CN107302306B - A kind of Switching Power Supply - Google Patents
A kind of Switching Power Supply Download PDFInfo
- Publication number
- CN107302306B CN107302306B CN201710497391.6A CN201710497391A CN107302306B CN 107302306 B CN107302306 B CN 107302306B CN 201710497391 A CN201710497391 A CN 201710497391A CN 107302306 B CN107302306 B CN 107302306B
- Authority
- CN
- China
- Prior art keywords
- voltage
- current
- power supply
- transistor
- switch
- 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
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
Abstract
A kind of Switching Power Supply, the Switching Power Supply includes inductance, main switch, the controlled on or off of main switch, so that the output end output of Switching Power Supply has output voltage, the Switching Power Supply further include: the first branch with inductance in parallel, the first branch includes that concatenated first switch and ring inhibit resistance, and the connecting node of inductance and main switch is denoted as switching node；Detection module, is adapted to detect for whether association voltage is less than threshold voltage, and it is associated with the voltage of switching node to be associated with voltage for output end output test result；Logic module, the output end of its first input end coupling detection module, the control terminal of its second input terminal coupling main switch, when main switch controlled shutdown and testing result instruction association voltage be less than threshold voltage when, logic module controls first switch conducting until the controlled conducting of main switch, otherwise, logic module control first switch shutdown.The present invention program can inhibit ring, and at low cost, and stability is high.
Description
Technical field
The present invention relates to power supply design field, in particular to a kind of Switching Power Supply.
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 converters generally by pulse width modulation (Pulse Width Modulation,
Abbreviation PWM) control circuit, energy-storage travelling wave tube (such as inductance) and switching tube composition.A large amount of switch electricity can be used in mobile terminal
Source converter, to the modules such as central processing unit (Central Processing Unit, abbreviation CPU) of its inside, client
Identification module (Subscriber Identification Module, abbreviation SIM) card, radio-frequency power amplifier etc. provides steady
Determine power supply.
Fig. 1 shows a kind of Switching Power Supply 100 of switch DC booster type, and the Switching Power Supply 100 may include inductance
L1, main switch M1, sustained diode 1 and first capacitor C1.The Switching Power Supply 100 accesses input voltage VIN, and the master opens
The controlled on or off of M1 is closed, so that it is that load supplies that the output of Switching Power Supply 100, which has output voltage VO UT, output voltage VO UT,
Electricity.When the electric current of load is smaller or does not have load current, such as electronic equipment enters standby or suspend mode, switch
Power supply 100 generally can all reduce working frequency, into discontinuous conduction mode (Discontinuous Conduction Mode,
Abbreviation DCM).At DCM, general load current is smaller, and working frequency is lower.At this point, the company of the inductance L1 and main switch M1
Serious inductance (Inductor, abbreviation L) capacitor (Capacity, abbreviation C) oscillation may occur at contact SW, it is existing to generate ring
As, and then cause serious electromagnetic interference (Electromagnetic Interference, abbreviation EMI) problem.
A kind of method of suppressed ringing is to seal in magnetic between the input terminal and inductance L1 of Switching Power Supply 100 in the prior art
Pearl L2, but this meeting is so that system cost increases；In addition, may result in all when the parameter of the magnetic bead L2 is not set appropriate
Such as system device is uttered long and high-pitched sounds extremely, namely produces the oscillation for falling into audio range (20Hz-20kHz).
Summary of the invention
Present invention solves the technical problem that being to reduce system cost simultaneously how when inhibiting the ringing in Switching Power Supply
Avoidance system is abnormal.
In order to solve the above technical problems, the embodiment of the present invention provides a kind of Switching Power Supply, the Switching Power Supply include inductance,
Main switch, the controlled on or off of main switch, so that the output end output of the Switching Power Supply has output voltage；It is described to open
Powered-down source further include: the first branch with the inductance in parallel, the first branch include concatenated first switch and ring suppression
The connecting node of resistance processed, the inductance and main switch is denoted as switching node；Whether small detection module is adapted to detect for association voltage
In threshold voltage, output end output test result, the association voltage is associated with the voltage of the switching node；Logic mould
Block, first input end couple the output end of the detection module, and the second input terminal couples the control terminal of the main switch, when
When the main switch controlled shutdown and the testing result indicate the association voltage less than the threshold voltage, the logic mould
Block controls the first switch conducting until the controlled conducting of the main switch, otherwise, the logic module control described first are opened
Shutdown.
