CN101762740B - Overvoltage comparison circuit - Google Patents
Overvoltage comparison circuit Download PDFInfo
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- CN101762740B CN101762740B CN2009102477993A CN200910247799A CN101762740B CN 101762740 B CN101762740 B CN 101762740B CN 2009102477993 A CN2009102477993 A CN 2009102477993A CN 200910247799 A CN200910247799 A CN 200910247799A CN 101762740 B CN101762740 B CN 101762740B
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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 a drain 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 effectively reduced, and the requirements of users are met.
Description
Technical field
The present invention relates to integrated circuit, relate in particular to a kind of overvoltage comparison circuit.
Background technology
In the prior art, whether detect a high-voltage signal in the high-tension circuit greater than supply voltage, promptly the structural representation of Chang Yong overvoltage comparison circuit as shown in Figure 1, this overvoltage comparison circuit comprises first resistance R 1 and second resistance R 2 that is connected in series, also comprise the comparator C MP that is connected in parallel on second resistance R, 2 two ends, when detecting high-voltage signal HV Signal whether greater than supply voltage (V for example
Dd+ V
Th, V
ThBe beyond supply voltage V
DdReference value) during (not shown), be about to voltage VD that high-voltage signal HV Signal obtains after by first resistance R 1 and second resistance R, 2 dividing potential drops and another datum (as band-gap reference) and be input to comparator C MP and compare, obtain testing result at last.Yet the disadvantage of above-mentioned sort circuit structure is to waste a large amount of chip areas, therefore more and more can not satisfy the use needs.
Summary of the invention
In order to overcome the shortcoming that above-mentioned prior art exists, the present invention aims to provide a kind of overvoltage comparison circuit of novelty, to reach under the prerequisite that consumes less chip area, realizes the purpose of overvoltage measuring ability reliably.
A kind of overvoltage comparison circuit of the present invention, it comprises a reverser and is connected in parallel on first to the 5th branch road between an external power source and the ground respectively,
Described first branch road comprises a current source and first low-voltage device that is connected in series, and the grid of this first low-voltage device is connected with drain electrode;
Described second branch road comprises first high tension apparatus and second low-voltage device that is connected in series, the grid of this second low-voltage device is connected with the grid of described first low-voltage device, and be in series with second high tension apparatus between described first high tension apparatus and the outside measured signal source, the grid of this second high tension apparatus is connected with drain electrode;
Described the 3rd branch road comprises the 4th high tension apparatus and the 4th low-voltage device that is connected in series, the grid of the 4th low-voltage device is connected with drain electrode, and be in series with the 3rd high tension apparatus between described the 4th high tension apparatus and the described outside measured signal source, the grid of the 3rd high tension apparatus is connected with the grid of described second high tension apparatus;
Described the 4th branch road comprises the 6th low-voltage device and the 3rd low-voltage device that is connected in series, and the grid of the 3rd low-voltage device is connected with the grid of described first low-voltage device, and the grid of described the 6th low-voltage device is connected with drain electrode;
Described the 5th branch road comprises the 7th low-voltage device and the 5th low-voltage device that is connected in series, and the grid of the 5th low-voltage device is connected with the drain electrode of described the 4th low-voltage device, and the grid of described the 7th low-voltage device is connected with the grid of described the 6th low-voltage device;
The input end of described reverser is connected between described the 7th low-voltage device and the 5th low-voltage device, and exports an identification signal.
In above-mentioned overvoltage comparison circuit, the source electrode of the grid of described first high tension apparatus, the 6th, seven low-voltage devices is connected with described external power source simultaneously, and the grid of described the 4th high tension apparatus is connected with described external power source; The source electrode of described first to the 5th low-voltage device is ground connection simultaneously.
In above-mentioned overvoltage comparison circuit, the source electrode of described second high tension apparatus is connected with described outside measured signal source, and its drain electrode is connected with the drain electrode of described first high tension apparatus; The source electrode of described the 3rd high tension apparatus is connected with described outside measured signal source, and its drain electrode is connected with the source electrode of described the 4th high tension apparatus.
Owing to adopted above-mentioned technical solution, the present invention utilizes conducting, the turn-off characteristic of high and low pressure device, realized the comparison of high-voltage signal and supply voltage, it is the overvoltage comparing function, simultaneously owing to adopted the high and low pressure device in the circuit structure, thereby significantly reduced the consumption area of chip, effectively reduced the chip manufacturing cost, satisfied user's needs.
