CN209659146U - A kind of switch power controller and Switching Power Supply - Google Patents
A kind of switch power controller and Switching Power Supply Download PDFInfo
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- CN209659146U CN209659146U CN201920396036.4U CN201920396036U CN209659146U CN 209659146 U CN209659146 U CN 209659146U CN 201920396036 U CN201920396036 U CN 201920396036U CN 209659146 U CN209659146 U CN 209659146U
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Abstract
The utility model embodiment discloses a kind of switch power controller, comprising: power switch tube, for controlling the power transmission of circuit for power conversion；Voltage detecting circuit obtains voltage detection signal for detecting input voltage；Zero cross detection circuit provides zero passage detection signal for detecting inductive current；Over-voltage detection circuit, for obtaining the inductive current degaussing time according to zero passage detection signal, and degaussing fiducial time is obtained according to voltage detection signal, reference voltage signal and input-output voltage relationship, and over-voltage detection signal is obtained according to inductive current degaussing time and degaussing fiducial time；And logic and driver circuitry, overvoltage protection movement is generated for detecting signal according to effective over-voltage, the auxiliary winding and sampling resistor for sampling and outputting voltage is saved, reduces the volume and cost of Switching Power Supply.The utility model embodiment also discloses a kind of Switching Power Supply.
Description
Technical field
The utility model relates to switch power technology field, relate more specifically to a kind of switch power controller and switch electricity
Source.
Background technique
Switching Power Supply is the time ratio that control switch pipe turns on and off using modern power electronics technology, remains steady
Determine a kind of power supply of output voltage, Switching Power Supply is widely used in industrial automatic control, military industry equipment, research equipment, LED
It (Light Emitting Diode) illumination, industrial control equipment, communication apparatus, power equipment, instrument and meter, Medical Devices and partly leads
The fields such as body cooling and warming.
In Switching Power Supply, overvoltage protection, which works normally tool to it, to have very great significance.In traditional Switching Power Supply
In, output voltage is generally detected using an individual transformer winding, overvoltage protection is then input to by divider resistance
The fixation pin of chip, thus judge Switching Power Supply whether over-voltage.
Traditional overvoltage protection scheme, in order to detect output voltage whether over-voltage, need to increase corresponding auxiliary winding, partial pressure
Resistance carries out the sampling of output voltage, increases the volume and cost of Switching Power Supply, is not suitable for the corpusculum of current Switching Power Supply
The demand for development of product, low cost.
Utility model content
In view of this, being conducive to the purpose of this utility model is to provide a kind of switch power controller and Switching Power Supply
Reduce the volume and cost of Switching Power Supply.
It is according to the present utility model in a first aspect, provide a kind of switch power controller, for controlling circuit for power conversion,
The circuit for power conversion is used to provide output electric current to load according to input voltage, and the switch power controller includes: function
Rate switching tube, for controlling the power transmission of the circuit for power conversion；Voltage detecting circuit is obtained for detecting input voltage
Voltage detection signal；Zero cross detection circuit provides zero passage detection according to the inductive current zero crossing for detecting inductive current
Signal；Over-voltage detection circuit, for obtaining the inductive current degaussing time according to the zero passage detection signal, and according to the function
The topological structure of rate conversion circuit obtains input-output voltage relationship, and according to the voltage detection signal, reference voltage signal
And the input-output voltage relationship obtains degaussing fiducial time, by the inductive current degaussing time and the degaussing base
It is compared between punctual, provides over-voltage according to comparison result and detect signal, wherein gone when the inductive current degaussing time is less than
When magnetic fiducial time, the over-voltage detection circuit provides effective over-voltage and detects signal；And logic and driver circuitry, for producing
Raw driving signal, while overvoltage protection movement is generated according to the effective over-voltage detection signal.
Preferably, the over-voltage detection circuit includes: electric current generation module, for according to the voltage detection signal, institute
It states reference voltage signal and the input-output voltage relationship obtains the first electric current and the second electric current；And detection module, it uses
In obtaining the inductance according to first electric current, second electric current and the driving signal and the zero passage detection signal
Electric current degaussing time and the degaussing fiducial time, and obtained according to the inductive current degaussing time and the degaussing fiducial time
Signal is detected to the over-voltage.
Preferably, the detection module includes: trigger unit, for being believed according to the driving signal and the zero passage detection
Number trigger signal is generated, the trigger signal characterizes the inductive current degaussing time；Timing unit receives the driving signal
With the trigger signal, according to first electric current and described second under the control of the driving signal and the trigger signal
Electric current generates timing signal；And logic unit, for according to the timing signal and zero passage detection signal generation
Over-voltage detects signal.
Preferably, the logic unit is configured that when the zero passage detection signal is effective, if the timing signal is to patrol
Volume high level then provides the effective over-voltage and detects signal, if the timing signal is logic low, it is invalid to provide
The over-voltage detects signal.
Preferably, the trigger unit is configured that the trigger unit is defeated when the driving signal is logic high
The trigger signal is logic low out, when the driving signal is logic low, described in the trigger unit output
Trigger signal is logic high, until the zero passage detection signal is effective.
Preferably, the timing unit includes: the first current source being connected in series between supply voltage and ground, first opens
Pass, second switch and the second current source；First capacitor, first end are connected between the first switch and the second switch
Obtain first node, second end ground connection；First comparator, normal phase input end are connected to the first node to receive first voltage,
Reverse inter-input-ing ending grounding, output end is for exporting the timing signal.
Preferably, the timing unit is configured that the trigger signal is to patrol when the driving signal is logic high
When collecting low level, the first switch conducting, the second switch is turned off, and the first capacitor is filled via first current source
Electricity, charging current are first electric current, and it is logic high that the first comparator, which exports the timing signal, when the drive
Dynamic signal is logic low, and when the trigger signal is logic high, the first switch shutdown, the second switch is led
Logical, the first capacitor discharge via second current source, and discharge current is second electric current, when being discharged to described first
Voltage is less than/when being equal to ground voltage, timing signal overturning is logic low.
Preferably, the trigger unit includes: the first nor gate, and first input end is for receiving the driving signal；The
Two nor gates, first input end are connected to the output end of first nor gate, and the second input terminal is for receiving the zero passage inspection
Signal is surveyed, output end is connected to the second input terminal of first nor gate；And third nor gate, first input end is for connecing
The driving signal is received, the second input terminal is connected to the output end of first nor gate, and output end is for exporting the triggering
Signal.
Preferably, the logic unit is realized by AND gate circuit, and first input end is used to receive the timing signal, the
Two input terminals are for receiving the zero passage detection signal, and output end is for exporting the over-voltage detection signal.
