CN106452040B - Start-up circuit - Google Patents
Start-up circuit Download PDFInfo
- Publication number
- CN106452040B CN106452040B CN201610917615.XA CN201610917615A CN106452040B CN 106452040 B CN106452040 B CN 106452040B CN 201610917615 A CN201610917615 A CN 201610917615A CN 106452040 B CN106452040 B CN 106452040B
- Authority
- CN
- China
- Prior art keywords
- circuit
- capacitor
- transistor
- resistance
- diode
- 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
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/36—Means for starting or stopping converters
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Electronic Switches (AREA)
- Dc-Dc Converters (AREA)
- Continuous-Control Power Sources That Use Transistors (AREA)
Abstract
The invention discloses a kind of start-up circuits, start-up circuit is on the basis of conventional linear pressure stabilizing start-up circuit, a capacitor is sealed between the control terminal and input power of transistor, it is powered moment in input power, the conducting of linear voltage stabilization start-up circuit is controlled by the charging current of capacitor, utilize capacitor delay effect, after capacitor is fully charged, linear voltage stabilization start-up circuit complete switches off, so that start-up circuit stand-by power consumption is reduced to 0, condenser voltage from 0V be charged to input voltage needed for the time be the timing turn-off time；After input voltage power-off, capacitor C1 will be by resistance R3, diode D3 and zener diode D1 and resistance R1, totally 3 discharge paths, while to the load discharge of input voltage rear end.
Description
Technical field
The present invention relates to Switching Power Supplies, in particular to supply in Switching Power Supply for the control circuit of power stage circuit or control IC
The start-up circuit of electricity.
Background technique
Start-up circuit is widely used in electronic technology field.In Switching Power Supply application, either DC-DC converter is still
AC-DC converter, product needs obtain stable direct current startup power supply (such as Vcc) from the input voltage of wide scope, to control IC
The power supply of (alternatively referred to as chip) or control circuit, then control circuit drives electronic switch, passes through electronic switch control inductive member
Device periodically transmits electric energy to output end.
For AC-DC switching power converters, input voltage is power frequency ac voltage (the usually 85VAC- of wide scope
264VAC), by rectifier bridge and filter capacitor rectifying and wave-filtering, it can only obtain the DC input voitage (120VDC- of wider range
373VDC), in order to obtain stable DC low-voltage startup power supply, if using traditional linear voltage-stabilizing circuit as starting electricity
Road, as shown in Figure 1, starting pinciple are as follows: product be powered moment, transistor Q1 conducting, the emitter current of transistor Q1 rapidly to
Capacitor C2 charging, when capacitor C2 voltage (namely the output plus terminal of start-up circuit be supplied to control IC feeder ear Vcc voltage)
The pressure stabilizing value for rising to zener diode D1 subtracts the base stage of transistor Q1 and when emitter conduction voltage drop, Vcc voltage will be stablized
It is not further added by, when Vcc voltage reaches the starting threshold value of chip, chip is started to work, the work of chip controls power stage circuit, defeated
Voltage is gradually begun setting up out, steady-state supply branch start to gradually replace by way of coupling output voltage start-up circuit to
Vcc power supply, when steady-state supply branch output voltage is higher than start-up circuit output voltage, start-up circuit diode D2 reverse bias
Cut-off, therefore transistor Q1 is also turned off, but start-up resistor R1 and zener diode D1 still can be generated after product enters stable state
Loss, in order to ensure starting current is enough when low pressure input, resistance R1 generally can not obtain too small, starting when leading to high input voltage
The stand-by power consumption of circuit is still very big.
For the DC-DC switching power converters of wide-range input voltage, equally can also there be start-up circuit stand-by power consumption
Greatly, the shortcomings that high input voltage starting power consumption big (starting ability for compatible low input).
Other than problem above point, when traditional linear voltage stabilization start-up circuit (such as Fig. 1) is applied to Switching Power Supply, opening
Powered-down source works under output short circuit protection state, output voltage 0V, at this time can not by way of coupling output voltage to
Vcc power supply, i.e., pressure stabilizing power supply bypass diodes shown in FIG. 1 are ended because of reverse bias, and start-up circuit will be continuously in work
State is powered for Vcc, and start-up circuit power consumption is very big, and fever is serious, such as present invention applicant in 2 grades of schemes of debugging 100W
When Switching Power Supply, when start-up circuit use conventional linear pressure stabilizing start-up circuit shown in FIG. 1, be in output short-circuit in Switching Power Supply
When guard mode, it can not be powered by coupling the Zhi Luxiang Vcc of output voltage (i.e. the steady-state supply branch of Fig. 1 disconnects), due to
The driving of the power switch tube of Switching Power Supply second level push-pull circuit is still non-switched off when output short-circuit (being determined by controlling IC), leads
Start-up circuit is caused persistently to provide driving current, when input voltage is maximum operating voltage, actual measurement starting power consumption reaches 3W, surveys under room temperature
The temperature of examination transistor Q1 is up to 120 degree.
In conclusion the application of start-up circuit is confined in industry at present: defeated after start-up circuit work or in Switching Power Supply
Start-up circuit can not be turned off when short-circuit out or thoroughly or need to increase extremely complex control logic circuit, performance at
Originally it can not get both.
Summary of the invention
In view of technological deficiency present in foregoing circuit, the present invention proposes that a kind of structure is simple, and component is few, at low cost,
Start-up circuit can complete switch off after starting, the start-up circuit of stand-by power consumption very little.
In order to achieve the above-mentioned object of the invention, the invention adopts the following technical scheme:
A kind of start-up circuit, for providing starting current, including transistor Q1 and crystal to the feeder ear Vcc of control circuit
The biasing circuit and output circuit of pipe Q1, the biasing circuit input terminal of transistor Q1 are the input terminal of start-up circuit, for it is defeated
Enter voltage connection；The output end of the output circuit of transistor Q1 is the output end of start-up circuit, for the power supply with control circuit
Hold Vcc connection, the biasing circuit of transistor Q1 include timing breaking circuit, timing breaking circuit, including resistance R1, resistance R3 and
Capacitor C1, in startup stage, input voltage charges to capacitor C1 by resistance R1 and resistance R3, after capacitor C1 is full of, electricity
Holding C1 makes resistance R1 and resistance R3 open a way, and then the base current of transistor Q1 is made to be reduced to 0, and transistor Q1 shutdown starts electricity
Road is turned off.
