CN103051216A - Flyback-type switch circuit - Google Patents
Flyback-type switch circuit Download PDFInfo
- Publication number
- CN103051216A CN103051216A CN 201210568159 CN201210568159A CN103051216A CN 103051216 A CN103051216 A CN 103051216A CN 201210568159 CN201210568159 CN 201210568159 CN 201210568159 A CN201210568159 A CN 201210568159A CN 103051216 A CN103051216 A CN 103051216A
- Authority
- CN
- China
- Prior art keywords
- coupled
- former limit
- lead
- terminal
- switch circuit
- 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.)
- Pending
Links
Images
Abstract
The invention provides a flyback-type switch circuit which solves the problem of low efficiency under the light load state of an existing flyback-type switch circuit. The flyback-type switch circuit comprises an input port, an output port, a rectifier unit, a primary power switch, a secondary diode, an output capacitor, a feedback component, a secondary connecting resistor, a primary connecting resistor, a first Zener diode, an error amplifier, a clamper, a frequency comparator, a sawtooth wave generator and a control and driving circuit. According to the flyback-type switch circuit, the efficiency of the flyback-type switch circuit in the light load state can be improved.
Description
Technical field
The present invention relates to electronic technology field, particularly a kind of switch flyback switch circuit.
Background technology
Switch flyback switch circuit is called again single-ended flyback or buck-boost transducer, and the voltage of the comparable power supply of its output voltage is high or low.Typical case's switch flyback switch circuit as shown in Figure 1, this switch flyback switch circuit comprises: input port receives input voltage vin; Output port provides output voltage V o; Rectification unit Rec is coupled to input port and receives input voltage vin; Transformer comprises former limit winding T1 and secondary winding T2, and described former limit winding T1 is coupled to rectification unit Rec; Former limit power switch S is coupled in former limit winding T1 and former limit with reference between the ground; Secondary diode D is coupled between secondary winding T2 and the output port; Output capacitor Co is coupled in output port and with reference between the ground.The switch periods of existing switch flyback switch circuit is triggered by the clock signal of fixed frequency usually, and namely its switching frequency is the clock frequency of fixed numbers.Under heavy condition, fixing switching frequency can make switch flyback switch circuit keep high efficiency.Yet under light condition, if the switching frequency under switching frequency or the heavy condition, meeting is so that the Efficiency Decreasing of switch flyback switch circuit.
Summary of the invention
The present invention proposes a kind of switch flyback switch circuit, has solved existing switch flyback switch circuit inefficient problem under light condition.
Technical scheme of the present invention is achieved in that
A kind of switch flyback switch circuit comprises: input port receives input voltage; Output port provides output voltage; Rectification unit is coupled to input port and receives input voltage, produces commutating voltage; Transformer comprises former limit winding and secondary winding, and its limit, Central Plains winding and secondary winding respectively have the first terminal and the second terminal, and the first terminal of former limit winding is coupled to rectification unit and receives commutating voltage, and the second terminal of secondary winding connects secondary with reference to ground; Former limit power switch is coupled in the second terminal of former limit winding and former limit with reference between the ground; The secondary diode is coupled between the first terminal and output port of secondary winding; Output capacitor is coupled in output port and secondary with reference between the ground; Feedback component comprises secondary part and former limit part; Secondary contact resistance, the first Zener diode and former limit contact resistance, wherein the secondary part of feedback component, secondary contact resistance and the first Zener diode are coupled in series in output port and secondary with reference between the ground, to produce feedback voltage in the former limit of feedback component part; Error amplifier, have in-phase input end, inverting input and lead-out terminal, its inverting input receives reference voltage, its in-phase input end is coupled to former limit with reference to ground via former limit part and the former limit contact resistance of feedback component, to receive feedback voltage, its lead-out terminal produces error amplification signal; Clamper is coupled in the lead-out terminal of error amplifier and with reference between the ground; Frequency comparator has in-phase input end, inverting input and lead-out terminal, and the lead-out terminal that its inverting input is coupled to error amplifier receives error amplification signal, and its lead-out terminal provides clock signal; Sawtooth generator is coupled to the lead-out terminal receive clock signal of frequency comparator, and provides the in-phase input end of sawtooth signal to frequency comparator based on clock signal; Control and drive circuit are coupled to the lead-out terminal receive clock signal of frequency comparator, and based on clock signal, produce switching drive signal, to control the break-make of former limit power switch.
Alternatively, described feedback component comprises photoelectrical coupler.
Alternatively, described switch flyback switch circuit also comprises: compensation condenser is coupled between the lead-out terminal and inverting input of error amplifier.
Alternatively, described clamper comprises the second Zener diode.
Alternatively, described sawtooth generator comprises: charging current source, charging capacitor and reset switch, three's coupled in parallel at the in-phase input end of frequency comparator with reference to ground between, wherein said reset switch further comprises control terminal, and described control terminal is coupled to the lead-out terminal receive clock signal of frequency comparator.
Alternatively, described rectification unit comprises the rectifier circuit that is comprised of four diodes.
The invention has the beneficial effects as follows: can improve the efficient of switch flyback switch circuit under light condition.
Description of drawings
In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the typical circuit structural representation of existing switch flyback switch circuit;
Fig. 2 is the electrical block diagram of a kind of switch flyback switch circuit 100 of the present invention;
Fig. 3 is the timing waveform signal of clock signal clk, sawtooth signal Vsw, frequency reference signal Vfr and output voltage V o in the switch flyback switch circuit 100 shown in Figure 2.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the invention, the technical scheme in the embodiment of the invention is clearly and completely described, obviously, described embodiment only is the present invention's part embodiment, rather than whole embodiment.Based on the embodiment among the present invention, those of ordinary skills belong to the scope of protection of the invention not paying the every other embodiment that obtains under the creative work prerequisite.
As shown in Figure 2, switch flyback switch circuit 100 of the present invention comprises: input port 101 receives input voltage vin; Output port 102 provides output voltage V o; Rectification unit 103 is coupled to input port 101 and receives input voltage vin, produces commutating voltage; Transformer, comprise former limit winding 104-1 and secondary winding 104-2, its limit, Central Plains winding 104-1 and secondary winding 104-2 respectively have the first terminal and the second terminal, the first terminal of former limit winding 104-1 is coupled to rectification unit 103 and receives commutating voltage, and the second terminal of secondary winding 104-2 connects secondary with reference to ground; Former limit power switch 105 is coupled in the second terminal of former limit winding 104-1 and former limit with reference between the ground; Secondary diode 106 is coupled between the first terminal and output port 102 of secondary winding 104-2; Output capacitor 107 is coupled in output port 102 and secondary with reference between the ground; Feedback component comprises secondary part 108-1 and former limit part 108-2; Secondary contact resistance 109, the first Zener diode 110 and former limit contact resistance 111, wherein the secondary part 108-1 of feedback component, secondary contact resistance 109 and the first Zener diode 110 are coupled in series in output port 102 and secondary with reference between the ground, produce feedback voltage Vfb with the former limit part 108-2 in feedback component; Error amplifier 112, have in-phase input end, inverting input and lead-out terminal, its inverting input receives reference voltage Vref, its in-phase input end is coupled to former limit with reference to ground via former limit part 108-2 and the former limit contact resistance 111 of feedback component, to receive feedback voltage Vfb, its lead-out terminal produces error amplification signal Vc; Clamper 113 is coupled in the lead-out terminal of error amplifier 112 and with reference between the ground; Frequency comparator 114 has in-phase input end, inverting input and lead-out terminal, and the lead-out terminal that its inverting input is coupled to error amplifier 112 receives error amplification signal Vc, and its lead-out terminal provides clock signal clk; Sawtooth generator 115 is coupled to the lead-out terminal receive clock signal CLK of frequency comparator 114, and provides the in-phase input end of sawtooth signal Vsw to frequency comparator 114 based on clock signal clk; Control and drive circuit 116 are coupled to the lead-out terminal receive clock signal of frequency comparator 114, and based on clock signal, produce switching drive signal, to control the break-make of former limit power switch 105.
Preferably, described sawtooth generator 115 comprises: charging current source 11, charging capacitor 12 and reset switch 13, three's coupled in parallel at the in-phase input end of frequency comparator 114 with reference to ground between, wherein said reset switch 13 further comprises control terminal, and described control terminal is coupled to the lead-out terminal receive clock signal CLK of frequency comparator 114.When clock signal clk is low level, reset switch 13 is disconnected, then charging current source 11 gives charging capacitor 12 chargings, the voltage linear at charging capacitor 12 two ends increases, when it increased to the magnitude of voltage of frequency reference signal Vfr of frequency comparator 114 inverting inputs, the clock signal clk of frequency comparator 114 outputs became high level.Correspondingly, reset switch 13 is closed.So charging capacitor 12 is pulled to ground, the voltage at its two ends is reset to rapidly zero, and namely the voltage of frequency comparator 114 in-phase input ends is reset to zero.Subsequently, clock signal clk becomes low level, reset switch 13 is disconnected, charging current source 11 restarts to charging capacitor 12 charging, until charging capacitor 12 both end voltage again reach frequency comparator 114 inverting inputs frequency reference signal Vfr magnitude of voltage and trigger clock signal clk and become high level.Sawtooth generator 115 and frequency comparator 114 are worked as previously mentioned again and again, thereby produce periodically variable sawtooth signal Vsw and clock signal clk.The timing waveform schematic diagram of clock signal clk, sawtooth signal Vsw, frequency reference signal Vfr and output voltage V o is referring to Fig. 3.
Preferably, described rectification unit 103 comprises the rectifier circuit that is comprised of four diodes.
Preferably, described feedback component comprises photoelectrical coupler.
Preferably, described clamper 113 comprises the second Zener diode, and has clamping voltage Vz
Preferably, described switch flyback switch circuit 100 also comprises: compensation condenser 117 is coupled between the lead-out terminal and inverting input of error amplifier 112.
When switch flyback switch circuit 100 normal operation, when clock signal clk output high level signal, then the switching drive signal of control and drive circuit 116 output is controlled power switch 105 conductings of former limit, input voltage vin via the former limit winding 104-1 of rectification unit 103, transformer and former limit power switch 105 to former limit with reference to ground.Former limit winding 104-1 begins stored energy.
When the load of switch flyback switch circuit 100 is relatively heavier, output voltage V o less, feedback voltage Vfb is less also.This moment, the difference of feedback voltage Vfb and reference voltage Vref was less, and then error amplification signal Vc is smaller.Namely under heavy condition, its magnitude of voltage of signal of frequency comparator 114 inverting inputs is less.Sawtooth signal Vsw can early reach its peak value, and makes clock signal clk be converted to earlier high level, has dwindled the cycle of clock signal clk, and also namely the switching frequency of this moment is higher.And along with the variation of load, error amplification signal Vc changes lentamente, so that switching frequency also changes slowly, as shown in Figure 3, the cycle of clock signal clk is T2 under heavy condition.
When the load of switch flyback switch circuit 100 was relatively light, output voltage V o was relatively large, and feedback voltage Vfb is also relatively large.This moment, the difference of feedback voltage Vfb and reference voltage Vref was larger, and then error amplification signal Vc is larger.Namely under light condition, its magnitude of voltage of signal of frequency comparator 114 inverting inputs is larger.Sawtooth signal Vsw reaches its peak value more lately, and makes clock signal clk be converted to high level more lately, has prolonged the cycle of clock signal clk, and also namely the switching frequency of this moment is lower.This moment, the difference of feedback voltage Vfb and reference voltage Vref was less, and then error amplification signal Vc is smaller.When error amplification signal Vc increased to the clamping voltage Vz of clamper 113, error amplification signal Vc was clamped at clamping voltage Vz place.This moment, switching frequency reached minimum value, thereby avoided switching frequency to enter the frequency that people's ear can be heard, caused noise.
As shown in Figure 3, the cycle of clock signal clk is T1 under light condition; When load became underloading from heavy duty, the cycle of clock signal clk was Ti.T2＜Ti＜T1 as seen from Figure 3, and in the process of load saltus step, switch periods increases gradually.Be the switching frequency of switch flyback switch circuit 100 under heavy condition greater than its frequency switching frequency under light condition, and its switching frequency reduces gradually in the process of load saltus step.
Therefore switch flyback switch circuit 100 is under light condition, and switching frequency is reduced, and has therefore reduced the loss under its light condition.Further, because the application of clamper, the minimum value of switch flyback switch circuit 100 switching frequencies is limited, and has avoided noise.
The above only is preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (6)
1. a switch flyback switch circuit is characterized in that, comprising:
Input port receives input voltage;
Output port provides output voltage;
Rectification unit is coupled to input port and receives input voltage, produces commutating voltage;
Transformer comprises former limit winding and secondary winding, and its limit, Central Plains winding and secondary winding respectively have the first terminal and the second terminal, and the first terminal of former limit winding is coupled to rectification unit and receives commutating voltage, and the second terminal of secondary winding connects secondary with reference to ground;
Former limit power switch is coupled in the second terminal of former limit winding and former limit with reference between the ground;
The secondary diode is coupled between the first terminal and output port of secondary winding;
Output capacitor is coupled in output port and secondary with reference between the ground;
Feedback component comprises secondary part and former limit part;
Secondary contact resistance, the first Zener diode and former limit contact resistance, wherein the secondary part of feedback component, secondary contact resistance and the first Zener diode are coupled in series in output port and secondary with reference between the ground, to produce feedback voltage in the former limit of feedback component part;
Error amplifier, have in-phase input end, inverting input and lead-out terminal, its inverting input receives reference voltage, its in-phase input end is coupled to former limit with reference to ground via former limit part and the former limit contact resistance of feedback component, to receive feedback voltage, its lead-out terminal produces error amplification signal;
Clamper is coupled in the lead-out terminal of error amplifier and with reference between the ground;
Frequency comparator has in-phase input end, inverting input and lead-out terminal, and the lead-out terminal that its inverting input is coupled to error amplifier receives error amplification signal, and its lead-out terminal provides clock signal;
Sawtooth generator is coupled to the lead-out terminal receive clock signal of frequency comparator, and provides the in-phase input end of sawtooth signal to frequency comparator based on clock signal;
Control and drive circuit are coupled to the lead-out terminal receive clock signal of frequency comparator, and based on clock signal, produce switching drive signal, to control the break-make of former limit power switch.
2. switch flyback switch circuit as claimed in claim 1 is characterized in that, wherein said clamper comprises the second Zener diode.
3. switch flyback switch circuit as claimed in claim 1 is characterized in that, also comprises:
Compensation condenser is coupled between the lead-out terminal and inverting input of error amplifier.
4. switch flyback switch circuit as claimed in claim 1 is characterized in that, described feedback component comprises photoelectrical coupler.
5. switch flyback switch circuit as claimed in claim 1 is characterized in that, described sawtooth generator comprises:
Charging current source, charging capacitor and reset switch, three's coupled in parallel at the in-phase input end of frequency comparator with reference to ground between, wherein
Described reset switch further comprises control terminal, and described control terminal is coupled to the lead-out terminal receive clock signal of frequency comparator.
6. switch flyback switch circuit as claimed in claim 1 is characterized in that, described rectification unit comprises the rectifier circuit that is comprised of four diodes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210568159 CN103051216A (en) | 2012-12-12 | 2012-12-12 | Flyback-type switch circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201210568159 CN103051216A (en) | 2012-12-12 | 2012-12-12 | Flyback-type switch circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN103051216A true CN103051216A (en) | 2013-04-17 |
Family
ID=48063747
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201210568159 Pending CN103051216A (en) | 2012-12-12 | 2012-12-12 | Flyback-type switch circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103051216A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105403302A (en) * | 2015-12-20 | 2016-03-16 | 青岛海特新蓝生物科技有限公司 | Small electronic scale |
| CN105471066A (en) * | 2015-12-25 | 2016-04-06 | 青岛海特新蓝生物科技有限公司 | Power generation base station |
| CN105491501A (en) * | 2015-12-30 | 2016-04-13 | 青岛玻莱莫斯新材料技术有限公司 | Portable electronic hearing aid |
| CN105547443A (en) * | 2015-12-25 | 2016-05-04 | 青岛北斗星云通信科技有限公司 | Portable electronic scale |
| CN105553075A (en) * | 2015-12-25 | 2016-05-04 | 青岛海特新蓝生物科技有限公司 | Power generation system |
| CN106059303A (en) * | 2015-04-10 | 2016-10-26 | 电力集成公司 | Load responsive jitter |
| CN110557003A (en) * | 2018-06-01 | 2019-12-10 | 宏碁股份有限公司 | Power supply conversion device |
-
2012
- 2012-12-12 CN CN 201210568159 patent/CN103051216A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106059303A (en) * | 2015-04-10 | 2016-10-26 | 电力集成公司 | Load responsive jitter |
| CN106059303B (en) * | 2015-04-10 | 2020-07-17 | 电力集成公司 | Load response jitter |
| CN105403302A (en) * | 2015-12-20 | 2016-03-16 | 青岛海特新蓝生物科技有限公司 | Small electronic scale |
| CN105471066A (en) * | 2015-12-25 | 2016-04-06 | 青岛海特新蓝生物科技有限公司 | Power generation base station |
| CN105547443A (en) * | 2015-12-25 | 2016-05-04 | 青岛北斗星云通信科技有限公司 | Portable electronic scale |
| CN105553075A (en) * | 2015-12-25 | 2016-05-04 | 青岛海特新蓝生物科技有限公司 | Power generation system |
| CN105491501A (en) * | 2015-12-30 | 2016-04-13 | 青岛玻莱莫斯新材料技术有限公司 | Portable electronic hearing aid |
| CN110557003A (en) * | 2018-06-01 | 2019-12-10 | 宏碁股份有限公司 | Power supply conversion device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103051184A (en) | Boosted circuit | |
| CN103051216A (en) | Flyback-type switch circuit | |
| CN101552560B (en) | Switch voltage stabilizing circuit and control method thereof | |
| CN100541995C (en) | Power factor correction circuit | |
| CN101156304B (en) | Switched mode power converter and method of operation thereof | |
| CN102347682B (en) | Current control system and method and signal generating circuit thereof | |
| CN103095129A (en) | Switch frequency hopping synchronous voltage reduction circuit | |
| CN104333216A (en) | Switching power supply controller and control method thereof | |
| CN103078512A (en) | Flyback switch circuit of switch frequency hopping | |
| CN103078496A (en) | Voltage reduction circuit | |
| CN110445376B (en) | Hysteretic control DC/DC converter device and operation method thereof | |
| US8901900B2 (en) | Buck power factor correction system | |
| CN102801341A (en) | Ac/dc converter with a pfc and a dc/dc converter | |
| CN103036428A (en) | Peak current gradient synchronous step-down circuit | |
| CN103036426A (en) | Peak current gradient synchronous booster circuit | |
| CN103051217A (en) | Flyback converter with gradually changing peak current | |
| CN103036427A (en) | Synchronous buck converter | |
| CN110995025A (en) | Switching power supply circuit | |
| CN111064369A (en) | Switching power supply circuit | |
| CN103051218A (en) | Flyback converter | |
| CN103036429A (en) | Synchronous boost converter | |
| US20210296984A1 (en) | Dc/dc power converter | |
| TW201117539A (en) | Voltage converter with high efficiency | |
| McDonald et al. | A novel LLC resonant controller with best-in-class transient performance and low standby power consumption | |
| CN2884685Y (en) | Microwave oven magnetron variable frequency power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| DD01 | Delivery of document by public notice |
Addressee: Lianmeng Electronic Instrument Co., Ltd. Document name: Notification that Application Deemed to be Withdrawn |
|
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20130417 |