Preferably, the voltage detecting circuit includes: first point be connected in series between the Input voltage terminal and ground
The intermediate node of piezoresistance and the second divider resistance, first divider resistance and second divider resistance is used to provide the described
Voltage detection signal.
Preferably, the circuit for power conversion includes buck topology, reverse exciting topological or buck topology.
Second aspect according to the present utility model, provides a kind of Switching Power Supply, including circuit for power conversion, sampling resistor,
And switch power controller, the circuit for power conversion are used to provide output electric current to load according to input voltage, wherein institute
Stating switch power controller includes: power switch tube, for controlling the power transmission of the circuit for power conversion；Voltage detecting electricity
Road obtains voltage detection signal for detecting input voltage；Zero cross detection circuit, for detecting inductive current, according to the electricity
Inducing current zero crossing provides zero passage detection signal；Over-voltage detection circuit, for obtaining inductance electricity according to the zero passage detection signal
The magnetic time is flowed away, and input-output voltage relationship is obtained according to the topological structure of the circuit for power conversion, and according to described
Voltage detection signal, reference voltage signal and the input-output voltage relationship obtain degaussing fiducial time, by the inductance
The electric current degaussing time is compared with the degaussing fiducial time, provides over-voltage according to comparison result and detects signal, wherein works as institute
When stating the inductive current degaussing time less than degaussing fiducial time, the over-voltage detection circuit provides effective over-voltage and detects signal；
And logic and driver circuitry, for generating driving signal, while over-voltage is generated according to the effective over-voltage detection signal and is protected
Shield movement.
Preferably, the over-voltage detection circuit includes: electric current generation module, for according to the voltage detection signal, institute
It states reference voltage signal and the input-output voltage relationship obtains the first electric current and the second electric current；And detection module, it uses
In obtaining the inductance according to first electric current, second electric current and the driving signal and the zero passage detection signal
Electric current degaussing time and the degaussing fiducial time, and obtained according to the inductive current degaussing time and the degaussing fiducial time
Signal is detected to the over-voltage.
Preferably, the detection module includes: trigger unit, for being believed according to the driving signal and the zero passage detection
Number trigger signal is generated, the trigger signal characterizes the inductive current degaussing time；Timing unit receives the driving signal
With the trigger signal, according to first electric current and described second under the control of the driving signal and the trigger signal
Electric current generates timing signal；And logic unit, for according to the timing signal and zero passage detection signal generation
Over-voltage detects signal.
Preferably, the logic unit is configured that when the zero passage detection signal is effective, if the timing signal is to patrol
Volume high level then provides the effective over-voltage and detects signal, if the timing signal is logic low, it is invalid to provide
The over-voltage detects signal.
Preferably, the trigger unit is configured that the trigger unit is defeated when the driving signal is logic high
The trigger signal is logic low out, when the driving signal is logic low, described in the trigger unit output
Trigger signal is logic high, until the zero passage detection signal is effective.
Preferably, the timing unit includes: the first current source being connected in series between supply voltage and ground, first opens
Pass, second switch and the second current source；First capacitor, first end are connected between the first switch and the second switch
Obtain first node, second end ground connection；First comparator, normal phase input end are connected to the first node to receive first voltage,
Reverse inter-input-ing ending grounding, output end is for exporting the timing signal.
Preferably, the timing unit is configured that the trigger signal is to patrol when the driving signal is logic high
When collecting low level, the first switch conducting, the second switch is turned off, and the first capacitor is filled via first current source
Electricity, charging current are first electric current, and it is logic high that the first comparator, which exports the timing signal, when the drive
Dynamic signal is logic low, and when the trigger signal is logic high, the first switch shutdown, the second switch is led
Logical, the first capacitor discharge via second current source, and discharge current is second electric current, when being discharged to described first
Voltage is less than/when being equal to ground voltage, timing signal overturning is logic low.
Preferably, the trigger unit includes: the first nor gate, and first input end is for receiving the driving signal；The
Two nor gates, first input end are connected to the output end of first nor gate, and the second input terminal is for receiving the zero passage inspection
Signal is surveyed, output end is connected to the second input terminal of first nor gate；And third nor gate, first input end is for connecing
The driving signal is received, the second input terminal is connected to the output end of first nor gate, and output end is for exporting the triggering
Signal.
Preferably, the logic unit is realized by AND gate circuit, and first input end is used to receive the timing signal, the
Two input terminals are for receiving the zero passage detection signal, and output end is for exporting the over-voltage detection signal.
Preferably, the voltage detecting circuit includes: first point be connected in series between the Input voltage terminal and ground
The intermediate node of piezoresistance and the second divider resistance, first divider resistance and second divider resistance is used to provide the described
Voltage detection signal.
Preferably, the circuit for power conversion includes buck topology, reverse exciting topological or buck topology.
The third aspect according to the present utility model provides a kind of pressure detection method excessively of Switching Power Supply, the Switching Power Supply
Including circuit for power conversion, the circuit for power conversion is used to provide output electric current to load according to input voltage, wherein described
Crossing pressure detection method includes: that the detection input voltage obtains voltage detection signal；According to the topology of the circuit for power conversion
Structure obtains input-output voltage relationship；Inductive current is detected, in response to the inductive current zero passage and provides zero passage detection letter
Number, and the inductive current degaussing time is obtained according to zero passage detection signal；And preset overpressure protects point, according to the input-
Output voltage relationship obtains degaussing fiducial time, and the inductive current degaussing time and the degaussing fiducial time are compared
Compared with when the inductive current degaussing time being less than degaussing fiducial time, the over-voltage detection circuit provides effective over-voltage inspection
Survey signal.
Preferably, the preset overpressure protects point, obtains degaussing fiducial time according to the input-output voltage relationship
Step includes: offer reference voltage signal；And according to the voltage detection signal and the reference voltage signal, by described
The degaussing fiducial time is calculated in input-output voltage relationship.
Preferably, described the step of obtaining the inductive current degaussing time according to zero passage detection signal includes: to generate driving letter
Number；And trigger signal is generated according to the driving signal and the zero passage detection signal, the trigger signal characterizes the electricity
The inducing current degaussing time.
Preferably, described according to the voltage detection signal and the reference voltage signal, pass through the input-output electricity
Pressure relationship be calculated the step of degaussing fiducial time include: according to the voltage detection signal, the reference voltage believe
Number and the input-output voltage relationship obtain the first electric current and the second electric current；And in the driving signal and the touching
Charge and discharge are carried out to first capacitor according to first electric current and second electric current under the control of signalling, described in the charging stage
The first voltage of first capacitor characterizes the degaussing fiducial time.
