CN110707660A - Load overcurrent protection circuit - Google Patents
Load overcurrent protection circuit Download PDFInfo
- Publication number
- CN110707660A CN110707660A CN201911114122.2A CN201911114122A CN110707660A CN 110707660 A CN110707660 A CN 110707660A CN 201911114122 A CN201911114122 A CN 201911114122A CN 110707660 A CN110707660 A CN 110707660A
- Authority
- CN
- China
- Prior art keywords
- pin
- current
- load
- limiting
- chip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
The embodiment of the invention discloses a load overcurrent protection circuit, which comprises a power supply, a load overcurrent protection circuit and a load overcurrent protection circuit, wherein the power supply is used for supplying power to a load; the current limiting IC chip is connected with the power supply and used for being connected with a load, the single chip microcomputer is respectively connected with the power supply and the current limiting IC chip and used for being connected with the load, and the current limiting resistor is connected with the current limiting IC chip at one end and grounded at the other end; when the load current exceeds a preset current value, the current-limiting IC chip outputs a low level to the single chip microcomputer to drive the single chip microcomputer to control the output of the current-limiting IC chip to be closed, so that the power supply of a power supply source to the load is cut off; the embodiment of the invention can ensure that the load part does not generate large current, thereby achieving the purpose of protecting the load from being damaged.
Description
Technical Field
The invention relates to the field of circuits, in particular to a load overcurrent protection circuit.
Background
In many electronic products on the market, no overcurrent protection measures are taken for a power supply or only one current-limiting IC chip is used for limiting current so as to achieve the aim of overcurrent protection. However, when a load part is short-circuited or otherwise abnormal, and a large current is generated in the load part, the current supply cannot be cut off rapidly and completely by the overcurrent protection measures on the market, but the large current is continuously supplied to the load part, which easily causes the load to be damaged due to overcurrent and overheating, and also easily damages the whole electronic equipment.
Disclosure of Invention
In view of this, the embodiment of the present invention provides a load overcurrent protection circuit, where a load overcurrent protection circuit is used, when a large current occurs in the load, a low level is output to a single chip microcomputer through a current-limiting IC chip, and the single chip microcomputer controls the output of the current-limiting IC chip to be turned off, so as to cut off power supplied from a power supply to a load portion, and ensure that the load portion does not generate the large current, thereby achieving the purpose of protecting the load from being damaged.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a load overcurrent protection circuit comprises a power supply, a load current detection circuit and a load overcurrent protection circuit, wherein the power supply is used for supplying power to a load; the current limiting IC chip is connected with the power supply and used for being connected with the load, the single chip microcomputer is respectively connected with the power supply and the current limiting IC chip and used for being connected with the load, and the current limiting resistor is connected with the current limiting IC chip at one end and grounded at the other end; when the load current exceeds a preset current value, the current-limiting IC chip outputs low level to the single chip microcomputer to drive the single chip microcomputer to control the output of the current-limiting IC chip to be closed, and therefore power supply of a power supply source to the load is cut off.
Optionally, the current-limiting IC chip includes a VIN pin, a VOUT pin, an EN pin, a FLAG pin, an ILIM pin, and a first GND pin, and the current-limiting IC chip is connected to a power supply through the VIN pin, to a load through the VOUT pin, to the single chip microcomputer through the EN pin and the FLAG pin, to the ground after being connected to the current-limiting resistor R through the ILIM pin, and to the ground through the GND pin.
Optionally, the singlechip includes VCC foot, second GND foot, first GPIO foot, second GPIO foot, third GPIO foot, fourth GPIO foot, fifth GPIO foot, sixth GPIO foot, the singlechip pass through VCC foot with power supply connects, through second GND foot ground connection, through first GPIO foot and second GPIO foot with current-limiting IC chip connects, through third GPIO foot with the load is connected, receives through fourth GPIO foot and fifth GPIO foot and burns the record procedure.
