CN201393057Y - Over-voltage and under-voltage protection circuit - Google Patents
Over-voltage and under-voltage protection circuit Download PDFInfo
- Publication number
- CN201393057Y CN201393057Y CN200920301041U CN200920301041U CN201393057Y CN 201393057 Y CN201393057 Y CN 201393057Y CN 200920301041 U CN200920301041 U CN 200920301041U CN 200920301041 U CN200920301041 U CN 200920301041U CN 201393057 Y CN201393057 Y CN 201393057Y
- Authority
- CN
- China
- Prior art keywords
- voltage
- resistance
- integrated circuit
- circuit
- under
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Protection Of Static Devices (AREA)
Abstract
An over-voltage and under-voltage protection circuit comprises a switch power supply integrated circuit, a first voltage-dividing circuit, a second voltage-dividing circuit and a transistor. The first voltage-dividing circuit comprises a first resistor and a second resistor. The second voltage-dividing circuit comprises a third resistor and a fourth resistor. The base of the transistor is connected with the common node of the first resistor and the second resistor, the collector is connected with the common node of the third resistor and the fourth resistor, and the emitter is grounded. The switch power supply integrated circuit includes an input pin, an enable pin and an output pin, wherein the input pin is connected with an external input DC power supply; the enable pin is connected with the common node of the third resistor and the fourth resistor; and the output pin is used for outputting the voltage of the external input DC power supply. The over-voltage and under-voltage protection circuit utilizes the enable pin of the switch power supply integrated circuit to be externally connected with the first voltage-dividing circuit, the second voltage-dividing circuit and the transistor, so as to realize over-voltage and under-voltage protection; the cost is lower; and the structure is simple.
Description
Technical field
The utility model relates to a kind of protective circuit, relates in particular to a kind of overvoltage and under-voltage protecting circuit.
Background technology
At present, various electronic products extensively utilize the Switching Power Supply integrated circuit to reach the purpose of under-voltage protection.The Switching Power Supply integrated circuit has an enable pin usually, and described enable pin is used for the operating state of control switching integrated circuit, and when input voltage was higher than a certain fixed value, the Switching Power Supply integrated circuit can operate as normal; Otherwise, then quit work.Utilize this characteristic, can effectively realize under-voltage protection, promptly when the voltage of input product was reduced to a certain limiting value, product promptly quit work, and has improved reliability of products.
But, only realize that the under-voltage protection of circuit can not the better protection circuit, enhance product performance.For the better protection circuit; further enhance product performance, general using Switching Power Supply integrated circuit and special-purpose overvoltage protection integrated circuit combine and realize circuit in the current circuit overvoltage and under-voltage protection, still; the cost of this way is higher, and complex structure.
The utility model content
In view of this, need provide a kind of overvoltage and under-voltage protecting circuit, can realize the overvoltage and the under-voltage protection of circuit, cost is lower, and simple in structure.
A kind of overvoltage and under-voltage protecting circuit are used to realize the overvoltage and the under-voltage protection of circuit, comprise Switching Power Supply integrated circuit, first bleeder circuit, second bleeder circuit and triode.Wherein, first bleeder circuit comprises first resistance and second resistance, and an end of described first resistance links to each other with the input DC power that adds; Second resistance is connected between the other end and ground of first resistance.Second bleeder circuit comprises the 3rd resistance and the 4th resistance, and an end of the 3rd resistance links to each other with the input DC power that adds; The 4th resistance is connected between the other end and ground of the 3rd resistance.The base stage of triode is connected in the common node of first resistance and second resistance, and its collector electrode is connected in the common node of the 3rd resistance and the 4th resistance, its grounded emitter; Wherein, when input supply voltage is excessive, first bleeder circuit causes the triode conducting, and the enable pin of Switching Power Supply integrated circuit is by triode ground connection, and the voltage that causes being added in the enable pin of Switching Power Supply integrated circuit is lower than operating voltage and it is quit work; When input supply voltage was too small, first bleeder circuit caused triode to end, and the voltage that second bleeder circuit causes being added in the enable pin of Switching Power Supply integrated circuit is lower than its operating voltage and it is quit work.