Preferably, described to be compared the inductive current degaussing time with the degaussing fiducial time, according to comparing
As a result the step of providing over-voltage detection signal includes: to generate timing signal according to the voltage of the first capacitor；According to described fixed
When signal and the zero passage detection signal generate the over-voltage and detect signal, when the zero passage detection signal is effective, if described
Timing signal is logic high, then provides the effective over-voltage and detect signal, if the timing signal is logic low,
Invalid over-voltage detection signal is then provided.
Preferably, described the step of generating timing signal according to the voltage of the first capacitor includes: when the driving is believed
Number be logic high, the trigger signal be logic low when, charge to the first capacitor, charging current is institute
The first electric current is stated, when the voltage of the first capacitor is greater than ground voltage, exporting the timing signal is logic high, when
The driving signal is logic low, when the trigger signal is logic high, the first capacitor electric discharge, and discharge current
For second electric current, when the voltage of the first capacitor is less than/be equal to ground voltage when, the timing signal overturning is logic
Low level.
Preferably, the circuit for power conversion includes buck topology, reverse exciting topological or buck topology.
Switch power controller, Switching Power Supply and pressure detection method excessively provided by the embodiment of the utility model pass through detection
Input voltage obtains voltage detection signal, then obtains input-output voltage relationship according to the topological structure of Switching Power Supply, finally
Degaussing fiducial time is obtained according to voltage detection signal, preset reference voltage signal and input-output voltage relationship, works as electricity
When the inducing current degaussing time is less than degaussing fiducial time, then it is assumed that output voltage is higher, and circuit enters overvoltage protection state, saves
Auxiliary winding and sampling resistor for sampling and outputting voltage, reduces the volume and cost of Switching Power Supply.
In a preferred embodiment, the overvoltage protection voltage obtained according to the utility model embodiment only with preset benchmark
Voltage signal is related to Proportional coefficient K, unrelated with the size of inductive current, and circuit consistency is more preferable.
Detailed description of the invention
By referring to the drawings to the description of the utility model embodiment, above-mentioned and other mesh of the utility model
, feature and advantage will be apparent from.
Fig. 1 shows a kind of circuit signal of the Switching Power Supply of buck topology according to the utility model first embodiment
Figure；
Fig. 2 shows the structural schematic diagrams according to a kind of over-voltage detection circuit of the utility model embodiment；
Fig. 3 shows the circuit diagram of the detection module in Fig. 2；
Fig. 4 shows the signal timing diagram of timing unit in Fig. 3；
Fig. 5 A and Fig. 5 B be shown respectively the detection module in Fig. 3 in the normal mode of operation with the letter under over-voltage detection pattern
Number timing diagram；
Fig. 6 shows a kind of circuit signal of the Switching Power Supply of reverse exciting topological according to the utility model second embodiment
Figure；
Fig. 7 shows a kind of circuit signal of the Switching Power Supply of buck topology according to the utility model 3rd embodiment
Figure；
Fig. 8 shows the flow diagram for crossing pressure detection method of the Switching Power Supply according to the utility model fourth embodiment.
Specific embodiment
Hereinafter reference will be made to the drawings is more fully described the utility model.In various figures, identical element is using similar
Appended drawing reference indicate.For the sake of clarity, the various pieces in attached drawing are not necessarily to scale.In addition, may in figure
Certain well known parts are not shown.
Many specific details of the utility model, such as the structure of component, material, size, place are described hereinafter
Science and engineering skill and technology, to be more clearly understood that the utility model.But just as the skilled person will understand,
The utility model can not be realized according to these specific details.
It should be appreciated that in the following description, " circuit ", which refers to, passes through electrical connection by least one element or sub-circuit
Or the galvanic circle that electromagnetism connects and composes.When title element or another element of circuit " being connected to " or element/circuit " being connected to "
When between two nodes, it can be directly coupled or connected to another element or may exist intermediary element, between element
Connection can be physically, in logic or its combination.On the contrary, when claiming element " being directly coupled to " or " being directly connected to
To " another element when, it is meant that the two be not present intermediary element.
Fig. 1 shows the circuit diagram of the Switching Power Supply according to the utility model first embodiment.As shown in Figure 1, this is opened
Powered-down source includes circuit for power conversion 101, switch power controller 100 and sampling resistor Rcs.Circuit for power conversion 101 is used
Electric current Iout is exported in providing according to input voltage vin to load.Switch power controller 100 is for controlling circuit for power conversion
101 working condition.
Exemplary, the utility model first embodiment provides a kind of Switching Power Supply of buck topology, circuit for power conversion
101 include sustained diode 1, load capacitance Cout and inductance L1.The cathode of sustained diode 1 connects input voltage vin
Anode, anode are connected to the first end of inductance L1, and the negative terminal of input voltage vin can be ground connection.The first end of load capacitance C1 connects
It is connected to the cathode of sustained diode 1, second end is connected to the second end of inductance L1, and load capacitance C1 connects in parallel with load
Connect, for example, with LED load parallel connection, load capacitance Cout plays the role of output voltage filtering, to reduce output electric current and defeated
The ripple of voltage out.
Switch power controller 100 includes over-voltage detection circuit 110, zero cross detection circuit 120, logic and driver circuitry
130, voltage detecting circuit 140 and power switch tube M1.
The drain electrode of power switch tube M1 (such as transistor, field-effect tube, controllable silicon thyristor etc.) is connected to inductance L1's
First end, grid are connected to logic and driver circuitry 130 to receive driving signal GT, and source electrode is grounded via sampling resistor Rcs.Function
Rate switching tube M1 is used to control the power transmission of circuit for power conversion 101 according to driving signal GT.Sampling resistor Rcs will be for that will flow
Inductive current through inductance L1, power switch tube M1 is converted to sampled voltage Vcs.
Zero cross detection circuit 120 is used to detect the zero crossing for the inductive current for flowing through inductance L1, when inductive current zero passage,
Export effective zero passage detection signal ZCD.For example, the input terminal of zero cross detection circuit 120 is connected to the leakage of power switch tube M1
The zero passage detection to inductive current is realized by detecting the drain signal of power switch tube M1, to generate zero passage detection in pole
Signal ZCD.Alternatively, the input terminal of zero cross detection circuit 120 is connected to the grid of power switch tube M1, by detecting power switch
The grid signal of pipe M1 realizes the zero passage detection to inductive current, to generate zero passage detection signal ZCD.Alternatively, zero passage is examined
The input terminal of slowdown monitoring circuit 120 can connect to the auxiliary winding coupled with inductance L1, and the electric current of auxiliary winding is flowed through by detecting
The zero passage detection to inductive current is realized, to generate zero passage detection signal ZCD.