Description of drawings
Fig. 1 is the structural representation of overvoltage comparison circuit of the prior art;
Fig. 2 is the structural representation of a kind of overvoltage comparison circuit of the present invention.
Embodiment
As shown in Figure 2, the present invention, promptly a kind of overvoltage comparison circuit comprises a reverser INV and is connected in parallel on first to the 5th branch road 1 to 5 between an external power source VDD and the ground respectively, wherein:
The 3rd branch road 3 comprises the 4th high tension apparatus M24 and the 4th low-voltage device M4 that is connected in series, wherein, the grid of the 4th low-voltage device M4 is connected with drain electrode, its source ground, the grid of the 4th high tension apparatus M24 is connected with external power source VDD, be in series with the 3rd high tension apparatus M23 between its source electrode and the outside measured signal source FB, the source electrode of the 3rd high tension apparatus M23 receives high-voltage signal to be measured, and its grid is connected with the grid of the second high tension apparatus M22;
The 4th branch road 4 comprises the 6th low-voltage device M6 and the 3rd low-voltage device M3 that is connected in series, wherein, the source ground of the 3rd low-voltage device M3, its grid is connected with the grid of the first low-voltage device M1, the source electrode of the 6th low-voltage device M6 is connected with external power source VDD, and its grid is connected with drain electrode;
The 5th branch road 5 comprises the 7th low-voltage device M7 and the 5th low-voltage device M5 that is connected in series, wherein, the source ground of the 5th low-voltage device M5, its grid is connected with the drain electrode of the 4th low-voltage device M4, the source electrode of the 7th low-voltage device M7 is connected with external power source VDD, and its grid is connected with the grid of the 6th low-voltage device M6;
The input end of reverser INV is connected between the 7th low-voltage device M7 and the 5th low-voltage device M5, and exports an identification signal OUT.
Principle of work of the present invention is as follows:
When the voltage of measured signal source FB is lower than V
Dd+ V
ThThe time (wherein, V
DdBe the magnitude of voltage of external power source VDD, V
ThBe beyond supply voltage V
DdReference value), then the 3rd high tension apparatus M23 ends, the 4th low-voltage device M4 no current passes through, promptly the 4th low-voltage device M4 enters cut-off region, at this moment, the pull-up current of the 7th low-voltage device M7 is much larger than the pull-down current of the 5th low-voltage device M5, thereby makes that identification signal OUT is a low level; Therefore, when identification signal OUT was low level, the voltage that can judge measured signal source FB this moment was less than V
Dd+ V
Th
When the voltage of measured signal source FB greater than V
Dd+ V
ThThe time, the 3rd high tension apparatus M23 conducting, the electric current that the 3rd high tension apparatus M23 mirror image obtains flows through the 4th low-voltage device M4, make the 4th low-voltage device M4 enter the saturation region, at this moment, the 4th low-voltage device M4 is mirrored to the pull-down current of the 5th low-voltage device M5 and the pull-up current of the 7th low-voltage device M7 carries out current ratio, thereby makes that identification signal OUT is a high level; Therefore, when identification signal OUT is high level, can judge the overtension of measured signal source FB this moment, promptly greater than V
Dd+ V
Th
In the present invention, the effect of the first high tension apparatus M21 is the device of protection low-pressure section, i.e. first to the 7th low-voltage device M1 to M7; The 4th high tension apparatus M24 can also be by being provided with the gate source voltage V of the 4th high tension apparatus M24 except shielding
GsDetermine beyond supply voltage V
DdReference value V
ThIn addition, in the present invention, the 7th low-voltage device M7 and the 5th low-voltage device M5 form current comparator, choose the 5th low-voltage device M5 with respect to the mirror image multiple of the 4th low-voltage device M4 greater than the mirror image multiple of the 7th low-voltage device M7 with respect to the 6th low-voltage device M6, increase the electric current pull-down capability of current comparator with this, to such an extent as to the voltage of measured signal source FB needs not exceed supply voltage V
DdA lot, promptly only need to surpass a very little V
Th, this over-voltage detection circuit just can be made overvoltage and judge.
