CN204046570U - One-chip machine port level input protection circuit - Google Patents
One-chip machine port level input protection circuit Download PDFInfo
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- CN204046570U CN204046570U CN201420398171.XU CN201420398171U CN204046570U CN 204046570 U CN204046570 U CN 204046570U CN 201420398171 U CN201420398171 U CN 201420398171U CN 204046570 U CN204046570 U CN 204046570U
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- level input
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- machine port
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Abstract
The utility model provides a kind of one-chip machine port level input protection circuit; it comprises pull-up resistor R1, current-limiting resistance R2, pull down resistor R3, diode D1 and filter capacitor C1; the negative electrode of described diode D1 is as external level input; the anode of described diode D1 connects one end of described resistance R2; the other end of described resistance R2, as the output of this level input protection circuit, is connected to one-chip machine port.One end of described pull-up resistor R1 connects the anode of described diode D1, and the other end connects power supply VCC.Described pull down resistor R3 and described filter capacitor C1 is serially connected with between one-chip machine port and ground respectively.The utility model masks high-voltage signal by the reverse break-in facility of diode, thus protection input circuit, there is the advantage that structure is simple, component number is few, safe and reliable.
Description
Technical field
The utility model relates to a kind of input protection circuit, specifically, relate to a kind of one-chip machine port level input protection circuit.
Background technology
Integrated level is high, volume is little, controlling functions is strong, reliability is high, cost performance advantages of higher owing to having for single-chip microcomputer, is widely used in the fields such as industrial measurement and control, intelligent instrumentation, consumer electronic product, penetrates into the various aspects of our life.Due to the electrical characteristic of one-chip machine port, its input port is difficult to when sampling low and high level the direct access realizing high-voltage signal, high-voltage signal has to pass through necessary process just can be connected to one-chip machine port, once there be high-voltage signal to enter one-chip machine port, single-chip microcomputer will be damaged.
In order to solve above Problems existing, people are seeking a kind of desirable technical solution always.
Utility model content
The purpose of this utility model is for the deficiencies in the prior art, thus provides the one-chip machine port level input protection circuit that a kind of structure is simple, component number is few, safe and reliable.
To achieve these goals; the technical scheme that the utility model adopts is: a kind of one-chip machine port level input protection circuit; it comprises pull-up resistor R1, current-limiting resistance R2, pull down resistor R3, diode D1 and filter capacitor C1; the negative electrode of described diode D1 is as external level input; the anode of described diode D1 connects one end of described current-limiting resistance R2; the other end of described current-limiting resistance R2, as the output of this level input protection circuit, is connected to one-chip machine port.One end of described pull-up resistor R1 connects the anode of described diode D1, and the other end connects power supply VCC.Described pull down resistor R3 and described filter capacitor C1 is serially connected with between one-chip machine port and ground respectively.
The utility model hinge structure has substantive distinguishing features and progress, and specifically, the utility model masks high-voltage signal by the reverse turn-off function of diode, thus protection input circuit, its structure is simple, component number is few, safe and reliable.
Accompanying drawing explanation
Fig. 1 is circuit theory schematic diagram of the present utility model.
Embodiment
Below by embodiment, the technical solution of the utility model is described in further detail.
As shown in Figure 1; a kind of one-chip machine port level input protection circuit; it comprises pull-up resistor R1, current-limiting resistance R2, pull down resistor R3, diode D1 and filter capacitor C1; the negative electrode of described diode D1 is as external level input; the anode of described diode D1 connects one end of described current-limiting resistance R2; the other end of described current-limiting resistance R2, as the output of this level input protection circuit, is connected to one-chip machine port.One end of described pull-up resistor R1 connects the anode of described diode D1, and the other end connects power supply VCC.Described pull down resistor R3 and described filter capacitor C1 is serially connected with between one-chip machine port and ground respectively.
