CN105337263A - Output overvoltage protection circuit and method for DC/DC converter - Google Patents
Output overvoltage protection circuit and method for DC/DC converter Download PDFInfo
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- CN105337263A CN105337263A CN201510779930.6A CN201510779930A CN105337263A CN 105337263 A CN105337263 A CN 105337263A CN 201510779930 A CN201510779930 A CN 201510779930A CN 105337263 A CN105337263 A CN 105337263A
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Abstract
The invention discloses an output overvoltage protection circuit for a DC/DC converter, which is characterized by comprising a threshold circuit, a locking circuit and a switching tube connected in series on an external input power line of the DC/DC converter, wherein the threshold circuit is used for sampling the output voltage of the DC/DC converter, and when the value of the output voltage exceeds the set value of the threshold voltage, the locking circuit is triggered to work, thereby controlling the switching tube connected in series on the external input power line of the DC/DC converter to be switched on or off. According to the protection circuit and method disclosed by the invention, output overvoltage protection is realized by controlling the switching on or off of the switching tube connected in series on the external input power line of the DC/DC converter, output overvoltage protection when the input voltage is directly connected in series to the output end and overvoltage protection caused by other faults can be effectively realized, and thus fault propagation is avoided.
Description
Technical field
The present invention relates to field of power supplies, particularly one is used for DC/DC converter output overvoltage protection circuit and method.
Background technology
DC/DC converter design time to consider to protect by electric loading and because of the inefficacy by electric loading to the protection of DC/DC converter.Consider that the contingent various fault of all parts components and parts of composition DC/DC converter is on the impact of DC/DC converter, must design corresponding protective circuit, to ensure to cause catastrophic consequence.
DC/DC converter is a closed loop feedback system, causes the fault point of output overvoltage to be not quite similar for different circuit topology.Such as the BUCK converter of non-isolated, the power MOSFET tube of its series connection is once leak source short, and input voltage directly can arrive output by string.And for example adopt Magnetic isolation sampling to add the multiple-channel output DC/DC converter exporting secondary pressure, for the three terminal regulator input and output short circuit of secondary pressure, also can cause output overvoltage.For another example for the DC/DC converter of multiple-channel output, because cross regulation rate missionary society brings certain output voltage to raise.
For general DC/DC converter, pulse width modulator reference voltage ripple, carry out Control loop output voltage because output voltage and this reference voltage compare generation error signal, reference voltage can cause output voltage also to drift about to height to height drift.In addition, pulse width modulator lost efficacy and causes high voltage to export, and time normal, the output voltage error amplifier of pulse width modulator depends on the size of error signal, and after inefficacy, this voltage keeps high level output, causes duty ratio to increase, make output overvoltage.If the open circuit of the feedback line of voltage sample, be equivalent to feedback resistance open circuit, power supply will work in open loop situations, and output voltage also can raise.
General output over-voltage protection can take Force Law, is namely realized with quicking break by TVS pipe clamp.As depicted in figs. 1 and 2, export by realizing clamp in output termination TVS pipe or controllable silicon, the method needs to select high withstand voltage TVS pipe and thyristor and can not disconnect the connection of input power and load in time when input voltage directly goes here and there output voltage.Be the output pressure limited protection circuit based on PWM as shown in Figure 3, the method cannot normal regulating when DC/DC inverter power pipe MOS leaks source short, does not realize locking function, does not realize protection when input voltage directly seals in output.
Summary of the invention
The object of the invention is to overcome the shortcoming of prior art and deficiency; there is provided a kind of for DC/DC converter output overvoltage protection circuit; can effectively realize input voltage directly go here and there output time output over-voltage protection and the overvoltage protection that causes of other fault, avoid failure propagation.
Another object of the present invention is to provide a kind of for DC/DC converter output over-voltage protection method.
