CN105790742A - Power-on reset circuit - Google Patents
Power-on reset circuit Download PDFInfo
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- CN105790742A CN105790742A CN201410836004.3A CN201410836004A CN105790742A CN 105790742 A CN105790742 A CN 105790742A CN 201410836004 A CN201410836004 A CN 201410836004A CN 105790742 A CN105790742 A CN 105790742A
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Abstract
The invention provides a power-on reset circuit. The power-on reset circuit is used for outputting a reset signal and comprises a power supply detection circuit, wherein the power supply detection circuit comprises a band-gap reference voltage source, a comparator and a voltage-dividing module; the voltage-dividing module outputs first divided voltage; the first divided voltage is compared with reference voltage output by the band-gap reference voltage source through the comparator; and, when the first divided voltage is greater than the reference voltage, the power supply detection circuit outputs a first signal. According to the power-on reset circuit disclosed by the invention, circuit structures of the band-gap reference voltage source and the comparator are adopted in the power supply detection part; furthermore, a low-voltage setting circuit is additionally arranged; and the accuracy of the output reset signal when voltage is low can be ensured.
Description
Technical field
The present invention relates to a kind of electrification reset circuit.
Background technology
For Digital Analog Hybrid Circuits, when powering on, it is necessary to be given to one reset signal of digital circuit, reset the indeterminate state brought that powers on so that integrated circuit can normal operation.
But at lower voltages, circuit is generally not capable of normal operation, it is impossible to correctly ensure output.Such as, the reset circuit of prior art is when powering on, and owing to supply voltage is relatively low, can cause that the logic of its output is uncertain, and the reset signal of its output is unreliable.
Accordingly, it would be desirable to a kind of safe and reliable electrification reset circuit provides reliable reset signal.
Summary of the invention
The invention provides a kind of novel electrification reset circuit, be used for exporting reset signal, it ensure that the effective and safe of electro-detection.
A kind of electrification reset circuit, for exporting reset signal, it includes power sense circuit, wherein, described power sense circuit includes bandgap voltage reference, comparator, division module, and described division module exports the first branch pressure voltage, its reference voltage exported with described bandgap voltage reference, being compared by described comparator, when described first branch pressure voltage is more than described reference voltage, described power sense circuit exports the first signal.
Further, described division module also exports the second branch pressure voltage less than described first branch pressure voltage, and described power sense circuit also includes: the first NMOS tube, its source ground, its drain electrode is connected to power supply by the first resistance, and its grid connects described second branch pressure voltage；Second NMOS tube, its source ground, its grid is connected to power supply by described first resistance, the grid of the metal-oxide-semiconductor that its drain electrode is connected on the output branch road of described bandgap voltage reference.
Further, described electrification reset circuit also includes the filter circuit and the count delay circuit that are sequentially connected with, is respectively used to described first signal is filtered and is postponed, the described reset signal of final output.
Further, described electrification reset circuit also includes the Schmidt trigger being connected between described power sense circuit and described filter circuit, for described first signal is carried out shaping.
The electrification reset circuit of the present invention, its power detecting part adopts the circuit structure of bandgap voltage reference and comparator, and adds and arrange circuit under low-voltage, it is possible to ensure the accuracy of output reset signal during low-voltage.
Accompanying drawing explanation
Fig. 1 is the structural representation of the electrification reset circuit of the present invention；
Fig. 2 is the structural representation of an embodiment of the power sense circuit of the electrification reset circuit of the present invention；
Fig. 3 is the structural representation of another embodiment of the power sense circuit of the electrification reset circuit of the present invention；
Fig. 4 is the waveform diagram of circuit shown in Fig. 3.
Detailed description of the invention
Below in conjunction with the drawings and specific embodiments, the electrification reset circuit of the present invention is described in further detail, but not as a limitation of the invention.
With reference to Fig. 1, the electrification reset circuit of the present invention, it is used for exporting reset signal Vpor, it is preferable that it includes the power sense circuit, Schmidt trigger, filter circuit and the count delay circuit that are sequentially connected with.Wherein, power sense circuit is used for detecting whether supply voltage reaches predetermined value, provides the first signal Vdet when reaching predetermined value；This first signal Vdet, after Schmidt trigger shaping, filter circuit filtering, count delay circuit delay, forms the reset signal Vpor of final output.
With reference to Fig. 2, power sense circuit includes bandgap voltage reference, comparator and division module.Wherein, division module exports the reference voltage V ref of the first branch pressure voltage V1, V1 and bandgap voltage reference output, is compared by comparator, and when the first branch pressure voltage V1 is more than described reference voltage V ref, power sense circuit exports the first signal Vdet.Bandgap voltage reference shown in Fig. 2 and comparator respectively simplify bandgap voltage reference and the comparator of structure, shown division module is the division module of series connection divider resistance, it is understandable that, these structures are not limited to the structure shown in Fig. 2, and it can be any other structures being capable of its similar functions well-known to those skilled in the art.
Due in side circuit, when supply voltage is relatively low, the level of bandgap voltage reference output is not normal value, now easily makes the testing result mistake of power sense circuit.For this, preferably, with reference to Fig. 3, division module also exports the second branch pressure voltage V2 less than the first branch pressure voltage V1, this power sense circuit also includes: the first NMOS tube MN1, and its source ground, drain electrode is connected to power supply by the first resistance R2, grid meets the second branch pressure voltage V2；And the second NMOS tube MN2, the grid of the metal-oxide-semiconductor M5 that its source ground, grid are connected to power supply by the first resistance R2, drain electrode is connected on the output branch road of bandgap voltage reference.
The operation principle of this power sense circuit is described with reference to the waveform of Fig. 4.
First stage: when power supply electrifying, owing to supply voltage is very low, therefore the second branch pressure voltage V2 is also low, and it makes the first NMOS tube MN1 close, and the grid (i.e. node A) of the second NMOS tube MN2 is connected to power supply through the first resistance R2.When power supply continues to raise so that when the gate source voltage of the second NMOS tube MN2 is more than its cut-in voltage Vth2, the second NMOS tube MN2 conducting so that grid (the i.e. node B) ground connection of M5.Now, the output node of this reference source is pulled to power supply through M5, namely can ensure that its output voltage Vref is identical with power values or slightly below power values, thus ensureing that the first branch pressure voltage V1 now is not more than Vref, namely ensure that Vdet now is output as low.Visible, this circuit structure can ensure that, when start powers on, supply voltage is not when relatively low circuit starts normal operation, and the reset signal Vpor of this electrification reset circuit output is low, does not namely provide reset signal.
Second stage: when supply voltage continues to raise, second branch pressure voltage V2 also may proceed to raise simultaneously, when it makes the gate source voltage of the first NMOS tube MN1 more than its cut-in voltage Vth1, and the first NMOS tube MN1 conducting, it makes node A ground connection, thus causing that the second NMOS tube MN2 closes.So far, bandgap voltage reference starts normal operation, the voltage lifting of node B, the output voltage Vref of bandgap voltage reference quickly falls to reference level, power sense circuit enters normal decision state, namely treat that power supply rises to predetermined value (it rises to Vref by the first branch pressure voltage V1 and indirectly judges), the output level of the output voltage Vdet of this power detecting module uprises, so that this electrification reset circuit when supply voltage is sufficiently high enable to normal circuit operation, just export power-on reset signal.
To sum up, the electrification reset circuit of the present invention, its power detecting part adopts the circuit structure of bandgap voltage reference and comparator, and adds and arrange circuit under low-voltage, it is possible to ensure the accuracy of output reset signal during low-voltage.
Above detailed description of the invention is only the illustrative embodiments of the present invention, it is impossible to being used for limiting the present invention, protection scope of the present invention is defined by the claims.The present invention in the essence of the present invention and protection domain, can be made various amendment or equivalent replacement by those skilled in the art, and these are revised or be equal to replacement and also should be regarded as being within the scope of the present invention.
Claims (4)
1. an electrification reset circuit, for exporting reset signal, it includes power sense circuit, wherein, described power sense circuit includes bandgap voltage reference, comparator, division module, and described division module exports the first branch pressure voltage, its reference voltage exported with described bandgap voltage reference, being compared by described comparator, when described first branch pressure voltage is more than described reference voltage, described power sense circuit exports the first signal.
2. electrification reset circuit according to claim 1, it is characterised in that described division module also exports the second branch pressure voltage less than described first branch pressure voltage, and described power sense circuit also includes:
First NMOS tube, its source ground, its drain electrode is connected to power supply by the first resistance, and its grid connects described second branch pressure voltage；
Second NMOS tube, its source ground, its grid is connected to power supply by described first resistance, the grid of the metal-oxide-semiconductor that its drain electrode is connected on the output branch road of described bandgap voltage reference.
3. electrification reset circuit according to claim 1, it is characterised in that described electrification reset circuit also includes the filter circuit and the count delay circuit that are sequentially connected with, is respectively used to described first signal is filtered and is postponed, the described reset signal of final output.
4. electrification reset circuit according to claim 3, it is characterised in that described electrification reset circuit also includes the Schmidt trigger being connected between described power sense circuit and described filter circuit, for carrying out shaping to described first signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410836004.3A CN105790742B (en) | 2014-12-23 | 2014-12-23 | Electrification reset circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410836004.3A CN105790742B (en) | 2014-12-23 | 2014-12-23 | Electrification reset circuit |
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| Publication Number | Publication Date |
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| CN105790742A true CN105790742A (en) | 2016-07-20 |
| CN105790742B CN105790742B (en) | 2019-04-26 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201410836004.3A Active CN105790742B (en) | 2014-12-23 | 2014-12-23 | Electrification reset circuit |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111555741A (en) * | 2019-02-12 | 2020-08-18 | 新唐科技股份有限公司 | Power-on clearing circuit |
| CN112217500A (en) * | 2020-12-03 | 2021-01-12 | 深圳英集芯科技有限公司 | High-precision low-power-consumption power-on reset circuit |
| WO2022067739A1 (en) * | 2020-09-30 | 2022-04-07 | 深圳市汇顶科技股份有限公司 | Power-on reset circuit |
| CN117118410A (en) * | 2023-10-25 | 2023-11-24 | 无锡众享科技有限公司 | Comparator, detection circuit, grading circuit and POE power supply system |
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| CN102244508A (en) * | 2010-04-28 | 2011-11-16 | 三美电机株式会社 | Power-on reset circuit |
| US20120274369A1 (en) * | 2011-04-28 | 2012-11-01 | Fairchild Semiconductor Corporation | Power-on-reset circuit and reset method |
| CN203135823U (en) * | 2012-12-31 | 2013-08-14 | 成都锐成芯微科技有限责任公司 | Ultra-low power consumption high-precision power-on reset circuit |
| CN204272062U (en) * | 2014-12-23 | 2015-04-15 | 上海贝岭股份有限公司 | Electrify restoration circuit |
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2014
- 2014-12-23 CN CN201410836004.3A patent/CN105790742B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102244508A (en) * | 2010-04-28 | 2011-11-16 | 三美电机株式会社 | Power-on reset circuit |
| US20120274369A1 (en) * | 2011-04-28 | 2012-11-01 | Fairchild Semiconductor Corporation | Power-on-reset circuit and reset method |
| CN203135823U (en) * | 2012-12-31 | 2013-08-14 | 成都锐成芯微科技有限责任公司 | Ultra-low power consumption high-precision power-on reset circuit |
| CN204272062U (en) * | 2014-12-23 | 2015-04-15 | 上海贝岭股份有限公司 | Electrify restoration circuit |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111555741A (en) * | 2019-02-12 | 2020-08-18 | 新唐科技股份有限公司 | Power-on clearing circuit |
| CN111555741B (en) * | 2019-02-12 | 2023-03-10 | 新唐科技股份有限公司 | Power-on clearing circuit |
| WO2022067739A1 (en) * | 2020-09-30 | 2022-04-07 | 深圳市汇顶科技股份有限公司 | Power-on reset circuit |
| US11431335B2 (en) | 2020-09-30 | 2022-08-30 | Shenzhen GOODIX Technology Co., Ltd. | Power-on reset circuit |
| CN112217500A (en) * | 2020-12-03 | 2021-01-12 | 深圳英集芯科技有限公司 | High-precision low-power-consumption power-on reset circuit |
| CN112217500B (en) * | 2020-12-03 | 2021-03-26 | 深圳英集芯科技有限公司 | High-precision low-power-consumption power-on reset circuit |
| CN117118410A (en) * | 2023-10-25 | 2023-11-24 | 无锡众享科技有限公司 | Comparator, detection circuit, grading circuit and POE power supply system |
| CN117118410B (en) * | 2023-10-25 | 2024-02-02 | 无锡众享科技有限公司 | Comparator, detection circuit, grading circuit and POE power supply system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105790742B (en) | 2019-04-26 |
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