Optionally, the threshold voltage is less than 0V.
Optionally, the detection module includes: the first current branch, is suitable for generating preset first reference current, and pass through
It is exported by its output end；Second current branch suitable for comparing electric current according to association voltage generation, and is exported via its output end；
Wherein, when first reference current is more than or equal to the relatively electric current, the testing result is the first logic level, to refer to
Show that the association voltage is more than or equal to the threshold voltage, it is described when first reference current is less than the relatively electric current
Testing result is the second logic level different from first logic level, to indicate that the association voltage is less than the threshold value
Voltage.
Optionally, first current branch includes: the first current mirror, is suitable for carrying out mirror image to the second reference current, with
Obtain the first reference current；Second current branch includes: the second current mirror, suitable for being obtained according to third reference current mirror image
The relatively electric current, the current value of the third reference current are equal to the current value of second reference current, second electricity
Stream mirror includes the first transistor and second transistor, and the first transistor accesses the third reference current, and described second is brilliant
The output end output of the body pipe relatively electric current, the input terminal of the second transistor access the association voltage；Wherein, described
The ratio of second reference current and first reference current is less than the breadth length ratio of the first transistor and second crystal
The ratio of the breadth length ratio of pipe.
Optionally, the first transistor and second transistor are NMOS transistor, and first current mirror includes third
Transistor and the 4th transistor, the third transistor and the 4th transistor are PMOS transistor.
Optionally, second current branch further include: third current mirror is suitable for carrying out mirror to second reference current
Picture to obtain the third reference current, and is exported via its output end.
Optionally, the third reference current is equal to first reference current.
Optionally, the detection module further include: potential-divider network, first input end couple the switching node, the
Two input terminals couple reference end, and partial pressure output end exports the association voltage.
Optionally, the logic module includes: d type flip flop, and reset terminal couples the control terminal of the main switch, data
Input terminal access the first control voltage, data output end couples the control terminal of the first switch, described in clock end coupling
The output end of detection module；Wherein, in the controlled conducting of the main switch, the d type flip flop resets, so that described first opens
Close controlled shutdown；In the main switch controlled shutdown and the testing result instruction association voltage is less than the threshold voltage
When, the d type flip flop data output end output it is described first control voltage so that the first switch it is controlled conducting until
The controlled conducting of main switch.
Optionally, the first switch is suitable for the controlled conducting when its control terminal is high level, the first control voltage
For the input voltage of the Switching Power Supply.
Compared with prior art, the technical solution of the embodiment of the present invention has the advantages that
The Switching Power Supply of the embodiment of the present invention passes through the detection association voltage (electricity of the association voltage and the switching node
Pressure is associated) whether it is less than threshold voltage to determine whether generation ringing then controls first once detecting ringing
Switch conduction, so that inductance and ring inhibit resistance to form access, to evade the generation of LC oscillation, suppressed ringing phenomenon changes
It is apt to the EMI of the Switching Power Supply.Scheme compared with the existing technology has system cost low and the high advantage of stability.
Furthermore, the detection module may include generate preset first reference current the first current branch and
The second current branch for comparing electric current is generated according to association voltage, wherein be more than or equal to the ratio in first reference current
When compared with electric current, the testing result is the first logic level, to indicate that the association voltage is more than or equal to the threshold voltage,
When first reference current is less than the relatively electric current, the testing result is different from the second of first logic level
Logic level, to indicate that the association voltage is less than the threshold voltage.That is, what the present invention program was compared by electric current
Mode occurs ringing to Switching Power Supply and detects, easy to implement, and at low cost, stability is high.
Detailed description of the invention
Fig. 1 is a kind of circuit diagram of Switching Power Supply in the prior art.
Fig. 2 is a kind of schematic block diagram of Switching Power Supply of the embodiment of the present invention.
Fig. 3 is a kind of circuit diagram of Switching Power Supply shown in Fig. 2.
Fig. 4 is a kind of working waveform figure of Switching Power Supply shown in Fig. 2.
Specific embodiment
As described in the background section, the method for ringing in Switching Power Supply is inhibited to make system cost in the prior art
Increase, it is also possible to cause system device utter long and high-pitched sounds it is equal extremely.
For techniques discussed above problem, the embodiment of the present invention proposes a kind of Switching Power Supply, can be existing with suppressed ringing
As improving the electromagnetic interference (Electromagnetic Interference, abbreviation EMI) of Switching Power Supply.
It is understandable to enable above-mentioned purpose of the invention, feature and beneficial effect to become apparent, with reference to the accompanying drawing to this
The specific embodiment of invention is described in detail.
Referring to fig. 2, the embodiment of the invention discloses a kind of Switching Power Supplies 200.The embodiment of the present invention can be adapted for
A plurality of types of Switching Power Supplies have universality.Specifically, the Switching Power Supply 200 can be switch DC booster circuit
(also referred to as Boost circuit), switch DC reduction voltage circuit (also referred to as Buck circuit) or switch DC step-up/step-down circuit (also referred to as Buck-
Boost circuit).
It is understood to one skilled in the art that when the Switching Power Supply 200 is Buck circuit or Buck-Boost circuit
Circuit topology with its be Boost circuit when it is essentially identical, only the coupling mode of the components such as the inductance in circuit, main switch slightly has
Difference, therefore, to put it more simply, the present embodiment is only illustrated by taking Boost circuit as an example.
Switching Power Supply 200 shown in Fig. 2 may include inductance L1, main switch M1, first in parallel with the inductance L1
Road 10, detection module 20 and logic module 30.
Wherein, the controlled on or off of main switch M1, so that the output end output of the Switching Power Supply 200 has output
Voltage VOUT, the output voltage VO UT are for load supplying.The control terminal incoming control signal PWM of the main switch M1,
The control signal PWM can be pulse-width signal, so that the Switching Power Supply 200 has switch periods.Specific real
Shi Zhong, the main switch M1 can be power switch tube.It specifically, can be NMOS tube shown in Fig. 2, but not limited to this, example
Such as, the main switch M1 can also be PMOS tube, triode etc., need to only suitably adjust the control strategy to the main switch M1
?.
When the controlled conducting of the main switch M1, the input voltage VIN of the Switching Power Supply 200 via the inductance L1 and
Main switch M1 extremely forms electric pathway, because of stream has electric current continuous energy storage on the inductance L1；When the controlled pass main switch M1
When disconnected, the electric energy stored by the inductance L1 is transmitted to the output end.Furthermore, the Switching Power Supply 200 can be with
Including synchronous switch (sustained diode 1 in referring to fig. 2) and first capacitor C1.Electric energy stored by the inductance L1 is institute
First capacitor C1 charging is stated, so that the voltage on the output end and the switching node SW increases, while the inductance
Electric energy stored by L1 is reduced.Under the control of the control signal PWM switching regulator, the Switching Power Supply 200 is again and again
Work.
Nowadays, electronic equipment has the development trend of low-power consumption.When application switch power supply electronic equipment be in it is standby or
When dormant state, the load current of Switching Power Supply is reduced, and equipment meeting control switch power supply enters discontinuous conduction mode
(Discontinuous Conduction Mode, abbreviation DCM), and reduce the switching frequency of Switching Power Supply.
When the Switching Power Supply 200 enters DCM mode, during the main switch M1 controlled shutdown, the inductance L1
Electric energy release when finishing, resonance may be generated with the parasitic capacitance of the main switch M1, which can be referred to as ring
(Ringing) phenomenon, generated inductance (Inductor, abbreviation L) capacitor (Capacity, abbreviation C) oscillation is so that described open
The EMI problem in powered-down source 200 is serious.
When occurring due to oscillation, acute variation can occur for the voltage of the switching node SW, and therefore, the present embodiment is for upper
It states LC oscillation detect, and is provided with corresponding energy and discharges access, to evade the generation of above-mentioned LC oscillation, suppression
Ringing processed.
The first branch 10 forms above-mentioned energy release access.Specifically, the first branch 10 may include string
The first switch S1 of connection and ring inhibit the connecting node of resistance Ring, the inductance L1 and main switch M1 to be denoted as switching node
SW.As long as the first switch S1 and ring inhibit resistance Ring series connection, the present embodiment does not limit its specifically connection side
Formula.
In specific implementation, the first switch S1 can be the semiconductor switch devices such as metal-oxide-semiconductor, triode, can also be with
For any other switching device or switch chip, the present embodiment is without specifically limited.Preferably, the first switch S1 is
NMOS tube, so that the Switching Power Supply 200 has better integrated level, and convenient for control.
The setting of the detection module 20 is for detect to ringing.Specifically, the detection module
20 are adapted to detect for whether association voltage SWT is less than threshold voltage, output end output test result Vcmp, the association voltage
SWT (it is associated that the two is represented by dashed line in Fig. 2) associated with the voltage of the switching node SW, for example, the two can be equal,
Or the association voltage SWT can be obtained through the voltage of the switching node SW, then alternatively, the association voltage SWT
It can be obtained through the voltage bias of the switching node SW.
In general, during the Switching Power Supply 200 works normally, the voltage of the switching node SW is usually
Greater than zero, when ringing occurs, the voltage of the switching node SW can occur acutely to vibrate, in oscillatory process, institute
The voltage for stating switching node SW can drop to 0V or less.Since the association voltage SWT is based on dropping to, 0V is below described opens
The voltage of artis SW is changed, and when ringing occurs, the association voltage SWT is largely also less than 0V
, therefore, in specific implementation, the threshold voltage can be set and be less than 0V, for example, -1.5V or -2V etc., it can be according to reality
The design requirement on border is configured.
It can be connected by controlling the identification of testing result Vcmp the first switch S1 in the first branch 10, with
So that the inductance L1 and the ring inhibit resistance Ring to form access, to evade the generation of LC oscillation；In addition, according to switch
The working principle of power supply is it is found that the LC vibrates during occurring only at main switch M1 controlled shutdown, therefore, when its controlled conducting
When, the first switch S1 is to disconnect.
Specifically, the first input end of the logic module 30 couples the output end of the detection module 20, namely access
The testing result Vcmp, the second input terminal of the logic module 30 couple the control terminal of the main switch M1.As the master
It is described to patrol when switch M1 controlled shutdown and the testing result Vcmp indicate the association voltage SWT less than the threshold voltage
It collects module 30 and controls the first switch S1 conducting until the controlled conducting of main switch M1, otherwise, the logic module 30 are controlled
Make the first switch S1 shutdown.
By detection association voltage SWT, (the association voltage SWT is opened the Switching Power Supply 200 of the embodiment of the present invention with described
The voltage of artis SW is associated) whether it is less than threshold voltage to determine whether ringing occurs, once detect that ring is existing
As the first switch S1 conducting then being controlled, so that the inductance L1 and ring inhibit resistance Ring to form access, to evade
The generation of LC oscillation, suppressed ringing phenomenon improve the EMI of the Switching Power Supply 200.Scheme compared with the existing technology, have be
It unites the at low cost and high advantage of stability.
It is situated between in detail below with reference to specific embodiment and working principle of the Fig. 2 and Fig. 3 to the Switching Power Supply
It continues.
Together referring to figs. 2 and 3, in embodiments of the present invention, the detection module 20 may include the first current branch
(not indicated in figure) and the second current branch (not indicated in figure).
Wherein, first current branch is suitable for generating preset first reference current Ir1, and defeated via its output end
Out；Second current branch is suitable for comparing electric current Ic according to association voltage SWT generation, and exports via its output end；Assuming that
The first reference current Ir1 charges to the output end of the detection module 20, and the relatively electric current Ic is to the detection module
20 output end electric discharge, when the first reference current Ir1 is more than or equal to the relatively electric current Ic, the testing result Vcmp
For the first logic level (logically high/low level), to indicate that the association voltage SWT is more than or equal to the threshold voltage, in institute
When stating the first reference current Ir1 less than the relatively electric current Ic, the testing result is different from first logic level
Second logic level (logic low/high level) to indicate that the association voltage SWT is less than the threshold voltage, namely has occurred
Ringing.
That is, to Switching Power Supply 200 ringing can occur for the embodiment of the present invention in such a way that electric current compares
It is detected, easy to implement, at low cost, stability is high.
