CN103856033A - Diode protection circuit - Google Patents
Diode protection circuit Download PDFInfo
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- CN103856033A CN103856033A CN201210499133.9A CN201210499133A CN103856033A CN 103856033 A CN103856033 A CN 103856033A CN 201210499133 A CN201210499133 A CN 201210499133A CN 103856033 A CN103856033 A CN 103856033A
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Abstract
The invention discloses a diode protection circuit. The diode protection circuit comprises a first diode, a second diode, a third diode and a three-terminal voltage regulator. According to the diode protection circuit, the rectification and low forward voltage drop characteristics of the diodes are utilized, the first diode is connected in parallel to the three- terminal voltage regulator, the second diode is added between an output pin of the three- terminal voltage regulator and a voltage output end, the third diode is added between the voltage output end and the ground, and therefore, a power supply circuit of a single chip microcomputer can be effectively protected. The protection circuit is simple in structure, has fewer components, and is highly reliable.
Description
Technical field
The present invention relates to electronic circuit field, particularly, relate to a kind of protective circuit of diode.
Background technology
The advantages such as single-chip microcomputer is strong with its function, reliability is high, volume is little, price is low, easy commercialization, are widely used in the fields such as intelligent instrument, Industry Control, communication equipment and household electrical appliance.At present, scm application system adopts mostly by Alternating Current Power Supply, after transformation, rectification, filtering and adjustment, obtain+5V volt tandem type DC power supply.This DC power supply in the time that AC power is unstable, will obtain stable and precision is higher+5V.
Conventional single-chip microcomputer power supply circuit is take three terminal regulator 78m05 as core, 12V power supply to input carries out voltage stabilizing, make its output 5V voltage, these power supply circuits are at input and output and connect 104 electric capacity and electrochemical capacitor, carry out ripple processing and interference filter, and two diodes of connecting are to the input pin of three terminal regulator, with to the suitable step-down of the input voltage of three terminal regulator with the power supply of reserve battery is isolated.The shortcoming of these single-chip microcomputer power supply circuits is, can not, at output voltage during lower than earth potential or when output voltage is more than or equal to input voltage, form effective protection to these power supply circuits.
Summary of the invention
The object of the present invention is to provide a kind of protective circuit of diode, be intended to solve the single-chip microcomputer power supply circuits that prior art exists and can not get the effectively problem of protection.
In order to realize object of the present invention, described protective circuit of diode comprises the first diode, the second diode, the 3rd diode and three terminal regulator; Wherein
The positive pole of described the first diode connects voltage output end, negative pole connects voltage input end, the positive pole of described the second diode connects the output pin of described three terminal regulator, negative pole connects positive pole and the described voltage output end of described the first diode, the plus earth of described the 3rd diode, negative pole is connected between the output pin of described three terminal regulator and the positive pole of described the second diode, the input pin of described three terminal regulator connects described voltage input end, the grounding leg ground connection of described three terminal regulator, described voltage input end is used for connecting DC power supply, described voltage output end is used for connecting single-chip microcomputer.
In above-mentioned protective circuit of diode; described protective circuit of diode also comprises the first electric capacity and the second electric capacity; one end of described the first electric capacity connects the input pin of described three terminal regulator; the other end connects the grounding leg of described three terminal regulator; one end of described the second electric capacity connects the output pin of described three terminal regulator, and the other end connects the positive pole of described the 3rd diode.
In above-mentioned protective circuit of diode, the model of described three terminal regulator is 78m05.
In above-mentioned protective circuit of diode, the model of described the first diode and described the second diode is IN4148.
In above-mentioned protective circuit of diode, the Schottky diode that described the 3rd diode is forward voltage drop, its model is EK03.
The present invention utilizes rectification and the low forward voltage drop characteristic of diode; by the first diode in parallel to three terminal regulator; between the output pin of three terminal regulator and voltage output end, add the second diode; and between voltage output end and ground, add the 3rd diode; can effectively protect the power supply circuits of single-chip microcomputer, this protective circuit formation is simple and direct, use element is few and reliability is high.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is some embodiments of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the structure principle chart of the protective circuit of diode that provides of the embodiment of the present invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment in the present invention, those of ordinary skills, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.
Fig. 1 shows the structure principle chart of the protective circuit of diode that the embodiment of the present invention provides.
Protective circuit of diode in this figure comprises the first diode D1, the second diode D2, the 3rd diode D3 and three terminal regulator U1, the positive pole of wherein stating the first diode D1 connects voltage output end OUT, negative pole connects voltage input end IN, the positive pole of the second diode D2 connects the output pin Vout of three terminal regulator U1, negative pole connects positive pole and the power output end OUT of the first diode D1, the plus earth of the 3rd diode D3, negative pole is connected between the output pin Vout of three terminal regulator U1 and the positive pole of the second diode D2, the input pin Vin of three terminal regulator U1 connects power input IN, the grounding leg GND ground connection of three terminal regulator U1, voltage input end IN is used for connecting DC power supply, voltage output end OUT is used for connecting single-chip microcomputer to power to single-chip microcomputer.
Protective circuit of diode shown in Fig. 1 also comprises the first capacitor C 1 and the second capacitor C 2; one end of the first capacitor C 1 connects the input pin Vin of three terminal regulator U1; the other end connects the grounding leg GND of three terminal regulator U1; one end of the second capacitor C 2 connects the output pin Vout of three terminal regulator U1, and the other end connects the positive pole of the 3rd diode D3.The effect of the first capacitor C 1 and the second capacitor C 2 is to carry out ripple processing and interference filter.
The model of three terminal regulator U1 is 78m05, and its output voltage is+5V, and the maximum of input voltage is 35V, and the model of the first diode D1 and the second diode D2 is IN4148, the Schottky diode that the 3rd diode D3 is forward voltage drop, and its model is EK03.
The specific works principle of the protective circuit of diode that the embodiment of the present invention provides is: in the time of voltage input end IN shorted to earth; its current potential approaches rapidly zero potential; and voltage output end OUT is owing to there being large electric capacity; store a lot of electric charges and have little time to discharge; at this moment the output adjustment pipe by three terminal regulator U1 is discharged electric charge by electric capacity, and its PN junction can be breakdown under the reverse bias voltage higher than 7V.If there has been protection diode, just can in time the electric charge of electric capacity be discharged, thereby protect three terminal regulator U1, that is to say, when the voltage of voltage output end OUT output is during higher than the voltage of voltage input end IN input, the first diode D1 conducting, punctures thereby can avoid three terminal regulator U1 to be reversed; Another kind of situation is, when the voltage of voltage output end OUT is during lower than earth potential, and D3 conducting, and then can form effective protection to three terminal regulator U1; In addition, in the time that the voltage of voltage output end OUT equals the voltage of voltage input end IN, D1 conducting, D2 cut-off, this state has also carried out the protection of actual effect to this circuit.
The foregoing is only preferred embodiment of the present invention, be not limited to the present invention, all any modifications of making within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included in protection scope of the present invention.
Claims (5)
1. a protective circuit of diode, is characterized in that, described protective circuit of diode comprises the first diode, the second diode, the 3rd diode and three terminal regulator; Wherein
The positive pole of described the first diode connects voltage output end, negative pole connects voltage input end, the positive pole of described the second diode connects the output pin of described three terminal regulator, negative pole connects positive pole and the described voltage output end of described the first diode, the plus earth of described the 3rd diode, negative pole is connected between the output pin of described three terminal regulator and the positive pole of described the second diode, the input pin of described three terminal regulator connects described voltage input end, the grounding leg ground connection of described three terminal regulator, described voltage input end is used for connecting DC power supply, described voltage output end is used for connecting single-chip microcomputer.
2. protective circuit of diode according to claim 1; it is characterized in that; described protective circuit of diode also comprises the first electric capacity and the second electric capacity; one end of described the first electric capacity connects the input pin of described three terminal regulator; the other end connects the grounding leg of described three terminal regulator; one end of described the second electric capacity connects the output pin of described three terminal regulator, and the other end connects the positive pole of described the 3rd diode.
3. protective circuit of diode according to claim 1 and 2, is characterized in that, the model of described three terminal regulator is 78m05.
4. protective circuit of diode according to claim 1 and 2, is characterized in that, the model of described the first diode and described the second diode is IN4148.
5. protective circuit of diode according to claim 1 and 2, is characterized in that, the Schottky diode that described the 3rd diode is forward voltage drop, and its model is EK03.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210499133.9A CN103856033A (en) | 2012-11-28 | 2012-11-28 | Diode protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210499133.9A CN103856033A (en) | 2012-11-28 | 2012-11-28 | Diode protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103856033A true CN103856033A (en) | 2014-06-11 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210499133.9A Pending CN103856033A (en) | 2012-11-28 | 2012-11-28 | Diode protection circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN103856033A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110737300A (en) * | 2019-10-25 | 2020-01-31 | 吉林北斗航天汽车研究院有限公司 | low-cost low dropout regulator parallel current-expanding equalizing circuit |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201466971U (en) * | 2009-05-29 | 2010-05-12 | 陈守约 | Special power supply circuit of motorcycle display instrument |
| CN202103578U (en) * | 2011-04-29 | 2012-01-04 | 浙江永泰隆电子有限公司 | Capacitance-resistance step down type switch power supply |
-
2012
- 2012-11-28 CN CN201210499133.9A patent/CN103856033A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201466971U (en) * | 2009-05-29 | 2010-05-12 | 陈守约 | Special power supply circuit of motorcycle display instrument |
| CN202103578U (en) * | 2011-04-29 | 2012-01-04 | 浙江永泰隆电子有限公司 | Capacitance-resistance step down type switch power supply |
Non-Patent Citations (2)
| Title |
|---|
| 武杰: "快速可重组机械工程测控实验平台的研制", 《中国优秀硕士学位论文全文数据库工程科技Ⅱ辑》 * |
| 赵超: "基于Atmel单片机的无线遥控密码锁设计", 《信息技术》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110737300A (en) * | 2019-10-25 | 2020-01-31 | 吉林北斗航天汽车研究院有限公司 | low-cost low dropout regulator parallel current-expanding equalizing circuit |
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| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20140611 |