Preferably, the output circuit of the transistor Q1, including diode D2 and capacitor C2, in startup stage, input electricity
Pressure also charges by resistance R1, transistor Q1, diode D2 to capacitor C2；When the emitter current of transistor Q1 is decreased below
When the output load current value of start-up circuit, capacitor C2 starts to discharge to the feeder ear Vcc of control circuit.
Preferably, the biasing circuit of the transistor Q1, further includes resistance R2, and the current collection of transistor Q1 is arranged in resistance R2
Between pole and input just.
Preferably, the biasing circuit of the transistor Q1, further includes zener diode D1, the cathode of zener diode D1 with
The base stage of transistor Q1 connects, the plus earth of zener diode D1, to form capacitor C1 to input voltage backend load
Discharge loop.
Preferably, the timing breaking circuit designs timed-shutoff by the capacitance of capacitor C1, the resistance value of resistance R1
Disconnected time T1, timing turn-off time T1 are slightly larger than Switching Power Supply output delay time T2.
Preferably, the transistor Q1 is NPN type triode or N-type metal-oxide-semiconductor, and in startup stage, transistor Q1 is worked in
Linear zone.
Preferably, the transistor Q1 works in linear zone, makes the charging current of capacitor C2 much larger than capacitor C1；Starting
In the stage, input voltage passes through resistance R1, the base stage of transistor Q1 and emitter, diode D2, while filling to capacitor C1, capacitor C2
Electricity, the charging current of capacitor C1 are the base current of transistor Q1, and the charging time of capacitor C1 forms timing turn-off time T1；Electricity
The charging current for holding C2 is the emitter current of transistor Q1, and the storing electricity of capacitor C2 is to the feeder ear to control circuit
Vcc power supply.
Preferably, the biasing circuit of the transistor Q1 further includes diode D3, and diode D3 is connected in parallel on the two of resistance R3
End, the cathode of diode D3 are connect with capacitor C1, the plus earth of diode D3, to form capacitor C1 to input voltage rear end
The discharge loop of load.
The present invention also provides a kind of start-up circuits, for providing starting current, including crystalline substance to the feeder ear Vcc of control circuit
The biasing circuit and output circuit of body pipe Q1 and transistor Q1, the biasing circuit of transistor Q1 include timing breaking circuit, wherein
The biasing circuit of transistor Q1, including resistance R1, resistance R2, resistance R3, zener diode D1 and capacitor C1, wherein timing turns off
Circuit, including resistance R1, resistance R3 and capacitor C1；The output circuit of transistor Q1, including diode D2 and capacitor C2, starting electricity
The specific connection relationship on road is the input anode of one end of capacitor C1 and one end of resistance R2 as start-up circuit, for it is defeated
Enter positive voltage terminal+Vin connection, one end of the other end connection resistance R1 of capacitor C1 and one end of resistance R3, resistance R3's is another
End ground connection；The collector of the other end connection transistor Q1 of resistance R2, the base stage of transistor Q1 are separately connected the another of resistance R1
The cathode of end and zener diode D1, the plus earth of zener diode D1；The emitter connection diode D2's of transistor Q1
Anode, one end of the cathode connection capacitor C2 of diode D2, the cathode of diode D2 are also used as the output end of start-up circuit, are used for
It is connect with the feeder ear Vcc of control circuit；The other end of capacitor C2 is grounded, and the other end of capacitor C2 is also used as the defeated of start-up circuit
Negative terminal out is connect for the ground terminal GND with control circuit.
Preferably, the biasing circuit of the transistor Q1 further includes diode D3, and diode D3 is connected in parallel on the two of resistance R3
End, the cathode of diode D3 are connect with capacitor C1, the plus earth of diode D3, to form capacitor C1 to input voltage rear end
The discharge loop of load.
Start-up circuit of the invention, input voltage unlatching after, input voltage by resistance R1, transistor Q1 base stage with
Emitter, diode D2, while charging to capacitor C1, capacitor C2, capacitor C1 charging current is equal to the base stage electricity of transistor Q1
Stream, so just transistor Q1 conducting when powering on, its emitter current charges to capacitor C2 after transistor Q1 conducting, and simultaneously to opening
Dynamic circuit load power supply, after capacitor C1 is full of, the base current of transistor Q1 is 0, and transistor Q1 shutdown, start-up circuit is closed
It is disconnected, capacitor C1 from 0V be charged to input voltage needed for the time be the timing turn-off time, after start-up circuit shutdown, start-up circuit is waited for
Machine power consumption is 0W.After input voltage power-off, capacitor C1 will discharge by resistance R3 and zener diode D1 and resistance R1, with logical
Cross the load discharge of input voltage rear end.
The present invention provides a kind of start-up circuit again, comprising: capacitor C1, capacitor C2, resistance R1, resistance R2, resistance R3, pressure stabilizing
Diode D1, diode D2, transistor Q1, the transistor Q1 are NPN type triode, the connection relationship of the start-up circuit
Are as follows: one end of the capacitor C1 and one end of resistance R2 are connect with+Vin, and the one of the other end connection resistance R1 of the capacitor C1
End and one end of resistance R3, the other end of the resistance R2 connect the collector of the transistor Q1, the base of the transistor Q1
Pole connects the other end of the resistance R1 and the cathode of the zener diode D1, and the anode of the zener diode D1 connects institute
It is connected to-Vin after stating the other end of resistance R3, the emitter of the transistor Q1 connects the anode of the diode D2, described
The cathode of diode D2 connects one end of the capacitor C2, and connects Vcc simultaneously, and the other end of the capacitor C2 connects GND, and
It is connected to-Vin simultaneously.
As the another kind application of start-up circuit of the present invention, transistor Q1 described in above scheme can select N-type metal
Oxide field-effect pipe (N-type MOSFET), abbreviation N-type metal-oxide-semiconductor, the transistor Q1 use the circuit arrangement packet of N-type metal-oxide-semiconductor
It includes: capacitor C1, capacitor C2, resistance R1, resistance R2, resistance R3, zener diode D1, diode D2, transistor Q1, circuit connection
Relationship are as follows: one end of the capacitor C1 and one end of resistance R2 are connect with+Vin, and the other end of the capacitor C1 connects resistance R1
One end and resistance R3 one end, the other end of the resistance R2 connects the drain electrode of the transistor Q1, the transistor Q1's
Grid connects the other end of the resistance R1 and the cathode of the zener diode D1, the anode connection of the zener diode D1
- Vin is connected to after the other end of the resistance R3, the source electrode of the transistor Q1 connects the anode of the diode D2, described
The cathode of diode D2 connects one end of the capacitor C2, and connects Vcc simultaneously, and the other end of the capacitor C2 connects GND, and
It is connected to-Vin simultaneously.
After the transistor Q1 is changed to N-type metal-oxide-semiconductor by NPN triode, the output voltage of start-up circuit is equal to pressure stabilizing two
The pressure stabilizing value of pole pipe D1 subtracts metal-oxide-semiconductor Q1 grid and source conduction voltage and the forward conduction voltage drop of diode D2, circuit work
It is identical when principle is with transistor Q1 selection triode.
As an improvement of the present invention, it in one diode D3 of the both ends resistance R3 of circuit parallel connection, is closed in input voltage
Have no progeny, capacitor C1 except through resistance R1 and resistance R3, zener diode D1 anode to cathode to input voltage backend load
Electric discharge is outer, can also releasing by diode D3 speed-up capacitor C1.
In summary, it is seen that the structure of start-up circuit of the present invention is simple, and required component counts are few (totally 8), design letter
It is single, and can easily achieve the object of the present invention: start-up circuit complete switches off after completing load starting, reduces start-up circuit
Stand-by power consumption, and in Switching Power Supply in application, Switching Power Supply is in output short-circuit state, start-up circuit is turned off completely, Vcc electricity
Pressure will remain in 0V, and short-circuit dissipation can be effectively reduced.
Start-up circuit of the present invention, timing breaking circuit is on the basis of conventional linear pressure stabilizing start-up circuit, by simply
Increase a capacitor, is automatically shut down after realizing normal starting, further decrease stand-by power consumption (about 0W), while start-up circuit
In Switching Power Supply in application, start-up circuit loss can be further reduced, so that reducing Switching Power Supply short-circuit dissipation.
Detailed description of the invention
Fig. 1 shows the circuit diagram of existing start-up circuit；
Fig. 2 shows the circuit diagrams of the start-up circuit of first embodiment of the invention；
Fig. 3 shows the improvement circuit diagram of first embodiment of the invention start-up circuit；
Fig. 4 shows the waveform diagram of the start-up circuit of first embodiment of the invention；
The Vcc that the start-up circuit that Fig. 5 shows first embodiment of the invention measures in Switching Power Supply application starts waveform
Figure；
Fig. 6 shows the circuit diagram of the start-up circuit of second embodiment of the invention；
Fig. 7 shows the improvement circuit diagram of second embodiment of the invention start-up circuit；
Fig. 8 shows the starting waveform diagram of the start-up circuit of second embodiment of the invention；
The Vcc that the start-up circuit that Fig. 9 shows second embodiment of the invention measures in Switching Power Supply application starts waveform
Figure.
Specific embodiment
Made improvement compared with the existing technology for a better understanding of the present invention, specific real to of the invention two kinds
Before the mode of applying is described in detail, first the prior art combination attached drawing that background technology part is previously mentioned is illustrated, in turn
Draw the inventive concept of this case.
Fig. 1 shows the circuit diagram of existing common start-up circuit, a kind of start-up circuit, for the power supply to control circuit
Vcc is held to provide starting current, including resistance R1, resistance R2, zener diode D1, transistor Q1, diode D2 and capacitor C2,
Middle resistance R1, resistance R2 and zener diode D1 constitute the biasing circuit of transistor Q1, and diode D2 and capacitor C2 constitute crystal
The output circuit of pipe Q1.
The specific connection relationship of start-up circuit is the input of one end of resistance R1 and one end of resistance R2 as start-up circuit
Anode, for being connect with input voltage anode+Vin, the collector of the other end connection transistor Q1 of resistance R2, transistor Q1's
Base stage is separately connected the other end of resistance R1 and the cathode of zener diode D1, the plus earth of zener diode D1；Transistor
The anode of the emitter connection diode D2 of Q1, one end of the cathode connection capacitor C2 of diode D2, the cathode of diode D2 is also
As the output end of start-up circuit, it is connect for the feeder ear Vcc with control circuit；The other end of capacitor C2 is grounded, capacitor C2
The other end be also used as the output negative terminal of start-up circuit, connect for the ground terminal GND with control circuit.
Above-mentioned Starting Technical scheme connection relationship is followed, for the starting in the DC/DC converter of wide-range input voltage
Circuit is gradually built up in the output voltage of power stage circuit, can be replaced by power stage circuit as steady-state supply branch and be started
Feeder ear Vcc power supply of the circuit to its control circuit (or control IC).But since existing start-up circuit can only rely on steady-state supply
The voltage of branch is higher than starting voltage to be turned off.
And after transistor Q1 shutdown, there are still the conducting circuits of connection input voltage+Vin and the both ends-Vin, i.e. resistance
R1 and zener diode D1 branch, therefore start-up circuit can still generate loss after transistor Q1 shutdown.And in order to ensure low pressure
Starting current is enough when input, and resistance R1 generally can not obtain too small, and the stand-by power consumption of start-up circuit is also when leading to high input voltage
It is very big.
In addition to this, in the case where DC/DC converter works in output short circuit protection state, output voltage 0V.Control electricity at this time
Road can not be powered from the steady-state supply branch of power stage circuit, then the conducting circuit of start-up circuit will be continuously in work shape
State is that the feeder ear Vcc of control circuit powers, causes start-up circuit power consumption very big, and it is serious to generate heat.
And start-up circuit of the invention, aiming at existing start-up circuit shutdown control it is complicated, close and constantly and it is non-just
Often improvement made by the odd height of power consumption when work.The thinking that substantially improves of the invention is managed in the crystal of conventional start-up circuit
A capacitor is cleverly sealed between end processed and input voltage, it is with after start completion, the biasing circuit of transistor is whole
Open circuit.
So both solved the problems, such as start-up circuit can not automatic shutoff, and start-up circuit automatic shutoff can also solve to switch
The problem of start-up circuit can not be turned off when power supply output short-circuit, and the stand-by power consumption of start-up circuit is made to be further reduced to 0W.Together
When start-up circuit in Switching Power Supply in application, can be further reduced start-up circuit normal work loss and non-normal working damage
Consumption, and then reduce the overall power of Switching Power Supply.
And the reset of the capacitor is put immediately by what the main topological circuit of Switching Power Supply carried out after input voltage power-off
Electricity, the electric discharge of capacitor thoroughly, releive and rapidly, eliminate the hidden danger that shocks by electricity caused by capacitor discharge, and input voltage powers off
Reboot operation afterwards can also be greatly simplified due to the latency issue without considering to restart without interval time restriction and be restarted circuit
Control design case factor.
Inventive concept accordingly is described in detail the principle of the present invention and embodiment below in conjunction with attached drawing.
First embodiment
Fig. 2 shows the circuit diagram of the start-up circuit of first embodiment of the invention, a kind of start-up circuit, comprising: electricity
Holding C1, capacitor C2, resistance R1, resistance R2, resistance R3, zener diode D1, diode D2 and transistor Q1, transistor Q1 is
NPN type triode, wherein resistance R1, resistance R2, resistance R3, zener diode D1 and capacitor C1 constitute the biased electrical of transistor Q1
Road, diode D2 and capacitor C2 constitute the output circuit of transistor Q1.
The connection relationship of start-up circuit are as follows: one end of capacitor C1 and one end of resistance R2 as start-up circuit input just
End, for being connect with input voltage+Vin, one end of the other end connection resistance R1 of capacitor C1 and one end of resistance R3, resistance R2
Other end connection transistor Q1 collector, the other end and zener diode D1 of the base stage connection resistance R1 of transistor Q1
Cathode is connected to input voltage-Vin (also referred to as input ground) after the other end of the anode connection resistance R3 of zener diode D1,
The anode of the emitter connection diode D2 of transistor Q1, one end of the cathode connection capacitor C2 of diode D2, and conduct simultaneously
The output plus terminal of start-up circuit, for connecting the feeder ear Vcc of control circuit, the other end of capacitor C2 is as the defeated of start-up circuit
Negative terminal out for connecting the ground terminal GND of control circuit, and is connected to input ground-Vin simultaneously.
First embodiment working principle explanation: the timing breaking circuit of start-up circuit of the present invention, including resistance R1, resistance R3
With capacitor C1, after+Vin and the both ends-Vin apply input voltage, input voltage charges (due to electricity to capacitor C1 by resistance R3
It is big to hinder R3 value, the branch charging current is negligible), while input voltage is by the base stage and transmitting of resistance R1, transistor Q1
Pole, diode D2, while charging to capacitor C1, capacitor C2, the base stage that wherein charging current of capacitor C1 is transistor Q1 works
The charging time of electric current Ib, capacitor C1 form timing turn-off time T1；The charging current of capacitor C2 is the emitter of transistor Q1
The storing electricity of electric current Ie, capacitor C2 to the feeder ear Vcc of control circuit to power.
Transistor Q1 works in linear zone during startup, it is known that Ie=(1+ β) Ib > > Ib, so the charging of capacitor C2
Electric current is much larger than capacitor C1, and the voltage climbing speed of capacitor C2 is caused to be greater than capacitor C1 (assuming that capacitor C1 and capacitor C2 capacitance
When equal), until the voltage of capacitor C2 reaches the pressure stabilizing value V of zener diode D1ZSubtract the base stage and emitter of transistor Q1
The forward conduction voltage drop (about 0.5V) of conduction voltage drop (about 0.7V) and diode D2, capacitor C2 voltage no longer climb, i.e. capacitor C2
Value is stabilized the output voltage after actuation: VC2=VZ- 1.2V, capacitor C1 also is continuing to charge at this time, the emitter electricity of transistor Q1
Stream Ie start the output end load supplying for start-up circuit, as the voltage of capacitor C1 is gradually increased, resistance R1 both end voltage by
Decrescence small, the base current of transistor Q1 is gradually reduced, and transistor Q1 emitter current Ie also starts to reduce, when Ie be reduced to it is low
When start-up circuit output load current value, capacitor C2 starts to load part electric current lacking in supplement to output end.
So will pass through trickle to capacitor C1 charge, formed have enough durations timing turn-off time T1, and by compared with
High current charges to capacitor C2, make capacitor C2 within the timing turn-off time can amount of charge stored as much as possible, with to load (i.e.
The feeder ear Vcc of control circuit) supplement transistor Q1 emitter current Ie in reduce by the increase of capacitor C1 relatively just
Part electric current lacking in normal output voltage.The ingenious combination for so utilizing capacitor C1 and capacitor C2, can be in stable state branch
Before power supply is established, the output voltage of start-up circuit is kept into for a period of time according to the power demands of backend load automatically, easily.
The output voltage of power stage circuit is established later, can be replaced by power stage circuit as steady-state supply branch and be started
Feeder ear Vcc power supply of the circuit to its control circuit (or control IC).And capacitor C2 voltage is begun to decline, until capacitor C1 fills
Full, transistor Q1 base current is reduced to 0, and the emitter current of transistor Q1 is also reduced to 0, and the voltage at the both ends capacitor C2 also will
It is discharged to 0V.
After input voltage power-off, capacitor C1 will pass through resistance R3 and zener diode D1 and resistance R1, pass through input electricity
The load discharge of rear end is pressed, i.e. capacitor C1 can be discharged by input circuit.The load of input voltage rear end, which refers to, to be connected in parallel on
The Switching Power Supply power stage circuit of input voltage+Vin and the both ends-Vin.
Capacitor C1 to realize the present invention start-up circuit timing shutdown purpose key components, in energization momentary capacitance C1
Be equivalent to short circuit, start-up circuit conducting, after capacitor C1 is full of, start-up circuit is disconnected, the timing turn-off time be capacitor C1 from
0V is full of time T1 needed for reaching input voltage, according to the charging time calculation formula of capacitor:It is found that T1's is big
It is small related with the charging current of the capacitance of capacitor C1 and C1, from the description of first embodiment working principle it is found that capacitor
The charging current of C1 is equal to the electric current for flowing through resistance R3 and flows through the sum of resistance R1 electric current, and as the voltage of capacitor C1 gradually increases
Greatly, it actually flows through the electric current of resistance R1 and flows through the electric current of R3 and all reduce always, flow through the electric current of resistance R1 on the one hand
Related with the current amplification factor of transistor Q1, in addition also related with the load current size of Vcc, resistance R3 guarantees capacitor C1's
Voltage can be filled to input voltage, complete switch off start-up circuit.
As the improvement of first embodiment of the invention, as shown in figure 3, in the both ends resistance R3 diode D3 in parallel, two
The tie point of cathode connection the resistance R3 and capacitor C1 of pole pipe D3, the anode connection input ground-Vin of diode D3.Increase by two poles
After pipe D3, accelerate the reset of capacitor C1: after input voltage shutdown, capacitor C1 is except through resistance R3 and resistance R1, pressure stabilizing
The anode of diode D1 to cathode to input voltage backend load electric discharge outside, can also be by diode D3 speed-up capacitor C1 to defeated
Entry loop is released.
Test as first embodiment confirms that the actual measurement that Fig. 4 shows the start-up circuit of first embodiment of the invention is opened
Dynamic waveform, start-up circuit input voltage are 24V, and start-up circuit backend load electric current is 24mA, and 101 represent start-up circuit in waveform
The input voltage+Vin that is accessed of input terminal and the both ends-Vin voltage waveform, 102 represent the output ends output of start-up circuit
To the voltage waveform of the feeder ear Vcc to ground terminal GND of control circuit.Fig. 5 shows the start-up circuit of first embodiment of the invention
Starting waveform in Switching Power Supply (input voltage 24V, output power 100W) application, 201 represent and open in test waveform
The voltage waveform of input voltage+Vin and the both ends-Vin that the input terminal of dynamic circuit is accessed, 202 represent the output of start-up circuit
Voltage waveform of the end output to the feeder ear Vcc to ground terminal GND of control circuit.It can be seen that start-up circuit from Fig. 4 test waveform
Start to export stable voltage 10.6V after input voltage foundation, and output voltage starts to be gradually reduced after lasting 10.2mS
To 0V；After accessing Switching Power Supply, from fig. 5, it can be seen that after start-up circuit powers about 6.8mS to the feeder ear Vcc of control circuit,
Switch power source output voltage is begun setting up, and replaces start-up circuit pair by way of the output voltage coupling steady-state supply branch
The feeder ear Vcc of control circuit powers.Steady-state supply branch is to work in stable state to provide the power stage circuit of output voltage.
Since the operating voltage of steady-state supply branch is higher than start-up circuit supply voltage, so the diode D2 of start-up circuit is reversed partially
It sets, the emitter path of transistor Q1 is blocked, and the output circuit of transistor Q1 will be turned off persistently, and capacitor C1 will be continued through
Resistance R3 and resistance R1, the charging of zener diode D1 branch, until being full of, and then make the base current of transistor Q1 be reduced to 0,
Transistor Q1 shutdown, start-up circuit are turned off, and the entire stand-by power consumption of start-up circuit will fall to 0W.
The beneficial effects of the present invention are: when timing shutdown start-up circuit is applied to Switching Power Supply, after input voltage access,
Start-up circuit starts to export burning voltage, by choosing the pressure stabilizing value of zener diode D1 and the control circuit of combination Switching Power Supply
Starting operating voltage needed for (or control IC) designs the value that stabilizes the output voltage of start-up circuit, and it is electric to guarantee that start-up circuit exports
Pressure meets the application needs of output backend load；In addition can by calculate the capacitance of capacitor C1, the resistance value of resistance R1 come
It designs timing turn-off time T1 (timeconstantτ=R1*C1), reaches the time T1 of setting in start-up circuit output voltage of voltage regulation
Afterwards, start-up circuit is begun to turn off, and setting time T1 needs are designed according to Switching Power Supply output delay time T2.Switching Power Supply
Output delay time T2, which refers to begin setting up from Switching Power Supply input voltage to output voltage, reaches the rated value time experienced,
Or it can be described as the starting time of Switching Power Supply.General setting timing turn-off time T1 is slightly larger than the starting time T2 of Switching Power Supply,
After the duration that start-up circuit supplies power to timing turn-off time T1, start-up circuit is open, the control IC of Switching Power Supply or control
Circuit starts to be powered by steady-state supply branch, to reduce start-up circuit loss, improves Switching Power Supply transfer efficiency.
When Switching Power Supply is in short-circuit condition, if using traditional linear voltage stabilization start-up circuit, due to steady-state supply
The output voltage of branch is 0V, can not be powered by the feeder ear Vcc of steady-state supply Zhi Luxiang control circuit, so control circuit
The power supply of feeder ear Vcc can only rely on start-up circuit.At this time if short-circuit protection circuit not additional inside Switching Power Supply,
Start-up circuit will flow continuously through driving current required for control circuit, and starting current will continue working, high input voltage
Lower start-up circuit will be easy to overpower and burn.Even if Switching Power Supply devises short-circuit protection circuit, due to general short-circuit protection
State is all designed to hiccup mode, start-up circuit also can intermittent work, start-up circuit can also generate biggish loss.
If applied using the start-up circuit of first embodiment of the invention in Switching Power Supply, in Switching Power Supply output short-circuit
Under state, steady-state supply branch and start-up circuit cannot all power to Vcc, at this time the feeder ear Vcc of control circuit or control IC
Will be power-down to 0V, control circuit or control IC will be in an off state.Under the application, since start-up circuit supplies power to timed-shutoff
After the duration of disconnected time T1, start-up circuit is just open, and the control IC or control circuit of Switching Power Supply start by steady-state supply branch
Road power supply, and the output voltage of steady-state supply branch is 0V at this time, therefore, overall power of the Switching Power Supply under output short-circuit
It will be reduced to 0, for the short-circuit protection circuit of hiccup operative scenario, start-up circuit of the invention easily eliminates short
Lu Shiyin start-up circuit closes and continuous caused many hidden danger risk factors out of control, for example fever, key components shift to an earlier date
Failure etc., and the overall power of Switching Power Supply declines to a great extent.
The start-up circuit of first embodiment of the invention, on the basis of conventional linear pressure stabilizing start-up circuit, in electronic switching tube
Control terminal and input power between seal in a capacitor C1, input power be powered moment, pass through the charging current of capacitor C1
The conducting of linear voltage stabilization start-up circuit is controlled, using capacitor delay effect, after capacitor C1 is fully charged, linear voltage stabilization start-up circuit is complete
Full shutdown makes start-up circuit stand-by power consumption be reduced to 0, capacitor C1 voltage from 0V be charged to input voltage needed for the time be timing
Turn-off time；Input voltage power-off after, capacitor C1 will by resistance R3, diode D3 and zener diode D1 and resistance R1,
Totally 3 discharge paths, while to the load discharge of input voltage rear end.
Now by taking the application of the Switching Power Supply of 18V-75V input voltage range as an example, using the start-up circuit of diagram 1, to guarantee
It can start under high/low temperature and full input voltage range, resistance R1 value is 22K Ω, and zener diode D1 chooses 12V pressure stabilizing two
Pole pipe, transistor Q1 choose common NPN triode, start-up circuit stand-by power consumption (resistance R1 when reality calculates input voltage 75V
With the power consumption of zener diode D1) reach 214mW (column can be calculated (75-12)/22K*75V=214mW).Switching Power Supply output
Under short-circuit condition, it is assumed that it is 20mA that the feeder ear Vcc of start-up circuit rear end control IC, which needs to provide electric current, then input voltage is
Start-up circuit power consumption reaches 1280mW under output short-circuit when 75V (column can be calculated (75V-10.8V) * 20mA=1280mW).
Same 18V-75V input voltage range Switching Power Supply application, if actually taken using the start-up circuit of diagram 2
Capacitor C1 is 2.2uF, start-up circuit when input voltage 75V after resistance R1 takes 10K Ω, actual measurement switch power source output voltage to establish
Stand-by power consumption is 0W.Consider the measuring accuracy of test equipment, and leakage current present in actually transistor Q1, stand-by power consumption
Exact value can be calculated by formula, and column can be calculated 75V*60uA=4.5mW, i.e. the exact value of stand-by power consumption is 4.5mW,
Wherein 60uA electric current is to survey the collector of transistor Q1 to the leakage current of emitter.When Switching Power Supply is in short-circuit condition,
Surveying start-up circuit power consumption is also 0W.Consider the measuring accuracy of test equipment, the exact value of start-up circuit power consumption can also when short-circuit
It is calculated by formula, column can be calculated 75V*60uA=4.5mW, i.e., the exact value of start-up circuit power consumption is when short-circuit
4.5mW, wherein 60uA electric current is to survey the collector of transistor Q1 to the leakage current of emitter.
Improvement such as the following table 1 of start-up circuit shown in the start-up circuit and Fig. 1 of practical comparison first embodiment of the invention
It is shown:
Table 1
| Working characteristics | First embodiment of the invention | Conventional start-up circuit |
| Start-up circuit stand-by power consumption | 4.5mW | 214mW |
| Start-up circuit power consumption when output short-circuit | 4.5mW | 1280mW |
From upper table 1 it is found that the start-up circuit of first embodiment of the invention can be effectively reduced in the case where normal starting
Start-up circuit stand-by power consumption, and after output voltage stabilization, start-up circuit can be turned off thoroughly, and be can be effectively reduced and answered
The short-circuit dissipation of Switching Power Supply.
Second embodiment
Fig. 6 shows the circuit diagram of the start-up circuit of second embodiment of the invention, a kind of start-up circuit, comprising: electricity
Hold C1, capacitor C2, start-up resistor R1, resistance R2, resistance R3, zener diode D1, diode D2 and transistor Q1, transistor Q1
For N-type metal-oxide-semiconductor, the connection relationship of start-up circuit are as follows: one end of capacitor C1 and one end of resistance R2 are connect with input voltage+Vin,
One end of the other end connection resistance R1 of capacitor C1 and one end of resistance R3, the leakage of the other end connection transistor Q1 of resistance R2
Pole, the other end of the grid connection resistance R1 of transistor Q1 and the cathode of zener diode D1, the anode of zener diode D1 connect
The anode of the source electrode connection diode D2 of input ground-Vin, transistor Q1, diode D2 are connected to after the other end of connecting resistance R3
Cathode connection capacitor C2 one end, the cathode of diode D2 is also used as the output end of start-up circuit, for connecting control circuit
Feeder ear Vcc, output negative terminal of the other end of capacitor C2 as start-up circuit, for connecting the ground terminal GND of control circuit, and
It is connected to input ground-Vin simultaneously.
The key components of the timing shutdown purpose of timing capacitor C1 to realize the present invention are suitable in energization momentary capacitance C1
In short circuit, start-up circuit conducting；After capacitor C1 is full of, capacitor C1 makes resistance R1 and resistance R3 just as open circuit, and start-up circuit is thorough
Bottom is disconnected；Charging resistor R3 guarantees that the voltage of capacitor C1 can be filled to input voltage, when turning off the timing of start-up circuit
Between reach after the gate source voltage of transistor Q1 be lower than its threshold voltage, start-up circuit complete switches off.
On the basis of first embodiment, after transistor Q1 is changed to N-type metal-oxide-semiconductor by NPN triode, start-up circuit
Maximum stable output voltage changes, the pressure stabilizing value V equal to zener diode D1ZSubtract the grid and source electrode door of metal-oxide-semiconductor Q1
The forward conduction voltage drop of sill voltage (different metal-oxide-semiconductor threshold voltages differ greatly, generally in 1~4V) and diode D2 are (about
0.5V), timing shutdown time constant is varied, in addition to the grid and source junction capacitance of resistance R2, capacitor C1, metal-oxide-semiconductor Q1
The timing turn-off time can be influenced, the specific time is subject to practical debugging result.
As the improvement circuit of second embodiment of the invention, as shown in fig. 7, in the both ends a resistance R3 diode in parallel
The tie point of cathode connection the resistance R3 and capacitor C1 of D3, diode D3, the anode connection input ground-Vin of diode.Increase by two
After pole pipe D3, accelerate the reset of capacitor C1: after input voltage shutdown, capacitor C1 is except through resistance R3 and resistance R1, steady
Press the anode of diode D1 to outside the electric discharge of input voltage backend load, can also pass through diode D3 speed-up capacitor C1's to cathode
It releases.
Now by 18V-75V input voltage range Switching Power Supply application for, to using diagram 6 start-up circuit sample into
Row test, the stand-by power consumption of start-up circuit is 0W when input voltage 75V after actual measurement switch power source output voltage is established.In switch electricity
When source is in short-circuit condition, actual measurement start-up circuit power consumption is also 0W.Test result shows the effect of embodiment two, with embodiment one
It is essentially identical.
Fig. 8 shows the actual measurement starting waveform of second embodiment of the invention start-up circuit, input voltage 24V, Vcc load
Electric current is 24mA, the voltage of the input voltage+Vin that 301 input terminals for representing start-up circuit are accessed in waveform and the both ends-Vin
Waveform, 302 output ends for representing start-up circuit are exported to the voltage waveform of feeder ear Vcc to the GND of control circuit.Fig. 9 is shown
The start-up circuit of second embodiment of the invention is when Switching Power Supply (input voltage 24V, output power 100W) is applied
Start waveform, the voltage wave of 401 input terminals for representing start-up circuit are accessed in waveform input voltage+Vin and the both ends-Vin
Shape, 402 output ends for representing start-up circuit are exported to the voltage waveform of feeder ear Vcc to the GND of control circuit.It can be with from Fig. 8
Find out, start-up circuit starts to export burning voltage 13.625V after input voltage foundation, and is continuing working 39.8mS (timing
Turn-off time) after, the output voltage of start-up circuit starts to fall, and is finally down to 0V.From fig. 9, it can be seen that start-up circuit to
Vcc powers after about 40mS, and Vcc voltage starts to reduce, and when Vcc voltage falls to the supply voltage of steady-state supply branch, then starts electricity
Diode D2 will start reverse bias in road, and the transistor Q1 output circuit of start-up circuit is turned off, after capacitor C1 is full of, makes
The base current of transistor Q1 is reduced to 0, and transistor Q1 shutdown, start-up circuit complete switches off, and stand-by power consumption is reduced to 0W.
It can be seen that from Fig. 5 and Fig. 9 using start-up circuit proposed by the invention, steady-state supply local road design voltage can
To be higher than the output voltage (output waveform figure of first embodiment as shown in Figure 5) of start-up circuit, start-up circuit can also be lower than
The design of output voltage (output waveform figure of second embodiment as shown in Figure 9), start-up circuit output voltage values depends on pressure stabilizing
The pressure stabilizing value of diode D1 and the base stage of transistor Q1 and emitter (or grid and source electrode) conduction voltage drop.And it is traditional linear steady
The steady-state supply branch voltage of pressure start-up circuit necessarily is greater than start-up circuit output voltage, could turn off transistor Q1.In this way, saying
The design of bright start-up circuit output voltage of the present invention is no longer limited by steady-state supply branch voltage, is designed simpler.
The control circuit of alleged Switching Power Supply above, refers to the governor circuit in the power stage circuit of Switching Power Supply, circuit
Form can be analog circuit, be also possible to control IC.
The above is only the preferred embodiment of the present invention, it is noted that above-mentioned preferred embodiment is not construed as pair
Limitation of the invention, for those skilled in the art, without departing from the spirit and scope of the present invention, also
Several improvements and modifications can be made, these modifications and embellishments should also be considered as the scope of protection of the present invention, here no longer with implementation
Example repeats, and protection scope of the present invention should be defined by the scope defined by the claims..
Claims (10)
1. a kind of start-up circuit, for providing starting current, including transistor Q1 and transistor to the feeder ear Vcc of control circuit
The biasing circuit and output circuit of Q1, the biasing circuit input terminal of transistor Q1 are the input terminal of start-up circuit, are used for and input
Voltage connection；The output end of the output circuit of transistor Q1 is the output end of start-up circuit, for the feeder ear with control circuit
Vcc connection, it is characterised in that: the biasing circuit of transistor Q1 includes timing breaking circuit,
Timing breaking circuit, including resistance R1, resistance R3 and capacitor C1,
In startup stage, input voltage charges to capacitor C1 by resistance R1 and resistance R3, after capacitor C1 is full of, capacitor C1
So that resistance R1 and resistance R3 is opened a way, and then the base current of transistor Q1 is made to be reduced to 0, transistor Q1 is turned off, start-up circuit quilt
Shutdown.
2. start-up circuit according to claim 1, it is characterised in that: the output circuit of the transistor Q1, including two poles
Pipe D2 and capacitor C2, in startup stage, input voltage also passes through resistance R1, transistor Q1, diode D2 and charges to capacitor C2；When
When the emitter current of transistor Q1 is decreased below the output load current value of start-up circuit, capacitor C2 starts to control circuit
Feeder ear Vcc electric discharge.
3. start-up circuit according to claim 1, it is characterised in that: the biasing circuit of the transistor Q1, further includes electricity
R2 is hindered, resistance R2 is arranged between the collector of transistor Q1 and input just.
4. start-up circuit according to claim 1, it is characterised in that: the biasing circuit of the transistor Q1 further includes steady
Diode D1 is pressed, the cathode of zener diode D1 is connect with the base stage of transistor Q1, the plus earth of zener diode D1.
5. start-up circuit according to claim 1, it is characterised in that: the timing breaking circuit passes through the electricity of capacitor C1
Capacity, resistance R1 resistance value design timing turn-off time T1, timing turn-off time T1 is slightly larger than Switching Power Supply output delay
Time T2.
6. start-up circuit according to claim 1, it is characterised in that: the transistor Q1 is NPN type triode or N-type
Metal-oxide-semiconductor, in startup stage, transistor Q1 works in linear zone.
7. start-up circuit according to claim 2, it is characterised in that: the transistor Q1 works in linear zone, makes capacitor
The charging current of C2 is much larger than capacitor C1；In startup stage, input voltage passes through the base stage and transmitting of resistance R1, transistor Q1
Pole, diode D2, while charging to capacitor C1, capacitor C2, the charging current of capacitor C1 is the base current of transistor Q1, capacitor
The charging time of C1 forms timing turn-off time T1；The charging current of capacitor C2 is the emitter current of transistor Q1, capacitor C2
Storing electricity to the feeder ear Vcc of control circuit power.
8. start-up circuit according to any one of claim 1 to 7, it is characterised in that: the biased electrical of the transistor Q1
Road further includes diode D3, and diode D3 is connected in parallel on the both ends of resistance R3, and the cathode of diode D3 connects capacitor C1 and resistance R1
Tie point, the plus earth of diode D3.
9. a kind of start-up circuit, for providing starting current, including transistor Q1 and transistor to the feeder ear Vcc of control circuit
The biasing circuit and output circuit of Q1, it is characterised in that: the biasing circuit of transistor Q1 includes timing breaking circuit,
The biasing circuit of transistor Q1, including resistance R1, resistance R2, resistance R3, zener diode D1 and capacitor C1, wherein timing
Breaking circuit, including resistance R1, resistance R3 and capacitor C1；
The output circuit of transistor Q1, including diode D2 and capacitor C2,
The specific connection relationship of start-up circuit is, one end of one end of capacitor C1 and resistance R2 as start-up circuit input just
End, for being connect with input voltage anode+Vin, one end of the other end connection resistance R1 of capacitor C1 and one end of resistance R3, electricity
Hinder the other end ground connection of R3；The collector of the other end connection transistor Q1 of resistance R2, the base stage of transistor Q1 are separately connected electricity
Hinder the other end of R1 and the cathode of zener diode D1, the plus earth of zener diode D1；The emitter of transistor Q1 connects
The anode of diode D2, one end of the cathode connection capacitor C2 of diode D2, the cathode of diode D2 are also used as start-up circuit
Output end is connect for the feeder ear Vcc with control circuit；The other end of capacitor C2 is grounded, the also conduct of the other end of capacitor C2
The output negative terminal of start-up circuit is connect for the ground terminal GND with control circuit.
10. start-up circuit according to claim 9, it is characterised in that: the biasing circuit of the transistor Q1 further includes two
Pole pipe D3, diode D3 are connected in parallel on the both ends of resistance R3, the tie point of the cathode connection capacitor C1 and resistance R1 of diode D3, and two
The plus earth of pole pipe D3, to form capacitor C1 to the discharge loop of input voltage backend load.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610917615.XA CN106452040B (en) | 2016-10-20 | 2016-10-20 | Start-up circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610917615.XA CN106452040B (en) | 2016-10-20 | 2016-10-20 | Start-up circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106452040A CN106452040A (en) | 2017-02-22 |
| CN106452040B true CN106452040B (en) | 2019-07-19 |
Family
ID=58176460
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610917615.XA Active CN106452040B (en) | 2016-10-20 | 2016-10-20 | Start-up circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106452040B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106849636B (en) * | 2017-04-13 | 2019-04-12 | 四川长虹电器股份有限公司 | Control circuit for Switching Power Supply |
| CN108233693A (en) * | 2018-02-26 | 2018-06-29 | 广州金升阳科技有限公司 | A kind of start-up circuit of ultralow input voltage |
| CN108173426A (en) * | 2018-02-26 | 2018-06-15 | 广州金升阳科技有限公司 | A kind of start-up circuit of low conduction voltage drop |
| CN108897366B (en) * | 2018-07-13 | 2020-04-28 | 上海东软载波微电子有限公司 | Bias starting circuit, integrated high-voltage circuit and integrated low-voltage circuit |
| CN108696114A (en) * | 2018-07-18 | 2018-10-23 | 广州金升阳科技有限公司 | Start-up circuit |
| CN108832807B (en) * | 2018-08-13 | 2024-06-18 | 中国电子科技集团公司第四十三研究所 | Starting circuit and starting method for miniaturized low-power-consumption switching power supply |
| CN111290555A (en) * | 2019-01-29 | 2020-06-16 | 展讯通信（上海）有限公司 | Automatic start-up circuit and electronic equipment |
| CN111817535B (en) * | 2020-09-11 | 2020-12-08 | 南京美斯玛微电子技术有限公司 | Standby zero-power-consumption switching power supply and electric equipment |
| CN112564471B (en) * | 2020-11-27 | 2022-06-07 | 国创移动能源创新中心(江苏)有限公司 | Working sequence control circuit in two-stage conversion circuit and method thereof |
| CN115333373A (en) * | 2022-07-20 | 2022-11-11 | 上海空间电源研究所 | Isolated form auxiliary power source is from starting circuit |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201039316Y (en) * | 2007-04-03 | 2008-03-19 | 青岛海信电器股份有限公司 | A reset circuit and TV set with above reset circuit |
| CN102594170A (en) * | 2012-03-09 | 2012-07-18 | 广州金升阳科技有限公司 | Wide-input-voltage power supply converter |
| CN102739029A (en) * | 2012-05-31 | 2012-10-17 | 德讯科技股份有限公司 | Soft start circuit for realizing large-current start of switching power supply |
| CN103840669A (en) * | 2012-11-26 | 2014-06-04 | 西安威正电子科技有限公司 | Auxiliary power supply circuit adopting main power circuit |
| CN204652212U (en) * | 2015-06-23 | 2015-09-16 | 杭州中恒派威电源有限公司 | Quasi-resonance Boost soft starting circuit |
| CN105281296A (en) * | 2015-11-18 | 2016-01-27 | 广州金升阳科技有限公司 | Switch power supply protection and control method and circuit |
| CN206117499U (en) * | 2016-10-20 | 2017-04-19 | 广州金升阳科技有限公司 | Start circuit |
-
2016
- 2016-10-20 CN CN201610917615.XA patent/CN106452040B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201039316Y (en) * | 2007-04-03 | 2008-03-19 | 青岛海信电器股份有限公司 | A reset circuit and TV set with above reset circuit |
| CN102594170A (en) * | 2012-03-09 | 2012-07-18 | 广州金升阳科技有限公司 | Wide-input-voltage power supply converter |
| CN102739029A (en) * | 2012-05-31 | 2012-10-17 | 德讯科技股份有限公司 | Soft start circuit for realizing large-current start of switching power supply |
| CN103840669A (en) * | 2012-11-26 | 2014-06-04 | 西安威正电子科技有限公司 | Auxiliary power supply circuit adopting main power circuit |
| CN204652212U (en) * | 2015-06-23 | 2015-09-16 | 杭州中恒派威电源有限公司 | Quasi-resonance Boost soft starting circuit |
| CN105281296A (en) * | 2015-11-18 | 2016-01-27 | 广州金升阳科技有限公司 | Switch power supply protection and control method and circuit |
| CN206117499U (en) * | 2016-10-20 | 2017-04-19 | 广州金升阳科技有限公司 | Start circuit |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106452040A (en) | 2017-02-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106452040B (en) | Start-up circuit | |
| CN206117499U (en) | Start circuit | |
| CN102097928B (en) | High voltage starting circuit applied to AC/DC converter | |
| CN103580506B (en) | Switching Power Supply and power supply control chip | |
| CN108539964A (en) | The driving circuit and its device of power switch tube | |
| CN102790516B (en) | Feedback clamping power metal oxide semiconductor (MOS) pipe drive circuit for power supply management | |
| CN103296880B (en) | Low-power-consumption boost DC-DC converter started at ultralow voltage | |
| CN106921284B (en) | A kind of MOSFET floating driving circuit | |
| CN108964434A (en) | A kind of power down delay protection circuit for Switching Power Supply | |
| CN105811747A (en) | High-voltage power supply system with enable control | |
| CN206922645U (en) | A kind of soft starting circuit of power switch | |
| CN109347311A (en) | A kind of self-powered driving circuit of double tube positive exciting circuit of synchronous rectification | |
| CN106533144B (en) | Anti-reverse and current flowing backwards circuit | |
| CN110138220A (en) | A kind of power supply and its switching power circuit | |
| CN2884679Y (en) | Driving circuit for synchronous rectification | |
| CN206807283U (en) | A kind of start-up circuit of Switching Power Supply | |
| CN105939104A (en) | Circuit reducing electromagnetic interference and increasing peak power through adjusting pulse | |
| CN201608638U (en) | Fly-back power supply overpower compensation device inputted by wide voltage | |
| CN105934021A (en) | Overvoltage adjusting circuit for linear constant-current driving LED | |
| CN102123553B (en) | COT mode LED lighting driving circuit | |
| CN205249042U (en) | Reduce switching power supply input impulse current's circuit | |
| CN102412611B (en) | Constant-current charging circuit applied to linear charger | |
| CN103683892B (en) | Switching Power Supply and controller thereof | |
| CN102075124A (en) | Low power consumption starter of compressor motor of refrigerator | |
| CN104377950B (en) | Starting circuit of power supply control chip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |