CN109742956A - Flyback switching power supply with power limiting power supply protection function - Google Patents
Flyback switching power supply with power limiting power supply protection function Download PDFInfo
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Abstract
The invention discloses a flyback switching power supply with a power supply limiting protection function. The feedback pin is coupled with the output end of the flyback switching power supply through the feedback circuit. The driving pin outputs a Pulse Width Modulation (PWM) square wave, and the working frequency of the PWM square wave in a heavy-load working mode is greater than that in a light-load working mode. The controller comprises an LPS detection module, a driving pin and a feedback pin, wherein the LPS detection module is coupled with the feedback pin and the driving pin and is used for detecting whether the voltage of the feedback pin is smaller than a voltage threshold value, and the voltage threshold value is equal to the voltage of the feedback pin in a light-load working mode; if the voltage of the feedback pin is smaller than the voltage threshold, whether the conduction time of the PWM square wave is larger than the time threshold is detected; and if the on-time of the PWM square wave is larger than the time threshold, the driving controller stops outputting the PWM square wave.
Description
Technical field
The present invention relates to a kind of inverse-excitation type switch power-supplies, and limit power power-supply (Limit especially with regard to a kind of tool
Power Source, LPS) defencive function inverse-excitation type switch power-supply.
Background technique
When test of Switching Power Supply under the conditions of normal condition and single failure all meet output no more than 8A/100W it
It is required that when, Switching Power Supply is a kind of limit power power-supply (LPS).Requiring information product in safety standard IEC 60950 must
Must provide flameproof case, still, when an information product be by limit power power-supply (LPS) to power when, if electronic component is to assign
Printed circuit board more than flame retardant rating V-1, then information product may not necessarily provide flameproof case, that is, resistance can be used
Fire the shell of grade HB.The enclosure material of flame retardant rating HB is also equipped with preferable physical characteristic, holds simultaneously other than price is low
Easily meet the requirement of environmental protection.Therefore, Switching Power Supply can often be added some circuits and do LPS protection, so as to normal condition with it is single
Test under fault condition can meet the requirement that output is not more than 8A/100W, and then be able to the shell using flame retardant rating HB.
The inverse-excitation type switch power-supply of single group output, such as output 19V/2A shown in Fig. 1 supply electricity to display.When being switched
When the single failure condition test of primary side current detecting resistor (i.e. resistor Rs) short circuit of power supply, due to existing switch electricity
The controller U1 in source is not directed to resistor Rs, and there is a situation where short circuits to protect, and when resistor Rs short circuit can make controller U1
The voltage that current sense foot CS is detected is constantly in very small state, causes controller U1 to judge Switching Power Supply by accident always and is in
Underloading condition the, so that pulsewidth modulation (Pulse of the driving foot DRI output services frequency lower (such as 20KHz or so) of controller U1
Width Modulation, PWM) square wave reduces to power switch Q1 and is exported by transformer T1 to the electric energy of load, and control
The feedback foot COMP of device U1 processed detects the voltage that output end OUT is fed back also can be in low-voltage state at light load.When
Resistor Rs not short circuit and when heavier loads, the driving foot DRI of controller U1 can output services frequency it is higher (such as 65KHz or so)
PWM square wave increase to power switch Q1 and exported by transformer T1 to the electric energy of load, and the feedback foot of controller U1
COMP voltage also can be in high-voltage state when overloaded.In addition, the inverse of the working frequency (being indicated with F) of PWM square wave is
Duty cycle (indicates) that each duty cycle T (indicates) institute by turn-on time (indicating with Ton) and turn-off time with Toff with T
Composition is connected in controlling power switch Q1 in turn-on time Ton, and controls power switch Q1 in turn-off time Toff and disconnect.
The working frequency F of PWM square wave is lower when resistor Rs short circuit, i.e. duty cycle T longer, therefore the turn-on time of power switch Q1
Ton also can be longer.Following table 1 is the inverse-excitation type switch power-supply on the existing wherein model power panel of our company in normal condition
With the test result under the conditions of the single failure of resistor Rs short circuit.
[table 1]
Turn-on time Ton is longer, and electric current caused by the primary side winding Np of transformer T1 is bigger.Power switch Q1 by
Conducting goes off moment, the junction capacitance of the auxiliary winding Na of transformer T1 corresponding leakage inductance and diode D1 parasitism
LC resonance occurs, higher rectification of the resonance electric energy through diode D1 can be generated and charged to capacitor C1, so that capacitor
C1 voltage rises.When output loading becomes larger, turn-on time Ton can become larger, and capacitor C1 voltage will continue to rise.Work as capacitor
C1 voltage reaches the guarantor of the power supply foot VCC internal overvoltage protection (Over Voltage Protection, OVP) of controller U1
When shield point, controller U1 starting protection function is without working.Therefore, the inverse-excitation type switch power-supply of single group output passes through controller U1
Power supply foot VCC inside OVP function incidentally do LPS protection.
However, the OVP function inside the power supply foot VCC that the inverse-excitation type switch power-supply of single group output passes through controller U1 is come attached
Band does LPS protection, and there are the following problems:
1. the power supply foot VCC voltage of controller U1 can be by the reaction speed of diode D1 itself and the auxiliary of transformer T1
Winding Na, which encloses number and winding structure, to be influenced.When because of electromagnetic interference (Electromagnetic Interference, EMI) the problems such as
And when using diode D1 instead diode at a slow speed or change transformer T1 design, it is defeated before controller U1 starts OVP function
Power will become larger out.Therefore, LPS protection point is not accurate, influences vulnerable to diode D1 materials and parts characteristic and transformer T1 design,
Lead to not test by LPS.
2. existing design carries out the LPS test of resistor Rs short trouble under the conditions of input voltage 264V, starting
Output power when LPS defencive function would generally fall in 80W~100W or so, and the LPS testing standard from IEC 60950 requires defeated
Power is too close no more than 100W out.If using diode D1 instead diode at a slow speed or change due to EMI the problems such as in the examination race stage
Transformer T1 design, then easily cause the output power before starting LPS defencive function just to exceed 100W.
The inverse-excitation type switch power-supply of double groups of output, such as one group of output 5V/2.5A supply electricity to display main board circuit, another
Group output 16V/1A supplies electricity to display backlight boosting driving plate circuit.In order to be detected by the primary side current of Switching Power Supply
The single failure condition test of resistor short circuit, it is common practice that concatenate 4A/250V disconnected type slowly in the biggish 5V output end of electric current
Fuse, and be used in lesser 16V output end concatenation such as 0 ohmic resistor of model 1206 of electric current as fuse.However, double
The inverse-excitation type switch power-supply of group output does LPS protection by concatenating fuse in output end, increases design cost.
Summary of the invention
The purpose of the present invention is to provide a kind of inverse-excitation type switch power-supplies of tool limit power power-supply defencive function, to be directed to
The single failure condition of the primary side current detecting resistor short circuit of Switching Power Supply does LPS protection, and LPS protection point is precisely, if
Cost is relatively low for meter.
To achieve the above object, the invention adopts the following technical scheme:
A kind of inverse-excitation type switch power-supply of tool limit power power-supply defencive function, has an input terminal and an output end, special
Sign is: inverse-excitation type switch power-supply includes:
One power switch, has a first end, a second end and a control terminal, and control terminal control first end is led with second end
On-off is opened；
One transformer has a primary side winding and a primary side winding, and primary side winding both ends are respectively coupled to input terminal
With first end, primary side winding both ends are respectively coupled to output end and ground；
One resistor, both ends are respectively coupled to second end and ground；
One feed circuit, one end couple output end；
One controller, has a feedback foot, a driving foot and a current sense foot, and feedback foot coupling feed circuit is another
End, driving foot couple control terminal, and current sense foot couples second end, and controller exports a pulsewidth modulation square wave from driving foot, and
Pulsewidth modulation square wave is greater than the working frequency under a underloading operating mode, control in the working frequency under a heavy duty work mode
Device includes a limit power power-supply detecting module, limit power power-supply detecting module coupling feedback foot and driving foot, for detecting feedback
Whether less than a voltage threshold, voltage threshold is equal in the feedback foot voltage being lightly loaded under operating mode foot voltage；If feeding back foot electricity
Pressure is less than voltage threshold, then whether the turn-on time for detecting pulsewidth modulation square wave again is greater than a time threshold；And if pulsewidth
The turn-on time of modulated square wave is greater than time threshold, then drive control device stops output pulse width modulated square wave.
Further, if the feedback foot voltage is not less than voltage threshold, the normal output pulse width modulation of drive control device
Square wave.
Further, if the turn-on time of the pulsewidth modulation square wave is not more than time threshold, drive control device is normal
Output pulse width modulated square wave.
The invention adopts the above technical scheme, has the advantages that the present invention in the control of inverse-excitation type switch power-supply
Device inside increase LPS detecting module, the PWM square wave that LPS detecting module is exported by detecting feedback foot voltage with driving foot are led
Lead to the time to determine whether to do LPS protection.By this LPS defencive function, when the primary side current detecting for carrying out Switching Power Supply
When the single failure condition test of resistor short circuit, LPS detecting module, which will make accurate judgment, starts LPS defencive function.Increase
Add LPS detecting module to be easy to realize inside existing controller, and has substantially no effect on the design cost of controller.The present invention overcomes
The OVP function inside power supply foot that the inverse-excitation type switch power-supply of existing single group output passes through controller incidentally does LPS protection
And the problem for bringing protection point not accurate, the inverse-excitation type switch power-supply of existing double group outputs is also overcomed by concatenating in output end
Fuse come do LPS protection and the problem of bring design cost to increase.
Detailed description of the invention
The present invention is described in further details below in conjunction with the drawings and specific embodiments:
Fig. 1 is a kind of circuit diagram of the inverse-excitation type switch power-supply of existing single group output；
Fig. 2 is the circuit diagram of the inverse-excitation type switch power-supply of one embodiment of the invention single group output；
Fig. 3 is the flow chart of the LPS defencive function Initiated Mechanism of one embodiment of the invention controller；
Fig. 4 is the internal circuit diagram of one embodiment of the invention controller；
Fig. 5 is the waveform diagram of the internal node working sequence of one embodiment of the invention controller；
Fig. 6 is the curve graph of feedback the foot voltage and PWM square wave working frequency of one embodiment of the invention controller.
Specific embodiment
Referring to figure 2., there is input terminal IN and output end OUT, input terminal IN to receive and hand over for inverse-excitation type switch power-supply of the present invention
Stream alternating current for example inputs 90V~264V/50Hz or 60Hz, and output end OUT for example exports 19V/2A and supplies electricity to display.Flyback
Formula Switching Power Supply includes power switch Q1, transformer T1, resistor Rs, feed circuit and controller U2.Power switch Q1 has
First end, second end and control terminal, control terminal control first end are turned on or off with second end；In the present embodiment, power is opened
Pass Q1 is N-channel metal oxide semiconductor field-effect transistor (Metal-Oxide-Semiconductor Field-
Effect Transistor, MOSFET), first end, second end and control terminal are respectively drain electrode end (Drain), source terminal
(Source) with gate terminal (Gate).Transformer T1 has primary side winding Np and auxiliary winding Na, transformer T1 in primary side
There is primary side winding Ns in primary side, wherein the both ends primary side winding Np are respectively coupled to (the input terminal IN reception city input terminal IN
With alternating current, carry out generating a tool later by EMI and power frequency filter circuit filtering again after full-wave rectification through bridge rectifier
There is the DC voltage of certain voltage ripple to input to transformer by the non-dotted end of the primary side winding Np of transformer T1) and power
Switch Q1 first end, the both ends primary side winding Ns are respectively coupled to output end OUT and ground (positioned at the ground of primary side).Resistor Rs two
End is respectively coupled to power switch Q1 second end and ground (positioned at the ground of primary side).Feed circuit one end couples output end OUT.Control
Device U2 has feedback foot COMP, driving foot DRI, current sense foot CS and power supply foot VCC, wherein feedback foot COMP coupling feedback electricity
The road other end, driving foot DRI couple power switch Q1 control terminal, and current sense foot CS couples power switch Q1 second end, and auxiliary
It helps the current rectifying and wave filtering circuit of winding Na coupling diode D1 and capacitor C1 composition and supplies electricity to controller U2 from power supply foot VCC.
Controller U2 exports PWM square wave from driving foot DRI, and (such as 65KHz is left for working frequency of the PWM square wave under heavy duty work mode
It is right) it is greater than in the working frequency (such as 20KHz or so) being lightly loaded under operating mode.With existing inverse-excitation type switch power-supply shown in Fig. 1
It compares, increases LPS detecting module inside the inverse-excitation type switch power-supply of present invention controller U1 shown in Fig. 1 and constitute controller
U2, LPS detecting module coupling feedback foot COMP and driving foot DRI, for detecting feedback foot COMP voltage and driving foot DRI output
PWM square wave turn-on time to determine whether starting LPS defencive function.
Referring to figure 3., in step S1, LPS detecting module detecting feedback foot COMP voltage.In step S2, LPS detecting module
Judge to feed back whether foot COMP voltage is less than voltage threshold, wherein voltage threshold is equal in the feedback foot being lightly loaded under operating mode
COMP voltage (such as 1V).When judgement feedback foot COMP voltage be not less than voltage threshold when, indicate inverse-excitation type switch power-supply be not
It is lightly loaded operating mode, therefore executes step S3, LPS detecting module drive control device U2 normally exports PWM square wave.When foot is fed back in judgement
When COMP voltage is less than voltage threshold, indicate that short circuit occurs in underloading operating mode or primary side current detecting resistor Rs,
Therefore it executes step S4 and makees further judgement.In step S4, the PWM square wave of LPS detecting module detecting driving foot DRI output is led
The logical time.In step
S5, LPS detecting module judge whether turn-on time is greater than time threshold (such as 4 μ s).When judging that turn-on time is little
It when time threshold, indicates in underloading operating mode, therefore executes step S6, LPS detecting module drive control device U2 is normally exported
PWM square wave.When judging that turn-on time is greater than time threshold, indicates that short circuit occurs for primary side current detecting resistor Rs, therefore hold
Row step S7, LPS detecting module starts LPS defencive function, and drive control device U2 stops output PWM square wave.
Referring to Fig. 2 to Fig. 6, Fig. 4 and Fig. 5 are respectively that the internal circuit diagram of controller U2 shown in Fig. 2 and inside are saved
The working sequence waveform diagram of point, and Fig. 6 is then the feedback foot COMP voltage Vcomp and PWM square wave working frequency F of controller U2
Curve graph.The working principle of the LPS defencive function of controller U2 is described as follows:
When inverse-excitation type switch power-supply is in heavy duty work mode, the feedback foot COMP of controller U2, which is received, carrys out self-feedback ciucuit
Feedback signal to learn output end OUT voltage status, therefore feed back foot COMP voltage Vcomp (calling feedback foot voltage Vcomp in the following text)
It is greater than 1.2V in high-voltage state when overloaded, such as feedback foot voltage Vcomp, at this time at the working frequency F of Switching Power Supply
Highest 65KHz or so (as shown in Figure 6).The negative input end voltage Va=(Vcomp- of PWM comparator inside controller U2
VD) × Ra2/ (Ral+Ra2) is also higher, and wherein VD is the conduction voltage drop of diode Da.The inside controller U2 PWM comparator is just
Input terminal voltage Vb is received from by leading edge blanking (Leading-Edge Blanking, LEB) module and slope compensation module
The voltage signal that the current sense foot CS managed is sampled to, as Vb > Va, PWM comparator exports a high levle trigger signal
Vc allows the PWM square wave of driving foot DRI output to become low level from high levle, that is, power switch Q1 is allowed to be gone off by being connected, and
Voltage Vcs=(Vin × Ton/L+Ip0) × Rs of current sense foot CS, wherein Vin be power switch Q1 be connected when primary side around
Group Np both end voltage, Ton are power switch Q1 turn-on time, and L is primary side winding Np inductance, and Ip0 is that power switch Q1 is led
Primary side winding Np initial current when logical, Ip0≤0A.When Switching Power Supply output loading is heavier, voltage Va can be higher, drives foot
The PWM square wave high levle of DRI also can be longer with the turn-on time Ton of corresponding power switch Q1, and transformer T1 is in unit period
It is interior to export more electric energy to load, the transformer T1 work electric energy E=Vin that unit period is exported in discontinuous mode2
×Ton2/2L.Opposite, when Switching Power Supply output loading lightens, the turn-on time Ton of power switch Q1 can shorten, transformation
Device T1 exports electric energy in unit period to be reduced.Therefore, when Switching Power Supply is in heavy duty work mode, due to feeding back foot voltage
Vcomp is greater than 1.2V, that is, is greater than voltage threshold (such as 1V) set by LPS detecting module, therefore LPS detecting module executes shown in Fig. 3
Step S1, S2 and S3 is without will start LPS defencive function.
When inverse-excitation type switch power-supply output loading is become at light load from heavy duty, in Switching Power Supply input voltage permanence condition
Under, the PWM square wave high levle of the driving foot DRI of controller U2 can become smaller with the turn-on time Ton of corresponding power switch Q1.?
In the case that load is increasingly lighter, controller U2 in order to reduce the switching loss of power switch Q1, by by the way of frequency reducing into
Row work.When the output loading of Switching Power Supply is reduced to certain value, the working frequency F of Switching Power Supply is by original heavy duty work mould
The 65KHz of formula become be lightly loaded operating mode 20KHz or so, at this time feed back foot voltage Vcomp can be reduced to be, for example, less than lV (such as
Shown in Fig. 6).The turn-on time Ton of power switch Q1 can be by as the 2.8 μ s of input voltage 264V when overloaded become at light load
1.6 μ s and 2.7 μ s (as shown in Table 2 below) at light load are become by the 7.l μ s of such as input voltage 90V when overloaded.Work as output
When load continues to reduce, the working frequency F of Switching Power Supply can also enter burst mode (Burst Mode) more energy-efficient work
Mode.Therefore, when Switching Power Supply output loading is entered at light load by heavy duty, although feedback foot voltage Vcomp can be dropped below
LV, but 1.6 μ s and input since the turn-on time Ton of power switch Q1 also becomes very little, when such as input voltage 264V
2.7 μ s when voltage 90V are less than time threshold (such as 4 μ s) set by LPS detecting module, therefore LPS detecting module executes Fig. 3
Shown step S1, S2, S4, S5 and S6 are without will start LPS defencive function.
When carrying out the single failure condition test of primary side current detecting resistor Rs short circuit of inverse-excitation type switch power-supply,
Since current sense foot CS earth impedance becomes very small, become when overloaded in output loading from being lightly loaded, current sense foot CS institute
The voltage detected is all very small, and feedback foot voltage Vcomp is made to have been at minimum value, such as 0.6V or so.And in Vcomp
Under the conditions of=0.6V or so, controller U2 will mistakenly believe that Switching Power Supply underloading operating mode, working frequency F can be reduced to as
Within 20KHz (as shown in Figure 6), under conditions of output loading is constant, when working frequency reduces, in order to ensure transformer T1
Identical electric energy when output services frequency is higher within the unit time is remained to, the driving foot DRI of controller U2 will be in unit week
Longer turn-on time Ton is provided in the phase and carrys out driving power switch Q1 conducting.Following table 2 is that inverse-excitation type switch power-supply of the present invention exists
Test result under the conditions of normal condition and the single failure of resistor Rs short circuit.
[table 2]
Therefore, when the single failure condition for the primary side current detecting resistor Rs short circuit for carrying out inverse-excitation type switch power-supply is surveyed
When examination, it as long as output band one suitably loads, that is, can reach the protective condition of LPS detecting module, such as feed back foot voltage Vcomp=
0.6V < voltage threshold=1V, turn-on time Ton=6.2 μ s > time threshold=4 μ s, therefore LPS detecting module executes shown in Fig. 3
Step S1, S2, S4, S5 and S7 and start LPS defencive function.
In the present embodiment, heavy duty and working frequency when underloading operating mode are respectively 65KHz and 20KHz or so, but
Not it is limited to this to the greatest extent, working frequency can be according to required different using different controllers；The voltage threshold of LPS protection point
It is set as 1V, time threshold is set as 4 μ s, but is not limited to this to the greatest extent, and voltage threshold and time threshold can be according to flyback switching electricity
Source actual conditions are arranged.Though controller therein still may be used in addition, the present embodiment is the inverse-excitation type switch power-supply of single group output
Inverse-excitation type switch power-supply applied to double groups of output.
The above description is only an embodiment of the present invention, when cannot be limited the scope of implementation of the present invention with this, it is all according to
Simple equivalent changes and modifications made by scope of the present invention patent and patent specification content, all still belong to the invention patent
In the range of covering.
Claims (3)
1. a kind of inverse-excitation type switch power-supply of tool limit power power-supply defencive function, has an input terminal and an output end, feature
Be: inverse-excitation type switch power-supply includes:
One power switch, has a first end, a second end and a control terminal, control terminal control first end be connected with second end or
It disconnects；
One transformer, has a primary side winding and a primary side winding, and primary side winding both ends are respectively coupled to input terminal and the
One end, primary side winding both ends are respectively coupled to output end and ground；
One resistor, both ends are respectively coupled to second end and ground；
One feed circuit, one end couple output end；
One controller, has a feedback foot, a driving foot and a current sense foot, and feedback foot couples the feed circuit other end, drives
Dynamic foot couples control terminal, and current sense foot couples second end, and controller exports a pulsewidth modulation square wave, and pulsewidth tune from driving foot
Square wave processed is greater than the working frequency under a underloading operating mode in the working frequency under a heavy duty work mode, and controller includes
One limit power power-supply detecting module, limit power power-supply detecting module coupling feedback foot and driving foot, for detecting feedback foot voltage
Whether less than a voltage threshold, voltage threshold is equal in the feedback foot voltage being lightly loaded under operating mode；If feedback foot voltage is less than
Whether voltage threshold, the then turn-on time for detecting pulsewidth modulation square wave again are greater than a time threshold；And if pulsewidth modulation side
The turn-on time of wave is greater than time threshold, then drive control device stops output pulse width modulated square wave.
2. a kind of inverse-excitation type switch power-supply of tool limit power power-supply defencive function according to claim 1, it is characterised in that:
If the feedback foot voltage is not less than voltage threshold, the normal output pulse width modulated square wave of drive control device.
3. a kind of inverse-excitation type switch power-supply of tool limit power power-supply defencive function according to claim 1, it is characterised in that:
If the turn-on time of the pulsewidth modulation square wave is not more than time threshold, the normal output pulse width modulated square wave of drive control device.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
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| TW107101954 | 2018-01-19 | ||
| TW107101954A TWI666860B (en) | 2018-01-19 | 2018-01-19 | Flyback switching power supply with lps protection function |
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| CN109742956A true CN109742956A (en) | 2019-05-10 |
| CN109742956B CN109742956B (en) | 2021-04-20 |
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| CN201910020397.3A Active CN109742956B (en) | 2018-01-19 | 2019-01-09 | Flyback switching power supply with power limiting power supply protection function |
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| CN113497567A (en) * | 2020-04-07 | 2021-10-12 | 通嘉科技股份有限公司 | Power supply with limited power protection and related control method |
| US12401262B2 (en) | 2022-11-02 | 2025-08-26 | Delta Electronics (Shanghai) Co., Ltd. | Power adapter with limited power source function and control method thereof |
| US12456857B2 (en) * | 2023-02-21 | 2025-10-28 | Cypress Semiconductor Corporation | Power converter current sense fault detection |
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| TWI717233B (en) | 2020-03-13 | 2021-01-21 | 群光電能科技股份有限公司 | Low power consumption protection circuit |
| US11336185B2 (en) | 2020-05-11 | 2022-05-17 | Alpha And Omega Semiconductor International Lp | Flyback converter, control circuit thereof, and associated control method |
| TWI741596B (en) * | 2020-05-11 | 2021-10-01 | 加拿大商萬國半導體國際有限合夥公司 | Flyback converter, control circuit thereof, and associated control method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6721192B1 (en) * | 2003-03-24 | 2004-04-13 | System General Corp. | PWM controller regulating output voltage and output current in primary side |
| CN1806380A (en) * | 2003-06-18 | 2006-07-19 | 崇贸科技股份有限公司 | Primary-side regulated pulse width modulation controller with improved load regulation |
| CN1852014A (en) * | 2006-04-14 | 2006-10-25 | 崇贸科技股份有限公司 | Control Circuits for Power Converters |
| CN101471609A (en) * | 2007-12-28 | 2009-07-01 | 尼克森微电子股份有限公司 | Three-terminal integrated synchronous rectifier and flyback synchronous rectification circuit |
| CN106329933A (en) * | 2015-07-10 | 2017-01-11 | Tdk株式会社 | Switching power supply device |
| CN206595898U (en) * | 2017-03-24 | 2017-10-27 | 无锡硅动力微电子股份有限公司 | Secondary inverse-excitation type switch power-supply based on SP6650 |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW200849778A (en) * | 2007-06-13 | 2008-12-16 | Richtek Technology Corp | Method and device to improve the light-load performance of switching-type converter |
| TWM372588U (en) * | 2009-04-08 | 2010-01-11 | chang-xing Chen | Isolated-driven frequency modulation PWM power device |
| TWI467362B (en) * | 2012-10-22 | 2015-01-01 | Chicony Power Tech Co Ltd | Power supply apparatus with low standby power consumption |
| TWI583114B (en) * | 2012-11-27 | 2017-05-11 | 通嘉科技股份有限公司 | Power controller with over power protection |
-
2018
- 2018-01-19 TW TW107101954A patent/TWI666860B/en active
-
2019
- 2019-01-09 CN CN201910020397.3A patent/CN109742956B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6721192B1 (en) * | 2003-03-24 | 2004-04-13 | System General Corp. | PWM controller regulating output voltage and output current in primary side |
| CN1806380A (en) * | 2003-06-18 | 2006-07-19 | 崇贸科技股份有限公司 | Primary-side regulated pulse width modulation controller with improved load regulation |
| CN1852014A (en) * | 2006-04-14 | 2006-10-25 | 崇贸科技股份有限公司 | Control Circuits for Power Converters |
| CN101471609A (en) * | 2007-12-28 | 2009-07-01 | 尼克森微电子股份有限公司 | Three-terminal integrated synchronous rectifier and flyback synchronous rectification circuit |
| CN106329933A (en) * | 2015-07-10 | 2017-01-11 | Tdk株式会社 | Switching power supply device |
| CN206595898U (en) * | 2017-03-24 | 2017-10-27 | 无锡硅动力微电子股份有限公司 | Secondary inverse-excitation type switch power-supply based on SP6650 |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110518790A (en) * | 2019-08-28 | 2019-11-29 | 南京微盟电子有限公司 | A kind of quick start and self-contained electric system of switching power converters |
| CN113497567A (en) * | 2020-04-07 | 2021-10-12 | 通嘉科技股份有限公司 | Power supply with limited power protection and related control method |
| CN113497567B (en) * | 2020-04-07 | 2025-11-25 | 通嘉科技股份有限公司 | Power supplies with power limiting protection and related control methods |
| CN111865059A (en) * | 2020-07-16 | 2020-10-30 | 珠海格力电器股份有限公司 | Output power adaptive adjustment circuit and control method thereof, and flyback switching power supply |
| CN111856330A (en) * | 2020-09-24 | 2020-10-30 | 深圳英集芯科技有限公司 | Power adapter circuit, power adapter chip and power adapter |
| US12401262B2 (en) | 2022-11-02 | 2025-08-26 | Delta Electronics (Shanghai) Co., Ltd. | Power adapter with limited power source function and control method thereof |
| US12456857B2 (en) * | 2023-02-21 | 2025-10-28 | Cypress Semiconductor Corporation | Power converter current sense fault detection |
Also Published As
| Publication number | Publication date |
|---|---|
| TWI666860B (en) | 2019-07-21 |
| CN109742956B (en) | 2021-04-20 |
| TW201933739A (en) | 2019-08-16 |
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