Object of the present invention is realized by following technical scheme:
A kind of for DC/DC converter output overvoltage protection circuit; comprise threshold circuit, locked circuit; and the switching tube be connected on described DC/DC converter external input power line; by the output voltage of threshold circuit sampling DC/DC converter; when output voltage values exceedes the threshold voltage of setting; trigger locked circuit working, thus control conducting and the shutoff of the switching tube be connected on DC/DC converter external input power line.Reach with shutoff the object being connected or cutting off input source and load by the conducting of switching tube, realize DC/DC converter output over-voltage protection.
Described DC/DC converter is non-isolated DC/DC converter.
The bleeder circuit that described threshold circuit comprises voltage stabilizing didoe D3, filter capacitor C2 and is made up of resistance R5, resistance R6; Wherein voltage stabilizing didoe D3 negative pole connects the voltage output end of DC/DC converter, and voltage stabilizing didoe D3 positive pole accesses the bleeder circuit be made up of resistance R5, resistance R6; Filter capacitor C2 is in parallel with resistance R6, one end ground connection, another termination voltage stabilizing didoe D3 positive pole; Resistance R5 mono-termination voltage stabilizing didoe D3 positive pole, the locked circuit of another termination.
Described locked circuit comprises half controlled thyristor SCR, voltage stabilizing didoe D2, current-limiting resistance R2, current-limiting resistance R3 and current-limiting resistance R4, switching tube Q2, voltage stabilizing didoe D1 and switching tube Q1, electric capacity C1, resistance R1; The wherein extreme connecting resistance R6 of half controlled thyristor scr gate, minus earth, anode is connected with current-limiting resistance R3, current-limiting resistance R4, voltage stabilizing didoe D2 negative pole, voltage stabilizing didoe D2 plus earth; Switching tube Q2 source ground, gate pole meets current-limiting resistance R3, and drain electrode meets current-limiting resistance R2; Switching tube Q1 is serially connected on input voltage input positive line, and between the gate pole that voltage stabilizing didoe D1, electric capacity C1 and resistance R1 are attempted by switching tube Q1 and source electrode, the negative pole of voltage stabilizing didoe D1 connects switching tube Q1 gate pole, and the positive pole of voltage stabilizing didoe D1 connects switching tube Q1 source electrode.
Object of the present invention is realized by following technical scheme:
A kind of for DC/DC converter output over-voltage protection method, comprise following steps:
When DC/DC converter exports normal, output overvoltage protection circuit is inoperative, and the switching tube on external input power line is in conducting state, and protective circuit does not affect the normal operating characteristic exported;
When DC/DC converter output voltage exceeded the threshold voltage of threshold circuit setting, switching tube turned off by locked circuit working, and load and input power disconnect, thus protection DC/DC converter and rear class equipment damage components and parts from high pressure punching press.
Described DC/DC converter is non-isolated DC/DC converter.
The bleeder circuit that described threshold circuit comprises voltage stabilizing didoe D3, filter capacitor C2 and is made up of resistance R5, resistance R6; Wherein voltage stabilizing didoe D3 negative pole connects the voltage output end of DC/DC converter, and voltage stabilizing didoe D3 positive pole accesses the bleeder circuit be made up of resistance R5, resistance R6; Filter capacitor C2 is in parallel with resistance R6, one end ground connection, another termination voltage stabilizing didoe D3 positive pole; Resistance R5 mono-termination voltage stabilizing didoe D3 positive pole, the locked circuit of another termination.
Described locked circuit comprises half controlled thyristor SCR, voltage stabilizing didoe D2, current-limiting resistance R2, current-limiting resistance R3 and current-limiting resistance R4, switching tube Q2, voltage stabilizing didoe D1 and switching tube Q1, electric capacity C1, resistance R1; The wherein extreme connecting resistance R6 of half controlled thyristor scr gate, minus earth, anode is connected with current-limiting resistance R3, current-limiting resistance R4, voltage stabilizing didoe D2 negative pole, voltage stabilizing didoe D2 plus earth; Switching tube Q2 source ground, gate pole meets current-limiting resistance R3, and drain electrode meets current-limiting resistance R2; Switching tube Q1 is serially connected on input voltage input positive line, and between the gate pole that voltage stabilizing didoe D1, electric capacity C1 and resistance R1 are attempted by switching tube Q1 and source electrode, the negative pole of voltage stabilizing didoe D1 connects switching tube Q1 gate pole, and the positive pole of voltage stabilizing didoe D1 connects switching tube Q1 source electrode.