Optionally, the load is an SD card, and the SD card is connected to the single chip microcomputer through a CD pin on the SD card.
Optionally, the current-limiting IC chip is an MP65151 chip.
Optionally, the single chip microcomputer is an STC15W100 single chip microcomputer.
Optionally, the input voltage of the VIN pin of the current-limiting IC chip is 2.5V to 5.5V.
Optionally, the output voltage of the VOUT pin of the current-limiting IC chip is 2.5V to 5.5V.
Optionally, the preset current value is 380 mA.
In summary, the embodiment of the present invention provides a load overcurrent protection circuit, which includes a power supply for supplying power to a load; the current limiting IC chip is connected with a power supply and is used for being connected with the load, the single chip microcomputer is respectively connected with the power supply and the current limiting IC chip and is used for being connected with the load, and one end of the current limiting resistor R is connected with the current limiting IC chip, and the other end of the current limiting resistor R is grounded; when the load current exceeds a preset current value, the current-limiting IC chip outputs a low level to the single chip microcomputer to drive the single chip microcomputer to control the output of the current-limiting IC chip to be closed, and therefore the power supply of the power supply to the load is cut off. The embodiment of the invention can ensure that the load part does not generate large current, thereby achieving the purpose of protecting the load from being damaged.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a load overcurrent protection circuit according to the present invention;
fig. 2 is a schematic circuit structure diagram of the load overcurrent protection circuit according to the present invention;
fig. 3 is a schematic diagram of another circuit structure of the load overcurrent protection circuit according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1 and fig. 2, a load overcurrent protection circuit according to an embodiment of the present invention includes a power supply 01 for supplying power to a load 02, a current-limiting IC chip 03 connected to the power supply 01 and to the load 02, a single chip 04 connected to the power supply 01 and the current-limiting IC chip 03 respectively and to the load 02, and a current-limiting resistor R having one end connected to the current-limiting IC chip 03 and the other end grounded; when the current of the load 02 exceeds a preset current value, the current-limiting IC chip 03 outputs a low level to the single chip 04 to drive the single chip 04 to control the output of the current-limiting IC chip 03 to be turned off, so that the power supply of the power supply 01 to the load 02 is cut off.
Specifically, as shown in fig. 2, the current-limiting IC chip 03 includes a VIN pin 031, a VOUT pin 032, an EN pin 033, a FLAG pin 034, an ILIM pin 035, and a first GND pin 036, the current-limiting IC chip 03 is connected to the power supply 01 through the VIN pin 031, to the load 02 through the VOUT pin 032, to the single chip 04 through the EN pin 033 and the FLAG pin 034, to the ground after being connected to the current-limiting resistor R through the ILIM pin 035, and to the ground through the GND pin 036.
Specifically, as shown in fig. 2, the single chip 04 includes a VCC pin 041, a second GND pin 042, a first GPIO pin 043, a second GPIO pin 044, a third GPIO pin 045, a fourth GPIO pin 046, a fifth GPIO pin 047, and a sixth GPIO pin 048, the single chip 04 is connected to the power supply 01 through the VCC pin 041, is grounded through the second GND pin 042, is connected to the current-limiting IC chip 03 through the first GPIO pin 043 and the second GPIO pin 044, is connected to the load 02 through the third GPIO pin 045, and receives the programming through the fourth GPIO pin 046 and the fifth GPIO pin 047.
Specifically, the load 01 may be an SD card, and the SD card is connected to the single chip 04 through a CD pin on the SD card, and more specifically, the SD card is connected to a third GPIO pin 045 on the single chip 04 through a CD pin on the SD card.
The current-limiting IC chip 03 adopts an MP65151 chip, the singlechip 04 adopts an STC15W100 singlechip, the input voltage of a VIN pin 031 of the current-limiting IC chip 03 is 2.5V-5.5V, and when the output end of the current-limiting IC chip 03 is light load, the output voltage of a VOUT pin 032 of the current-limiting IC chip 03 is 2.5V-5.5V.
The preset current value is 380 mA.
The principle of the embodiment of the invention is as follows:
the embodiment of the present invention describes the present invention by using an SD card as a load, and the load in the present invention may also be other electronic products, and the specific electronic product is not limited herein.
As shown in fig. 3, after the load overcurrent protection circuit is added, the power supply 01 supplies power to the current-limiting IC chip 03 and the single chip 04 through a VIN pin 031 of the current-limiting IC chip 03 and a VCC pin 041 of the single chip 04, respectively, a VOUT pin 032 of the current-limiting IC chip 03 supplies power to the SD card 02, and when the SD card 02 is not inserted into (pulled out of) the card slot, a third GPIO pin 045 of the single chip 04 is at a high level; after the SD card 02 is inserted into the card slot, the third GPIO pin 045 immediately changes to the low level and keeps the low level, when an abnormality occurs at the SD card 02 end, for example, the SD card 02 is broken, and a large current flows through the card body of the SD card 02, the FLAG pin 034 of the current-limiting IC chip 03 outputs the low level (default is the high level), and the single chip 04 outputs the low level through the first GPIO pin 043 after detecting the change (that is, the output voltage changes from the high level to the low level) through the second GPIO pin 044, so as to pull down the EN pin 033 of the current-limiting IC chip 03, and further, the output of the current-limiting IC chip 03 is turned off. Therefore, no large current passes through the SD card 02, the safety of the SD card 02 is ensured, and the purpose of protecting the load from being damaged is achieved.
In the embodiment of the invention, when the abnormal SD card 02 is removed, the CD pin of the SD card 02 card slot has level change, if the single chip 04 detects the level change, it knows that the abnormality does not exist, and then releases the EN pin 033 on the current-limiting IC chip 03 to recover the high level, that is, to reach the normal working state of the current-limiting IC chip 03, so as to ensure that the SD card 02 can work normally when a new SD card 02 is inserted subsequently.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (9)
1. A load overcurrent protection circuit is characterized by comprising
The power supply is used for supplying power to the load;
a current limiting IC chip connected with a power supply and used for being connected with the load,
a single chip microcomputer connected with the power supply and the current limiting IC chip respectively and used for connecting with the load, and
one end of the current-limiting resistor R is connected with the current-limiting IC chip, and the other end of the current-limiting resistor R is grounded;
when the load current exceeds a preset current value, the current-limiting IC chip outputs a low level to the single chip microcomputer to drive the single chip microcomputer to control the output of the current-limiting IC chip to be closed, and therefore the power supply of the power supply to the load is cut off.
2. The load overcurrent protection circuit as claimed in claim 1, wherein the current-limiting IC chip includes a VIN pin, a VOUT pin, an EN pin, a FLAG pin, an ILIM pin, and a first GND pin, and the current-limiting IC chip is connected to a power supply through the VIN pin, to a load through the VOUT pin, to the single chip microcomputer through the EN pin and the FLAG pin, to the current-limiting resistor R through the ILIM pin, and to ground through the GND pin.
3. The load overcurrent protection circuit of claim 1, wherein the single chip microcomputer includes a VCC pin, a second GND pin, a first GPIO pin, a second GPIO pin, a third GPIO pin, a fourth GPIO pin, a fifth GPIO pin, and a sixth GPIO pin, the single chip microcomputer is connected to the power supply through the VCC pin, is grounded through the second GND pin, is connected to the current-limiting IC chip through the first GPIO pin and the second GPIO pin, is connected to the load through the third GPIO pin, and receives the programming program through the fourth GPIO pin and the fifth GPIO pin.
4. The load overcurrent protection circuit of any one of claims 1-3, wherein the load is an SD card, and the SD card is connected to the single chip microcomputer through a CD pin on the SD card.
5. The load overcurrent protection circuit of any one of claims 1-3, wherein the current-limiting IC chip is an MP65151 chip.
6. The load overcurrent protection circuit of any one of claims 1-3, wherein the single-chip microcomputer is an STC15W100 single-chip microcomputer.
7. The load over-current protection circuit of claim 2, wherein an input voltage of a VIN pin of the current-limiting IC chip is 2.5V to 5.5V.
8. The load overcurrent protection circuit of claim 2, wherein an output voltage of a VOUT pin of the current-limiting IC chip is 2.5V to 5.5V.
9. The load overcurrent protection circuit of claim 1, wherein the predetermined current value is 380 mA.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911114122.2A CN110707660A (en) | 2019-11-14 | 2019-11-14 | Load overcurrent protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911114122.2A CN110707660A (en) | 2019-11-14 | 2019-11-14 | Load overcurrent protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110707660A true CN110707660A (en) | 2020-01-17 |
Family
ID=69204302
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911114122.2A Pending CN110707660A (en) | 2019-11-14 | 2019-11-14 | Load overcurrent protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110707660A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111788752A (en) * | 2020-05-25 | 2020-10-16 | 深圳市锐明技术股份有限公司 | Protection circuit, power supply system of hard disk device and vehicle-mounted device |
| CN112367580A (en) * | 2020-10-21 | 2021-02-12 | Oppo广东移动通信有限公司 | Noise reduction circuit and earphone |
| CN112636740A (en) * | 2020-12-28 | 2021-04-09 | 潍柴动力股份有限公司 | Signal input mode control circuit and method |
-
2019
- 2019-11-14 CN CN201911114122.2A patent/CN110707660A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111788752A (en) * | 2020-05-25 | 2020-10-16 | 深圳市锐明技术股份有限公司 | Protection circuit, power supply system of hard disk device and vehicle-mounted device |
| CN112367580A (en) * | 2020-10-21 | 2021-02-12 | Oppo广东移动通信有限公司 | Noise reduction circuit and earphone |
| CN112636740A (en) * | 2020-12-28 | 2021-04-09 | 潍柴动力股份有限公司 | Signal input mode control circuit and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110707660A (en) | Load overcurrent protection circuit | |
| CN101470507B (en) | Power supply control circuit | |
| US9112352B2 (en) | Condition responsive circuit protection apparatus which can enter an energy saving mode | |
| CN105788556B (en) | A kind of overvoltage crowbar and method, liquid crystal display drive circuit | |
| CN102047519A (en) | Technique for removing in-rush current limiting and short circuit current limiting | |
| CN101373388B (en) | Adjusting apparatus | |
| US20100045117A1 (en) | Protection device for a power source and power unit using same | |
| CN105281296A (en) | Switch power supply protection and control method and circuit | |
| US20160191000A1 (en) | Protection device | |
| US20070152738A1 (en) | Pull-up circuit | |
| CN102316629B (en) | Dc power supply unit and led lighting apparatus | |
| JP2006048594A (en) | Usb device | |
| CN213846228U (en) | Power supply circuit of electronic equipment and electronic equipment | |
| CN210724182U (en) | Load overcurrent protection circuit | |
| JP6201410B2 (en) | Power circuit | |
| TWI479763B (en) | Protecion apparatus for a dc-dc converter | |
| CN214506546U (en) | No-load protection circuit | |
| CN107332203A (en) | A kind of Over Current Protection System and method for inductive load | |
| CN108880528A (en) | The interface circuit of electronic device | |
| CN210136418U (en) | Monitoring circuit and relay protection device | |
| JP4205072B2 (en) | Power supply device | |
| KR101889948B1 (en) | Short detection circuit of multi-terminal | |
| CN203690882U (en) | Computer USB interface short circuit prevention circuit | |
| US20060133001A1 (en) | Protection circuit | |
| CN218648565U (en) | Overcurrent protection circuit of optical module and optical module |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |