CN205490115U - Switching power supply circuit - Google Patents
Switching power supply circuit Download PDFInfo
- Publication number
- CN205490115U CN205490115U CN201620018705.0U CN201620018705U CN205490115U CN 205490115 U CN205490115 U CN 205490115U CN 201620018705 U CN201620018705 U CN 201620018705U CN 205490115 U CN205490115 U CN 205490115U
- Authority
- CN
- China
- Prior art keywords
- connects
- switching tube
- circuit
- resistance
- voltage
- 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.)
- Active
Links
- 238000006243 chemical reaction Methods 0.000 claims abstract description 46
- 238000005070 sampling Methods 0.000 claims description 15
- 230000005611 electricity Effects 0.000 description 10
- 238000010586 diagram Methods 0.000 description 7
- 230000001939 inductive effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000008878 coupling Effects 0.000 description 2
- 238000010168 coupling process Methods 0.000 description 2
- 238000005859 coupling reaction Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000009795 derivation Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005538 encapsulation Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model discloses a switching power supply circuit, which comprises a power supply input end, a load output end, a voltage conversion circuit, a switching power supply chip and a short-circuit protection circuit; the voltage conversion circuit increases the voltage of the power supply input end and outputs the voltage to the load input end, and the load output end is grounded through a load connecting pin of the chip; the load connection pin is connected with the anode of the first diode, and the cathode of the first diode is connected with a preset voltage supply end; when short circuit occurs between the load input end and the load output end, the voltage of the voltage conversion output end is directly loaded on the load connecting pin, and the voltage of the load connecting pin is higher than the voltage of the preset voltage providing end, so that the first diode is in a forward conduction state, the voltage of the load connecting pin of the chip is the sum of the conduction voltage drop of the diode and the voltage value of the preset voltage, the overvoltage damage of the chip can not be caused, and the low voltage-resistant chip can be matched with a high-voltage load.
Description
Technical field
This utility model relates to electronic technology field, particularly relates to a kind of switching power circuit.
Background technology
Switching Power Supply is to be directly control coupled inductive element (inductance or transformator) by switching tube, logical
Cross energy storage and the exergonic process of inductive element, it is achieved voltage or a kind of power supply of current transformation.It is by adjusting
Switching tube conducting and cut-off time scale, maintain stable output signal, be widely used in Industry Control,
In the various electronic equipments such as communication office, household consumption.
The circuit theory diagrams of a kind of Switching Power Supply of the prior art shown in Fig. 1, this Switching Power Supply include by
The voltage up converting circuit of inductance LB802, diode DB801, electric capacity EB801, switching tube QB801 composition,
And power input VBL and power output end LED+, power input VBL and inductance LB802
First end connects, and the power output end LED+ being connected with the negative pole of diode DB801 can connect load；Should
Switching Power Supply also includes switching power source chip, exportable PWM waveform, controls the conducting of switching tube QB801
And cut-off, thus affect boosting ratio；This switching power source chip has current detecting pin, connects sampling electricity
First end of resistance RB821；This switching power source chip also has load and connects pin LED1～LED4, Fig. 1
Middle load is four groups of LED strings, and often the positive pole of group LED string is all connected with power output end LED+, often group
The negative pole of LED string connects the load of chip respectively and connects by chip ground after pin LED1～LED4,
Chip, by the electric current in sample circuit, adjusts the dutycycle of output PWM waveform, controls constant output current,
Power for LED load.This switching power circuit there is the problem that when load short circuits, and power supply exports
The voltage of end LED+ can be directly connected to the load of chip and connect pin, and chip is limited by technique and encapsulation, and one
As pressure voltage limited, therefore can cause chip excessive pressure damages.
Utility model content
The purpose of this utility model is, it is provided that a kind of switching power circuit, has short-circuit protection function, energy
Solve the chip excessive pressure damages problem caused because of load short circuits.
To achieve these goals, this utility model provides a kind of switching power circuit, including power input,
Load input terminal, load outputs, voltage conversion circuit, switching power source chip and short-circuit protection circuit；
Described voltage conversion circuit includes voltage conversion inputs, voltage conversion output, switch control terminal；
Described power input connects described voltage conversion inputs；Described voltage conversion output connects described load
Input；
Described switching power source chip includes that load connects pin and drives signal output pin；Described load connects
Pin connects described load outputs；Described driving signal output pin connects described switch control terminal；
Described short-circuit protection circuit includes that chip connects end, the first diode and predeterminated voltage and provides end；Described
Chip connects end and connects described load connection pin；Described chip connects end and is just connecting described first diode
Pole, the negative pole of described first diode connects described predeterminated voltage provides end.
Further, described voltage conversion circuit also includes inductance, the second diode, the first switching tube and electricity
Hold；
Described voltage conversion inputs connects the first end of described inductance, and the second end of described inductance connects described
The positive pole of the second diode, the negative pole of described second diode connects described voltage conversion output；
First end of described first switching tube connects the second end of described inductance, the second of described first switching tube
End ground connection, the control end of described first switching tube connects described switch control terminal；
First end of described electric capacity connects described voltage conversion output, the second end ground connection of described electric capacity.
Preferably, described switching power source chip also includes that start enables pin；Described short-circuit protection circuit also wraps
Include second switch pipe and second switch pipe control circuit；
The negative pole of described first diode connects described predeterminated voltage provides end, particularly as follows: described one or two pole
The negative pole of pipe connects described predeterminated voltage by described second switch pipe provides end, wherein, described second switch
First end of pipe connects the negative pole of described first diode, and the second end of described second switch pipe connects described pre-
If voltage provides end；
Described second switch pipe control circuit includes starting-up signal incoming end, feeder ear and control signal outfan；
Described starting-up signal incoming end connects the start of described switching power source chip and enables pin, and described control signal is defeated
Go out end and connect the control end of described second switch pipe.
Further, described second switch pipe control circuit also include the 3rd switching tube, the 4th switching tube,
One resistance, the second resistance, the 3rd resistance, the 4th resistance, the 5th resistance and the 6th resistance；
Described starting-up signal incoming end connects the first end of described first resistance, the second end of described first resistance
Connecting the control end of described 3rd switching tube, the end that controls of described 3rd switching tube connects described second resistance
First end, the second end of described second resistance connects the second end of described 3rd switching tube, described 3rd switch
First end of pipe connects the first end of described 3rd resistance, the second end ground connection of described 3rd switching tube；
Second end of described 3rd resistance connects the control end of described 4th switching tube, described 4th switching tube
Controlling end and connect the first end of described 5th resistance, the second end of described 5th resistance connects described 4th switch
First end of pipe；Described feeder ear connects the first end of described 4th resistance, the second end of described 4th resistance
Connect the first end of described 4th switching tube；Second end of described 4th switching tube connects described 6th resistance
First end, the second end of described 6th resistance connects described control signal outfan.
Preferably, the feeder ear of described second switch pipe control circuit connects described power input；Described
Two switch controlled circuit also include clamp circuit and clamper reference edge；
Described clamp circuit includes clamp circuit input, clamp circuit outfan and clamper reference connection end；
Second end of described 6th resistance connects described control signal outfan, particularly as follows: described 6th resistance
The second end by described clamp circuit connect described control signal outfan, wherein, described clamp circuit is defeated
Entering end and connect the second end of described 6th resistance, described clamp circuit outfan connects the output of described control signal
End；
Described clamper reference connection end connects described clamper reference edge, and described clamper reference edge connects described second
Second end of switching tube.
Further, described clamp circuit also includes stabilivolt, the 7th resistance and the 8th resistance；
First end of described 7th resistance connects described clamp circuit input, the second end of described 7th resistance
Connect described clamp circuit outfan；The positive pole of described stabilivolt connects described clamper reference connection end, described
The negative pole of stabilivolt connects described clamp circuit input；First end of described 8th resistance connects described clamper
Circuit output end, the second end of described 8th resistance connects described clamper reference connection end.
Further, described voltage conversion circuit also includes sampling resistor and current sample outfan；Described open
Close power supply chip and also include current detecting pin；
Second end ground connection of described first switching tube, particularly as follows: the second end of described first switching tube passes through institute
Stating sampling resistor ground connection, wherein, the first end of described sampling resistor connects the second end of described first switching tube,
Second end ground connection of described sampling resistor；
First end of described sampling resistor connects described current sample outfan；Described current sample outfan is even
Connect described current detecting pin.
Preferably, described first switching tube is N-channel MOS pipe, and the control end of described first switching tube is institute
Stating the grid of N-channel MOS pipe, the first end of described first switching tube is the leakage of described N-channel MOS pipe
Pole, the second end of described first switching tube is the source electrode of described N-channel MOS pipe.
Preferably, described second switch pipe is N-channel MOS pipe, and the control end of described second switch pipe is institute
Stating the grid of N-channel MOS pipe, the first end of described second switch pipe is the leakage of described N-channel MOS pipe
Pole, the second end of described second switch pipe is the source electrode of described N-channel MOS pipe.
Preferably, described 3rd switching tube is NPN type triode；The control end of described 3rd switching tube is institute
State the base stage of NPN type triode, the collection that the first end is described NPN type triode of described 3rd switching tube
Electrode, the emitter stage that the second end is described NPN type triode of described 3rd switching tube；
Described 4th switching tube is PNP type triode；The control end of described 4th switching tube is described positive-negative-positive
The base stage of audion, the emitter stage that the first end is described PNP type triode of described 4th switching tube, described
The colelctor electrode that second end is described PNP type triode of the 4th switching tube.
Implement this utility model, have the advantages that
The switching power circuit that this utility model provides, the voltage of power input is raised by voltage conversion circuit
Exporting to load input terminal, load outputs connects pin ground connection by the load of chip；Load connects pin
Connecting the positive pole of the first diode, the negative pole of the first diode connects predeterminated voltage provides end, when normally working,
It is relatively low that the load of chip connects pin voltage, provides the magnitude of voltage of end less than predeterminated voltage, due to the one or two pole
The reverse cutoff function of pipe, does not affect normal work；Occur short between load input terminal and load outputs
Lu Shi, the voltage of voltage conversion output is loaded directly into connecting on pin in load, owing to load connects pin
Voltage higher than predeterminated voltage provide end voltage, therefore the first diode is in forward conduction state, conducting
Pressure drop is relatively low, and the load of chip connects the conduction voltage drop that voltage is diode and the voltage of predeterminated voltage of pin
Value sum, is in the pressure scope of chip, therefore, the switching power circuit that this utility model provides, has
Short-circuit protection function, will not cause chip excessive pressure damages because of load short circuits, enables low pressure chip
Join the load of high pressure.
Accompanying drawing explanation
Fig. 1 is the circuit theory diagrams of a kind of Switching Power Supply of the prior art；
Fig. 2 is the circuit block diagram of the switching power circuit that this utility model provides；
Fig. 3 is the circuit theory diagrams of the first embodiment of the switching power circuit that this utility model provides；
Fig. 4 is the circuit theory diagrams of second embodiment of the switching power circuit that this utility model provides.
Detailed description of the invention
Below in conjunction with the accompanying drawing in this utility model embodiment, to the technical side in this utility model embodiment
Case is clearly and completely described, it is clear that described embodiment is only that this utility model part is real
Execute example rather than whole embodiments.Based on the embodiment in this utility model, ordinary skill people
The every other embodiment that member is obtained under not making creative work premise, broadly falls into this utility model
The scope of protection.
See Fig. 2, be the circuit block diagram of the switching power circuit that this utility model provides.This switch power supply
Road includes power input VBL, load input terminal Load+, load outputs Load-, voltage conversion circuit
201, switching power source chip U1 and short-circuit protection circuit 202；
Described voltage conversion circuit 201 includes voltage conversion inputs Vin, voltage conversion output Vout, opens
Close and control end Ctrl；Described power input VBL connects described voltage conversion inputs Vin；Described voltage
Conversion output Vout connects described load input terminal Load+；
Described switching power source chip U1 includes that load connects pin LED1 and drives signal output pin GATE；
Described load connects pin LED1 and connects described load outputs Load-；Described driving signal output pin
GATE connects described switch control terminal Ctrl；
Described short-circuit protection circuit includes that chip connects end, the first diode D1 and predeterminated voltage and provides end Vcc；
Described chip connects end and connects described load connection pin LED1；Described chip connects end and connects the described 1st
The positive pole A of pole pipe, the negative pole K of described first diode connects described predeterminated voltage provides end Vcc.
During concrete application switching power circuit of the present utility model, the load input terminal of the accessible circuit of load
Between Load+ and load outputs Load-, the voltage of power input VBL is entered by voltage conversion circuit 201
Row transformation is changed, and output voltage is load supplying, and load outputs Load-connects chip, bearing by chip
Carry and connect pin ground connection LED1.It is connected to pre-owing to load connects pin LED1 by the first diode D1
If voltage provides end Vcc, this predeterminated voltage provides end to provide and normally works higher than load connection pin LED1
Time voltage, 12V voltage is such as provided, when the most normally working, the positive pole A of the first diode D1 electricity
Pressure cannot provide end Vcc to be formed by the first diode D1 with predeterminated voltage less than negative pole K voltage, electric current
Loop, predeterminated voltage provides end Vcc to have no effect on circuit and provides power supply for load；And when short circuit occurs in load
Time, i.e. load input terminal Load+ and load outputs Load-connects, the positive pole A electricity of the first diode D1
Pressure flows to predeterminated voltage by the first diode D1 and provides end Vcc more than negative pole K voltage, electric current, formed back
Road, therefore the voltage of load connection pin LED1 is only the conduction voltage drop of diode and the voltage of predeterminated voltage
Value sum, if N is 1V, the voltage that predeterminated voltage provides end Vcc to provide is 12V, then
Load connects the voltage of pin LED1 and only has 13V, is unlikely and causes wafer damage.
See Fig. 3, be the circuit theory diagrams of the first embodiment of the switching power circuit that this utility model provides.
In the present embodiment, voltage conversion circuit 201 is voltage up converting circuit, including inductance L1, the second diode D2,
First switching tube Q1, sampling resistor RS, current sample outfan and electric capacity C1；First switching tube Q1 is
N-channel MOS pipe, has grid G, source S and drain D；Voltage conversion inputs connects inductance L1
The first end, inductance L1 second end connect described second diode D2 positive pole, the second diode D2
Negative pole connect voltage conversion output；The drain D of the first switching tube Q1 connects second end of inductance L1,
The source S of the first switching tube Q1 passes through sampling resistor RS ground connection, and the grid G of the first switching tube Q1 connects
Described switch control terminal；First end of electric capacity C1 connects voltage conversion output, second termination of electric capacity C1
Ground.
When the first switching tube Q1 conducting, inductance L1 charging absorbs energy, when the first switching tube Q1 ends
Time, inductive discharge charges to electric capacity, and therefore electric capacity both end voltage raises, higher than the electricity of voltage conversion inputs
Pressure, owing to the first switching tube Q1 is controlled by switching power source chip U1, switching power source chip U1 regulates driving
The dutycycle of the pwm signal of signal output pin GATE output can control the boosting of voltage conversion circuit
Ratio.
In the present embodiment, switching power source chip U1 also includes current detecting pin ISENSE, voltage conversion electricity
First end of the sampling resistor RS on road 201 connects current sample outfan；Current sample outfan connecting valve
The current detecting pin ISENSE of power supply chip U1.Switching Power Supply is by obtaining the electricity of current sample outfan
Pressure, i.e. obtains the current information on sampling resistor, can adjust according to current information and drive signal output part GATE
The dutycycle of the pwm signal of output, can realize exporting the constant of electric current.
Further, the present embodiment can expansive approach in the switching power circuit with multiple load outputs,
As it is shown on figure 3, in addition to load outputs Load-, also include multiple load outputs Load_2-～Load_4,
Switching power source chip also correspondence includes that multiple load connects pin LED2～LED4, when there is multiple load output
When end and multiple load connect pin, the switching power circuit that this utility model provides can connect multiple load,
Such as when being applied to liquid crystal display television LED backlight product, LED-backlit product has multiple LED string,
The positive pole of each LED string is all connected with load input terminal Load+, the negative pole of each LED string respectively with
Multiple load outputs connect one to one, and short-circuit protection circuit correspondingly arranges multiple first diode, its
Positive pole is connected pin LED1～LED4 coupling and connects with load, and the negative pole of multiple first diodes is all with default
Voltage provides end to connect.
See Fig. 4, be the circuit theory of second embodiment of the switching power circuit that this utility model provides
Figure.The present embodiment difference from above-mentioned first embodiment is, in the present embodiment, and switching power source chip U1
Also include that start enables pin EN；
Short-circuit protection circuit 202 also includes second switch pipe Q2 and second switch pipe control circuit；One or two pole
The negative pole of pipe D1 connects predeterminated voltage by second switch pipe Q2 provides end Vcc, wherein, second switch pipe
Being N-channel MOS pipe, the drain electrode of second switch pipe Q2 connects the negative pole of the first diode D1, and second opens
The source electrode closing pipe Q2 connects predeterminated voltage offer end Vcc；The grid of second switch pipe and second switch management and control system
The control signal outfan of circuit connects；
Second switch pipe control circuit includes starting-up signal incoming end BL_ON, feeder ear and control signal output
End；Starting-up signal incoming end BL_ON connects the start of described switching power source chip and enables pin EN；Second
Switch controlled circuit also includes the 3rd switching tube Q3, the 4th switching tube Q4, the first resistance R1, the second electricity
Resistance R2, the 3rd resistance R3, the 4th resistance R4, the 5th resistance R5 and the 6th resistance R6；Wherein, the 3rd
Switching tube is NPN type triode, and the 4th switching tube is PNP type triode；Starting-up signal incoming end BL_ON
Connecting first end of the first resistance R1, second end of the first resistance R2 connects the base stage of the 3rd switching tube Q3,
The base stage of the 3rd switching tube Q3 connects first end of the second resistance R2, and second end of the second resistance R2 connects
The emitter stage of the 3rd switching tube Q3, the colelctor electrode of the 3rd switching tube Q3 connects first end of the 3rd resistance R3,
The grounded emitter of the 3rd switching tube Q3；
Second end of the 3rd resistance R3 connects the base stage of the 4th switching tube Q4, the base stage of the 4th switching tube Q4
Connecting first end of the 5th resistance R5, second end of the 5th resistance R5 connects the transmitting of the 4th switching tube Q4
Pole；Feeder ear connects first end of the 4th resistance R4, and second end of the 4th resistance R4 connects the 4th switching tube
The emitter stage of Q4；The colelctor electrode of the 4th switching tube Q4 connects first end of the 6th resistance R6, the 6th resistance
The second end connection control signal outfan of R6.
In the present embodiment, switching power circuit has start and standby two kinds of mode of operations, start enable pin
EN controls, and when start enable pin EN is high level, is i.e. in start mode of operation, letter of now starting shooting
Number incoming end BL_ON is also high level, the 3rd switching tube Q3 conducting, and then the 4th switching tube Q4 conducting,
The high level of feeder ear is connected to second is opened by the 4th resistance R4, the 6th resistance R6, control signal outfan
Close the grid of pipe Q2, make second switch pipe Q2 turn on, therefore, under start mode of operation, switch power supply
The operation principle on road is consistent with above-described embodiment；
When start enable pin EN is low level, i.e. it is in standy operation mode, voltage conversion electricity will be controlled
Road 201 and switching power source chip U1 do not work, and i.e. cannot complete boosting and current constant control, but owing to voltage turns
Changing circuit 201 is voltage up converting circuit, and voltage up converting circuit, idle time, still can export and voltage
The high voltage that conversion inputs is the same, and the load input terminal Load+ in switching power circuit and load outputs
Connect between Load-and have idle load, if now Q2 conducting, the high voltage meeting of voltage conversion output
It is connected to loading of chip by load and connects pin LED1 and the positive pole of the first diode D1, the one or two
Pole pipe D1 can be in forward conduction state, and electric current flows into predeterminated voltage provides end Vcc to form loop, can cause
Load is in abnormal duty, such as when load is liquid crystal display television LED backlight product, owing to returning
The existence of road electric current, LED backlight string can produce faint light, and LCD TV is when holding state,
Need to control backlight not work, this situation can affect the normal work of LCD TV.Therefore, in the present embodiment
Control second switch pipe by second switch pipe control circuit to end, i.e. during standy operation mode, opening of chip
It is low level that machine enables the starting-up signal incoming end BL_ON of pin EN and second switch pipe control circuit, the
Three switching tube Q3 cut-offs, and then the 4th switching tube Q4 cut-off, second switch pipe Q2 ends, and voltage is changed
Outfan, load, the first diode D1 and predeterminated voltage provide end cannot form loop, eliminate load
Irregular working problem.
For saving external power source, in the present embodiment, can to connect power supply defeated for the feeder ear of second switch pipe control circuit
Enter to hold VBL, when being in start mode of operation, the overtension of power input VBL, it is connected to second
May result in during switching tube Q2 and burn out second switch pipe Q2, therefore the present embodiment is also in second switch management and control
Being provided with clamp circuit and clamper reference edge in circuit processed, clamper reference edge connects the source of second switch pipe Q2
Pole, i.e. connecting predeterminated voltage provides end Vcc, makes the output voltage absolute presupposition voltage of clamp circuit provide end
Vcc clamper is in certain voltage range.Specifically, clamp circuit includes clamp circuit input, clamp circuit
Outfan and clamper reference connection end, also include stabilivolt ZD1, the 7th resistance R7 and the 8th resistance R8；
Second end of the 6th resistance R6 connects described control signal outfan, the i.e. the 6th resistance R6 by clamp circuit
Second end connect clamper circuit input end, clamp circuit outfan connection control signal outfan；Clamper base
The accurate end that connects connects clamper reference edge；First end of the 7th resistance R7 connects clamper circuit input end, the 7th electricity
Second end of resistance R7 connects clamper circuit output end；The positive pole of stabilivolt ZD1 connects clamper reference connection end,
The negative pole of stabilivolt ZD1 connects clamper circuit input end；First end of the 8th resistance R8 connects clamp circuit
Outfan, second end of the 8th resistance R8 connects described clamper reference connection end.
It should be noted that in above-described embodiment, the first switching tube Q1 and second switch pipe Q2 is with N-channel
As a example by metal-oxide-semiconductor, the 3rd switching tube Q3 is as a example by NPN type triode, and the 4th switching tube Q4 is with positive-negative-positive
As a example by audion, a kind of embodiment the most therein, in other embodiments, the first switching tube Q1,
Second switch pipe Q2, the 3rd switching tube Q3, the 4th switching tube Q4 be all substitutable for other include control end and
There is the first end of interconnection function, the three ports for control switching device of the second end or its derivation device, different
In application scenario, control unit depending on the power consumption of side circuit, cost, driving power and the driving with switching tube
Part parameter coupling etc. requires reasonable selection and setting, selects and arranges the conventional design that switching tube is prior art
Process, does not repeats at this.
The switching power circuit that this utility model provides, the voltage of power input is raised by voltage conversion circuit
Exporting to load input terminal, load outputs connects pin ground connection by the load of chip；Load connects pin
Connecting the positive pole of the first diode, the negative pole of the first diode connects predeterminated voltage provides end, when normally working,
It is relatively low that the load of chip connects pin voltage, provides the magnitude of voltage of end less than predeterminated voltage, due to the one or two pole
The reverse cutoff function of pipe, does not affect normal work；Occur short between load input terminal and load outputs
Lu Shi, the voltage of voltage conversion output is loaded directly into connecting on pin in load, owing to load connects pin
Voltage higher than predeterminated voltage provide end voltage, therefore the first diode is in forward conduction state, conducting
Pressure drop is relatively low, and the load of chip connects the conduction voltage drop that voltage is diode and the voltage of predeterminated voltage of pin
Value sum, is in the pressure scope of chip, therefore, the switching power circuit that this utility model provides, has
Short-circuit protection function, will not cause chip excessive pressure damages because of load short circuits, enables low pressure chip
Join the load of high pressure.
The above is preferred implementation of the present utility model, it is noted that general for the art
For logical technical staff, on the premise of without departing from this utility model principle, it is also possible to make some improvement and
Deformation, these improve and deformation is also considered as protection domain of the present utility model.
Claims (10)
1. a switching power circuit, it is characterised in that described switching power circuit includes power input, load input terminal, load outputs, voltage conversion circuit, switching power source chip and short-circuit protection circuit；
Described voltage conversion circuit includes voltage conversion inputs, voltage conversion output, switch control terminal；Described power input connects described voltage conversion inputs；Described voltage conversion output connects described load input terminal；
Described switching power source chip includes that load connects pin and drives signal output pin；Described load connects pin and connects described load outputs；Described driving signal output pin connects described switch control terminal；
Described short-circuit protection circuit includes that chip connects end, the first diode and predeterminated voltage and provides end；Described chip connects end and connects described load connection pin；Described chip connects end and connects the positive pole of described first diode, and the negative pole of described first diode connects described predeterminated voltage provides end.
2. switching power circuit as claimed in claim 1, it is characterised in that described voltage conversion circuit also includes inductance, the second diode, the first switching tube and electric capacity；
Described voltage conversion inputs connects the first end of described inductance, and the second end of described inductance connects the positive pole of described second diode, and the negative pole of described second diode connects described voltage conversion output；
First end of described first switching tube connects the second end of described inductance, the second end ground connection of described first switching tube, and the control end of described first switching tube connects described switch control terminal；
First end of described electric capacity connects described voltage conversion output, the second end ground connection of described electric capacity.
3. switching power circuit as claimed in claim 2, it is characterised in that described switching power source chip also includes that start enables pin；Described short-circuit protection circuit also includes second switch pipe and second switch pipe control circuit；
The negative pole of described first diode connects described predeterminated voltage provides end, particularly as follows: the negative pole of described first diode connects described predeterminated voltage by described second switch pipe provides end, wherein, first end of described second switch pipe connects the negative pole of described first diode, and the second end of described second switch pipe connects described predeterminated voltage provides end；
Described second switch pipe control circuit includes starting-up signal incoming end, feeder ear and control signal outfan；Described starting-up signal incoming end connects the start of described switching power source chip and enables pin, and described control signal outfan connects the control end of described second switch pipe.
4. switching power circuit as claimed in claim 3, it is characterised in that described second switch pipe control circuit also includes the 3rd switching tube, the 4th switching tube, the first resistance, the second resistance, the 3rd resistance, the 4th resistance, the 5th resistance and the 6th resistance；
Described starting-up signal incoming end connects the first end of described first resistance, second end of described first resistance connects the control end of described 3rd switching tube, the end that controls of described 3rd switching tube connects the first end of described second resistance, second end of described second resistance connects the second end of described 3rd switching tube, first end of described 3rd switching tube connects the first end of described 3rd resistance, the second end ground connection of described 3rd switching tube；
Second end of described 3rd resistance connects the control end of described 4th switching tube, and the end that controls of described 4th switching tube connects the first end of described 5th resistance, and the second end of described 5th resistance connects the first end of described 4th switching tube；Described feeder ear connects the first end of described 4th resistance, and the second end of described 4th resistance connects the first end of described 4th switching tube；Second end of described 4th switching tube connects the first end of described 6th resistance, and the second end of described 6th resistance connects described control signal outfan.
5. switching power circuit as claimed in claim 4, it is characterised in that the feeder ear of described second switch pipe control circuit connects described power input；Described second switch pipe control circuit also includes clamp circuit and clamper reference edge；
Described clamp circuit includes clamp circuit input, clamp circuit outfan and clamper reference connection end；
Second end of described 6th resistance connects described control signal outfan, particularly as follows: the second end of described 6th resistance connects described control signal outfan by described clamp circuit, wherein, described clamp circuit input connects the second end of described 6th resistance, and described clamp circuit outfan connects described control signal outfan；
Described clamper reference connection end connects described clamper reference edge, and described clamper reference edge connects the second end of described second switch pipe.
6. switching power circuit as claimed in claim 5, it is characterised in that described clamp circuit also includes stabilivolt, the 7th resistance and the 8th resistance；
First end of described 7th resistance connects described clamp circuit input, and the second end of described 7th resistance connects described clamp circuit outfan；The positive pole of described stabilivolt connects described clamper reference connection end, and the negative pole of described stabilivolt connects described clamp circuit input；First end of described 8th resistance connects described clamp circuit outfan, and the second end of described 8th resistance connects described clamper reference connection end.
7. the switching power circuit as described in any one of claim 2 to 6, it is characterised in that described voltage conversion circuit also includes sampling resistor and current sample outfan；Described switching power source chip also includes current detecting pin；
Second end ground connection of described first switching tube, particularly as follows: the second end of described first switching tube is by described sampling resistor ground connection, wherein, the first end of described sampling resistor connects the second end of described first switching tube, the second end ground connection of described sampling resistor；
First end of described sampling resistor connects described current sample outfan；Described current sample outfan connects described current detecting pin.
8. the switching power circuit as described in any one of claim 2 to 6, it is characterized in that, described first switching tube is N-channel MOS pipe, the grid that control end is described N-channel MOS pipe of described first switching tube, first end of described first switching tube is the drain electrode of described N-channel MOS pipe, and the second end of described first switching tube is the source electrode of described N-channel MOS pipe.
9. the switching power circuit as described in any one of claim 3 to 6, it is characterized in that, described second switch pipe is N-channel MOS pipe, the grid that control end is described N-channel MOS pipe of described second switch pipe, first end of described second switch pipe is the drain electrode of described N-channel MOS pipe, and the second end of described second switch pipe is the source electrode of described N-channel MOS pipe.
10. the switching power circuit as described in any one of claim 4 to 6, it is characterised in that described 3rd switching tube is NPN type triode；The base stage that control end is described NPN type triode of described 3rd switching tube, the colelctor electrode that the first end is described NPN type triode of described 3rd switching tube, the emitter stage that the second end is described NPN type triode of described 3rd switching tube；
Described 4th switching tube is PNP type triode；The base stage that control end is described PNP type triode of described 4th switching tube, the emitter stage that the first end is described PNP type triode of described 4th switching tube, the colelctor electrode that the second end is described PNP type triode of described 4th switching tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620018705.0U CN205490115U (en) | 2016-01-05 | 2016-01-05 | Switching power supply circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620018705.0U CN205490115U (en) | 2016-01-05 | 2016-01-05 | Switching power supply circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205490115U true CN205490115U (en) | 2016-08-17 |
Family
ID=56665577
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620018705.0U Active CN205490115U (en) | 2016-01-05 | 2016-01-05 | Switching power supply circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205490115U (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106655776A (en) * | 2017-01-16 | 2017-05-10 | 深圳市华星光电技术有限公司 | Voltage conversion device |
| CN107077618A (en) * | 2017-01-24 | 2017-08-18 | 深圳市汇顶科技股份有限公司 | Fingerprint identification system |
| CN107197184A (en) * | 2017-07-05 | 2017-09-22 | 青岛海信电器股份有限公司 | A kind of supplying power for tuner control circuit, system and top box of digital machine |
| CN110399031A (en) * | 2019-06-28 | 2019-11-01 | 武汉高德红外股份有限公司 | The method and board of power consumption are reduced based on integrated form boost-buck power chip |
| CN112468135A (en) * | 2018-07-26 | 2021-03-09 | 华为技术有限公司 | Level conversion circuit and electronic device |
| CN112582999A (en) * | 2020-11-16 | 2021-03-30 | 惠州市德赛西威汽车电子股份有限公司 | Protection circuit for preventing chip pin overvoltage in standby process and after starting |
| CN114968378A (en) * | 2021-02-23 | 2022-08-30 | 广州视源电子科技股份有限公司 | Control method, device, equipment and storage medium |
-
2016
- 2016-01-05 CN CN201620018705.0U patent/CN205490115U/en active Active
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106655776A (en) * | 2017-01-16 | 2017-05-10 | 深圳市华星光电技术有限公司 | Voltage conversion device |
| CN107077618A (en) * | 2017-01-24 | 2017-08-18 | 深圳市汇顶科技股份有限公司 | Fingerprint identification system |
| WO2018137164A1 (en) * | 2017-01-24 | 2018-08-02 | 深圳市汇顶科技股份有限公司 | Fingerprint recognition system |
| CN107077618B (en) * | 2017-01-24 | 2019-03-08 | 深圳市汇顶科技股份有限公司 | Fingerprint identification system |
| US10650216B2 (en) | 2017-01-24 | 2020-05-12 | Shenzhen GOODIX Technology Co., Ltd. | Fingerprint identification system |
| CN107197184A (en) * | 2017-07-05 | 2017-09-22 | 青岛海信电器股份有限公司 | A kind of supplying power for tuner control circuit, system and top box of digital machine |
| CN112468135A (en) * | 2018-07-26 | 2021-03-09 | 华为技术有限公司 | Level conversion circuit and electronic device |
| CN110399031A (en) * | 2019-06-28 | 2019-11-01 | 武汉高德红外股份有限公司 | The method and board of power consumption are reduced based on integrated form boost-buck power chip |
| CN112582999A (en) * | 2020-11-16 | 2021-03-30 | 惠州市德赛西威汽车电子股份有限公司 | Protection circuit for preventing chip pin overvoltage in standby process and after starting |
| CN112582999B (en) * | 2020-11-16 | 2023-02-14 | 惠州市德赛西威汽车电子股份有限公司 | Protection circuit for preventing chip pin overvoltage in standby process and after starting |
| CN114968378A (en) * | 2021-02-23 | 2022-08-30 | 广州视源电子科技股份有限公司 | Control method, device, equipment and storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205490115U (en) | Switching power supply circuit | |
| CN105656307B (en) | Charge pump circuit and gate turn-on voltage generative circuit | |
| CN103531156B (en) | Backlight drive circuit and liquid crystal indicator | |
| CN103384436B (en) | LED backlight constant current circuit | |
| CN102013802A (en) | BOOST circuit with short circuit protection function | |
| CN108377142A (en) | A kind of electronic switching circuit | |
| US8912731B2 (en) | LED backlight driving circuit and backlight module | |
| CN108880230B (en) | Power sources in parallel control module and parallel system based on Switching Power Supply chopping voltage | |
| CN106533144B (en) | Anti-reverse and current flowing backwards circuit | |
| CN206210358U (en) | Overvoltage protection circuit and LED backlight driving circuit | |
| CN107834634A (en) | A kind of charging current limiter circuit for energy-storage battery group management system and the energy-storage battery group management system comprising charging current limiter circuit | |
| CN204117010U (en) | Switching mode mu balanced circuit, constant pressure and flow produce circuit and constant voltage constant current power equipment | |
| CN107071988B (en) | Multiple constant current output driving circuit and display equipment | |
| CN206559040U (en) | A kind of electric equipment and its power supply output overvoltage regulating circuit | |
| CN203967963U (en) | Off-line power supply conversion circuit | |
| CN103023004A (en) | Surge suppression circuit | |
| CN104821156A (en) | LED backlight driving circuit | |
| CN203055409U (en) | Led backlight drive circuit and liquid crystal display device | |
| CN206226057U (en) | A kind of power control circuit and portable power source for portable power source | |
| CN1909354B (en) | Starting circuit for power converter | |
| CN205960636U (en) | Surge current control circuit and power supply unit | |
| CN104185344B (en) | Control circuit for light source, backlight module and display device | |
| CN206323124U (en) | Over-voltage and under-voltage protection circuit, backlight circuit and liquid crystal television | |
| CN206060166U (en) | A kind of point is mended adjuster circuit | |
| CN100578583C (en) | Multi-mode switch for plasma display panel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |