CN106787750B - Valley bottom opening control circuit under constant current state - Google Patents
Valley bottom opening control circuit under constant current state Download PDFInfo
- Publication number
- CN106787750B CN106787750B CN201611175086.7A CN201611175086A CN106787750B CN 106787750 B CN106787750 B CN 106787750B CN 201611175086 A CN201611175086 A CN 201611175086A CN 106787750 B CN106787750 B CN 106787750B
- Authority
- CN
- China
- Prior art keywords
- control circuit
- circuit
- valley bottom
- switch control
- detection 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.)
- Active
Links
Images
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
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Abstract
The invention relates to the technical field of switch control, in particular to a valley bottom switching-on control circuit under a constant current state, which comprises: the device comprises a sampling circuit, a valley bottom detection circuit, a secondary side degaussing time detection circuit, a primary side switch starting time detection circuit, a CV control circuit, an arithmetic unit, a first switch control circuit, a reference voltage circuit, a second switch control circuit, an integrator, a comparator, a third switch control circuit, a sampling resistor, an MOS (metal oxide semiconductor) tube, a primary side inductor, a secondary side inductor, a diode and a first capacitor; the valley bottom switching-on control circuit in the constant current state enables an AC-DC switching power supply to be switched on when the system works at the constant current and always works at the first valley bottom, and the power MOS tube is switched on at the valley bottom when the system works at the constant voltage, so that the radiation of the system is greatly reduced, and compared with a common valley bottom switching-on circuit, the system efficiency can be improved by 2 percent.
Description
Technical Field
The invention relates to the technical field of switch control, in particular to a valley bottom switching-on control circuit in a constant current state.
Background
In general, in an AC-DC switching power supply system, in order to improve efficiency and reduce radiation interference of the system, a switch valley conduction mode is adopted, but the switching power supply has two working modes, one is a constant voltage working mode, namely, a constant output voltage, and the other is a constant current working mode, wherein the output voltage at this time is lower than the voltage at the time of constant voltage output; the existing switching power supply is switched on at the bottom of a constant voltage valley, and is not switched on at the bottom of a first valley, while the constant-current working mode adopts a mode of fixed proportion of degaussing time and period, and generally adopts the following steps of 1: the method has the advantages that 1, valley bottom opening is completely avoided, if a constant current working mode is adopted to realize valley bottom opening, breakthrough innovation is needed on a constant current structure, the constant current valley bottom opening is realized by the existing structure, but the circuit structure is too complex, the chip cost is too high, and the overall performance-price ratio is lower.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: a valley bottom turn-on control circuit under a constant current state is provided.
In order to solve the technical problems, the invention adopts the technical scheme that:
a valley bottom opening control circuit under a constant current state comprises: the device comprises a sampling circuit, a valley bottom detection circuit, a secondary side degaussing time detection circuit, a primary side switch starting time detection circuit, a CV control circuit, an arithmetic unit, a first switch control circuit, a reference voltage circuit, a second switch control circuit, an integrator, a comparator, a third switch control circuit, a sampling resistor, an MOS (metal oxide semiconductor) tube, a primary side inductor, a secondary side inductor, a diode and a first capacitor;
the valley bottom detection circuit, the secondary side degaussing time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively connected with the sampling circuit;
the valley bottom detection circuit is connected with the third switch control circuit;
the secondary side degaussing time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively connected with the arithmetic unit;
the first switch control circuit and the second switch control circuit are respectively connected with the arithmetic unit;
the reference voltage circuit is connected with the first switch control circuit; the second switch control circuit is grounded;
the comparator comprises a positive input end, a negative input end and an output end;
the first switch control circuit and the second switch control circuit are respectively connected with the input end of the integrator;
the output end of the integrator is connected with the positive input end of the comparator;
the output end of the comparator is connected with the MOS tube through a third switch control circuit;
the MOS tube is grounded through a sampling resistor; the MOS tube is connected with the negative electrode input end of the comparator; the MOS tube is connected with the primary side inductor;
one end of the secondary inductor is connected with the anode of the diode; the cathode of the diode is connected with one end of the first capacitor; the other end of the first capacitor is connected with the other end of the secondary inductor.
The invention has the beneficial effects that: the valley bottom switching-on control circuit in the constant current state provided by the invention enables the AC-DC switching power supply to be switched on when the system works at the constant current and always works at the first valley bottom, and the power tube is always switched on at the valley bottom when the system works at the constant voltage, so that the radiation of the system is greatly reduced.
Because the constant current adopts the first valley bottom to conduct, the secondary side degaussing duty ratio is more than the previous 1:1, when working at high line voltage, the secondary side degaussing duty ratio can reach 10:1, under the condition of the same output current, the peak current can be reduced by 10 times, so that the consumption on a secondary freewheeling diode and the consumption of a parasitic resistor are greatly reduced, in addition, the primary current is also reduced to one tenth of the original current, the consumption on a sampling resistor is changed to one tenth of the original current, the system loss is reduced to more than 0.3W comprehensively, and compared with a common valley bottom switching-on circuit, the system efficiency can be improved by 2 percent.
The valley bottom switching-on control circuit in the constant current state provided by the invention adopts a logic architecture that the demagnetizing time and the magnetism gathering time determine the peak current of the primary side, realizes that the peak current is variable, the demagnetizing duty ratio is variable, the first valley bottom is switched on, the constant current mode works in the BCM, the system efficiency is greatly improved, and the first valley bottom switching-on in the constant current mode is realized on the basis of the original chip cost.
Drawings
Fig. 1 is a circuit connection diagram of a valley bottom turn-on control circuit in a constant current state according to the present invention.
Detailed Description
In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.
The most key concept of the invention is as follows: when the system works at a constant current, the AC-DC switching power supply is switched on when working at the first valley all the time, so that the radiation of the system is greatly reduced, and the system efficiency is improved.
Referring to fig. 1, the present invention provides a valley bottom turn-on control circuit under a constant current state, including: the device comprises a sampling circuit, a valley bottom detection circuit, a secondary side degaussing time detection circuit, a primary side switch starting time detection circuit, a CV control circuit, an arithmetic unit, a first switch control circuit, a reference voltage circuit, a second switch control circuit, an integrator, a comparator, a third switch control circuit, a sampling resistor, an MOS (metal oxide semiconductor) tube, a primary side inductor, a secondary side inductor, a diode and a first capacitor;
the valley bottom detection circuit, the secondary side demagnetization time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively connected with the sampling circuit;
the valley bottom detection circuit is connected with the third switch control circuit;
the secondary side degaussing time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively connected with the arithmetic unit;
the first switch control circuit and the second switch control circuit are respectively connected with the arithmetic unit;
the reference voltage circuit is connected with the first switch control circuit; the second switch control circuit is grounded;
the comparator comprises a positive input end, a negative input end and an output end;
the first switch control circuit and the second switch control circuit are respectively connected with the input end of the integrator;
the output end of the integrator is connected with the positive input end of the comparator;
the output end of the comparator is connected with the MOS tube through a third switch control circuit;
the MOS tube is grounded through a sampling resistor; the MOS tube is connected with the negative electrode input end of the comparator; the MOS tube is connected with the primary side inductor;
one end of the secondary inductor is connected with the anode of the diode; the cathode of the diode is connected with one end of the first capacitor; the other end of the first capacitor is connected with the other end of the secondary inductor.
From the above description, the beneficial effects of the present invention are:
the valley bottom switching-on control circuit in the constant current state provided by the invention enables the AC-DC switching power supply to be switched on when the system works at the constant current and always works at the first valley bottom, and the power tube is always switched on at the valley bottom when the system works at the constant voltage, so that the radiation of the system is greatly reduced.
Because the constant current adopts the first valley bottom to conduct, the secondary side degaussing duty ratio is more than the previous 1:1, when working at high line voltage, the secondary side degaussing duty ratio can reach 10:1, under the same output current condition, the peak current can be reduced by 10 times, so that the consumption on a secondary freewheeling diode and the consumption of a parasitic resistor are greatly reduced, in addition, the primary current is also reduced to one tenth of the original current, the consumption on a sampling resistor is changed to one tenth of the original current, the system loss is reduced to more than 0.3W comprehensively, and compared with a common valley bottom open circuit, the system efficiency can be improved by 2 percent.
The valley bottom switching-on control circuit in the constant current state provided by the invention adopts a logic architecture that the demagnetizing time and the magnetism gathering time determine the peak current of the primary side, realizes that the peak current is variable, the demagnetizing duty ratio is variable, the first valley bottom is switched on, the constant current mode works in the BCM, the system efficiency is greatly improved, and the first valley bottom switching-on in the constant current mode is realized on the basis of the original chip cost.
Further, the sampling circuit comprises an auxiliary winding, a first resistor and a second resistor;
one end of the auxiliary winding is respectively connected with the valley bottom detection circuit, the secondary side degaussing time detection circuit, the primary side switch on time detection circuit and the CV control circuit through a first resistor;
the other end of the auxiliary winding is respectively connected with the valley bottom detection circuit, the secondary side degaussing time detection circuit, the primary side switch turn-on time detection circuit and the CV control circuit through a second resistor;
the other end of the auxiliary winding is grounded.
Further, the MOS tube comprises a grid electrode, a source electrode and a drain electrode;
the grid electrode of the MOS tube is connected with the third switch control circuit;
the source electrode of the MOS tube is connected with the negative electrode input end of the comparator;
and the drain electrode of the MOS tube is connected with the primary side inductor.
Further, the integrator comprises a third resistor and a second capacitor;
the first switch control circuit and the second switch control circuit are respectively connected with one end of the third resistor; the other end of the third resistor is grounded through a first capacitor; the other end of the third resistor is connected with the positive input end of the comparator.
Referring to fig. 1, a first embodiment of the present invention is:
the invention provides a valley bottom opening control circuit under a constant current state, which comprises: the device comprises a sampling circuit, a valley bottom detection circuit, a secondary side degaussing time detection circuit, a primary side switch opening time detection circuit, a CV control circuit, an arithmetic unit, a first switch control circuit, a reference voltage circuit, a second switch control circuit, an integrator, a comparator CMP, a third switch control circuit, a sampling resistor Rcs, an MOS (metal oxide semiconductor) tube N1, a primary side inductor Lp, a secondary side inductor Ls, a DIODE DIODE and a first capacitor Cout;
the valley bottom detection circuit, the secondary side demagnetization time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively and electrically connected with the sampling circuit; the secondary side demagnetization time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively connected with the arithmetic unit;
the bottom detection module is used for calculating the voltage signal detected by the sampling circuit to find a bottom signal, namely a first bottom signal or an Nth bottom signal after resonance starts after the secondary side demagnetization finishes; the CV control circuit is used for generating a constant voltage control signal and controlling the arithmetic unit; the secondary side demagnetization time detection circuit is used for accurately detecting the demagnetization time of the secondary side inductor Ls and feeding back a detection result to the arithmetic unit; the primary side switch opening time detection circuit is used for accurately detecting the conduction time of the primary side inductor Lp and feeding back a detection result to the arithmetic unit;
the sampling circuit specifically comprises an auxiliary winding La, a first resistor R1 and a second resistor R2; one end of the auxiliary winding La is respectively connected with the valley bottom detection circuit, the secondary side degaussing time detection circuit, the primary side switch on time detection circuit and the CV control circuit through a first resistor R1; the other end of the auxiliary winding La is respectively connected with the valley bottom detection circuit, the secondary side demagnetization time detection circuit, the primary side switch opening time detection circuit and the CV control circuit through a second resistor R2; the other end of the auxiliary winding La is grounded.
Description of the principle: the voltage and current change of the primary side inductor (winding) Lp is accurately detected through the auxiliary winding La, the voltage and current change of the primary side inductor (winding) Lp is mapped to the auxiliary winding La, and the voltage and current change of the auxiliary winding La is transmitted to the inside of the control circuit through the first resistor R1 and the second resistor R2.
The valley bottom detection circuit is electrically connected with the input end of the third switch control circuit;
the output end of the first switch control circuit and the output end of the second switch control circuit are respectively and electrically connected with the arithmetic unit; the arithmetic unit generates control signals for controlling the first switch control circuit and the second switch control circuit after operation according to the time detected by the secondary side degaussing time detection circuit and the primary side switch starting time detection circuit.
The reference voltage circuit is electrically connected with the input end of the first switch control circuit; the reference current circuit generates an internal voltage reference VREF for the first switch control circuit. The second switch control circuit is grounded;
the comparator CMP comprises a positive input end, a negative input end and an output end;
the output end of the first switch control circuit and the output end of the second switch control circuit are respectively connected with the input end of the integrator; the output end of the integrator is electrically connected with the positive input end of the comparator CMP;
the output end of the comparator CMP is electrically connected with the grid electrode of the MOS tube through a third switch control circuit;
the integrator comprises a third resistor R and a second capacitor C; the output end of the first switch control circuit and the output end of the second switch control circuit are respectively connected with one end of the third resistor R; the other end of the third resistor R is grounded through a first capacitor C; the other end of the third resistor R is connected to the positive input terminal of the comparator CMP.
The first switch control circuit is used for controlling the reference voltage circuit to be connected to the third resistor R, the second switch control circuit is used for controlling the third resistor R to be grounded, the rest non-first switch control circuits and the rest non-second switch control circuits are not in the on-time, and the input end of the integrator is in the high-impedance state. An integrator is formed by the third resistor R and the first capacitor C, low-pass filtering is carried out on a signal at the input end of the integrator, and a filtered direct-current component is used as a comparator CMP to provide reference voltage.
The MOS tube N1 is grounded through a sampling resistor Rcs; the MOS tube N1 is connected with the negative electrode input end of the comparator CMP; the MOS tube N1 is connected with the primary side inductor Lp; the method specifically comprises the following steps: the MOS transistor N1 comprises a grid electrode, a source electrode and a drain electrode; the grid electrode of the MOS tube N1 is connected with a third switch control circuit; the source electrode of the MOS tube N1 is connected with the negative electrode input end of the comparator CMP; and the drain electrode of the MOS tube N1 is connected with the primary side inductor Lp. The sampling resistor Rcs is used for sampling the current of the primary inductor Lp, and when the current of the primary inductor Lp reaches the filtered direct-current component level, the comparator CMP inverts and transmits an inverted signal to the third switch control circuit; the third switch control circuit generates control signals of the primary side switch, specifically comprising opening and closing.
One end of the secondary inductor Ls is connected with the anode of the DIODE DIODE; the cathode of the DIODE is connected with one end of the first capacitor Cout; the other end of the first capacitor Cout is connected with the other end of the secondary inductor Ls.
In a constant-current working mode, the valley bottom detection module detects a first valley bottom, the power MOS tube N1 is opened, after the power MOS tube N1 is conducted, the current of the primary side inductor Lp is linearly increased at the moment, the voltage flowing through the sampling resistor Rcs is linearly increased along with the current, the sampling resistor Rcs samples the current of the primary side inductor Lp, when the current of the primary side inductor Lp reaches the filtered direct-current component level, the comparator CMP reverses, and a reverse signal is transmitted to the third switch control circuit;
after the power MOS tube N1 is turned off, the secondary side inductor Ls starts to discharge along with the power MOS tube N1 to supply power to an output load of a system, at the moment, the size of the output voltage of the system can be detected through the auxiliary winding La, the first resistor R1 and the second resistor R2, and the variable quantity of the voltage and the current of the auxiliary winding La is transmitted to the valley bottom detection circuit, the secondary side degaussing time detection circuit, the primary side switch opening time detection circuit and the CV control circuit through the first resistor R1 and the second resistor R2; the demagnetization time of the secondary side inductor Ls is accurately detected through the secondary side demagnetization time detection circuit, the detection result is fed back to the arithmetic unit, and the secondary side demagnetization time detection circuit always outputs a high level in the demagnetization time; the on-time of the primary side inductor Lp is accurately detected through the primary side switch on-time detection circuit, and a detection result is fed back to the arithmetic unit, so that the primary side switch on-time detection circuit always outputs a high level within the energy storage time of the primary side inductor Lp; in the first secondary side demagnetization time, the first switch control circuit is switched on, the reference voltage circuit generates an internal voltage reference VREF to charge the second capacitor C through the third resistor R, the secondary side demagnetization time detection circuit detects that the secondary side demagnetization is finished, and the first switch control circuit is switched off; when the valley bottom detection module detects a first valley bottom, the primary side switch starts to be conducted again, the arithmetic unit records the conducting time of the primary side switch, after the primary side switch is disconnected, the second secondary side demagnetization time starts to be detected, the first switch control circuit continues to be conducted, the conducting time is the conducting time of the primary side switch recorded by the arithmetic unit, when the second secondary side demagnetization time is longer than the conducting time of the primary side switch recorded by the arithmetic unit, the second switch control circuit is conducted, the third resistor R is grounded, and the second capacitor C discharges through the third resistor R.
Repeating the steps, and continuing, integrating a level in the capacitor C, wherein the specific output current is calculated as follows:
the voltage of the second capacitor is VC, the demagnetization time of the secondary side is Td, the conduction time of the primary side is Ton, and the whole period is equal to T; the output current is Iout; the primary side peak current Ipeak, and the pound ratio of the primary side to the secondary side is Nps.
VC＝VREF×(Td+Ton)/(2×Td) (1)；
T＝Td+Ton (2)；
Iout＝Nps×Ipeak×Td/(Td+Ton) (3)；
Ipeak＝VC/Rcs (4)；
From the above (1), (2), (3) and (4), it can be obtained that:
Iout＝Nps×VREF/(2×Rcs) (5)；
through the formula (5), the final output current is only related to the smash ratio of the primary side to the secondary side of Nps, the internal reference voltage REF is related to the resistance value of the sampling resistor Rcs, and the first valley bottom is switched on and is controlled in a constant current mode.
In summary, the valley bottom turn-on control circuit provided by the invention enables the AC-DC switching power supply to be turned on when the system works at a constant current and always works at the first valley bottom, and the power tube is always turned on at the valley bottom when the system works at a constant voltage, so that the radiation of the system is greatly reduced. Because the constant current adopts the first valley bottom to conduct, the secondary side degaussing duty ratio is more than the previous 1:1, when working at high line voltage, the secondary side degaussing duty ratio can reach 10:1, under the condition of the same output current, the peak current can be reduced by 10 times, so that the consumption on a secondary freewheeling diode and the consumption of a parasitic resistor are greatly reduced, in addition, the primary current is also reduced to one tenth of the original current, the consumption on a sampling resistor is changed to one tenth of the original current, the system loss is reduced to more than 0.3W comprehensively, and compared with a common valley bottom switching-on circuit, the system efficiency can be improved by 2 percent. The valley bottom opening control circuit in the constant current state provided by the invention adopts a logic framework that the demagnetization time and the magnetism gathering time determine the primary side peak current, realizes that the peak current is variable, the demagnetization duty ratio is variable, the first valley bottom is opened, and the constant current mode works in BCM (binary-coded decimal), thereby greatly improving the system efficiency and realizing the first valley bottom conduction in the constant current mode on the basis of the original chip cost.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to the related technical fields, are included in the scope of the present invention.
Claims (4)
1. A valley bottom opening control circuit under a constant current state is characterized by comprising: the device comprises a sampling circuit, a valley bottom detection circuit, a secondary side degaussing time detection circuit, a primary side switch starting time detection circuit, a CV control circuit, an arithmetic unit, a first switch control circuit, a reference voltage circuit, a second switch control circuit, an integrator, a comparator, a third switch control circuit, a sampling resistor, an MOS (metal oxide semiconductor) tube, a primary side inductor, a secondary side inductor, a diode and a first capacitor;
the valley bottom detection circuit, the secondary side demagnetization time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively connected with the sampling circuit;
the valley bottom detection circuit is connected with the third switch control circuit;
the secondary side demagnetization time detection circuit, the primary side switch opening time detection circuit and the CV control circuit are respectively connected with the arithmetic unit;
the first switch control circuit and the second switch control circuit are respectively connected with the arithmetic unit;
the reference voltage circuit is connected with the first switch control circuit; the second switch control circuit is grounded;
the comparator comprises a positive input end, a negative input end and an output end;
the first switch control circuit and the second switch control circuit are respectively connected with the input end of the integrator;
the output end of the integrator is connected with the positive input end of the comparator;
the output end of the comparator is connected with the MOS tube through a third switch control circuit;
the MOS tube is grounded through a sampling resistor; the MOS tube is connected with the negative electrode input end of the comparator; the MOS tube is connected with the primary side inductor;
one end of the secondary inductor is connected with the anode of the diode; the cathode of the diode is connected with one end of the first capacitor; the other end of the first capacitor is connected with the other end of the secondary inductor;
when the system works at a constant current, the AC-DC switching power supply is switched on when the AC-DC switching power supply always works at the first valley bottom.
2. The valley bottom turn-on control circuit in the constant current state according to claim 1, wherein the sampling circuit comprises an auxiliary winding, a first resistor and a second resistor;
one end of the auxiliary winding is respectively connected with the valley bottom detection circuit, the secondary side degaussing time detection circuit, the primary side switch on time detection circuit and the CV control circuit through a first resistor;
the other end of the auxiliary winding is respectively connected with the valley bottom detection circuit, the secondary side degaussing time detection circuit, the primary side switch turn-on time detection circuit and the CV control circuit through a second resistor;
the other end of the auxiliary winding is grounded.
3. The valley turn-on control circuit in a constant current state of claim 1, wherein the MOS transistor comprises a gate, a source and a drain;
the grid electrode of the MOS tube is connected with the third switch control circuit;
the source electrode of the MOS tube is connected with the negative electrode input end of the comparator;
and the drain electrode of the MOS tube is connected with the primary side inductor.
4. The valley bottom turn-on control circuit in the constant current state of claim 1, wherein the integrator comprises a third resistor and a second capacitor;
the first switch control circuit and the second switch control circuit are respectively connected with one end of the third resistor; the other end of the third resistor is grounded through a first capacitor; the other end of the third resistor is connected with the positive input end of the comparator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611175086.7A CN106787750B (en) | 2016-12-19 | 2016-12-19 | Valley bottom opening control circuit under constant current state |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611175086.7A CN106787750B (en) | 2016-12-19 | 2016-12-19 | Valley bottom opening control circuit under constant current state |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106787750A CN106787750A (en) | 2017-05-31 |
| CN106787750B true CN106787750B (en) | 2023-02-28 |
Family
ID=58889854
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611175086.7A Active CN106787750B (en) | 2016-12-19 | 2016-12-19 | Valley bottom opening control circuit under constant current state |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106787750B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108365757B (en) * | 2018-03-27 | 2023-10-17 | 深圳市群芯科创电子有限公司 | Constant-current device |
| CN110572038A (en) * | 2019-09-18 | 2019-12-13 | 苏州锴威特半导体股份有限公司 | inductive current detection circuit suitable for switching power converter |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN203233327U (en) * | 2013-04-23 | 2013-10-09 | 深圳市明微电子股份有限公司 | Constant current driving control circuit with high power factor and driving device |
| CN103929849B (en) * | 2014-03-26 | 2016-05-25 | 无锡市晶源微电子有限公司 | Isolation led drive circuit |
| CN103956899B (en) * | 2014-04-04 | 2016-08-17 | 深圳市明微电子股份有限公司 | Constant-current controller and BUCK constant-current circuit |
| CN103986335B (en) * | 2014-05-23 | 2016-03-02 | 浙江大学 | A kind of based on the inverse-excitation type LED constant-current driver without auxiliary winding construction |
| CN104333936B (en) * | 2014-08-04 | 2017-07-14 | 深圳天源中芯半导体有限公司 | A kind of closed control circuit for constant current driver circuit for LED |
| CN104333216B (en) * | 2014-11-28 | 2017-04-12 | 矽力杰半导体技术(杭州)有限公司 | Switching power supply controller and control method thereof |
-
2016
- 2016-12-19 CN CN201611175086.7A patent/CN106787750B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN106787750A (en) | 2017-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI535175B (en) | Load driving circuit and method thereof | |
| CN102231605B (en) | Synchronous rectification control circuit of switch power supply secondary and flyback switch power supply | |
| US9577530B1 (en) | Boost converter with zero voltage switching | |
| CN103152951B (en) | LED (light emitting diode) driving control circuit and driving circuit structure of LED driving control circuit | |
| US7894213B2 (en) | DC to DC converter | |
| CN107271756B (en) | Load voltage detection circuit and method | |
| US9698671B2 (en) | Single-stage AC-to-DC converter with variable duty cycle | |
| TW201421882A (en) | DC converting circuit | |
| US20140347021A1 (en) | Sampling negative coil current in a switching power converter and method thereof | |
| CN106787750B (en) | Valley bottom opening control circuit under constant current state | |
| CN109088536B (en) | Active power factor correction circuit and method for improving harmonic waves and driving system | |
| CN105099201A (en) | Micro-power consumption single-ended flyback high-voltage power supply circuit | |
| CN105471231B (en) | A kind of Flyback ac-dc converter circuit and inverse-excitation type electric pressure converter | |
| CN105471291B (en) | A kind of inverse-excitation type AC-DC voltage conversion circuits and inverse-excitation type electric pressure converter | |
| CN210640810U (en) | High-voltage BUCK switch converter and related integrated circuit | |
| CN105101572B (en) | A kind of High Power Factor LED drive integrated circults | |
| US9698666B2 (en) | Power supply and gate driver therein | |
| CN108365757B (en) | Constant-current device | |
| KR101456654B1 (en) | A common-core power factor correction resonant converter | |
| TWI586092B (en) | Single-stage ac-to-dc converter | |
| WO2013190914A1 (en) | Switching power supply circuit | |
| US7894217B2 (en) | DC to DC converter | |
| US20210057979A1 (en) | Switching power supply controlling circuit and controlling method thereof | |
| CN101378197B (en) | Charger with boundary mode control | |
| CN104638946A (en) | Dual-winding transformer primary-side detection output voltage AC-DC converter |
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 |