In specific implementation, first current branch may include the first current mirror (not indicating in figure), and described first
Current mirror is suitable for carrying out mirror image to the second reference current Ir2, to obtain the first reference current Ir1.Second current branch can
To include the second current mirror (not indicating in figure), second current mirror is suitable for obtaining institute according to third reference current Ir3 mirror image
It states and compares electric current Ic, the current value of the third reference current Ir3 is equal to the current value of the second reference current Ir2, namely
The first reference current Ir1 and the third reference current Ir3 can be obtained according to same current mirror.It is being embodied
In, the second reference current Ir2 can be generated by output current value current source 201 appropriate, or can be by other electricity
Stream mirror (not shown) mirror image obtains, and the present embodiment is to the source of the second reference current Ir2 without particular determination.
It is understood to one skilled in the art that current mirror (can be able to be MOS transistor or three poles by a pair of transistor
Pipe) it constitutes, the present embodiment is illustrated by taking the current mirror that MOS transistor forms as an example.The grid of a pair of transistor in current mirror
Extremely it is connected, source electrode is connected；When the breadth length ratio of the two is equal, the electric current of the drain electrode of one of transistor is equal to another crystal
The electric current of the drain electrode of pipe；When the breadth length ratio of the two is unequal, the electric current of the drain electrode of one of transistor and another crystal
The ratio between electric current of drain electrode of pipe is equal to the ratio between the breadth length ratio of the two.
In the present embodiment, second current mirror may include the first transistor NM1 and second transistor NM2, described
The first transistor NM1 accesses the third reference current Ir3, output end (namely drain electrode) output of the second transistor NM2
The relatively electric current Ic, the input terminal (namely source electrode) of the second transistor NM2 access the association voltage SWT.Wherein, institute
State breadth length ratio of the ratio less than the first transistor NM1 and the institute of the second reference current Ir2 and the first reference current Ir1
State the ratio of the breadth length ratio of second transistor NM2.That is, the first transistor NM1 in second current mirror and the
When the source voltage of two-transistor NM2 is equal, the ratio of the second reference current Ir2 and the first reference current Ir1 are small
In the third reference current Ir3 (current value is equal with the second reference current Ir2) ratio of electric current Ic compared with described.
Namely when the source voltage of the first transistor NM1 and second transistor NM2 in second current mirror it is equal (such as both
Source grounding) when, the first reference current Ir1 be more than or equal to it is described relatively electric current Ic, and when the association voltage SWT because
For ringing occurs and when dropping to such as 0V or less, between grid and source electrode that the second transistor NM2 can be made
Voltage rises (grid voltage remains unchanged), and when the second transistor NM2 is NMOS transistor, drain electrode is exported described
Compare electric current Ic to steeply rise, when it is increased over the first reference current Ir1, the inspection of the output of detection module 20
The logic level overturning of result Vcmp is surveyed, to realize the detection to ringing.
It is understood to one skilled in the art that current mirror can be divided into p-type current mirror and N-type current mirror, namely correspond to by
Two PMOS transistors are constituted and are made of two NMOS transistors.
Preferably, the first transistor NM1 in the present embodiment and second transistor NM2 is NMOS transistor, described
It may include third transistor PM1 and the 4th transistor PM2 in first current mirror, the third transistor PM1 and the 4th crystal
Pipe PM2 is PMOS transistor.Wherein, the source electrode of the third transistor PM1 and the 4th transistor PM2 can access the switch
The source electrode of the input voltage VIN of power supply 200, the first transistor NM1 can be grounded.
It should be noted that first current mirror and the second current mirror are not limited to above scheme, for example, described
One transistor and second transistor can be PMOS transistor, and the third transistor and the 4th transistor can be NMOS crystal
Pipe.
It should also be noted that, how the embodiment of the present invention according to the second reference current Ir2 obtains institute if not limiting
State third reference current Ir3.
Preferably, second current branch can also include third current mirror (not indicating in figure), the third electric current
Mirror is suitable for carrying out mirror image to the second reference current Ir2, to obtain the third reference current Ir3, and via its output end
(namely drain electrode of the 5th transistor PM3 in figure) output.Preferably, in the present embodiment, the third current mirror can be with
First current mirror shares the third transistor PM3.
In a change case, the third reference current Ir3 can be equal to the second reference current Ir2.
Optionally, the third reference current Ir3 is equal to the first reference current Ir1, the first transistor NM1's
The ratio of breadth length ratio and the breadth length ratio of the second transistor NM2 is greater than 1.
It should be noted that breadth length ratio as mentioned in the embodiments of the present invention is equivalent breadth length ratio.For example, the first crystal
The ratio of the breadth length ratio of pipe NM1 and the breadth length ratio of the second transistor NM2 is greater than 1, and 1 breadth length ratio can be greater than using quantity
Equal NMOS tube is in parallel, and the breadth length ratio of the NMOS tube is equal with the breadth length ratio of the second transistor NM2.
Preferably, in specific implementation, the detection module 20 can also include potential-divider network (not indicating in figure), the
One input terminal couples the switching node SW, and the second input terminal couples reference end, and partial pressure output end exports the association electricity
Press SWT.The reference end can be ground namely voltage be zero port, but not limited to this, the reference end may be with
Outer port.The potential-divider network may include first resistor R1 and second resistance R2.The resistance value and two of the first resistor R1
The ratio of person's resistance value is the intrinsic standoff ratio of the potential-divider network.The circuit knot being known to the skilled person due to the potential-divider network
Structure, to put it more simply, no longer expansion description one by one herein.
In embodiments of the present invention, the logic module 30 may include d type flip flop 301.Its reset terminal R couples the master
The control terminal of switch M1, namely the access control signal PWM, optionally, the control signal PWM can be via buffer B2
Access the reset terminal R；The first control of its data input pin D access voltage V1；Its data output end Q couples the first switch
The control terminal of S1, clock end CLK couple the output end of the detection module 20, it is preferable that the testing result Vcmp via
Buffer B1 accesses the clock end CLK.
Wherein, in the controlled conducting of the main switch M1, the d type flip flop 301 resets, so that the first switch S1
Controlled shutdown；In the main switch M1 controlled shutdown and the testing result Vcmp instruction association voltage SWT is less than described
When threshold voltage, the data output end Q output of the d type flip flop 301 first control voltage V1, so that described first opens
The controlled conducting of S1 is closed until the controlled conducting of main switch M1.In specific implementation, the d type flip flop 301 can be rising edge
Triggering is also possible to failing edge triggering, can carry out the regulation of electrical circuit according to the logic level of the testing result Vcmp.
When the first switch S1 is suitable for the controlled conducting when its control terminal is high level, it is preferable that first control
Voltage V1 processed is the input voltage VIN of the Switching Power Supply 200, and the input voltage VIN can be identified as logic high.
It is understood to one skilled in the art that realize can there are many allocation plan, Ke Yigen for logic in digital circuit
It is configured according to the truth table output and input, therefore, the logic module 30 can be using other than the d type flip flop 301
Other logic modules are realized.
Fig. 4 shows the working waveform figure of the Switching Power Supply 200.
Together referring to Fig. 3 and Fig. 4, the voltage of the control terminal of the low tension switch S1 is indicated with Q, and is divided with " 1 " and " 0 "
It Biao Shi not logic high and logic low.Assuming that the first switch M1 is connected in logic high, the d type flip flop
301 be to be triggered by failing edge, and reset in logic high.
The control signal PWM is periodic signal, and the switch periods of period T namely the Switching Power Supply 200 are T.
T is made of T1 and T2, wherein T1 corresponds to PWM=" 1 ", and the switching tube M1 conducting, T2 corresponds to PWM=" 0 ", described to open
Close pipe M1 shutdown.
It is in T in switch periods, during PWM=" 1 ", the d type flip flop 301 resets, so that Q=" 0 ", described first
Switch S1 shutdown；At PWM=" 0 ", the d type flip flop 301 is detached from reset state, since the voltage of the switching node SW is
" 1 ", therefore, the association voltage are " 1 ", and the source electrode of the second transistor NM2 is positive voltage, first reference current
Ir1 is more than or equal to the relatively electric current Ic, Vcmp=" 1 ", the d type flip flop 301 not more new data to its data output end, because
This, the first switch S1 shutdown；At the 1. moment, since the electric energy of inductance L1 storage discharges completely, namely ring occurs
Phenomenon, the association voltage SWT decline rapidly, when its deteriorate to less than zero it is even lower when so that first reference current
Ir1 is less than relatively electric current Ic, the Vcmp to be become " 0 " from " 1 ", and the d type flip flop 301 updates number under the action of the failing edge
According into and Q being set to " 1 ", the charge of the first switch S1 conducting, the inductance L1 storage passes through ring inhibition resistance Ring
It quickly releases, so as to avoid LC oscillation；At the 2. moment, PWM becomes " 1 ", and Q is set to " 0 ", the first switch S1 shutdown,
So that the Switching Power Supply 200 works again and again.