A kind of overvoltage and under-voltage protecting circuit; be connected between voltage source and the integrated circuit; be used to realize overvoltage and under-voltage protection to integrated circuit, integrated circuit comprises power end and enable pin, and described overvoltage and under-voltage protecting circuit comprise first bleeder circuit, triode and second bleeder circuit.Wherein, first bleeder circuit is connected between voltage source and the ground, is used to export first voltage division signal; The base stage of triode receives first voltage division signal, and its collector electrode is connected to the enable pin of integrated circuit, its grounded emitter; Second bleeder circuit is connected between voltage source and the ground, is used to export the enable pin of second voltage division signal to integrated circuit.When power source voltage is excessive, first voltage division signal of first bleeder circuit output makes the triode conducting, thereby the voltage that makes the enable pin of integrated circuit is reduced to the emitter voltage of triode, and emitter voltage is lower than the operating voltage of integrated circuit and it is quit work; When supply voltage was too small, first voltage division signal was ended triode, and second voltage division signal of second bleeder circuit output is the voltage of the enable pin that is added in integrated circuit, thereby second voltage division signal quits work because of the operating voltage that is lower than integrated circuit makes it.
Overvoltage of the present utility model and under-voltage protecting circuit adopt external first bleeder circuit of enable pin, second bleeder circuit and the triode of Switching Power Supply integrated circuit, can realize the overvoltage and the under-voltage protection of circuit, and cost is lower, and simple in structure.
Description of drawings
Fig. 1 is the overvoltage of the utility model one execution mode and the circuit diagram of under-voltage circuit.
Embodiment
Figure 1 shows that the circuit diagram of the under-voltage and overvoltage crowbar of the utility model one execution mode.In the present embodiment, described under-voltage and overvoltage crowbar comprises first bleeder circuit 10, second bleeder circuit 20 and triode Q1, is used to realize the protection of Switching Power Supply integrated circuit U1 and load circuit.
Further improvement as the utility model one execution mode; this overvoltage and under-voltage protecting circuit also comprise the 5th resistance R 5; one end is connected in the common node of first resistance R 1 and second resistance R 2, and the other end is connected in the base stage of triode Q1, is used to limit the base current of triode Q1.
In the present embodiment, the input voltage of overvoltage and under-voltage protecting circuit is VIN, and output voltage is VOUT.When the input voltage VIN of the enable pin EN of Switching Power Supply integrated circuit U1 is suitable size, in the time of can driven Switching Power Supply integrated circuit U1, Switching Power Supply integrated circuit U1 starts working, by output pin output voltage VO UT.Wherein, the input voltage VEN of the enable pin of Switching Power Supply integrated circuit U1 is greater than 1V.
In this embodiment, overvoltage and under-voltage protecting circuit obtain voltage V1 after by first bleeder circuit, 10 dividing potential drops, and V1=(VIN * R2)/(R1+R2).By obtaining voltage V2 after second bleeder circuit, 20 dividing potential drops, and V2=(R4 * VIN)/(R4+R3).When the input voltage VIN of overvoltage and under-voltage protecting circuit is excessive; voltage V1 is greater than the cut-in voltage of triode Q1; triode Q1 conducting; be operated in the amplification region; the enable pin EN of Switching Power Supply integrated circuit U1 is by triode Q1 ground connection; the voltage of the enable pin EN of input switch power IC U1 will be reduced to below the 1V, and Switching Power Supply integrated circuit U1 quits work, thereby realize the effect to the overvoltage protection of switch power IC U1 and load circuit.
When the input voltage VIN of overvoltage and under-voltage protecting circuit was too small, the voltage VEN of the enable pin of Switching Power Supply integrated circuit U1 equaled V2.When V2 reduces to 1V when following, Switching Power Supply integrated circuit U1 quits work, thereby has realized the effect to the under-voltage protection of switch power IC U1 and load circuit.
Overvoltage of the present utility model and under-voltage protecting circuit; adopt a spot of discrete elements (as resistance; triode etc.); the operating characteristic of the enable pin by integrated circuit; do not need to use special-purpose overvoltage and under-voltage protection integrated circuit; just can realize integrated circuit itself and load circuit are protected, simple in structure, and cost is low.