Operation principle of the present utility model is: composition graphs 1, when external level input access high level signal, diode D1 oppositely ends, the voltage of circuit output end is pulled upward to working power voltage VCC+ by current-limiting resistance R2 by pull-up resistor R1, now the voltage of level input protection circuit output is the dividing potential drop after pull-up resistor R1, current-limiting resistance R2 and pull down resistor R3 tri-resistant series on pull down resistor R3: VCC+*R3/ (R1+R2+R3), and this voltage signal delivers to one-chip machine port as high level input after filter capacitor C1 filtering; When external level input access low level signal; diode D1 forward conduction; within pull-up resistor R1 and current-limiting resistance R2 junction voltage are limited in the conduction voltage drop 0.7V of diode D1; now the voltage of level input protection circuit output is the dividing potential drop of conduction voltage drop after current-limiting resistance R2, pull down resistor R3 series connection on pull down resistor R3 of diode D1: 0.7*R3/(R2+R3), this voltage signal delivers to one-chip machine port as low level input after filter capacitor C1 filtering.
The utility model is applicable to polytype one-chip machine port; only need the value regulating pull-up resistor R1, current-limiting resistance R2 and pull down resistor R3 according to the electrical characteristic of different single-chip microcomputer, make it can realize low level input protection within the scope of single-chip microcomputer low and high level.
Finally should be noted that: above embodiment is only in order to illustrate that the technical solution of the utility model is not intended to limit; Although be described in detail the utility model with reference to preferred embodiment, those of ordinary skill in the field have been to be understood that: still can modify to embodiment of the present utility model or carry out equivalent replacement to portion of techniques feature; And not departing from the spirit of technical solutions of the utility model, it all should be encompassed in the middle of the technical scheme scope of the utility model request protection.
Claims (1)
1. an one-chip machine port level input protection circuit, it is characterized in that: it comprises pull-up resistor R1, current-limiting resistance R2, pull down resistor R3, diode D1 and filter capacitor C1, the negative electrode of described diode D1 is as external level input, the anode of described diode D1 connects one end of described current-limiting resistance R2, the other end of described current-limiting resistance R2, as the output of this level input protection circuit, is connected to one-chip machine port; One end of described pull-up resistor R1 connects the anode of described diode D1, and the other end connects power supply VCC; Described pull down resistor R3 and described filter capacitor C1 is serially connected with between one-chip machine port and ground respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420398171.XU CN204046570U (en) | 2014-07-18 | 2014-07-18 | One-chip machine port level input protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420398171.XU CN204046570U (en) | 2014-07-18 | 2014-07-18 | One-chip machine port level input protection circuit |
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| Publication Number | Publication Date |
|---|---|
| CN204046570U true CN204046570U (en) | 2014-12-24 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
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| CN201420398171.XU Active CN204046570U (en) | 2014-07-18 | 2014-07-18 | One-chip machine port level input protection circuit |
Country Status (1)
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| CN (1) | CN204046570U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106992775A (en) * | 2017-03-27 | 2017-07-28 | 深圳易能电气技术股份有限公司 | It is a kind of by negative voltage transition into zero level signal device and method |
| CN109426641A (en) * | 2017-09-01 | 2019-03-05 | 意法半导体(鲁塞)公司 | The protection circuit for high voltage for USB Type C receiver |
| CN109617462A (en) * | 2018-12-11 | 2019-04-12 | 上海肖可雷电子科技有限公司 | A kind of recognition methods of electric motor starting state |
-
2014
- 2014-07-18 CN CN201420398171.XU patent/CN204046570U/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106992775A (en) * | 2017-03-27 | 2017-07-28 | 深圳易能电气技术股份有限公司 | It is a kind of by negative voltage transition into zero level signal device and method |
| CN106992775B (en) * | 2017-03-27 | 2020-11-10 | 深圳易能电气技术股份有限公司 | Device and method for converting negative voltage into zero level signal |
| CN109426641A (en) * | 2017-09-01 | 2019-03-05 | 意法半导体(鲁塞)公司 | The protection circuit for high voltage for USB Type C receiver |
| CN109426641B (en) * | 2017-09-01 | 2023-06-13 | 意法半导体(鲁塞)公司 | Protection circuit for USB Type C receiver aiming at high voltage |
| CN109617462A (en) * | 2018-12-11 | 2019-04-12 | 上海肖可雷电子科技有限公司 | A kind of recognition methods of electric motor starting state |
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| GR01 | Patent grant |