It should be noted that " logic high " herein refers to can be identified as the level model of digital signal " 1 "
It encloses, " logic low " refers to can be identified as the level range of digital signal " 0 ", and the two is opposite concept, specific
Level range is simultaneously not particularly limited.
Although present disclosure is as above, present invention is not limited to this.Anyone skilled in the art are not departing from this
It in the spirit and scope of invention, can make various changes or modifications, therefore protection scope of the present invention should be with claim institute
Subject to the range of restriction.
Claims (8)
1. a kind of Switching Power Supply, including inductance, main switch, the controlled on or off of main switch, so that the Switching Power Supply
Output end output have output voltage, which is characterized in that further include:
With the first branch of the inductance in parallel, the first branch includes that concatenated first switch and ring inhibit resistance, institute
The connecting node for stating inductance and main switch is denoted as switching node；
Detection module, is adapted to detect for whether association voltage is less than threshold voltage, output end output test result, the association electricity
It presses associated with the voltage of the switching node；
Logic module, first input end couple the output end of the detection module, and the second input terminal couples the main switch
Control terminal, when the main switch controlled shutdown and the testing result indicates the association voltage less than the threshold voltage
When, the logic module controls the first switch conducting up to the controlled conducting of the main switch, otherwise, the logic module control
Make the first switch shutdown；
The detection module includes:
First current branch is suitable for generating preset first reference current, and exports via its output end；
Second current branch suitable for comparing electric current according to association voltage generation, and is exported via its output end；
Wherein, when first reference current is more than or equal to the relatively electric current, the testing result is the first logic level,
To indicate that the association voltage is more than or equal to the threshold voltage, when first reference current is less than the relatively electric current,
The testing result is the second logic level different from first logic level, to indicate that it is described that the association voltage is less than
Threshold voltage；
First current branch includes: the first current mirror, is suitable for carrying out mirror image to the second reference current, to obtain the first reference
Electric current；
Second current branch includes: the second current mirror, suitable for obtaining the relatively electric current according to third reference current mirror image,
The current value of the third reference current is equal to the current value of second reference current, and second current mirror includes first brilliant
Body pipe and second transistor, the first transistor access the third reference current, and the output end of the second transistor is defeated
The relatively electric current, the input terminal of the second transistor access the association voltage out；
Wherein, the ratio of second reference current and first reference current be less than the breadth length ratio of the first transistor with
The ratio of the breadth length ratio of the second transistor.
2. Switching Power Supply according to claim 1, which is characterized in that the threshold voltage is less than 0V.
3. Switching Power Supply according to claim 1, which is characterized in that the first transistor and second transistor are NMOS
Transistor, first current mirror include third transistor and the 4th transistor, and the third transistor is with the 4th transistor
PMOS transistor.
4. Switching Power Supply according to claim 1, which is characterized in that second current branch further include: third electric current
Mirror is suitable for carrying out mirror image to second reference current, to obtain the third reference current, and exports via its output end.
5. Switching Power Supply according to claim 4, which is characterized in that the third reference current is equal to first reference
Electric current.
6. Switching Power Supply according to any one of claim 1 to 5, which is characterized in that the detection module further include: point
Pressure network network, first input end couple the switching node, and the second input terminal couples reference end, and partial pressure output end exports institute
State association voltage.
7. Switching Power Supply according to any one of claim 1 to 5, which is characterized in that the logic module includes:
D type flip flop, reset terminal couple the control terminal of the main switch, data input pin access the first control voltage, number
The control terminal of the first switch is coupled according to output end, clock end couples the output end of the detection module；
Wherein, in the controlled conducting of the main switch, the d type flip flop resets, so that the first switch controlled shutdown；?
When the main switch controlled shutdown and the testing result indicate that the association voltage is less than the threshold voltage, the D is triggered
Device data output end output it is described first control voltage so that the first switch it is controlled conducting until the main switch by
Conduct is logical.
8. Switching Power Supply according to claim 7, which is characterized in that the first switch is suitable in its control terminal being high electricity
Usually controlled conducting, the first control voltage are the input voltage of the Switching Power Supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710497391.6A CN107302306B (en) | 2017-06-26 | 2017-06-26 | A kind of Switching Power Supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710497391.6A CN107302306B (en) | 2017-06-26 | 2017-06-26 | A kind of Switching Power Supply |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107302306A CN107302306A (en) | 2017-10-27 |
| CN107302306B true CN107302306B (en) | 2019-05-24 |
Family
ID=60135892
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710497391.6A Active CN107302306B (en) | 2017-06-26 | 2017-06-26 | A kind of Switching Power Supply |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107302306B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112311227B (en) * | 2019-08-01 | 2021-10-15 | 圣邦微电子（北京）股份有限公司 | Switch power supply and ringing elimination circuit and ringing elimination method thereof |
| CN113541220A (en) * | 2020-04-21 | 2021-10-22 | 圣邦微电子（北京）股份有限公司 | Load detection circuit and charging system |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200906038A (en) * | 2007-07-26 | 2009-02-01 | Richtek Technology Corp | Non-synchronous step-up voltage converter with anti-oscillation function and the anti-oscillation method thereof |
| CN103427624B (en) * | 2013-08-21 | 2015-09-09 | 电子科技大学 | For the anti-ringing circuit of integrated form voltage-dropping type DC/DC switch converters |
-
2017
- 2017-06-26 CN CN201710497391.6A patent/CN107302306B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN107302306A (en) | 2017-10-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10218283B2 (en) | Insulated synchronous rectification DC/DC converter | |
| CN103580000B (en) | Switching Power Supply output over-voltage protection method and circuit and the Switching Power Supply with this circuit | |
| TWI774085B (en) | Pulse width modulation control chip and power conversion system | |
| US20090179625A1 (en) | Voltage converter | |
| CN109428489A (en) | System and method for generating feedback current in DC-DC converter | |
| CN101926079A (en) | Self-oscillating regulated low-ripple charge pump and method | |
| CN103684374B (en) | The electric power starting of zero or ultralow DC current drain and undervoltage detector | |
| CN108964426A (en) | A kind of the control chip and AC-DC system of synchronous rectifier | |
| US20110210712A1 (en) | AC or DC POWER SUPPLY EMPLOYING SAMPLING POWER CIRCUIT | |
| CN105988495A (en) | LDO (Low Drop-out voltage regulator) overshooting protection circuit | |
| CN106787702B (en) | Switching Power Supply and its audio-frequency noise suppressing method | |
| CN103715878A (en) | Power supply and starting circuit thereof | |
| TW201347381A (en) | Direct current converter for bootstrap circuit | |
| CN107302306B (en) | A kind of Switching Power Supply | |
| CN105099184A (en) | Light-load switching power supply chip | |
| TWI534600B (en) | A power management device of a touchable control system | |
| CN109756215A (en) | A kind of multifunction switch controller and changeable method | |
| CN105119485A (en) | Charge pump circuit | |
| CN107294383B (en) | A kind of Switching Power Supply | |
| CN112653324B (en) | Boost converter system without direct power supply | |
| CN208316290U (en) | A kind of current foldback circuit | |
| US8829877B2 (en) | Resonance frequency adjusting circuit | |
| US10389222B2 (en) | Systems and methods for sensing current in a power converter | |
| WO2019015414A1 (en) | Frequency jittering control circuit and control method | |
| CN209692611U (en) | Relative constant CMOS charge pump is exported based on wide-range input voltage |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP02 | Change in the address of a patent holder |
Address after: 201199 Room 1201, Lane 908, Xiuwen Road, Minhang District, Shanghai Patentee after: SHANGHAI AWINIC ELECTRONIC TECHNOLOGY CO., LTD. Address before: Room 303-39, 33 Block 680 Guiping Road, Xuhui District, Shanghai, 2003 Patentee before: SHANGHAI AWINIC ELECTRONIC TECHNOLOGY CO., LTD. |
|
| CP02 | Change in the address of a patent holder |