Voltage detecting circuit 140 obtains voltage detection signal Vs for detecting input voltage vin.It is exemplary, voltage detecting
Circuit 140 includes the divider resistance R1 and divider resistance R2 being connected in series between the anode of input voltage vin and ground, partial pressure electricity
The intermediate node of resistance R1 and divider resistance R2 is used to provide the described voltage detection signal Vs.Wherein, voltage detection signal are as follows:
Vs=K*Vin=R2/ (R1+R2) * Vin
Wherein, K is proportionality coefficient, and Vin is input voltage, can pass through the resistance value of setting divider resistance R1 and divider resistance R2
Adjust Proportional coefficient K.
Over-voltage detection circuit 110 be used for according to voltage detection signal Vs, reference voltage signal Vref, driving signal GT and
Zero passage detection signal ZCD provides over-voltage to logic and driver circuitry 130 and detects signal OVP.
Specifically, over-voltage detection circuit 110 obtains input-output voltage relationship according to the topological structure of Switching Power Supply, so
Voltage detection signal Vs and reference voltage signal Vref is substituted into input-output voltage relationship afterwards and obtains inductive current degaussing benchmark
Time Tx.The inductive current degaussing time Tdis that finally will test is compared with degaussing fiducial time Tx, when inductance electricity
When flowing away magnetic time Tdis less than degaussing fiducial time Tx, then determine that output voltage is excessively high, effective over-voltage detection signal is provided
OVP。
Further, when over-voltage detection circuit 110 determines switch conduction according to driving signal GT and zero passage detection signal ZCD
Between Ton and inductive current degaussing time Tdis.Wherein, inductive current degaussing time Tdis is the subsequent of power switch tube M1 shutdown
It flows the time of diode continuousing flow, namely drops to for zero a period of time from power switch tube M1 shutdown to inductive current.
It is exemplary, for Switching Power Supply shown in FIG. 1, work as input voltage according to input-output voltage relationship is available
When Vin is greater than output voltage Vout:
(Vin-Vout) * Ton=Vout*Tdis
Wherein, Vin is input voltage, and Vout is output voltage, and Ton is switch conduction times, and Tdis goes for inductive current
The magnetic time.
Then the expression formula of inductive current degaussing time is obtained:
Tdis=((Vin-Vout) * Ton)/Vout
Input voltage vin in above formula is replaced with into voltage detection signal Vs, by electricity on the basis of output voltage Vout replacement
Signal Vref is pressed, the expression formula of degaussing fiducial time can be obtained:
Tx=((K*Vin-Vref) * Ton)/Vref
Degaussing fiducial time was made the difference with the inductive current degaussing time available:
Tx-Tdis=((K*Vin)/Vref-Vin/Vout) * Ton
When
Tx>Tdis
When, Vout > Vref/K, then it is assumed that output voltage is higher, and circuit needs to enter overvoltage protection state.The then mistake of system
Pressure protection voltage Vovp are as follows:
Vovp=Vref/K
Wherein, Vref is preset reference voltage signal, and K is proportionality coefficient.
Logic and driver circuitry 130, which is used to detect signal OVP according to over-voltage, generates corresponding driving signal GT to the function
The grid of rate switching tube M1 to generate overvoltage protection movement, such as reduces the turn-on time of power switch tube M1 or increases function
The turn-off time etc. of rate switching tube M1.
Overvoltage protection scheme in order to solve the problems, such as the prior art is at high cost, the Switching Power Supply of the utility model embodiment
Controller obtains voltage detection signal by detecting input voltage, then inputted according to the topological structure of Switching Power Supply-defeated
Voltage relationship out is finally gone according to voltage detection signal, preset reference voltage signal and input-output voltage relationship
Magnetic fiducial time, when the inductive current degaussing time being less than degaussing fiducial time, then it is assumed that output voltage is higher, and circuit entered
Press guard mode, save the auxiliary winding and sampling resistor for sampling and outputting voltage, reduce Switching Power Supply volume and
Cost.
In addition, by above formula it can be concluded that, the overvoltage protection voltage obtained according to the utility model embodiment only with it is preset
Reference voltage signal is related to Proportional coefficient K, unrelated with the size of inductive current, and circuit consistency is more preferable.
Fig. 2 shows a kind of concrete structure schematic diagrams for realizing over-voltage detection provided by the embodiment of the utility model.Such as Fig. 2 institute
Show, over-voltage detection circuit 110 includes electric current generation module 111 and detection module 112.Electric current generation module 111 is examined according to voltage
It surveys signal Vs, reference voltage signal Vref and input-output voltage relationship and obtains the first electric current I1 and the second electric current I2.
First electric current I1 are as follows:
I1=(K*Vin-Vref)/R3
Second electric current I2 are as follows:
I2=Vref/R3
Wherein, Vref is preset reference voltage signal, and K is proportionality coefficient, and R3 is the coefficient that voltage is converted into electric current.
It should be noted that electric current generation module 111 is obtained according to voltage detection signal Vs and reference voltage signal Vref
The method of first electric current I1 and the second electric current I2 are the conventional technical means of those skilled in the art, and details are not described herein.
Detection module 112 is used for according to the first electric current I1, the second electric current I2 and driving signal GT and zero passage detection signal
ZCD obtains over-voltage detection signal.Detection module 112 compares inductive current degaussing time Tdis and degaussing fiducial time Tx
Compared with providing over-voltage detection signal OVP when degaussing fiducial time Tx is greater than inductive current degaussing time Tdis.
Fig. 3 shows a kind of circuit diagram of detection module 112 shown in Fig. 2.As shown in figure 3, detection module 112 includes
Timing unit 210 and logic unit 220.
Timing unit 210 includes the first current source 211 being connected in series between supply voltage Vdd and ground, first switch
S1, second switch S2 and the second current source 212；First capacitor C1, first end are connected to first switch S1 and second switch
First node between S2, second end ground connection.First comparator 213, normal phase input end are connected to the first of first capacitor C1
End, reverse inter-input-ing ending grounding, output end is for exporting timing signal Vo.
