first low-voltage device are connected, the second branch circuit comprises a first high-voltage device and a second low-voltage device which are in serial connection, a grid electrode of the second low-voltage device is connected with the grid electrode of the first low-voltage device, in addition, a second high-voltage device is connected in series between the first high-voltage device and an external signal source to be detected, and a grid electrode and a drain electrode of the second high-voltage device are connected. The invention utilizes the conduction and shut-off feathers of the high-voltage devices and the low-voltage devices to realize the comparison of the high-voltage signals and the power supply voltage, i.e. the overvoltage comparison function, at the same time, because the high-voltage devices and the low-voltage devices are adopted in a circuit structure, the consumption area of chips is greatly reduced, the chip manufacture cost is effectivelyreduced, and the requirements of users are met.

Description

technical field [0001] The invention relates to an integrated circuit, in particular to an overvoltage comparator circuit. Background technique [0002] In the prior art, it is necessary to detect whether a high-voltage signal in the high-voltage circuit is greater than the power supply voltage, that is, the structural diagram of a commonly used overvoltage comparison circuit is as follows: figure 1 As shown, the overvoltage comparison circuit includes a first resistor R1 and a second resistor R2 connected in series, and also includes a comparator CMP connected in parallel to both ends of the second resistor R2. dd +V th , V th for supply voltages in excess of V dd When the reference value) (not shown in the figure), the voltage VD obtained after the high-voltage signal HV Signal is divided by the first resistor R1 and the second resistor R2 and another reference level (such as a bandgap reference) are input to the comparator CMP is compared, and finally the test result ...

AI Technical Summary

Problems solved by technology

However, the biggest disadvantage of the above-mentioned circuit structure is that it will waste a lot of chip area, so it is increasingly unable to meet the needs of use.

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