CN113346757A - Self-driven synchronous rectification circuit and working method and application thereof - Google Patents
Self-driven synchronous rectification circuit and working method and application thereof Download PDFInfo
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- 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
- H02M3/33576—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 having at least one active switching element at the secondary side of an isolation transformer
- H02M3/33592—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 having at least one active switching element at the secondary side of an isolation transformer having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
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- 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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal 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
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal 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
- H02M7/219—Conversion of ac power input into dc power output without possibility of reversal 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 in a bridge configuration
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- 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
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Abstract
The invention relates to the technical field of synchronous rectification circuits, and discloses a self-driven synchronous rectification circuit, which comprises a transformer T1, a first synchronous rectification control circuit, a second synchronous rectification control circuit, an inductor L3 and a capacitor C20, wherein the transformer T1 is connected with the first synchronous rectification control circuit; the first synchronous rectification control circuit comprises an MOS tube Q3, a voltage-dividing resistor R51, a voltage-dividing resistor R53, a voltage-stabilizing tube Z3, a voltage-stabilizing tube Z4 and a capacitor C18, and the second synchronous rectification control circuit comprises an MOS tube Q4, a voltage-dividing resistor R54, a voltage-dividing resistor R56, a voltage-stabilizing tube Z5, a voltage-stabilizing tube Z6 and a capacitor C19. The working method and the application of the circuit are also disclosed, the grid driving problem of a wide input voltage range is solved, and the proper driving voltage of the MOS tube of the synchronous rectifier tube is ensured when low voltage and high voltage are input by dividing the pulse signal of the transformer by alternating current and direct current and adjusting the amplitude of the grid driving signal; the problems that the traditional self-driven synchronous rectification circuit is complex in structure, limited in application range and the like are solved, and the application of the synchronous rectification circuit with high efficiency and wide input voltage range is realized.
Description
Technical Field
The invention relates to the technical field of synchronous rectification circuits, in particular to a self-driven synchronous rectification circuit and a working method and application thereof.
Background
The self-driven synchronous rectification technology comprises a voltage type and a current type. The typical circuit of voltage-type self-driving is shown in fig. 1, wherein the grid electrode and the drain electrode of the SR (self-drive recovery) are respectively connected with two ends of the secondary output of the transformer, namely the secondary voltage of the transformer is used as the driving signal voltage of the SR, and the characteristic is simple and practical; the driving voltage of the SR is in direct proportion to the input voltage of the converter, and when the variation range of the input voltage is wide, the SR is difficult to be driven safely and effectively in the whole voltage variation range.
The current type self-driving circuit is shown in figure 2, and has four windings: diodes D1 and D2 are respectively connected in series in a loop of the current detection winding N1, the driving winding N2, the energy feedback winding N3, the magnetic reset winding N4, the winding N3 and the winding N4, and Vo is a voltage source. Before the rectifier tube is conducted, forward current flows from the source electrode to the drain electrode of the MOS tube through the diode of the rectifier tube body, the winding N1 detects the direction of the flowing current, driving voltage is induced in the winding N2, and the MOS tube is conducted. The voltage of the winding N3 rises to turn on the diode D1, and all the energy of the current detection element is fed to the dc power source Vo. When the forward current in the rectifier tube is reduced to zero and tends to reverse, D1 is cut off, D2 is conducted, the magnetic core of the current transformer is reset, and the magnetic field energy is fed back to the direct-current voltage source Vo. And the grid voltage of the MOS tube becomes negative, and the MOS tube is turned off. The current type self-driven synchronous rectification technology is characterized in that: the driving waveform has no dead zone, the driving operation is not influenced by input voltage, but the current type self-driven synchronous rectification circuit has a complex structure, the loss generated at the current detection end is large, and the circuit debugging is difficult.
In summary, the existing self-driven synchronous rectification circuit has advantages and disadvantages in performance, the voltage type self-driven circuit is simple, and the problems that the driving voltage is influenced by the input voltage, the application range is limited, and the circuit is only suitable for occasions with small input voltage change and small change of the grid driving voltage of the later-stage synchronous rectification tube are solved; the current type self-driving waveform is not influenced by input voltage, but the circuit structure is complex and the debugging is difficult.
Disclosure of Invention
The invention aims to provide a self-driven synchronous rectification circuit and a working method and application thereof, and solves the problem of grid drive in a wide input voltage range.
The invention is realized by the following technical scheme:
a self-driven synchronous rectification circuit comprises a transformer T1, a first synchronous rectification control circuit, a second synchronous rectification control circuit, an inductor L3 and a capacitor C20;
the first synchronous rectification control circuit comprises an MOS tube Q3, a voltage dividing resistor R51, a voltage dividing resistor R53, a voltage stabilizing tube Z3, a voltage stabilizing tube Z4 and a capacitor C18, wherein a grid electrode and a source electrode of the MOS tube Q3 are respectively connected with one end of the voltage dividing resistor R53, the voltage stabilizing tube Z3 and the voltage stabilizing tube Z4 are reversely connected and then connected in parallel at two ends of the voltage dividing resistor R53, the voltage dividing resistor R51 and the voltage dividing resistor R53 are connected in series, and the capacitor C18 is connected in parallel at two ends of the voltage dividing resistor R51;
the second synchronous rectification control circuit comprises an MOS tube Q4, a voltage dividing resistor R54, a voltage dividing resistor R56, a voltage stabilizing tube Z5, a voltage stabilizing tube Z6 and a capacitor C19, wherein a grid electrode and a source electrode of the MOS tube Q4 are respectively connected with one end of a voltage dividing resistor R56, a voltage stabilizing tube Z5 and a voltage stabilizing tube Z6 are reversely connected and then connected in parallel with two ends of a voltage dividing resistor R56, the voltage dividing resistor R54 and the voltage dividing resistor R56 are connected in parallel, one end of the voltage dividing resistor R54 is connected with an interface on one side of an output end of a transformer T1, the other end of the voltage dividing resistor R54 is connected with a grid electrode of an MOS tube Q4, and a drain electrode of the MOS tube Q4 is connected with an interface on the other side of the output end of the transformer T1; c19 is connected in parallel across divider resistor R54.
Further, a resistor R52 is connected in series between the voltage dividing resistor R51 and the voltage dividing resistor R53.
Further, a resistor R55 is connected in series between the voltage dividing resistor R54 and the gate of the MOS transistor Q4.
Further, an active fast turn-off circuit is connected in the second synchronous rectification control circuit, the active fast turn-off circuit comprises a triode Q41, a resistor R57, a diode D5 and a resistor R58, one end of the resistor R57 is connected with the output end of the transformer T1, the other end of the resistor R57 is connected with the base of a triode Q41, one end of the resistor R58 is connected with the source of the MOS transistor Q3, and the other end of the resistor R58 is connected with the collector of a triode Q41; the anode of the diode D5 is connected to one end of the resistor R54, and the other end is connected to one end of the resistor R55, the emitter of the transistor Q41, and one end of the capacitor C19.
When the input voltage is lower, the pulse signal at the secondary winding of the transformer is divided by the synchronous rectification control circuit, and unipolar grid driving voltage is provided for the MOS tube Q3 and the MOS tube Q4;
when the input voltage is high, the pulsating signal at the secondary winding of the transformer is divided by the synchronous rectification control circuit and converted into bipolar voltage, and bipolar driving voltage is provided for the gates of the MOS tube Q3 and the MOS tube Q4.
Further, the working method of the self-driven synchronous rectification circuit specifically comprises the following steps: in the ton period, the secondary winding T1-3 is at a high level, the MOS tube Q3 is turned on at the moment, the MOS tube Q4 is turned off, the voltage at the T1-3 is divided by the resistor R51 and the resistor R53 to provide a driving voltage for the gate of the MOS tube Q3, and when the divided voltage value at the resistor R53 is smaller than the stabilized voltage value of the voltage regulator tube Z3, the driving voltage is unipolar; when the voltage dividing value at the resistor R53 is larger than the voltage stabilizing value of the voltage stabilizing tube Z3, the driving voltage is bipolar;
during toff, the position of a secondary winding T1-4 is at a high level, at the moment, an MOS tube Q4 is switched on, an MOS tube Q3 is switched off, the voltage at the position of T1-4 is divided by a resistor R54 and a resistor R56, driving voltage is provided for a grid electrode of an MOS tube Q4, and when the divided voltage value at the position of the resistor R56 is smaller than the stabilized voltage value of a voltage stabilizing tube Z5, the driving voltage is unipolar; when the voltage dividing value at the resistor R56 is larger than the voltage stabilizing value of the voltage stabilizing tube Z3, the driving voltage is bipolar.
The invention also discloses a DC/DC conversion circuit which comprises the self-driven synchronous rectification circuit.
The invention also discloses a DC/DC converter which comprises the self-driven synchronous rectification circuit.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention discloses a self-driven synchronous rectification circuit and a working method thereof, and the self-driven synchronous rectification circuit comprises a transformer T1, a first synchronous rectification control circuit, a second synchronous rectification control circuit, rectifier tubes Q3 and Q4, an inductor L3 and a capacitor C20. When the input voltage is lower, the pulsating signals at T1-3 and T1-4 are subjected to alternating current and direct current voltage division to provide unipolar gate driving voltage for MOS transistors Q3 and Q4, so that the gate is ensured to have enough amplitude to normally work; when the input voltage is high, the pulsating signals at T1-3 and T1-4 are converted into bipolar voltage through alternating current and direct current voltage division, and safe driving voltage is provided for the gates of MOS tubes Q3 and Q4. The circuit structure solves the grid driving problem of wide input voltage range, and the amplitude of the grid driving signal is adjusted by dividing the alternating current and the direct current of the transformer pulse signal, so that the MOS tube of the synchronous rectifier tube has proper driving voltage when low voltage and high voltage are input; the self-driven synchronous rectification circuit is suitable for occasions with wide input voltage variation range, overcomes the problems of complex structure, limited application range and the like of the traditional self-driven synchronous rectification circuit, does not need to increase extra transformer windings, realizes the application of high efficiency and wide input voltage range of the synchronous rectification circuit, and has the characteristics of less number of components and high reliability.
Furthermore, an active fast discharge circuit is added at the synchronous rectification MOS tube which bears the follow current function, so that the synchronous rectification MOS tube is forced to be rapidly cut off after the excitation magnetic flux of the main transformer is reset, the reverse flow of inductive current under light load is avoided, and the circuit efficiency and the product reliability under light load are effectively improved.
The invention also discloses that the self-driven synchronous rectification circuit can be applied to a DC/DC conversion circuit or a DC/DC converter, the effect verification is carried out through practical tests, and the circuit parameters used for the experiments are as follows: the input voltage is 16V-50V, the typical input voltage is 28V, the output voltage is 15V, the load current is 3.33A, and the efficiency is 91%. The self-driven synchronous rectification circuit is suitable for occasions with wide input voltage change range, and has the characteristics of simple circuit structure, small number of components, high efficiency and high reliability.
Drawings
FIG. 1 is a schematic diagram of the connection of a voltage-type self-driven synchronous rectification circuit;
FIG. 2 is a schematic diagram of the connection of a current-mode self-driven synchronous rectification circuit;
FIG. 3 is a schematic connection diagram of the self-driven synchronous rectification circuit of the present invention;
FIG. 4 is a diagram of the application of the self-driven synchronous rectification circuit of the present invention in a DC/DC conversion circuit;
FIG. 5 is a self-driving waveform diagram of the self-driving synchronous rectification circuit of the present invention.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
As shown in fig. 3, the present invention discloses a self-driven synchronous rectification circuit, which includes a transformer T1, a first synchronous rectification control circuit, a second synchronous rectification control circuit, an inductor L3, and a capacitor C20; the first synchronous rectification control circuit comprises an MOS tube Q3, a voltage-dividing resistor R51, a voltage-dividing resistor R53, a voltage-stabilizing tube Z3, a voltage-stabilizing tube Z4 and a capacitor C18, wherein the grid electrode and the source electrode of the MOS tube Q3 are respectively connected with one end of the voltage-dividing resistor R53, the voltage-stabilizing tube Z3 and the voltage-stabilizing tube Z4 are reversely connected and then connected in parallel at two ends of the voltage-dividing resistor R53, the voltage-dividing resistor R51 is connected in series with the voltage-dividing resistor R53, and the capacitor C18 is connected in parallel at two ends of the voltage-dividing resistor R51.
The voltage dividing resistor R51 and the voltage dividing resistor R53 form a first direct current voltage divider, the capacitor C18 and an internal gate-source capacitor Cgs (Q3) of the switch Q3 form a first alternating current voltage divider, and the voltage regulator tube Z3 and the voltage regulator tube Z4 form a first control node voltage limiting circuit.
The second synchronous rectification control circuit comprises an MOS tube Q4, a voltage-dividing resistor R54, a voltage-dividing resistor R56, a voltage-stabilizing tube Z5, a voltage-stabilizing tube Z6 and a capacitor C19, wherein the grid and the source of the MOS tube Q4 are respectively connected with one end of the voltage-dividing resistor R56, the voltage-stabilizing tube Z5 and the voltage-stabilizing tube Z6 are reversely connected and then are connected with the two ends of the voltage-dividing resistor R56 in parallel, the voltage-dividing resistor R54 and the voltage-dividing resistor R56 are connected in parallel, one end of the voltage-dividing resistor R54 is connected with an interface on one side of the output end of the transformer T1, the other end of the voltage-dividing resistor R54 is connected with the grid of the MOS tube Q4, and the drain of the MOS tube Q4 is connected with an interface on the other side of the output end of the transformer T1; c19 is connected in parallel across divider resistor R54.
The voltage dividing resistor R54 and the voltage dividing resistor R56 form a second direct current voltage divider, the capacitor C19 and an internal gate-source capacitor Cgs (Q4) of the switch Q4 form a second alternating current voltage divider, and the voltage stabilizing tubes Z5 and Z6 form a second control node voltage limiting circuit.
Preferably, a first peak current limiting resistor R52 is connected in series between the voltage dividing resistor R51 and the voltage dividing resistor R53 to limit the Q3 gate driving peak current.
Preferably, a second peak current limiting resistor R55 is connected in series between the voltage dividing resistor R54 and the gate of the MOS transistor Q4 in sequence to limit the gate drive peak current of the Q4.
Preferably, in order to prevent the current backflow phenomenon during light load, an active fast turn-off circuit taking a PNP BJT triode Q41 as a core is added in a Q4 driving circuit, the active fast turn-off circuit comprises a triode Q41, a resistor R57, a diode D5 and a resistor R58, one end of the resistor R57 is connected with the output end of a transformer T1, the other end of the resistor R57 is connected with the base of the triode Q41, one end of the resistor R58 is connected with the source of an MOS transistor Q3, and the other end of the resistor R58 is connected with the collector of the triode Q41; the anode of the diode D5 is connected to one end of the resistor R54, and the other end is connected to one end of the resistor R55, the emitter of the transistor Q41, and one end of the capacitor C19.
Under the light-load working condition, after the exciting current of the transformer T1 returns to zero, the drive signal of the rectifier tube Q4 disappears, at the moment, the triode Q41 is conducted, a quick discharge path is provided for the grid of the Q4, the rectifier tube Q4 is ensured to be reliably closed before the current of the filter inductor L3 returns to zero, the reverse flow of the inductor current is avoided, and the circuit efficiency index under the light-load working state is improved. The diode D5 is cut off reversely when the rectifier tube Q4 discharges, and R56 and R57 are static bias resistors of the triode Q41.
The self-driven synchronous rectification circuit is suitable for occasions with large input voltage range change. When the input voltage is lower, the pulse signal at the secondary winding of the transformer is subjected to alternating current and direct current voltage division to provide unipolar gate driving voltage for MOS transistors Q3 and Q4, so that the gate is ensured to have enough amplitude to normally work; when the input voltage is high, the pulsating signal at the secondary winding of the transformer is converted into bipolar voltage through alternating current and direct current voltage division, and safe driving voltage is provided for the gates of the MOS transistors Q3 and Q4.
The specific working process is as follows:
in the ton period, the secondary winding T1-3 is at a high level, the MOS transistor Q3 is turned on, the MOS transistor Q4 is turned off, the voltage at the T1-3 is divided by the resistors R51 and R53 to provide a proper driving voltage for the Q3 grid, and when the divided voltage value at the R53 is smaller than the Z3 regulated voltage value, the driving voltage is unipolar; when the voltage division value at the resistor R53 is larger than the Z3 stable voltage value, the driving voltage is bipolar. The Z3 and the Z4 play a role in voltage clamping, the C18 is an accelerating capacitor and is connected in parallel with two ends of the R51, so that the waveform at the T1-3 position of the transformer is transmitted without distortion after voltage division; r52 is the Q3 gate peak current limiting resistance.
During toff, the secondary winding T1-4 is at a high level, the MOS transistor Q4 is turned on, the Q3 is turned off, the voltage at the T1-4 is divided by resistors R54 and R56 to provide a proper driving voltage for the grid of the Q4, and when the divided voltage value at the R56 is smaller than the voltage stabilizing value of Z5, the driving voltage is unipolar; when the voltage division value at the resistor R56 is larger than the Z5 stable voltage value, the driving voltage is bipolar. The Z5 and the Z6 play a role in voltage clamping, the C19 is an accelerating capacitor and is connected in parallel with two ends of the R54, so that the waveform at the T1-4 position of the transformer is transmitted without distortion after voltage division; r55 is Q4 grid peak current limiting resistor, and Q41, D5, R57 and R58 are active rapid turn-off circuits in light load, so that the current backflow in light load is avoided.
As shown in fig. 4 and 5, the self-driven synchronous rectification circuit of the present invention is applied to a DC/DC conversion circuit, in which the circuit includes functional units of input filtering, PWM control, power conversion, output filtering, voltage error amplification and isolation feedback, and the driving circuit of the present invention is added at a post-stage synchronous rectification MOS. The input voltage range is 16V-50V, the typical input voltage is 28V, the output voltage is 15V, the load current is 3.33A, and the efficiency of the DC/DC power supply module is 91%. The self-driven synchronous rectification circuit is suitable for occasions with large input voltage range changes and has the characteristics of simple circuit structure, small number of components, high efficiency and high reliability.
The grid driving problem of wide input voltage range is solved by adopting the circuit structure. The amplitude of a grid driving signal is adjusted by dividing the alternating current and the direct current of a pulse signal of the transformer, so that the MOS tube of the synchronous rectifier tube has proper driving voltage when low voltage and high voltage are input; meanwhile, an active fast discharge circuit is added at the synchronous rectification MOS tube which has the follow current function, so that the synchronous rectification MOS tube is forced to be rapidly cut off after the excitation magnetic flux of the main transformer is reset, the reverse flow of the inductive current under light load is avoided, and the circuit efficiency and the product reliability under light load are effectively improved.
The self-driven synchronous rectification circuit is already put into the design of a 28V series high-efficiency series DC/DC converter, has simple and reliable circuit and few components, and meets the index requirements of small volume, high efficiency and high density of the circuit.
Claims (8)
1. A self-driven synchronous rectification circuit is characterized by comprising a transformer T1, a first synchronous rectification control circuit, a second synchronous rectification control circuit, an inductor L3 and a capacitor C20;
the first synchronous rectification control circuit comprises an MOS tube Q3, a voltage-dividing resistor R51, a voltage-dividing resistor R53, a voltage-stabilizing tube Z3, a voltage-stabilizing tube Z4 and a capacitor C18, wherein the grid electrode and the source electrode of the MOS tube Q3 are respectively connected with one end of the voltage-dividing resistor R53, the voltage-stabilizing tube Z3 and the voltage-stabilizing tube Z4 are reversely connected and then connected in parallel with the two ends of the voltage-dividing resistor R53, the voltage-dividing resistor R51 is connected in series with the voltage-dividing resistor R53, and the capacitor C18 is connected in parallel with the two ends of the voltage-dividing resistor R51;
the second synchronous rectification control circuit comprises an MOS tube Q4, a voltage-dividing resistor R54, a voltage-dividing resistor R56, a voltage-stabilizing tube Z5, a voltage-stabilizing tube Z6 and a capacitor C19, wherein the grid and the source of the MOS tube Q4 are respectively connected with one end of the voltage-dividing resistor R56, the voltage-stabilizing tube Z5 and the voltage-stabilizing tube Z6 are reversely connected and then are connected with the two ends of the voltage-dividing resistor R56 in parallel, the voltage-dividing resistor R54 and the voltage-dividing resistor R56 are connected in parallel, one end of the voltage-dividing resistor R54 is connected with an interface on one side of the output end of the transformer T1, the other end of the voltage-dividing resistor R54 is connected with the grid of the MOS tube Q4, and the drain of the MOS tube Q4 is connected with an interface on the other side of the output end of the transformer T1; c19 is connected in parallel across divider resistor R54.
2. The self-driven synchronous rectification circuit as claimed in claim 1, wherein a resistor R52 is connected in series between the voltage dividing resistor R51 and the voltage dividing resistor R53.
3. The self-driven synchronous rectification circuit as claimed in claim 1, wherein a resistor R55 is connected in series between the voltage dividing resistor R54 and the gate of the MOS transistor Q4.
4. A self-driven synchronous rectification circuit as claimed in claim 1, wherein an active fast turn-off circuit is connected in the second synchronous rectification control circuit, the active fast turn-off circuit comprises a transistor Q41, a resistor R57, a diode D5 and a resistor R58, one end of the resistor R57 is connected with the output end of the transformer T1, the other end is connected with the base of a transistor Q41, one end of the resistor R58 is connected with the source of a MOS transistor Q3, and the other end is connected with the collector of a transistor Q41; the anode of the diode D5 is connected to one end of the resistor R54, and the other end is connected to one end of the resistor R55, the emitter of the transistor Q41, and one end of the capacitor C19.
5. The working method of the self-driven synchronous rectification circuit of any one of claims 1 to 4, wherein when the input voltage is low, the pulsating signal at the secondary winding of the transformer is divided by the synchronous rectification control circuit to provide unipolar gate drive voltages for MOS transistor Q3 and MOS transistor Q4;
when the input voltage is high, the pulsating signal at the secondary winding of the transformer is divided by the synchronous rectification control circuit and converted into bipolar voltage, and bipolar driving voltage is provided for the gates of the MOS tube Q3 and the MOS tube Q4.
6. The operating method of the self-driven synchronous rectification circuit as claimed in claim 5, characterized by comprising the following steps: in the ton period, the secondary winding T1-3 is at a high level, the MOS tube Q3 is turned on at the moment, the MOS tube Q4 is turned off, the voltage at the T1-3 is divided by the resistor R51 and the resistor R53 to provide a driving voltage for the gate of the MOS tube Q3, and when the divided voltage value at the resistor R53 is smaller than the stabilized voltage value of the voltage regulator tube Z3, the driving voltage is unipolar; when the voltage dividing value at the resistor R53 is larger than the voltage stabilizing value of the voltage stabilizing tube Z3, the driving voltage is bipolar;
during toff, the position of a secondary winding T1-4 is at a high level, at the moment, an MOS tube Q4 is switched on, an MOS tube Q3 is switched off, the voltage at the position of T1-4 is divided by a resistor R54 and a resistor R56, driving voltage is provided for a grid electrode of an MOS tube Q4, and when the divided voltage value at the position of the resistor R56 is smaller than the stabilized voltage value of a voltage stabilizing tube Z5, the driving voltage is unipolar; when the voltage dividing value at the resistor R56 is larger than the voltage stabilizing value of the voltage stabilizing tube Z3, the driving voltage is bipolar.
7. A DC/DC conversion circuit comprising the self-driven synchronous rectification circuit as claimed in any one of claims 1 to 4.
8. A DC/DC converter comprising the self-driven synchronous rectification circuit as claimed in any one of claims 1 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110656527.XA CN113346757A (en) | 2021-06-11 | 2021-06-11 | Self-driven synchronous rectification circuit and working method and application thereof |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2490748Y (en) * | 2001-06-13 | 2002-05-08 | 中国科学院电工研究所 | Quickly overcurrent protection device for dc-to-ac converter |
| CN101895281A (en) * | 2010-07-28 | 2010-11-24 | 佛山市顺德区瑞德电子实业有限公司 | Novel MOS tube drive circuit for switch power supply |
| CN106712551A (en) * | 2016-12-02 | 2017-05-24 | 中惠创智无线供电技术有限公司 | Synchronous rectifier switch, synchronous rectifier chip and synchronous rectifier circuit |
| CN107690747A (en) * | 2015-07-17 | 2018-02-13 | 克兰电子公司 | Self-device synchronous rectification for the automatic enhancing of electric power converter |
| CN109347311A (en) * | 2018-12-07 | 2019-02-15 | 广州金升阳科技有限公司 | A kind of self-powered driving circuit of double tube positive exciting circuit of synchronous rectification |
| CN112332821A (en) * | 2020-12-02 | 2021-02-05 | 中北大学 | MOSFET passive isolation direct connection prevention quick-closing drive circuit |
| CN213213349U (en) * | 2020-06-30 | 2021-05-14 | 江苏舾普泰克自动化科技有限公司 | Energy-saving marine inverter |
-
2021
- 2021-06-11 CN CN202110656527.XA patent/CN113346757A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2490748Y (en) * | 2001-06-13 | 2002-05-08 | 中国科学院电工研究所 | Quickly overcurrent protection device for dc-to-ac converter |
| CN101895281A (en) * | 2010-07-28 | 2010-11-24 | 佛山市顺德区瑞德电子实业有限公司 | Novel MOS tube drive circuit for switch power supply |
| CN107690747A (en) * | 2015-07-17 | 2018-02-13 | 克兰电子公司 | Self-device synchronous rectification for the automatic enhancing of electric power converter |
| CN106712551A (en) * | 2016-12-02 | 2017-05-24 | 中惠创智无线供电技术有限公司 | Synchronous rectifier switch, synchronous rectifier chip and synchronous rectifier circuit |
| CN109347311A (en) * | 2018-12-07 | 2019-02-15 | 广州金升阳科技有限公司 | A kind of self-powered driving circuit of double tube positive exciting circuit of synchronous rectification |
| CN213213349U (en) * | 2020-06-30 | 2021-05-14 | 江苏舾普泰克自动化科技有限公司 | Energy-saving marine inverter |
| CN112332821A (en) * | 2020-12-02 | 2021-02-05 | 中北大学 | MOSFET passive isolation direct connection prevention quick-closing drive circuit |
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