Fig. 4 shows the signal timing diagram of timing unit in Fig. 3.In conjunction with Fig. 3 and Fig. 4, power switch tube M1 conducting (driving letter
Number GT is logic high) when, first switch S1 conducting, second switch S2 shutdown, the first current source 211 fills first capacitor C1
Electricity, charging current are the first electric current I1；When power switch tube M1 shutdown (driving signal GT is logic low), first switch
S1 shutdown, second switch S2 conducting, the second current source 212 discharge to first capacitor C1, and discharge current is the second electric current I2.It has served as
When zero detection signal ZCD becomes logic high, first switch S1 and second switch S2 are simultaneously turned off, and first capacitor C1 stopping is put
Electricity.
As a kind of unrestricted example, detection module 112 further includes trigger unit 230, and trigger unit 230 is used for root
Trigger signal A is provided according to driving signal GT and zero passage detection signal ZCD, controls the turn-on and turn-off of second switch S2.
Wherein, when driving signal GT is logic high, trigger signal A is logic low；When driving signal GT is
When logic low, trigger signal A is logic high, and until zero passage detection signal ZCD occurs, trigger signal A becomes again
Logic low, therefore trigger signal A can reflect the duration of inductive current degaussing time Tdis.
As shown in figure 3, trigger unit 230 includes: nor gate 231, first input end is for receiving driving signal GT；Or it is non-
Door 232, first input end are connected to the output end of nor gate 231, and the second input terminal is defeated for receiving zero passage detection signal ZCD
Outlet is connected to the second input terminal of nor gate 231；Nor gate 233, for first input end for receiving driving signal GT, second is defeated
Enter the output end that end is connected to nor gate 231, output end is used to provide the described trigger signal A.
Logic unit 220, which is used to provide the over-voltage according to timing signal Vo and zero passage detection signal ZCD, detects signal
OVP。
As a kind of unrestricted example, logic unit 220 for example realizes that first input end is connected to by AND gate circuit
To receive the timing signal Vo, the second input terminal exports the output end of comparator 213 for receiving zero passage detection signal ZCD
End is used to provide the described over-voltage detection signal OVP.
The signal sequence under 112 normal mode of operation of detection module and under over-voltage detection pattern is shown respectively in Fig. 5 A and Fig. 5 B
Figure.In conjunction with Fig. 3, Fig. 4, Fig. 5 A and Fig. 5 B, when driving signal GT is converted to logic high, first switch S1 conducting, second is opened
S2 shutdown is closed, the first current source 211 charges to first capacitor C1, and charging current is the first electric current I1, the both ends first capacitor C1
First voltage Vc1 rises, and the timing signal Vo of the output end output of comparator 213 is logic high；When driving signal GT turns
When being changed to logic low, first switch S1 shutdown, second switch S2 is connected, and the second current source 212 discharges to first capacitor C1,
Discharge current is the second electric current I2, and the first voltage Vc1 at the both ends first capacitor C1 declines, the inductive current until flowing through inductance L1
ILZero passage, zero passage detection signal ZCD are converted to logic high, and first switch S1 and second switch S2 are simultaneously turned off, the first electricity
Hold C1 and stops electric discharge, furthermore when the first voltage Vc1 at the both ends first capacitor C1 is less than or equal to ground voltage, comparator 213
The timing signal Vo overturning of output is logic low.
The first voltage Vc1 at charging stage first capacitor C1 both ends are as follows:
Vc1=(((K*Vin-Vref)/R3) * Ton)/C1
The first voltage Vc1 at the both ends discharge regime first capacitor C1 are as follows:
Vc1=(Vref/R3*Tdis)/C1
Therefore the voltage at charging stage first capacitor C1 both ends is directly proportional to switch conduction times Ton, discharge regime first
The voltage at the both ends capacitor C1 is directly proportional to inductive current degaussing time Tdis, therefore the voltage at charging stage first capacitor C1 both ends
The duration of degaussing fiducial time Tx can be characterized.
With continued reference to Fig. 3, logic unit 220 is used to provide over-voltage inspection according to timing signal Vo and zero passage detection signal ZCD
Survey signal OVP.When zero passage detection signal ZCD is effective, if timing signal Vo is logic low, illustrate inductive current degaussing
Time Tdis is more than or equal to degaussing fiducial time Tx, and Switching Power Supply is temporarily without exception, does not need to enter overvoltage protection state, over-voltage inspection
It surveys signal OVP and is maintained original levels, as shown in Figure 5A.When zero passage detection signal ZCD is effective, if timing signal Vo is logic
High level then illustrates that inductive current degaussing time Tdis is less than degaussing fiducial time Tx, and Switching Power Supply has been likely to occur output electricity
It presses through, needs to enter overvoltage protection mode, provide effective over-voltage detection signal OVP at this time, as shown in Figure 5 B.Thus
Inductive current degaussing time Tdis is realized compared between degaussing fiducial time Tx, then realizes the over-voltage inspection to output voltage
It surveys.
With reference to Fig. 6, in the Switching Power Supply of second embodiment shown in Fig. 6, by the switch power controller 100 in Fig. 1
Applied in the Switching Power Supply of reverse exciting topological, which includes circuit for power conversion 301, switch power controller 300
And sampling resistor Rcs.Likewise, circuit for power conversion 301 is used to provide output electric current to load according to input voltage vin
Iout。
Exemplary, the circuit for power conversion 301 of inverse-excitation type switch power-supply as shown in FIG. 6 includes: transformer T1 (including original
Side winding L1, vice-side winding L2, auxiliary winding L3), sustained diode 1 and load capacitance Cout.
Switch power controller 300 and the switch power controller 100 of first embodiment are essentially identical, and difference exists
In: in switch power controller 300, zero cross detection circuit 120 flows through the electricity of auxiliary winding L3 by feedback resistance FB detection
Stream realizes the zero passage detection to inductive current, to generate zero passage detection signal ZCD.
In addition, because the input-output voltage relationship in inverse-excitation type switch power-supply and the input-in step-down switching power supply are defeated
Voltage relationship is different out, so the first electric current I1 and the second electric current I2 and first embodiment in switch power controller 300
The difference of switch power controller 100.
It is exemplary, available according to input-output voltage relationship for Switching Power Supply shown in fig. 6:
Vin*Ton=nVout*Tdis
Wherein, Vin is input voltage, and Vout is output voltage, and n is the turn ratio of primary side winding L1 and vice-side winding L2,
Ton is switch conduction times, and Tdis is the inductive current degaussing time.