Claims (3)
1. overvoltage and under-voltage protecting circuit are used to realize the overvoltage and the under-voltage protection of circuit, it is characterized in that described overvoltage and under-voltage protecting circuit comprise:
First bleeder circuit comprises:
First resistance, the one end links to each other with the input DC power that adds;
Second resistance is connected between the other end and ground of described first resistance;
Second bleeder circuit comprises:
The 3rd resistance, the one end links to each other with the input DC power that adds;
The 4th resistance is connected between the other end and ground of described the 3rd resistance; And
Triode, its base stage are connected in the common node of described first resistance and described second resistance, and its collector electrode is connected in the common node of described the 3rd resistance and described the 4th resistance, its grounded emitter; And
The Switching Power Supply integrated circuit, comprise input pin, enable pin and output pin, described input pin is connected in the described input DC power that adds, described enable pin is connected in the common node of described the 3rd resistance and described the 4th resistance, and described output pin is used to export the voltage of the described input DC power that adds;
Wherein, when the voltage of the described input DC power that adds is excessive, described first bleeder circuit causes described triode conducting, the enable pin of described Switching Power Supply integrated circuit is by described triode ground connection, and the voltage that causes being added in the enable pin of described Switching Power Supply integrated circuit is lower than its operating voltage and it is quit work;
When the voltage of the described input DC power that adds is too small, described first bleeder circuit causes described triode to end, and the voltage that described second bleeder circuit causes being added in the enable pin of described Switching Power Supply integrated circuit is lower than its operating voltage and it is quit work.
2. overvoltage as claimed in claim 1 and under-voltage protecting circuit; it is characterized in that, also comprise the 5th resistance, an end is connected in the common node of described first resistance and described second resistance; the other end is connected in the base stage of described triode, is used to limit the base current of described triode.
3. overvoltage and under-voltage protecting circuit; be connected between voltage source and the integrated circuit, be used to realize overvoltage and under-voltage protection to described integrated circuit, described integrated circuit comprises power end and enable pin; it is characterized in that described overvoltage and under-voltage protecting circuit comprise:
First bleeder circuit is connected between described voltage source and the ground, is used to export first voltage division signal;
Triode, its base stage receive described first voltage division signal, and its collector electrode is connected to the enable pin of described integrated circuit, its grounded emitter;
Second bleeder circuit is connected between described voltage source and the ground, is used to export the enable pin of second voltage division signal to described integrated circuit;
Wherein, when the voltage of described voltage source is excessive, first voltage division signal of described first bleeder circuit output makes described triode conducting, thereby the voltage that makes the enable pin of described integrated circuit is reduced to the emitter voltage of described triode, and described emitter voltage is lower than the operating voltage of described integrated circuit and it is quit work; When described supply voltage is too small, described first voltage division signal is ended described triode, second voltage division signal of described second bleeder circuit output is the voltage of the enable pin that is added in described integrated circuit, thereby described second voltage division signal quits work because of the operating voltage that is lower than described integrated circuit makes it.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920301041U CN201393057Y (en) | 2009-03-04 | 2009-03-04 | Over-voltage and under-voltage protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200920301041U CN201393057Y (en) | 2009-03-04 | 2009-03-04 | Over-voltage and under-voltage protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201393057Y true CN201393057Y (en) | 2010-01-27 |
Family
ID=41599878
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200920301041U Expired - Fee Related CN201393057Y (en) | 2009-03-04 | 2009-03-04 | Over-voltage and under-voltage protection circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201393057Y (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101951133A (en) * | 2010-08-11 | 2011-01-19 | 京信通信系统（中国）有限公司 | Device for inhibiting impact current at electrifying moment of repeater power supply system |
| CN101976823A (en) * | 2010-10-15 | 2011-02-16 | 鸿富锦精密工业（深圳）有限公司 | Undervoltage protection circuit for battery |
| CN102082416A (en) * | 2010-12-15 | 2011-06-01 | 深圳茂硕电源科技股份有限公司 | Method for realizing input undervoltage and over-temperature protection based on over voltage protection (OVP) function of Boost control chip |
| CN102377417A (en) * | 2010-08-25 | 2012-03-14 | 鸿富锦精密工业（深圳）有限公司 | Recovery circuit |
| WO2014089855A1 (en) * | 2012-12-14 | 2014-06-19 | 深圳市华星光电技术有限公司 | Led backlight drive circuit and liquid crystal display device |
| US9198254B2 (en) | 2012-12-14 | 2015-11-24 | Shenzhen China Star Optoelectronics Technology Co., Ltd | LED backlight driving circuit and LCD device |
| CN106773639A (en) * | 2016-11-10 | 2017-05-31 | 上海航天测控通信研究所 | Power module positive logic enables electrifying control circuit |
| CN110531821A (en) * | 2019-09-27 | 2019-12-03 | 北京兆芯电子科技有限公司 | Voltage-regulating circuit |
| CN112736843A (en) * | 2020-12-30 | 2021-04-30 | 珠海拓芯科技有限公司 | Switching power supply overvoltage and undervoltage protection circuit, switching power supply and air conditioner |
-
2009
- 2009-03-04 CN CN200920301041U patent/CN201393057Y/en not_active Expired - Fee Related
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101951133A (en) * | 2010-08-11 | 2011-01-19 | 京信通信系统（中国）有限公司 | Device for inhibiting impact current at electrifying moment of repeater power supply system |
| CN102377417A (en) * | 2010-08-25 | 2012-03-14 | 鸿富锦精密工业（深圳）有限公司 | Recovery circuit |
| CN102377417B (en) * | 2010-08-25 | 2014-06-25 | 鸿富锦精密工业（深圳）有限公司 | Recovery circuit |
| CN101976823A (en) * | 2010-10-15 | 2011-02-16 | 鸿富锦精密工业（深圳）有限公司 | Undervoltage protection circuit for battery |
| CN101976823B (en) * | 2010-10-15 | 2013-06-05 | 鸿富锦精密工业（深圳）有限公司 | Undervoltage protection circuit for battery |
| CN102082416A (en) * | 2010-12-15 | 2011-06-01 | 深圳茂硕电源科技股份有限公司 | Method for realizing input undervoltage and over-temperature protection based on over voltage protection (OVP) function of Boost control chip |
| WO2014089855A1 (en) * | 2012-12-14 | 2014-06-19 | 深圳市华星光电技术有限公司 | Led backlight drive circuit and liquid crystal display device |
| US9198254B2 (en) | 2012-12-14 | 2015-11-24 | Shenzhen China Star Optoelectronics Technology Co., Ltd | LED backlight driving circuit and LCD device |
| CN106773639A (en) * | 2016-11-10 | 2017-05-31 | 上海航天测控通信研究所 | Power module positive logic enables electrifying control circuit |
| CN110531821A (en) * | 2019-09-27 | 2019-12-03 | 北京兆芯电子科技有限公司 | Voltage-regulating circuit |
| CN112736843A (en) * | 2020-12-30 | 2021-04-30 | 珠海拓芯科技有限公司 | Switching power supply overvoltage and undervoltage protection circuit, switching power supply and air conditioner |
| CN112736843B (en) * | 2020-12-30 | 2022-12-02 | 珠海拓芯科技有限公司 | Switching power supply overvoltage and undervoltage protection circuit, switching power supply and air conditioner |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201393057Y (en) | Over-voltage and under-voltage protection circuit | |
| CN102761110B (en) | Power supply delay circuit | |
| CN201656423U (en) | Overvoltage protective device and electronic equipment therewith | |
| CN103606895B (en) | A kind of overvoltage turn-off protection circuit | |
| CN103280765A (en) | Overvoltage protection circuit | |
| CN102081418B (en) | Linear constant voltage control circuit | |
| CN201629569U (en) | Over-voltage protection circuit of USB interface | |
| CN103474954A (en) | Overvoltage and undervoltage protective circuit based on three-end adjustable shunt reference source | |
| CN104393760B (en) | The positive negative output low voltage difference with short-circuit protection function adjusts circuit | |
| CN104102318A (en) | Power source circuit | |
| CN201374556Y (en) | Protective circuit for transmitting disk of electric tool rest | |
| CN203553906U (en) | Protection circuit for input voltage of switch power supply | |
| CN103475205B (en) | Protective circuit | |
| CN202856324U (en) | Inverter overvoltage and under-voltage protective circuit | |
| CN104122971A (en) | Power circuit | |
| CN103902001A (en) | Power circuit | |
| CN103902009A (en) | Discharge circuit | |
| CN203313057U (en) | Power supply circuit | |
| CN202110209U (en) | Undervoltage acquisition circuit | |
| CN110601512A (en) | Discrete high-side driving circuit system | |
| CN220305706U (en) | Overvoltage and undervoltage protection circuit of Darlington voltage stabilizer | |
| CN202817719U (en) | Multifunctional power supply protection circuit | |
| CN203275499U (en) | Inverter overload detection circuit | |
| CN203352552U (en) | Large current on-off control circuit | |
| CN212849825U (en) | Overvoltage and undervoltage protection circuit with automatic power-off of design voltage |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100127 Termination date: 20120304 |