Compared with prior art, tool has the following advantages and beneficial effect in the present invention:
(1) the locked protection of output overvoltage is realized by the shutoff of the switching tube on control DC/DC external input power line.
(2) during output overvoltage, input power and load disconnect, and protect DC/DC converter and load simultaneously, avoid failure propagation.
(3) be applied to input voltage when non-isolation DC/DC converter energy available protecting power MOS pipe leaks source short and directly go here and there output and the output voltage that causes raises the rear class device damage caused.
Accompanying drawing explanation
Fig. 1 is the circuit diagram of the output overvoltage protection circuit exporting termination voltage-stabiliser tube.
Fig. 2 is the circuit diagram of the output overvoltage protection circuit of output thyristor.
Fig. 3 is the circuit diagram of the output pressure limited protection circuit based on PWM.
Fig. 4 is a kind of structured flowchart for DC/DC converter output overvoltage protection circuit of the present invention.
Fig. 5 is the circuit diagram of the protective circuit described in Fig. 4.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited thereto.
As shown in Figure 4, be system block diagram of the present invention.In order to realize output over-voltage protection, the system block diagram realizing the inventive method comprises DC/DC converter, load, is connected on switching tube, threshold circuit and locked circuit on DC/DC converter external input power line.For protection load power consumption equipment damages element from impacting with high pressure, when output voltage exceedes the threshold voltage of threshold circuit setting, locked circuit working turns off the switching tube be connected on DC/DC converter external input power line, and input power and load disconnect.
As shown in Figure 5, be a specific embodiment of method for designing of the present invention.Realize output over-voltage protection by the shutoff controlling the P channel MOS tube be series on DC/DC converter external input power line, when output voltage exceedes the threshold voltage of setting, set high P channel MOS tube and make it to turn off, thus input power and load are disconnected.
When DC/DC converter normally exports, voltage-stabiliser tube ZD3 not conducting, thyristor scr gate pole ground short circuit, thyristor ends, now N-channel MOS pipe Q2 grid sets high, Q2 conducting, causes P channel MOS tube Q1 grounded-grid, Q1 conducting, threshold circuit and locked circuit do not affect DC/DC converter and normally export.
When DC/DC converter output voltage raises, voltage-stabiliser tube ZD3 punctures conducting, and the gate pole of thyristor obtains trigger voltage, turn on thyristors, thyristor is once conducting, gate pole and effect out of hand, turn on thyristors makes Q2 grid voltage shorted to earth, and Q2 disconnects, series connection Q1 grid voltage on the power line sets high, Q1 disconnects, and input power and load is disconnected, stops the work of whole power circuit.
Above-described embodiment is the present invention's preferably execution mode; but embodiments of the present invention are not restricted to the described embodiments; change, the modification done under other any does not deviate from Spirit Essence of the present invention and principle, substitute, combine, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.
Claims (8)
1. one kind for DC/DC converter output overvoltage protection circuit; it is characterized in that: comprise threshold circuit, locked circuit; and the switching tube be connected on described DC/DC converter external input power line; by the output voltage of threshold circuit sampling DC/DC converter; when output voltage values exceedes the threshold voltage of setting; trigger locked circuit working, thus control conducting and the shutoff of the switching tube be connected on DC/DC converter external input power line.
2. according to claim 1 for DC/DC converter output overvoltage protection circuit, it is characterized in that: described DC/DC converter is non-isolated DC/DC converter.