Then the expression formula of inductive current degaussing time is obtained:
Tdis=(Vin*Ton)/nVout
Input voltage vin in above formula is replaced with into voltage detection signal Vs, by electricity on the basis of output voltage nVout replacement
Signal Vref is pressed, the expression formula of degaussing fiducial time can be obtained:
Tx=(K*Vin*Ton)/Vref
Degaussing fiducial time was made the difference with the inductive current degaussing time available:
Tx-Tdis=((K*Vin)/Vref-Vin/nVout) * Ton
When
Tx>Tdis
When, Vout > Vref/nK, then it is assumed that output voltage is higher, and circuit needs to enter overvoltage protection state.Then system
Overvoltage protection voltage Vovp are as follows:
Vovp=Vref/nK
Wherein, Vref is preset reference voltage signal, and K is proportionality coefficient.
It is hereby achieved that in the switch power controller 300 of second embodiment, the first electric current I1 are as follows:
I1=K*Vin/R3
Second electric current I2 are as follows:
I2=Vref/R3
Wherein, Vref is preset reference voltage signal, and K is proportionality coefficient, and R3 is the coefficient that voltage is converted into electric current.
Referring to Fig. 7, in 3rd embodiment shown in Fig. 7, the switch power controller 100 in Fig. 1 is applied to lifting
In the Switching Power Supply for pressing topology.The Switching Power Supply includes: circuit for power conversion 401, switch power controller 400 and sampling electricity
Rcs is hindered, the circuit for power conversion 401 of the buck Switching Power Supply can be any circuit structure appropriate.
Exemplary, the circuit for power conversion 401 of buck Switching Power Supply as shown in Figure 7 includes: transformer T2 (including original
Side winding L4 and auxiliary winding L5), sustained diode 1 and load capacitance Cout.
Switch power controller 400 and the switch power controller 100 of first embodiment are essentially identical, and difference exists
In: in switch power controller 400, zero cross detection circuit 120 flows through the electricity of auxiliary winding L5 by feedback resistance FB detection
Stream realizes the zero passage detection to inductive current, to generate zero passage detection signal ZCD.
In addition to the topological structure of circuit for power conversion is different, 3rd embodiment shown in Fig. 7 and Fig. 1 and shown in fig. 6 the
One embodiment and second embodiment are essentially identical.
It is exemplary, available according to input-output voltage relationship for Switching Power Supply shown in Fig. 7:
Vin*Ton=Vout*Tdis
Wherein, Vin is input voltage, and Vout is output voltage, and Ton is switch conduction times, and Tdis goes for inductive current
The magnetic time.
Then the expression formula of inductive current degaussing time is obtained:
Tdis=(Vin*Ton)/Vout
Input voltage vin in above formula is replaced with into voltage detection signal Vs, by electricity on the basis of output voltage Vout replacement
Signal Vref is pressed, the expression formula of degaussing fiducial time can be obtained:
Tx=(K*Vin*Ton)/Vref
Degaussing fiducial time was made the difference with the inductive current degaussing time available:
Tx-Tdis=((K*Vin)/Vref-Vin/Vout) * Ton
When
Tx>Tdis
When, Vout > VrefK, then it is assumed that output voltage is higher, and circuit needs to enter overvoltage protection state.The then mistake of system
Pressure protection voltage Vovp are as follows:
Vovp=Vref/K
Wherein, Vref is preset reference voltage signal, and K is proportionality coefficient.
It is hereby achieved that in the switch power controller 400 of 3rd embodiment, the first electric current I1 are as follows:
I1=K*Vin/R3
Second electric current I2 are as follows:
I2=Vref/R3
Wherein, Vref is preset reference voltage signal, and K is proportionality coefficient, and R3 is the coefficient that voltage is converted into electric current.
Fig. 8 shows the flow diagram for crossing pressure detection method of the Switching Power Supply according to the utility model fourth embodiment.
The Switching Power Supply of the present embodiment can be the Switching Power Supply in the various embodiments described above, including circuit for power conversion, open
Power-supply controller of electric and sampling resistor are closed, the circuit for power conversion is used to provide output electric current to load according to input voltage.
As shown in figure 8, the over-voltage detection method includes the following steps S110 to S150.
In step s 110, detection input voltage obtains voltage detection signal.
As one embodiment, the divider resistance being connected in series between the anode of input voltage vin and ground can be set
The intermediate node of R1 and divider resistance R2, divider resistance R1 and divider resistance R2 are used to provide the described voltage detection signal Vs.Its
In, voltage detection signal are as follows:
Vs=K*Vin=R2/ (R1+R2) * Vin
Wherein, K is proportionality coefficient, and Vin is input voltage, can pass through the resistance value of setting divider resistance R1 and divider resistance R2
Adjust Proportional coefficient K.
In the step s 120, input-output voltage relationship is obtained according to the topological structure of Switching Power Supply.
For example, when Switching Power Supply is buck topology, the input-output voltage relationship are as follows:
(Vin-Vout) * Ton=Vout*Tdis
Wherein, Vin is the input voltage, and Vout is output voltage, and Ton is switch conduction times, and Tdis is the electricity
The inducing current degaussing time.
Alternatively, when Switching Power Supply is reverse exciting topological, the input-output voltage relationship are as follows:
Vin*Ton=nVout*Tdis
Wherein, Vin is the input voltage, and Vout is output voltage, and n is the turn ratio of primary side winding and vice-side winding,
Ton is switch conduction times, and Tdis is the inductive current degaussing time.
Or when Switching Power Supply is buck topology, the input-output voltage relationship are as follows:
Vin*Ton=Vout*Tdis
Wherein, Vin is the input voltage, and Vout is output voltage, and Ton is switch conduction times, and Tdis is the electricity
The inducing current degaussing time.
In step s 130, the inductive current degaussing time is detected.Specifically, true according to driving signal and zero passage detection signal
Determine switch conduction times and inductive current degaussing time.Wherein, the inductive current degaussing time is the subsequent of power switch tube shutdown
It flows the time of diode continuousing flow, namely drops to for zero a period of time from power switch tube shutdown to inductive current.
As one embodiment, trigger unit is provided, trigger unit provides touching according to driving signal and zero passage detection signal
It signals.When driving signal is logic high, trigger signal is logic low；When driving signal is logic low
When, trigger signal is logic high, and until zero passage detection signal occurs, trigger signal becomes logic low again, therefore
Trigger signal can reflect the duration of inductive current degaussing time.
In step S140, preset overpressure protects point, obtains degaussing fiducial time according to input-output voltage relationship.
Specifically, reference voltage signal is provided according to preset voltage protection point, then by voltage detection signal and benchmark
Voltage signal substitutes into input-output voltage relationship, and degaussing fiducial time is calculated.
Further, it is closed according to the voltage detection signal, the reference voltage signal and the input-output voltage
System obtains the first electric current and the second electric current, then generates trigger signal according to driving signal and zero passage detection signal, is finally driving
According to the charge and discharge of the first electric current and the second electric current progress capacitor to generate timing signal under the control of dynamic signal and trigger signal,
Degaussing fiducial time described in the charge and discharge time representation of the capacitor.
In step S150, the inductive current degaussing time is compared with degaussing fiducial time, is mentioned according to comparison result
Signal is detected for over-voltage.
As one embodiment, it can determine that over-voltage detects signal according to timing signal and zero passage detection signal.Such as it serves as
When zero detection signal is effective, if timing signal is logic high, when illustrating that the inductive current degaussing time is less than degaussing benchmark
Between, Switching Power Supply has been likely to occur output voltage over-voltage, needs to enter overvoltage protection mode, provides effective over-voltage detection at this time
Signal；If timing signal is logic low, illustrate that the inductive current degaussing time is more than or equal to degaussing fiducial time, switch electricity
Source is temporarily without exception, does not need to enter overvoltage protection state, over-voltage detection signal is maintained original levels.
In conclusion switch power controller provided by the embodiment of the utility model, Switching Power Supply and over-voltage detection side
Method obtains voltage detection signal by detecting input voltage, then obtains input-output electricity according to the topological structure of Switching Power Supply
Pressure relationship finally obtains degaussing base according to voltage detection signal, preset reference voltage signal and input-output voltage relationship
Between punctual, when the inductive current degaussing time being less than degaussing fiducial time, then it is assumed that output voltage is higher, and circuit enters over-voltage guarantor
Shield state saves auxiliary winding and sampling resistor for sampling and outputting voltage, reduces the volume and cost of Switching Power Supply.
In a preferred embodiment, the overvoltage protection voltage obtained according to the utility model embodiment only with preset benchmark
Voltage signal is related to Proportional coefficient K, unrelated with the size of inductive current, and circuit consistency is more preferable.
It should be noted that herein, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any actual relationship or order or sequence.Moreover, the terms "include", "comprise" or its any other variant are intended to
Non-exclusive inclusion, so that the process, method, article or equipment including a series of elements is not only wanted including those
Element, but also including other elements that are not explicitly listed, or further include for this process, method, article or equipment
Intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that
There is also other identical elements in process, method, article or equipment including the element.
It is as described above according to the embodiments of the present invention, these embodiments details all there is no detailed descriptionthe,
Also not limiting the utility model is only the specific embodiment.Obviously, as described above, many modification and change can be made
Change.These embodiments are chosen and specifically described to this specification, is in order to preferably explain the principles of the present invention and actually to answer
With so that skilled artisan be enable to utilize the utility model and repairing on the basis of the utility model well
Change use.The utility model is limited only by the claims and their full scope and equivalents.
Claims (22)
1. a kind of switch power controller, for controlling circuit for power conversion, the circuit for power conversion is used for according to input electricity
It presses to load and output electric current is provided, which is characterized in that the switch power controller includes:
Power switch tube, for controlling the power transmission of the circuit for power conversion；
Voltage detecting circuit obtains voltage detection signal for detecting input voltage；
Zero cross detection circuit provides zero passage detection signal according to the inductive current zero crossing for detecting inductive current；
Over-voltage detection circuit, for obtaining the inductive current degaussing time according to the zero passage detection signal, and according to the function
The topological structure of rate conversion circuit obtains input-output voltage relationship, and according to the voltage detection signal, reference voltage signal
And the input-output voltage relationship obtains degaussing fiducial time, by the inductive current degaussing time and the degaussing base
It is compared between punctual, provides over-voltage according to comparison result and detect signal,
Wherein, when the inductive current degaussing time being less than degaussing fiducial time, the over-voltage detection circuit provides effective
Over-voltage detects signal；And
Logic and driver circuitry for generating driving signal, while generating over-voltage according to the effective over-voltage detection signal and protecting
Shield movement.
2. switch power controller according to claim 1, which is characterized in that the over-voltage detection circuit includes:
Electric current generation module, for according to the voltage detection signal, the reference voltage signal and input-output electricity
Pressure relationship obtains the first electric current and the second electric current；And
Detection module, for according to first electric current, second electric current and the driving signal and the zero passage detection
Signal obtains the inductive current degaussing time and the degaussing fiducial time, and according to the inductive current degaussing time and institute
Stating degaussing fiducial time obtains over-voltage detection signal.
3. switch power controller according to claim 2, which is characterized in that the detection module includes:
Trigger unit, for generating trigger signal, the trigger signal according to the driving signal and the zero passage detection signal
Characterize the inductive current degaussing time；
Timing unit receives the driving signal and the trigger signal, in the control of the driving signal and the trigger signal
Timing signal is generated according to first electric current and second electric current under system；And
Logic unit detects signal for generating the over-voltage according to the timing signal and the zero passage detection signal.
4. switch power controller according to claim 3, which is characterized in that the logic unit is configured that
When the zero passage detection signal is effective, if the timing signal is logic high, the effective over-voltage is provided
Signal is detected, if the timing signal is logic low, provides invalid over-voltage detection signal.
5. switch power controller according to claim 3, which is characterized in that the trigger unit is configured that
When the driving signal is logic high, it is logic low that the trigger unit, which exports the trigger signal,
When the driving signal is logic low, it is logic high that the trigger unit, which exports the trigger signal, directly
It is effective to the zero passage detection signal.
6. switch power controller according to claim 3, which is characterized in that the timing unit includes:
The first current source, first switch, second switch and the second current source being connected in series between supply voltage and ground；
First capacitor, first end, which is connected between the first switch and the second switch, obtains first node, second end ground connection；
First comparator, normal phase input end are connected to the first node to receive first voltage, reverse inter-input-ing ending grounding, output
End is for exporting the timing signal.
7. switch power controller according to claim 6, which is characterized in that the timing unit is configured that
When the driving signal is logic high, and the trigger signal is logic low, the first switch conducting, institute
Second switch shutdown is stated, the first capacitor charges via first current source, and charging current is first electric current, described
It is logic high that first comparator, which exports the timing signal,
When the driving signal is logic low, and the trigger signal is logic high, the first switch shutdown, institute
Second switch conducting is stated, the first capacitor discharge via second current source, and discharge current is second electric current, when putting
Electricity to the first voltage is less than/when being equal to ground voltage, timing signal overturning is logic low.
