CN104426372A - Switching type power conversion device and method for improving the conversion efficiency thereof - Google Patents
Switching type power conversion device and method for improving the conversion efficiency thereof Download PDFInfo
- Publication number
- CN104426372A CN104426372A CN201310380568.6A CN201310380568A CN104426372A CN 104426372 A CN104426372 A CN 104426372A CN 201310380568 A CN201310380568 A CN 201310380568A CN 104426372 A CN104426372 A CN 104426372A
- Authority
- CN
- China
- Prior art keywords
- load
- voltage
- power supply
- current
- drive
- 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
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
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
A switching type power conversion device and a method for improving the conversion efficiency thereof are provided. The power conversion device comprises a power converter and a driving circuit. The power converter comprises at least one power switch. The driving circuit outputs a driving voltage to a controlled end of the power converter to control the at least one power switch to be switched on or off. The driving circuit acquires a load current and a load voltage, judges whether a load is in the state of light load or heavy load according to the load current and the load voltage, and correspondingly decreases or increases the amplitude of the driving voltage according to the light-load or heavy-load state of the load. The load current and the load voltage are detected in real time and the load current is converted so as to dynamically adjust the amplitude of the driving voltage. Therefore, loss to the power switch can be greatly reduced, and the overall conversion efficiency can be effectively improved.
Description
Technical field
The present invention relates to a kind of power supply change-over device, particularly relate to a kind of switched-mode power supply conversion equipment and improve the method for its conversion efficiency.
Background technology
Switched-mode power supply is as the term suggests be the conversion reaching voltage swing through the mode switched.Existing switched-mode power supply uses metal-oxide half field effect transistor (MOSFET) as power switch usually, its mode switched is by its power switch of high-frequency switching, and in conjunction with the inductance of its circuit topology and coupling and electric capacity, input Power Level can be converted to different output end power grades, as usual is seen boosting type converter (Boost converter), or buck converter (Buck converter).
But, because MOS switch is imperfect element, not only can produce into switch cost (Switching loss) in the process switched, it is in the process of conducting, also can produce conduction losses (Conduction loss), and these two kinds are lost the conversion efficiency all affecting electronic power converter.As shown in Figure 1, in saturation region, the grid voltage V of MOS switch
gSwith On current I
dSproportional.Have experiment to prove, such as, being manufactured by Infineon shown in Fig. 2, model is the conducting resistance R of the MOSFET of BSC060N10NS3
dS (on)with On current I
dgraph of a relation show, the conducting internal resistance R of MOS switch
dS (on)with grid voltage V
gSinversely.And traditional drive voltage generating circuit, along with the change of load, only can change load current, i.e. On current, but can't change the size of the driving voltage of the grid of MOS element, its switch cost can almost be considered as identical.Therefore, as shown in Figure 3, in underloading, namely load voltage comparatively large or load current is less time, the proportion that its switch cost accounts for total losses is higher, but in heavy duty, namely load voltage less or load current is larger time, the proportion that its conduction losses accounts for total losses is then higher.
Therefore, how to reduce above-mentioned two kinds of losses to improve conversion efficiency, become a technical problem urgently to be resolved hurrily.
Summary of the invention
In view of this, be necessary to provide a kind of switched-mode power supply conversion equipment improving conversion efficiency.
A kind of switched-mode power supply conversion equipment, be connected between a power supply and a load, it is load supplying that the supply voltage for providing this power supply changes the suitable voltage of rear output.This switched-mode power supply conversion equipment comprises a voltage input end, a voltage output end, a power supply changeover device, a current detector and one drive circuit.This voltage input end is connected with this power supply, and this voltage output end is connected with this load.This power supply changeover device is electrically connected between this voltage input end and this voltage output end, this power supply changeover device includes at least one power switch, this power switch is electrically connected between this voltage input end and voltage output end, this power supply changeover device also has a controlled end, the signal that this at least one power switch receives according to this controlled end and conducting or cut-off.This current detector is connected between this power supply changeover device and this voltage output end, and this current detector is used for the load current of this load of detecting real-time.This drive circuit is connected with the controlled end of this power supply changeover device, for exporting the controlled end of a driving voltage to this power supply changeover device.This drive circuit is also connected with this current detector and this voltage output end respectively, for receiving the load current the load voltage of this voltage output end of detecting real-time that this current detector detects, then judge that the state of this load is underloading or heavy duty according to this load current received and the load voltage that detects, and according to the corresponding reduction of light heavy condition of this load or the amplitude increasing this driving voltage.
There is a need to provide a kind of method improving the conversion efficiency of switched-mode power supply conversion equipment.
Improve a method for the conversion efficiency of switched-mode power supply conversion equipment, this power supply change-over device comprises a power supply changeover device and one drive circuit, and this power supply changeover device comprises at least one power switch.The method comprises the following steps:
This drive circuit exports the controlled end of a driving voltage to this power supply changeover device to control this power switch conducting or cut-off;
This drive circuit obtains a load current and a load voltage;
According to this load current and load voltage, this drive circuit judges that the state of a load is underloading or heavy duty; And
This drive circuit is according to the corresponding reduction of light heavy condition of this load or the amplitude increasing this driving voltage.
The present invention by the electric current on detecting real-time main circuit, and converts to detecting current, with the size of dynamic conditioning driving voltage, thus significantly can be reduced in the loss on switch, improves overall transformation efficiency.
Accompanying drawing explanation
Fig. 1 is the output characteristic schematic diagram of MOS switch in prior art.
Fig. 2 is the conducting resistance of MOS switch and the curve chart of On current in prior art.
Fig. 3 is the switch cost of MOS switch in prior art and the schematic diagram of conduction losses and load capacity.
The functional block diagram of a kind of switched-mode power supply conversion equipment in Fig. 4 the present invention.
Fig. 5 is a kind of flow chart improving the method for the conversion efficiency of switched-mode power supply conversion equipment of the present invention.
Main element symbol description
| Power supply change-over device | 100 |
| Voltage input end | 101 |
| Voltage output end | 102 |
| Power supply changeover device | 20 |
| Power switch | 21 |
| Controlled end | 211 |
| Current detector | 30 |
| Drive circuit | 40 |
| PDM keyer | 41 |
| Drive voltage generating circuit | 42 |
| Power supply | 50 |
| Load | 60 |
| Step | S501-S504 |
Following embodiment will further illustrate the present invention in conjunction with above-mentioned accompanying drawing.
Embodiment
Refer to Fig. 4, the invention provides a kind of switched-mode power supply conversion equipment 100 improving conversion efficiency, comprise power supply changeover device 20, current detector 30, one drive circuit 40, voltage input end 101 and a voltage output end 102.Wherein, this switched-mode power supply conversion equipment 100 is connected between a power supply 50 and a load 60, and the supply voltage for providing this power supply 50 is changed the suitable voltage of rear output and powered into load 60.This voltage input end 101 is for being connected with power supply 50, and this voltage output end 102 is for being connected with load 60.
Wherein, this power supply changeover device 20 is electrically connected between this voltage input end 101 and this voltage output end 102.This power supply changeover device 20 includes at least one power switch 21, and this power switch 21 is electrically connected between this voltage input end 101 and voltage output end 102, for conducting or the connection between cut-off power supply 50 and load 60.This power supply changeover device 20 also has a controlled end 211, conducting or the cut-off for the signal received according to this controlled end 211 of this at least one power switch 21.Make when power switch 21 conducting this power supply 50 be connected to this load 60, and cut off the connection of this power supply 50 and this load 60 when power switch 21 ends.
This drive circuit 40 is connected with the controlled end 211 of this power supply changeover device 20, controls this power switch 21 conducting or cut-off for exporting a driving voltage to the controlled end 211 of this power supply changeover device 20.
This current detector 30 is connected between this power supply changeover device 20 and voltage output end 102, for the load current of detecting real-time load 60.
This drive circuit 40 is also connected with this current detector 30 and this voltage output end 102 respectively, for receiving the load current the load voltage of detecting real-time voltage output end 102 that this current detector 30 detects, then judge that the state of this load 60 is underloading or heavy duty according to this load current received and the load voltage that detects, and change the conducting degree of this power switch 21 according to the corresponding reduction of light heavy condition of this load 60 or the amplitude increasing this driving voltage, thus change conducting internal resistance and the On current of power switch 21.
In the present embodiment, if this load voltage higher than a predetermined reference voltage or this load current lower than a preset reference electric current time, then drive circuit 40 judges that load 60 is as underloading, and this drive circuit 40 reduces the driving voltage exporting the controlled end 211 of this power supply changeover device 20 to.Thus the conducting degree of this power switch 21 reduces and electric current reduces, and make the switch cost of power switch 21 reduce, that is, loss when making power switch 21 be switched to cut-off state from conducting state or be switched to conducting state from cut-off state reduces.If this load voltage lower than this predetermined reference voltage or this load current higher than this preset reference electric current time, then judge that load 60 is as heavy duty, this drive circuit 40 increases the driving voltage exporting the controlled end 211 of this power supply changeover device 20 to.Thus the conducting degree of this power switch 21 increases, and conducting internal resistance reduces, and makes the conduction losses of power switch 21 reduce, that is, the loss caused when making power switch 21 be in conducting reduces.
In the present embodiment, those power switchs 21 are high level actuating switch, concrete, and those power switchs 21 are nmos switch or NPN switch.Obviously, in other embodiments, those power switchs 21 can adopt low level actuating switch, when driving voltage reduces, the conducting degree of those power switchs 21 will be made to increase, thus the voltage that voltage output end 102 exports increases.
Due to when underloading the switch cost of power switch 21 to account for the proportion of total losses higher, and when heavy duty the conduction losses of power switch 21 to account for the proportion of total losses higher.Adopt switched-mode power supply conversion equipment 100 of the present invention, the switch cost of power switch 21 is reduced when underloading, and the conduction losses of power switch 21 is reduced when heavy duty, thus significantly can be reduced in the total losses on this power switch 21, and effectively improve overall transformation efficiency.
Concrete, this drive circuit 40 comprises PDM keyer 41 and a drive voltage generating circuit 42.Wherein, this PDM keyer 41 is connected with this current detector 30, this voltage output end 102 and this drive voltage generating circuit 42 respectively.This PDM keyer 41 is for the load voltage of the load current that receives this current detector 30 and detect and detecting real-time voltage output end 102, the load current detected according to this and load voltage judge that the state of this load 60 is underloading or heavy duty, and carry the corresponding PWM (Pulse Width Modulation, pulse-width modulation) of State-output one according to the weight of this load 60 and control signal to this drive voltage generating circuit 42.Wherein, if the underloading of being judged as, this PDM keyer 41 exports a underloading pwm control signal; If be judged as heavy duty, this PDM keyer 41 exports a heavily loaded pwm control signal.
This drive voltage generating circuit 42 is also connected with the controlled end 211 of this current detector 30 and this power supply changeover device 20.The pwm control signal that this drive voltage generating circuit 42 exports for the load current that receives this current detector 30 and detect and this PDM keyer 41, and according to a predetermined operation rule and this pwm control signal, this load current is converted, thus export the controlled end 211 of a corresponding driving voltage to this power supply changeover device 20.In the present embodiment, this drive voltage generating circuit 42 reduces the amplitude of the driving voltage of this output according to this underloading pwm control signal, or increases the amplitude of the driving voltage of this output according to this heavily loaded pwm control signal.
Concrete, this predetermined operation rule is: first this load current is carried out a predetermined multiplying power conversion by this drive voltage generating circuit 42, after adding the minimum conducting voltage of this power switch 21, is multiplied with this pwm control signal, thus obtains this driving voltage.In the present embodiment, this driving voltage is PWM drive voltage signal.
In the present invention, do not change the duty ratio of this driving voltage, and only change the amplitude of this driving voltage, thus realize the adjustment of the loss on this power switch 21.
Refer to Fig. 5, a kind of method improving the conversion efficiency of switched-mode power supply conversion equipment is provided.
Step S501, first, this drive circuit 40 exports a driving voltage and controls this power switch 21 conducting or cut-off.
Step S502, this drive circuit 40 obtains load current and load voltage.
Concrete, this current detector 30 sensing load current also delivers to this PDM keyer 41 and this drive voltage generating circuit 42, and this PDM keyer 41 receives this load current, detects load voltage simultaneously.
Step S503, according to this load current and load voltage, this drive circuit 40 judges that the state of this load 60 is underloading or heavy duty.
Concrete, according to the load current of this reception and the load voltage that detects, this PDM keyer 41 judges that the state of this load 60 is underloading or heavy duty.
Step S504, this drive circuit 40 is according to the corresponding reduction of light heavy condition of this load 60 or the amplitude increasing this driving voltage.
Concrete, if the underloading of being judged as, then this PDM keyer 41 exports a underloading pwm control signal, and delivers to this drive voltage generating circuit 42.This drive voltage generating circuit 42 reduces the amplitude of the driving voltage of this output according to this underloading pwm control signal.
If be judged as heavy duty, then this PDM keyer 41 exports a heavily loaded pwm control signal, and delivers to this drive voltage generating circuit 42.This drive voltage generating circuit 42 increases the amplitude of the driving voltage of this output according to this heavily loaded pwm control signal.
The present invention by the load current on detecting real-time main circuit and load voltage, and converts to load current, with the size of dynamic conditioning driving voltage, thus significantly can be reduced in the loss on power switch, and effectively improves overall transformation efficiency.
Those skilled in the art will be appreciated that; above execution mode is only used to the present invention is described; and be not used as limitation of the invention; as long as within spirit of the present invention, the appropriate change do above execution mode and change all drop within the scope of protection of present invention.
Claims (10)
1. a switched-mode power supply conversion equipment, be connected between a power supply and a load, it is load supplying that the supply voltage for providing this power supply changes the suitable voltage of rear output, it is characterized in that, this switched-mode power supply conversion equipment comprises:
One voltage input end is connected with this power supply;
One voltage output end is connected with this load;
One power supply changeover device is electrically connected between this voltage input end and this voltage output end, this power supply changeover device includes at least one power switch, this power switch is electrically connected between this voltage input end and voltage output end, this power supply changeover device also has a controlled end, the signal that this at least one power switch receives according to this controlled end and conducting or cut-off;
One current detector is connected between this power supply changeover device and this voltage output end, and this current detector is used for the load current of this load of detecting real-time; And
One drive circuit is connected with the controlled end of this power supply changeover device, for exporting the controlled end of a driving voltage to this power supply changeover device; This drive circuit is also connected with this current detector and this voltage output end respectively, for receiving the load current the load voltage of this voltage output end of detecting real-time that this current detector detects, then judge that the state of this load is underloading or heavy duty according to this load current received and the load voltage that detects, and according to the corresponding reduction of light heavy condition of this load or the amplitude increasing this driving voltage.
2. power supply change-over device as claimed in claim 1, it is characterized in that, this drive circuit comprises a PDM keyer and a drive voltage generating circuit, this PDM keyer respectively with this current detector, this voltage output end and this drive voltage generating circuit connect, this PDM keyer is for the load voltage of the load current that receives this current detector and detect and this voltage output end of detecting real-time, the load current detected according to this and load voltage judge that the state of this load is underloading or heavy duty, and carry the corresponding pwm control signal of State-output one to this drive voltage generating circuit according to the weight of this load.
3. power supply change-over device as claimed in claim 2, it is characterized in that, if this PDM keyer judges that the state of this load is underloading, this PDM keyer exports a underloading pwm control signal; If this PDM keyer judges that the state of this load is as heavy duty, this PDM keyer exports a heavily loaded pwm control signal.
4. power supply change-over device as claimed in claim 3, it is characterized in that, this drive voltage generating circuit is also connected with the controlled end of this current detector and this power supply changeover device, the pwm control signal that this drive voltage generating circuit exports for the load current that receives this current detector and detect and this PDM keyer, and according to a predetermined operation rule and this pwm control signal, this load current is converted, thus export the controlled end of a corresponding driving voltage to this power supply changeover device.
5. power supply change-over device as claimed in claim 4, it is characterized in that, this drive voltage generating circuit reduces the amplitude of the driving voltage of this output according to this underloading pwm control signal, or increases the amplitude of the driving voltage of this output according to this heavily loaded pwm control signal.
6. power supply change-over device as claimed in claim 5, it is characterized in that, first this load current is carried out a predetermined multiplying power conversion by this drive voltage generating circuit, after adding the minimum conducting voltage of this power switch, be multiplied with this pwm control signal, thus obtain this driving voltage.
7. power supply change-over device as claimed in claim 1, is characterized in that, this power switch adopts MOS switch.
8. improve a method for the conversion efficiency of switched-mode power supply conversion equipment, this power supply change-over device comprises a power supply changeover device and one drive circuit, and this power supply changeover device comprises at least one power switch, it is characterized in that, the method comprises the following steps:
This drive circuit exports the controlled end of a driving voltage to this power supply changeover device to control this power switch conducting or cut-off;
This drive circuit obtains a load current and a load voltage;
According to this load current and load voltage, this drive circuit judges that the state of a load is underloading or heavy duty; And
This drive circuit is according to the corresponding reduction of light heavy condition of this load or the amplitude increasing this driving voltage.
9. method as claimed in claim 8, it is characterized in that, this drive circuit comprises a current detector, a PDM keyer and a drive voltage generating circuit, this current detector is used for sensing load current and delivers to this PDM keyer and this drive voltage generating circuit, this PDM keyer is for receiving this load current, detect load voltage simultaneously, and judge that the state of this load is underloading or heavy duty according to the load current of this reception and the load voltage that detects.
10. method as claimed in claim 9, is characterized in that, the step that this drive circuit reduces or improve this driving voltage according to the light heavy condition of this load current and this load comprises:
If judge, this load is underloading, and this PDM keyer exports a underloading pwm control signal, and delivers to this drive voltage generating circuit, and this drive voltage generating circuit reduces the amplitude of the driving voltage of this output according to this underloading pwm control signal;
If judge, this load is as heavy duty, and this PDM keyer exports a heavily loaded pwm control signal, and delivers to this drive voltage generating circuit, and this drive voltage generating circuit increases the amplitude of the driving voltage of this output according to this heavily loaded pwm control signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310380568.6A CN104426372A (en) | 2013-08-28 | 2013-08-28 | Switching type power conversion device and method for improving the conversion efficiency thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310380568.6A CN104426372A (en) | 2013-08-28 | 2013-08-28 | Switching type power conversion device and method for improving the conversion efficiency thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104426372A true CN104426372A (en) | 2015-03-18 |
Family
ID=52974544
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310380568.6A Pending CN104426372A (en) | 2013-08-28 | 2013-08-28 | Switching type power conversion device and method for improving the conversion efficiency thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104426372A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109842295A (en) * | 2017-11-27 | 2019-06-04 | 安电株式会社 | Load driving circuits |
| CN110299840A (en) * | 2019-07-05 | 2019-10-01 | 西安易朴通讯技术有限公司 | Power circuit |
| CN111193383A (en) * | 2020-01-22 | 2020-05-22 | 维沃移动通信有限公司 | Power control circuit and electronic device |
| CN111525799A (en) * | 2020-05-29 | 2020-08-11 | 联想(北京)有限公司 | Power supply circuit, electronic equipment and method for improving power supply conversion efficiency |
| CN112953262A (en) * | 2019-12-10 | 2021-06-11 | 产晶积体电路股份有限公司 | Dynamic regulating power controller |
-
2013
- 2013-08-28 CN CN201310380568.6A patent/CN104426372A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109842295A (en) * | 2017-11-27 | 2019-06-04 | 安电株式会社 | Load driving circuits |
| CN109842295B (en) * | 2017-11-27 | 2021-06-25 | 株式会社电装电子 | Load driving circuit |
| CN110299840A (en) * | 2019-07-05 | 2019-10-01 | 西安易朴通讯技术有限公司 | Power circuit |
| CN112953262A (en) * | 2019-12-10 | 2021-06-11 | 产晶积体电路股份有限公司 | Dynamic regulating power controller |
| CN112953262B (en) * | 2019-12-10 | 2022-06-28 | 产晶积体电路股份有限公司 | Dynamic regulating power supply controller |
| CN111193383A (en) * | 2020-01-22 | 2020-05-22 | 维沃移动通信有限公司 | Power control circuit and electronic device |
| CN111525799A (en) * | 2020-05-29 | 2020-08-11 | 联想(北京)有限公司 | Power supply circuit, electronic equipment and method for improving power supply conversion efficiency |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101552560B (en) | Switch voltage stabilizing circuit and control method thereof | |
| CN103023299B (en) | Control method of power factor conversion device | |
| CN100592237C (en) | Intelligent switch power source power detection and control device | |
| CN104426372A (en) | Switching type power conversion device and method for improving the conversion efficiency thereof | |
| CN107359792A (en) | A kind of power optimization device and its control method and control device | |
| CN203368304U (en) | Novel buck drive circuit | |
| CN101562395A (en) | Voltage modulation circuit capable of increasing light load efficiency | |
| CN103036427A (en) | Synchronous buck converter | |
| CN203104280U (en) | Interleaving PFC circuit and air conditioner | |
| CN103036429A (en) | Synchronous boost converter | |
| CN104767379A (en) | Buck direct-current converter | |
| CN104601015B (en) | Inverse-excitation type AC DC converters | |
| CN102684492B (en) | High power factor converter | |
| CN204886731U (en) | Switching power supply controller and contain switching power supply of this switching power supply controller | |
| CN109921615A (en) | Instantaneous negative pressure switch-off power metal-oxide-semiconductor driving circuit and driving method | |
| CN102474184B (en) | For controlling the Method and circuits of the boost converter in circuit of power factor correction | |
| CN104393755B (en) | High-efficiency booster circuit | |
| CN203574903U (en) | High-power factor constant current control circuit and LED lighting equipment | |
| CN203660911U (en) | Flyback AC-DC converter | |
| CN201243392Y (en) | LED drive circuit | |
| CN202797867U (en) | Short circuit protection circuit and power supply circuit provided with the same | |
| CN102255513B (en) | Bridge type synchronous rectification circuit | |
| CN105591542B (en) | A kind of Buck converters and its reflux control circuit | |
| CN103889121B (en) | A kind of ripple current suppresses circuit | |
| CN103187870A (en) | Voltage drop converting circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20150318 |
|
| WD01 | Invention patent application deemed withdrawn after publication |