3. according to claim 1 for DC/DC converter output overvoltage protection circuit, it is characterized in that: the bleeder circuit that described threshold circuit comprises voltage stabilizing didoe D3, filter capacitor C2 and is made up of resistance R5, resistance R6; Wherein voltage stabilizing didoe D3 negative pole connects the voltage output end of DC/DC converter, and voltage stabilizing didoe D3 positive pole accesses the bleeder circuit be made up of resistance R5, resistance R6; Filter capacitor C2 is in parallel with resistance R6, one end ground connection, another termination voltage stabilizing didoe D3 positive pole; Resistance R5 mono-termination voltage stabilizing didoe D3 positive pole, the locked circuit of another termination.
4. according to claim 3 for DC/DC converter output overvoltage protection circuit, it is characterized in that: described locked circuit comprises half controlled thyristor SCR, voltage stabilizing didoe D2, current-limiting resistance R2, current-limiting resistance R3 and current-limiting resistance R4, switching tube Q2, voltage stabilizing didoe D1 and switching tube Q1, electric capacity C1, resistance R1; The wherein extreme connecting resistance R6 of half controlled thyristor scr gate, minus earth, anode is connected with current-limiting resistance R3, current-limiting resistance R4, voltage stabilizing didoe D2 negative pole, voltage stabilizing didoe D2 plus earth; Switching tube Q2 source ground, gate pole meets current-limiting resistance R3, and drain electrode meets current-limiting resistance R2; Switching tube Q1 is serially connected on input voltage input positive line, and between the gate pole that voltage stabilizing didoe D1, electric capacity C1 and resistance R1 are attempted by switching tube Q1 and source electrode, the negative pole of voltage stabilizing didoe D1 connects switching tube Q1 gate pole, and the positive pole of voltage stabilizing didoe D1 connects switching tube Q1 source electrode.
5., for a DC/DC converter output over-voltage protection method, it is characterized in that, comprise following steps:
When DC/DC converter exports normal, output overvoltage protection circuit is inoperative, and the switching tube on external input power line is in conducting state, and protective circuit does not affect the normal operating characteristic exported;
When DC/DC converter output voltage exceeded the threshold voltage of threshold circuit setting, switching tube turned off by locked circuit working, and load and input power disconnect, thus protection DC/DC converter and rear class equipment damage components and parts from high pressure punching press.
6. according to claim 5ly it is characterized in that for DC/DC converter output over-voltage protection method, described DC/DC converter is non-isolated DC/DC converter.
7. according to claim 5ly to it is characterized in that for DC/DC converter output over-voltage protection method, the bleeder circuit that described threshold circuit comprises voltage stabilizing didoe D3, filter capacitor C2 and is made up of resistance R5, resistance R6; Wherein voltage stabilizing didoe D3 negative pole connects the voltage output end of DC/DC converter, and voltage stabilizing didoe D3 positive pole accesses the bleeder circuit be made up of resistance R5, resistance R6; Filter capacitor C2 is in parallel with resistance R6, one end ground connection, another termination voltage stabilizing didoe D3 positive pole; Resistance R5 mono-termination voltage stabilizing didoe D3 positive pole, the locked circuit of another termination.