8. switch power controller according to claim 5, which is characterized in that the trigger unit includes:
First nor gate, first input end is for receiving the driving signal；
Second nor gate, first input end are connected to the output end of first nor gate, and the second input terminal is described for receiving
Zero passage detection signal, output end are connected to the second input terminal of first nor gate；And
Third nor gate, for first input end for receiving the driving signal, the second input terminal is connected to first nor gate
Output end, output end is for exporting the trigger signal.
9. switch power controller according to claim 4, which is characterized in that the logic unit passes through AND gate circuit reality
Existing, first input end is used for receiving the timing signal, the second input terminal for receiving the zero passage detection signal, output end
Signal is detected in exporting the over-voltage.
10. switch power controller according to claim 1, which is characterized in that the voltage detecting circuit includes:
The first divider resistance and the second divider resistance being connected in series between the Input voltage terminal and ground, first partial pressure
The intermediate node of resistance and second divider resistance is used to provide the described voltage detection signal.
11. switch power controller according to claim 1, which is characterized in that the circuit for power conversion includes decompression
Formula topology, reverse exciting topological or buck topology.
12. a kind of Switching Power Supply, which is characterized in that including circuit for power conversion, sampling resistor and switch power controller,
The circuit for power conversion is used to provide output electric current to load according to input voltage, wherein the switch power controller packet
It includes:
Power switch tube, for controlling the power transmission of the circuit for power conversion；
Voltage detecting circuit obtains voltage detection signal for detecting input voltage；
Zero cross detection circuit provides zero passage detection signal according to the inductive current zero crossing for detecting inductive current；
Over-voltage detection circuit, for obtaining the inductive current degaussing time according to the zero passage detection signal, and according to the function
The topological structure of rate conversion circuit obtains input-output voltage relationship, and according to the voltage detection signal, reference voltage signal
And the input-output voltage relationship obtains degaussing fiducial time, by the inductive current degaussing time and the degaussing base
It is compared between punctual, provides over-voltage according to comparison result and detect signal,
Wherein, when the inductive current degaussing time being less than degaussing fiducial time, the over-voltage detection circuit provides effective
Over-voltage detects signal；And
Logic and driver circuitry for generating driving signal, while generating over-voltage according to the effective over-voltage detection signal and protecting
Shield movement.
13. Switching Power Supply according to claim 12, which is characterized in that the over-voltage detection circuit includes:
Electric current generation module, for according to the voltage detection signal, the reference voltage signal and input-output electricity
Pressure relationship obtains the first electric current and the second electric current；And
Detection module, for according to first electric current, second electric current and the driving signal and the zero passage detection
Signal obtains the inductive current degaussing time and the degaussing fiducial time, and according to the inductive current degaussing time and institute
Stating degaussing fiducial time obtains over-voltage detection signal.
14. Switching Power Supply according to claim 13, which is characterized in that the detection module includes:
Trigger unit, for generating trigger signal, the trigger signal according to the driving signal and the zero passage detection signal
Characterize the inductive current degaussing time；
Timing unit receives the driving signal and the trigger signal, in the control of the driving signal and the trigger signal
Timing signal is generated according to first electric current and second electric current under system；And
Logic unit detects signal for generating the over-voltage according to the timing signal and the zero passage detection signal.
15. Switching Power Supply according to claim 14, which is characterized in that the logic unit is configured that
When the zero passage detection signal is effective, if the timing signal is logic high, the effective over-voltage is provided
Signal is detected, if the timing signal is logic low, provides invalid over-voltage detection signal.
16. Switching Power Supply according to claim 14, which is characterized in that the trigger unit is configured that
When the driving signal is logic high, it is logic low that the trigger unit, which exports the trigger signal,
When the driving signal is logic low, it is logic high that the trigger unit, which exports the trigger signal, directly
It is effective to the zero passage detection signal.
17. Switching Power Supply according to claim 14, which is characterized in that the timing unit includes:
The first current source, first switch, second switch and the second current source being connected in series between supply voltage and ground；
First capacitor, first end, which is connected between the first switch and the second switch, obtains first node, second end ground connection；
First comparator, normal phase input end are connected to the first node to receive first voltage, reverse inter-input-ing ending grounding, output
End is for exporting the timing signal.
18. Switching Power Supply according to claim 17, which is characterized in that the timing unit is configured that
When the driving signal is logic high, and the trigger signal is logic low, the first switch conducting, institute
Second switch shutdown is stated, the first capacitor charges via first current source, and charging current is first electric current, described
It is logic high that first comparator, which exports the timing signal,
When the driving signal is logic low, and the trigger signal is logic high, the first switch shutdown, institute
Second switch conducting is stated, the first capacitor discharge via second current source, and discharge current is second electric current, when putting
Electricity to the first voltage is less than/when being equal to ground voltage, timing signal overturning is logic low.
19. Switching Power Supply according to claim 16, which is characterized in that the trigger unit includes:
First nor gate, first input end is for receiving the driving signal；
Second nor gate, first input end are connected to the output end of first nor gate, and the second input terminal is described for receiving
Zero passage detection signal, output end are connected to the second input terminal of first nor gate；And
Third nor gate, for first input end for receiving the driving signal, the second input terminal is connected to first nor gate
Output end, output end is for exporting the trigger signal.
20. Switching Power Supply according to claim 15, which is characterized in that the logic unit by AND gate circuit realize,
First input end is for receiving the timing signal, and for receiving the zero passage detection signal, output end is used for the second input terminal
Export the over-voltage detection signal.
21. Switching Power Supply according to claim 12, which is characterized in that the voltage detecting circuit includes:
The first divider resistance and the second divider resistance being connected in series between the Input voltage terminal and ground, first partial pressure
The intermediate node of resistance and second divider resistance is used to provide the described voltage detection signal.
22. Switching Power Supply according to claim 12, which is characterized in that the circuit for power conversion includes that buck is opened up
Flutter, reverse exciting topological or buck topology.
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| CN201920396036.4U CN209659146U (en) | 2019-03-26 | 2019-03-26 | A kind of switch power controller and Switching Power Supply |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109921624A (en) * | 2019-03-26 | 2019-06-21 | 杭州士兰微电子股份有限公司 | A kind of switch power controller, Switching Power Supply and its cross pressure detection method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109921624A (en) * | 2019-03-26 | 2019-06-21 | 杭州士兰微电子股份有限公司 | A kind of switch power controller, Switching Power Supply and its cross pressure detection method |
| CN109921624B (en) * | 2019-03-26 | 2024-02-23 | 杭州士兰微电子股份有限公司 | Switching power supply controller, switching power supply and overvoltage detection method of switching power supply |
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