CN201113384Y - Electricized overvoltage protection circuit and mobile terminal possessing the circuit - Google Patents
Electricized overvoltage protection circuit and mobile terminal possessing the circuit Download PDFInfo
- Publication number
- CN201113384Y CN201113384Y CNU2007200277293U CN200720027729U CN201113384Y CN 201113384 Y CN201113384 Y CN 201113384Y CN U2007200277293 U CNU2007200277293 U CN U2007200277293U CN 200720027729 U CN200720027729 U CN 200720027729U CN 201113384 Y CN201113384 Y CN 201113384Y
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- overvoltage protection
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Abstract
The utility model discloses a charging overvoltage protection circuit, which comprises a charging circuit and a power supply providing operating voltage for the charging circuit, wherein a switching circuit is connected between the power supply and the charging circuit; the switching circuit comprises a diode, two triodes and an MOS transistor; the negative electrode of the diode is connected with the power supply, while the positive electrode is connected in series with a resistor and then is earthed; the base electrode of a first triode is connected with the positive electrode of the diode, while the emitter electrode is earthed and the collector electrode is connected with both the power supply and the base electrode of a second triode; the emitter electrode of the second triode is earthed, while the collector electrode is connected with both the power supply and the grid electrode of the MOS transistor; and the source electrode and the drain electrode of the MOS transistor are connected in series between the power supply and the charging circuit. The charging overvoltage protection circuit, which has a simple and effective structure and a small occupied area of a circuit board, can realize charging overvoltage protection when used in mobile terminal products such as a mobile phone.
Description
Technical field
The utility model belongs to the overvoltage crowbar technical field, specifically, relate to a kind of portable terminal charging voltage when excessive protective circuit and adopt the mobile phone of this charging overvoltage protection circuit.
Background technology
Regulation among the national standard YD/T 1591-2006 " mobile phone charger and interfacing require and method of testing ": the hand-held set charging inlet is when importing the above voltage of 6Vdc; if can not guarantee safe charging; should start safeguard measure; under unexpected voltage condition, the phenomenon that overheated, burning, blast and other circuit damage should not appear.After voltage recovered, hand-held set should be able to operate as normal.
In order to make mobile phone meet YD/T 1591-2006 national standard, need increase overvoltage crowbar at the front end of cell phone charging circuit, when overvoltage appearred in charging voltage, action took place to guarantee the safety of back-end circuit in overvoltage crowbar.The technical scheme of using in the mobile phone mainly contains following two kinds of overvoltage protection modes at present: a kind of is to adopt special-purpose overvoltage protection chip to realize overvoltage protection, its advantage is that circuit is simple, it is less to take printed circuit board area, and shortcoming is that cost is higher, flexibility is not enough, may needs to select for use different integrated circuit (IC) chip to protect for different mobile phones design platforms; Another is to adopt the mode of resolution element to realize overvoltage protection, and its advantage is that cost is lower, flexibility strong, can be based on a kind of circuit protection at different cell phone platforms, and its shortcoming is the circuit complexity, it is bigger to take printed circuit board area.
If adopt the mode of resolution element to realize overvoltage protection; usually adopt reference voltage source and voltage comparator parts to realize jointly in circuit design, the voltage comparator parts control whether cut off cell phone charging circuit by the size that compares input voltage and reference voltage.Because specialized voltages comparator component costs is higher, for the electronic product of this production in enormous quantities of mobile phone and not exclusively suitable.
Based on this, how the technical scheme of simple and effective charging overvoltage protection circuit in a kind of mobile phone products is provided, be subject matter to be solved in the utility model.
Summary of the invention
The purpose of this utility model just is to provide a kind of mobile phone separate type overvoltage crowbar of optimization, is satisfying under the situation of national Specification, reduces circuit cost, and can reduce printed circuit board area.
For achieving the above object, the utility model adopts following technical scheme:
A kind of charging overvoltage protection circuit; comprise charging circuit and the power supply of operating voltage is provided for described charging circuit; between described power supply and charging circuit, be connected with a switching circuit; described switching circuit comprises a diode; two triodes and a metal-oxide-semiconductor; the negative pole of described diode connects power supply; ground connection behind the cathode series resistance; the base stage of described first triode connects the positive pole of described diode; grounded emitter; collector electrode connects power supply on the one hand; the base stage that connects second triode on the other hand, the grounded emitter of described second triode, collector electrode connects power supply on the one hand; the grid that connects described metal-oxide-semiconductor on the other hand, the source electrode of described metal-oxide-semiconductor and drain electrode are serially connected between power supply and the charging circuit.
Another technical characterictic that the technical program had is: described diode is that Zener voltage is the Zener diode of 4.7V, ground connection after 2 precision resistance R1 of positive pole series connection of diode and the R2 dividing potential drop.
Another technical characterictic that the technical program had is: the collector electrode of described two triodes resistance of connecting respectively, be connected to power supply then, and two triodes adopt the double-triode valve packagings.
Another technical characterictic that the technical program had is: described metal-oxide-semiconductor is a P channel metal-oxide field effect transistor, and gate voltage is 0.1V.
Same mentality of designing according to above-mentioned charging overvoltage protection circuit; the utility model has proposed the portable terminal of this charging overvoltage protection circuit of a kind of application again; comprise charging circuit and the power supply of operating voltage is provided for described charging circuit; between described power supply and charging circuit, be connected with a switching circuit; described switching circuit comprises a diode; two triodes and a metal-oxide-semiconductor; the negative pole of described diode connects power supply; ground connection behind the cathode series resistance; the base stage of described first triode connects the positive pole of described diode; grounded emitter; collector electrode connects power supply on the one hand; the base stage that connects second triode on the other hand; the grounded emitter of described second triode; collector electrode connects power supply on the one hand, connects the grid of described metal-oxide-semiconductor on the other hand, and the source electrode of described metal-oxide-semiconductor and drain electrode are serially connected between power supply and the charging circuit.
Compared with prior art; advantage of the present utility model and good effect are that this charging overvoltage protection circuit structure is simple; and when the power supply overvoltage, can disconnect charging circuit; enter guard mode; and this circuit just can change the magnitude of voltage size of overvoltage protection by the resistance that changes diode series resistance R1 and R2, can be applied in flexibly in the various mobile terminal devices.
Description of drawings
Fig. 1 is an overvoltage crowbar schematic diagram of the present utility model.
Embodiment
Below in conjunction with accompanying drawing the utility model is described in further detail.
The utility model adopts Zener diode, resistance, NPN type numeral triode and P channel metal-oxide field effect transistor (MOSFET) to constitute a kind of cell-phone charging overvoltage crowbar; wherein NPN type numeral transistor circuit replaces conventional voltage comparator chip to realize that voltage threshold detects; employing Zener diode and resistance serial arrangement realize the incoming level conversion, and the mode that adopts triode to control MOSFET disconnection or conducting realizes protecting the charging circuit of mobile phone rear end.
As shown in Figure 1, VIN is the input voltage of outer handset power supply, and VOUT is that VOUT provides the voltage to mobile phone rear end charging circuit through the output voltage behind the overvoltage crowbar.
The negative pole of diode D1 connects power supply VIN, ground connection behind the cathode series resistance, wherein Zener diode D1 and precision resistance R1, R2 has constituted bleeder circuit, the base stage of first triode Q1 connects the positive pole of diode, grounded emitter, collector electrode connects power supply VIN by resistance R 3 on the one hand, the base stage that connects second triode Q2 on the other hand, the grounded emitter of second triode Q2, collector electrode connects power supply VIN by resistance R 4 on the one hand, the grid that connects MOSFET field effect transistor Q3 on the other hand, the source electrode of MOSFET field effect transistor Q3 and drain electrode are serially connected between power supply VIN and the output voltage VO UT.
In specifically selecting for use, can select D1 is that Zener voltage is the Zener diode of 4.7V, when power supply VIN voltage excessive, then under the situation of VIN voltage greater than 4.7V and D1 Zener breakdown, the voltage of triode Q1 base stage is (VIN-4.7V) * R2/ (R1+R2), and wherein the resistance of R1 and R2 can be selected its size according to concrete application, calculates the voltage of triode Q1 base stage, make the turn-on threshold voltage of this voltage, then triode Q1 conducting greater than triode Q1.Triode Q1 conducting causes triode Q2 to end; and then the gate leve voltage that causes MOSFET to manage Q3 is VIN voltage; the source voltage that is MOSFET pipe Q3 equals its grid voltage; this moment, MOSFET pipe Q3 entered cut-off state; output voltage VO UT and power supply VIN disconnect, and the charging circuit of rear end enters the overvoltage protection state.
If the voltage of triode Q1 base stage is less than the turn-on threshold voltage of Q1, then triode Q1 ends.Triode Q1 is by causing triode Q2 conducting, and then cause MOSFET to manage the source voltage of Q3 greater than its grid voltage, the gate leve voltage of MOSFET pipe Q3 is about about 0.1V, this moment, MOSFET pipe Q3 entered conducting state, output voltage VO UT equals power supply VIN substantially, and the rear end charging circuit enters normal charging condition.
In the utility model, the charging input voltage VIN is connected to the base stage of NPN type numeral triode Q1 after Zener diode D1 and two precision resistance R1, R2 dividing potential drop, if the partial pressure value of Q1 input voltage is higher than the switching voltage of this triode, then triode Q1 conducting, P channel metal-oxide field effect transistor Q3 in the protective circuit turn-offs, and has reached the purpose of protection rear end charging circuit; If the partial pressure value of Q1 input voltage is lower than the switching voltage of triode, then this triode Q1 ends, and the P channel metal-oxide field effect transistor Q3 in the protective circuit opens, and has reached the purpose that charges normal.Wherein NPN triode Q1, Q2 have constituted that thresholding is judged and level shifting circuit is controlled MOSFET pipe Q3 and opened or closed charging circuit.
Checking by experiment, this circuit meets the requirement of national standard YD/T 1591-2006, in 0 ℃~50 ℃ the temperature range protection precision arrived+/-level of 0.1V.And can change the value of the overvoltage protection voltage of circuit by the resistance value that changes R1, R2, so the utlity model has suitable flexibility, various mobile phones design platforms all can use this circuit to realize overvoltage protection.
The cell-phone charging overvoltage crowbar that the utility model has constituted by Zener diode, resistance, NPN triode and P channel metal-oxide field effect transistor, needed cost only be traditional scheme 50% or lower.If adopt the double-triode valve encapsulation technology that Q1 and Q2 are encapsulated into together, the printed circuit board area that this programme takies is about 12mm
2
Should be noted that; above-mentioned explanation is not to be to restriction of the present utility model; the utility model also is not limited in above-mentioned giving an example; described charge protector also can adopt other multiple version to realize; as adopt independent MOSFET pipe, transistor or relay or the like; variation, remodeling, interpolation or replacement that those skilled in the art are made in essential scope of the present utility model also should belong to protection range of the present utility model.
Claims (10)
1. charging overvoltage protection circuit; comprise charging circuit and the power supply of operating voltage is provided for described charging circuit; it is characterized in that between described power supply and charging circuit, being connected with a switching circuit; described switching circuit comprises a diode; two triodes and a metal-oxide-semiconductor; the negative pole of described diode connects power supply; ground connection behind the cathode series resistance; the base stage of described first triode connects the positive pole of described diode; grounded emitter; collector electrode connects power supply on the one hand; the base stage that connects second triode on the other hand, the grounded emitter of described second triode, collector electrode connects power supply on the one hand; the grid that connects described metal-oxide-semiconductor on the other hand, the source electrode of described metal-oxide-semiconductor and drain electrode are serially connected between power supply and the charging circuit.
2. charging overvoltage protection circuit according to claim 1 is characterized in that described diode is that Zener voltage is the Zener diode of 4.7V.
3. according to claim 1 or 2 described charging overvoltage protection circuit, it is characterized in that ground connection after 2 the precision resistance R1 of positive pole series connection of described diode and the R2 dividing potential drop.
4. charging overvoltage protection circuit according to claim 1, the collector electrode that it is characterized in that described two triodes resistance of connecting respectively is connected to power supply then.
5. according to claim 1 or 4 described charging overvoltage protection circuit, it is characterized in that described two triodes adopt the double-triode valve packaging.
6. according to claim 1 or 2 described charging overvoltage protection circuit, it is characterized in that described metal-oxide-semiconductor is a P channel metal-oxide field effect transistor, gate voltage is 0.1V.
7. portable terminal with charging overvoltage protection circuit; comprise charging circuit and the power supply of operating voltage is provided for described charging circuit; it is characterized in that between described power supply and charging circuit, being connected with a switching circuit; described switching circuit comprises a diode; two triodes and a metal-oxide-semiconductor; the negative pole of described diode connects power supply; ground connection behind the cathode series resistance; the base stage of described first triode connects the positive pole of described diode; grounded emitter; collector electrode connects power supply on the one hand; the base stage that connects second triode on the other hand, the grounded emitter of described second triode, collector electrode connects power supply on the one hand; the grid that connects described metal-oxide-semiconductor on the other hand, the source electrode of described metal-oxide-semiconductor and drain electrode are serially connected between power supply and the charging circuit.
8. charging overvoltage protection circuit according to claim 7 is characterized in that described diode is that Zener voltage is the Zener diode of 4.7V.
9. according to claim 7 or 8 described charging overvoltage protection circuit, it is characterized in that ground connection after 2 the precision resistance R1 of positive pole series connection of described diode and the R2 dividing potential drop.
10. charging overvoltage protection circuit according to claim 7, the collector electrode that it is characterized in that described two triodes resistance of connecting respectively is connected to power supply then.
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CNU2007200277293U CN201113384Y (en) | 2007-09-12 | 2007-09-12 | Electricized overvoltage protection circuit and mobile terminal possessing the circuit |
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CNU2007200277293U CN201113384Y (en) | 2007-09-12 | 2007-09-12 | Electricized overvoltage protection circuit and mobile terminal possessing the circuit |
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Cited By (22)
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CN101783503A (en) * | 2009-01-16 | 2010-07-21 | 鸿富锦精密工业(深圳)有限公司 | Overvoltage protection circuit |
CN101834436A (en) * | 2010-05-06 | 2010-09-15 | 日银Imp微电子有限公司 | Overvoltage protection circuit for integrated circuit |
CN101394435B (en) * | 2008-11-12 | 2011-05-25 | 闻泰集团有限公司 | Device for automatically detecting over-voltage protection of mobile phone |
CN102158571A (en) * | 2010-12-31 | 2011-08-17 | Tcl集团股份有限公司 | Charging anti-theft protection method for mobile terminal |
CN101714757B (en) * | 2008-10-06 | 2012-01-25 | 厦门雅迅网络股份有限公司 | Anti-surge device of on-vehicle power supply |
CN102467630A (en) * | 2010-11-18 | 2012-05-23 | Tcl集团股份有限公司 | Mobile terminal charging anti-theft protection method and system, and mobile terminal |
CN102891466A (en) * | 2011-07-22 | 2013-01-23 | 富泰华工业(深圳)有限公司 | Overvoltage/overcurrent protection circuit |
CN103178500A (en) * | 2011-12-23 | 2013-06-26 | 联芯科技有限公司 | Overvoltage protection circuit and overvoltage protection method of terminal VCHG pin |
CN104505807A (en) * | 2014-12-10 | 2015-04-08 | 无锡必创传感科技有限公司 | Automobile sensor protection circuit |
CN104577961A (en) * | 2013-10-22 | 2015-04-29 | 深圳市海洋王照明工程有限公司 | Overvoltage power-off protection circuit |
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WO2016095346A1 (en) * | 2014-12-19 | 2016-06-23 | 中兴通讯股份有限公司 | Charging circuit for mobile terminal and mobile terminal |
CN105846402A (en) * | 2016-06-01 | 2016-08-10 | 江苏安纳金机械有限公司 | Power source protection circuit |
CN106058798A (en) * | 2016-05-30 | 2016-10-26 | 安徽华米信息科技有限公司 | Voltage protection device, method and wearable device |
CN102891466B (en) * | 2011-07-22 | 2016-12-14 | 富泰华工业(深圳)有限公司 | Over-voltage over-current protection circuit |
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CN101394435B (en) * | 2008-11-12 | 2011-05-25 | 闻泰集团有限公司 | Device for automatically detecting over-voltage protection of mobile phone |
CN101783503B (en) * | 2009-01-16 | 2014-02-26 | 鸿富锦精密工业(深圳)有限公司 | Overvoltage protection circuit |
CN101783503A (en) * | 2009-01-16 | 2010-07-21 | 鸿富锦精密工业(深圳)有限公司 | Overvoltage protection circuit |
CN101834436A (en) * | 2010-05-06 | 2010-09-15 | 日银Imp微电子有限公司 | Overvoltage protection circuit for integrated circuit |
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CN102158571A (en) * | 2010-12-31 | 2011-08-17 | Tcl集团股份有限公司 | Charging anti-theft protection method for mobile terminal |
CN102158571B (en) * | 2010-12-31 | 2013-07-31 | Tcl集团股份有限公司 | Charging anti-theft protection method for mobile terminal |
CN102891466A (en) * | 2011-07-22 | 2013-01-23 | 富泰华工业(深圳)有限公司 | Overvoltage/overcurrent protection circuit |
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CN104577954B (en) * | 2013-10-22 | 2018-07-27 | 深圳市海洋王照明工程有限公司 | Transformer short-circuit protects circuit |
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CN108448533A (en) * | 2018-03-29 | 2018-08-24 | 河南首翔电子有限公司 | Overvoltage alarm and overpressure protection circuit |
CN108494036A (en) * | 2018-03-29 | 2018-09-04 | 安克创新科技股份有限公司 | Charging unit |
CN110401171A (en) * | 2019-08-15 | 2019-11-01 | 福州京东方光电科技有限公司 | A kind of excess voltage protection and its control method, power supply IC, display device |
CN111049213A (en) * | 2019-12-05 | 2020-04-21 | 维沃移动通信有限公司 | Charging stand |
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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: 20080910 Termination date: 20110912 |