8. according to claim 7 for DC/DC converter output over-voltage protection method, it is characterized in that, described locked circuit comprises half controlled thyristor SCR, voltage stabilizing didoe D2, current-limiting resistance R2, current-limiting resistance R3 and current-limiting resistance R4, switching tube Q2, voltage stabilizing didoe D1 and switching tube Q1, electric capacity C1, resistance R1; The wherein extreme connecting resistance R6 of half controlled thyristor scr gate, minus earth, anode is connected with current-limiting resistance R3, current-limiting resistance R4, voltage stabilizing didoe D2 negative pole, voltage stabilizing didoe D2 plus earth; Switching tube Q2 source ground, gate pole meets current-limiting resistance R3, and drain electrode meets current-limiting resistance R2; Switching tube Q1 is serially connected on input voltage input positive line, and between the gate pole that voltage stabilizing didoe D1, electric capacity C1 and resistance R1 are attempted by switching tube Q1 and source electrode, the negative pole of voltage stabilizing didoe D1 connects switching tube Q1 gate pole, and the positive pole of voltage stabilizing didoe D1 connects switching tube Q1 source electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201510779930.6A CN105337263A (en) | 2015-11-13 | 2015-11-13 | Output overvoltage protection circuit and method for DC/DC converter |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201510779930.6A CN105337263A (en) | 2015-11-13 | 2015-11-13 | Output overvoltage protection circuit and method for DC/DC converter |
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| CN105337263A true CN105337263A (en) | 2016-02-17 |
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| CN201510779930.6A Pending CN105337263A (en) | 2015-11-13 | 2015-11-13 | Output overvoltage protection circuit and method for DC/DC converter |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106155261A (en) * | 2016-08-24 | 2016-11-23 | 柳州鹏达科技有限责任公司 | Computer power supply system protection circuit |
| CN107843807A (en) * | 2016-09-20 | 2018-03-27 | 丰郅(上海)新能源科技有限公司 | A kind of moment in Voltage Drop can turn off the monitoring system of power network in time |
| CN109390917A (en) * | 2018-12-19 | 2019-02-26 | 北京天诚同创电气有限公司 | Control method, device and the DCDC power protecting circuit of DCDC power supply |
| CN109698619A (en) * | 2017-10-20 | 2019-04-30 | 湖南金杯新能源发展有限公司 | Load driving circuits and device |
| CN109950878A (en) * | 2019-03-19 | 2019-06-28 | 华南理工大学 | One kind is for DC/DC converter self- recoverage protection circuit and over-voltage protection method |
| CN113281640A (en) * | 2021-07-20 | 2021-08-20 | 常州今创电工有限公司 | Self-diagnosis system and method for direct current chopping acquisition for rail transit |
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| CN203325124U (en) * | 2013-04-10 | 2013-12-04 | 杨远静 | Dialing integrated dual-boot burglar alarm |
| CN203423477U (en) * | 2013-08-08 | 2014-02-05 | 深圳市同洲电子股份有限公司 | Overvoltage protection circuit |
| CN103606895A (en) * | 2013-12-06 | 2014-02-26 | 悉雅特万科思自动化(杭州)有限公司 | Overvoltage turn-off protection circuit |
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2015
- 2015-11-13 CN CN201510779930.6A patent/CN105337263A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203325124U (en) * | 2013-04-10 | 2013-12-04 | 杨远静 | Dialing integrated dual-boot burglar alarm |
| CN203423477U (en) * | 2013-08-08 | 2014-02-05 | 深圳市同洲电子股份有限公司 | Overvoltage protection circuit |
| CN103606895A (en) * | 2013-12-06 | 2014-02-26 | 悉雅特万科思自动化(杭州)有限公司 | Overvoltage turn-off protection circuit |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106155261A (en) * | 2016-08-24 | 2016-11-23 | 柳州鹏达科技有限责任公司 | Computer power supply system protection circuit |
| CN107843807A (en) * | 2016-09-20 | 2018-03-27 | 丰郅(上海)新能源科技有限公司 | A kind of moment in Voltage Drop can turn off the monitoring system of power network in time |
| CN109698619A (en) * | 2017-10-20 | 2019-04-30 | 湖南金杯新能源发展有限公司 | Load driving circuits and device |
| CN109698619B (en) * | 2017-10-20 | 2020-06-23 | 湖南金杯新能源发展有限公司 | Load driving circuit and device |
| CN109390917A (en) * | 2018-12-19 | 2019-02-26 | 北京天诚同创电气有限公司 | Control method, device and the DCDC power protecting circuit of DCDC power supply |
| CN109950878A (en) * | 2019-03-19 | 2019-06-28 | 华南理工大学 | One kind is for DC/DC converter self- recoverage protection circuit and over-voltage protection method |
| CN113281640A (en) * | 2021-07-20 | 2021-08-20 | 常州今创电工有限公司 | Self-diagnosis system and method for direct current chopping acquisition for rail transit |
| CN113281640B (en) * | 2021-07-20 | 2021-11-02 | 常州今创电工有限公司 | Self-diagnosis system and method for direct current chopping acquisition for rail transit |
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Application publication date: 20160217 |