Among the present invention, the second high tension apparatus M22, the 3rd high tension apparatus M23, the 4th high tension apparatus M24, the 6th low-voltage device M6 and the 7th low-voltage device M7 can adopt the PMOS pipe to realize, all the other high and low pressure devices then adopt the NMOS pipe to realize.
Below embodiment has been described in detail the present invention in conjunction with the accompanying drawings, and those skilled in the art can make the many variations example to the present invention according to the above description.Thereby some details among the embodiment should not constitute limitation of the invention, and the scope that the present invention will define with appended claims is as protection scope of the present invention.
Claims (1)
1. an overvoltage comparison circuit is characterized in that, described comparator circuit comprises a reverser and be connected in parallel on first to the 5th branch road between an external power source and the ground respectively,
Described first branch road comprises a current source and first low-voltage device that is connected in series, and the grid of this first low-voltage device is connected with drain electrode;
Described second branch road comprises first high tension apparatus and second low-voltage device that is connected in series, the grid of this second low-voltage device is connected with the grid of described first low-voltage device, and be in series with second high tension apparatus between described first high tension apparatus and the outside measured signal source, the grid of this second high tension apparatus is connected with drain electrode;
Described the 3rd branch road comprises the 4th high tension apparatus and the 4th low-voltage device that is connected in series, the grid of the 4th low-voltage device is connected with drain electrode, and be in series with the 3rd high tension apparatus between described the 4th high tension apparatus and the described outside measured signal source, the grid of the 3rd high tension apparatus is connected with the grid of described second high tension apparatus;
Described the 4th branch road comprises the 6th low-voltage device and the 3rd low-voltage device that is connected in series, and the grid of the 3rd low-voltage device is connected with the grid of described first low-voltage device, and the grid of described the 6th low-voltage device is connected with drain electrode;
Described the 5th branch road comprises the 7th low-voltage device and the 5th low-voltage device that is connected in series, and the grid of the 5th low-voltage device is connected with the drain electrode of described the 4th low-voltage device, and the grid of described the 7th low-voltage device is connected with the grid of described the 6th low-voltage device;
The input end of described reverser is connected between described the 7th low-voltage device and the 5th low-voltage device, and exports an identification signal;
The source electrode of the grid of described first high tension apparatus, the 6th, seven low-voltage devices is connected with described external power source simultaneously, and the grid of described the 4th high tension apparatus is connected with described external power source; The source electrode of described first to the 5th low-voltage device is ground connection simultaneously;
The source electrode of described second high tension apparatus is connected with described outside measured signal source, and its drain electrode is connected with the drain electrode of described first high tension apparatus; The source electrode of described the 3rd high tension apparatus is connected with described outside measured signal source, and its drain electrode is connected with the source electrode of described the 4th high tension apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102477993A CN101762740B (en) | 2009-12-31 | 2009-12-31 | Overvoltage comparison circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009102477993A CN101762740B (en) | 2009-12-31 | 2009-12-31 | Overvoltage comparison circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101762740A CN101762740A (en) | 2010-06-30 |
| CN101762740B true CN101762740B (en) | 2011-08-31 |
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ID=42494029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009102477993A Expired - Fee Related CN101762740B (en) | 2009-12-31 | 2009-12-31 | Overvoltage comparison circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101762740B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107966608A (en) * | 2017-12-02 | 2018-04-27 | 上海仪电科学仪器股份有限公司 | A kind of measuring circuit for gathering bi-directional voltage signal |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1760681A (en) * | 2004-10-14 | 2006-04-19 | 三洋电机株式会社 | Voltage detection circuit |
| CN101379406A (en) * | 2006-02-09 | 2009-03-04 | Nxp股份有限公司 | Circuit arrangement and method for detecting a power down situation of a voltage supply source |
-
2009
- 2009-12-31 CN CN2009102477993A patent/CN101762740B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1760681A (en) * | 2004-10-14 | 2006-04-19 | 三洋电机株式会社 | Voltage detection circuit |
| CN101379406A (en) * | 2006-02-09 | 2009-03-04 | Nxp股份有限公司 | Circuit arrangement and method for detecting a power down situation of a voltage supply source |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101762740A (en) | 2010-06-30 |
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Granted publication date: 20110831 |