CN114583983A - Switching type conversion circuit controlled by secondary side - Google Patents

Switching type conversion circuit controlled by secondary side Download PDF

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Publication number
CN114583983A
CN114583983A CN202011373776.XA CN202011373776A CN114583983A CN 114583983 A CN114583983 A CN 114583983A CN 202011373776 A CN202011373776 A CN 202011373776A CN 114583983 A CN114583983 A CN 114583983A
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CN
China
Prior art keywords
control signal
module
transistor
electrically connected
switched
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Pending
Application number
CN202011373776.XA
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Chinese (zh)
Inventor
梁伟成
张平
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Xinqiao Technology Co ltd
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Xinqiao Technology Co ltd
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Priority to CN202011373776.XA priority Critical patent/CN114583983A/en
Publication of CN114583983A publication Critical patent/CN114583983A/en
Pending legal-status Critical Current

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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
    • 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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • H02M1/092—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices the control signals being transmitted optically
    • 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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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention relates to a switching type conversion circuit controlled by a secondary side, which is mainly composed of a transformer module, a switch module, a digital isolation coupling module and a control module, wherein the switch module is electrically connected with the transformer module, the control module is electrically connected with the transformer module and receives the output voltage of the transformer module, the digital isolation coupling module is electrically connected between the switch module and the control module, and the control module directly sends a control signal to the switch module through the digital isolation coupling module according to the voltage change of the output voltage so as to regulate and control the output voltage of the switching type conversion circuit, thereby achieving the purpose of improving the control precision.

Description

Switching type conversion circuit controlled by secondary side
Technical Field
The present invention relates to a switching converter circuit, and more particularly, to a switching converter circuit controlled by a secondary side.
Background
Generally, since electronic devices (smart phones, notebook computers, etc.) cannot be charged directly by using the end power (e.g., commercial power, the end of a power distribution system, etc.), it is necessary to convert the end power into the power required by the electronic devices through a power converter, for example, to convert 110V ac into 5V dc.
In order to effectively control the operation state of the power converter, a signal corresponding to the output voltage is usually required as a feedback signal, and in the prior art, a sampling signal at the primary side or a signal generated by an isolation coupling element is usually used as the feedback signal.
However, the output voltage state of the secondary side is simulated by the sampling signal of the primary side, and cannot be accurately reflected, and the isolation coupling element is usually driven by an analog signal (such as an analog voltage signal or a current signal) to generate the feedback signal, but the analog signal cannot realize accurate synchronous control.
In summary, in the prior art, the precise synchronous control cannot be realized by using the primary sampling signal or the signal generated by the isolated coupling element driven by the analog signal as the feedback signal, and thus, a need for a better solution is certainly to be provided.
Disclosure of Invention
In view of the above-mentioned deficiencies of the prior art, a primary objective of the present invention is to provide a switching converter circuit controlled by a secondary side, which utilizes a digital signal to regulate an output voltage of the switching converter circuit, thereby achieving an objective of improving control accuracy.
The main technical means adopted to achieve the above object is to make the switching type converting circuit controlled by the secondary side comprise:
a transformer module outputting an output voltage;
the switch module is electrically connected with the transformer module;
the digital isolation coupling module is electrically connected with the switch module; and
a control module electrically connected to the transformer module and the digital isolation coupling module for receiving the output voltage,
the control module directly transmits a control signal to the switch module through the digital isolation coupling module according to the change of the output voltage so as to regulate and control the output voltage.
With the structure, the control module can send a control signal to the switch module through the digital isolation coupling module by a digital signal according to the change of the output voltage so as to regulate and control the output voltage of the switching type conversion circuit according to the load, thereby achieving the purpose of improving the control precision.
For a better understanding of the nature and technical content of the present invention, reference should be made to the following detailed description of the invention, taken in conjunction with the accompanying drawings, which are set forth to illustrate, but are not to be construed to limit the scope of the invention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive labor.
FIG. 1 is a block diagram of a system architecture of an embodiment of the present invention;
FIG. 2 is a block diagram of another system architecture of an embodiment of the present invention; and
FIG. 3 is a timing diagram of an embodiment of the present invention.
Reference numerals
10 transformer module 11 transformer
12 peripheral circuit 13 output rectifier module
20 switch module 30 digital isolation coupling module
40 control module 100 switching type conversion circuit
Vi input voltage Vcc supply voltage
Vo output voltage Vsen sense voltage
C1 load capacitor D1 LED
L1 Primary winding L2 auxiliary winding
Secondary side winding of LC logic circuit Ls
Primary side grounding terminal of Cs digital control signal PGND
SGND secondary side grounding terminal Ss light sensing signal
Ip primary side current Is secondary side current
T1, T2, Q1, Q2 transistors
Ta, Tb and Tc time point
G1, G2, PGate, SGate control signals
PD photodiode module
Detailed Description
Referring to fig. 1, an embodiment of a switching converter circuit 100 controlled by a secondary side according to the present invention includes a transformer module 10, a switch module 20, a digital isolation coupling module 30, and a control module 40.
The switch module 20 is electrically connected to the transformer module 10, the digital isolation coupling module 30 is electrically connected to the switch module 20, and the control module 40 is electrically connected to the digital isolation coupling module 30 and configured to receive an output voltage Vo of the transformer module 10, wherein the control module 40 generates a corresponding digital control signal Cs to the digital isolation coupling module 30 according to a change of the output voltage Vo, so that the digital isolation coupling module 30 sends a control signal PGate to the switch module 20 according to the received digital control signal Cs, and the control signal PGate regulates and controls on and off times of the switch module 20, thereby adjusting the output voltage Vo. Therefore, the digital isolating and coupling module 30 can send the control signal PGate to the switch module 20 in real time according to the digital control signal Cs, so that the transformer module 10 can accurately adjust the output voltage Vo according to the control of the switch module 20, that is, adjust the output voltage Vo according to the load, thereby achieving the purpose of improving the control accuracy.
In an embodiment, the digital control signal Cs may be a PWM (pulse Width modulation) control signal, a PDM (pulse Density modulation) control signal, or a mixed control signal formed by mixing a PWM control signal and a PDM control signal, or the control signal may sometimes control the output power in a manner of modulating the frequency in a resonance driving mode, for example, and the invention is not limited thereto.
In one embodiment, the switching converter circuit 100 is, for example, a flyback (flyback) converter, a forward (forward) converter or a resonant (resonance) converter, and the invention is not limited thereto.
To further explain the switching converter circuit 100 controlled by the secondary side of the present invention, please refer to fig. 2, in which the transformer module 10 at least includes a transformer 11, a peripheral circuit 12 and an output rectifier module 13, the peripheral circuit 12 is electrically connected to the primary side of the transformer 11, and the output rectifier module 13 is electrically connected to the secondary side of the transformer 11.
Further, referring to fig. 2, the transformer 11 includes a primary winding L1 on the primary side, an auxiliary winding L2, and a secondary winding Ls on the secondary side, wherein the primary winding L1, the auxiliary winding L2 and the secondary winding Ls are magnetically coupled to each other, and the secondary winding Ls is configured to generate a sensing voltage Vsen corresponding to the primary winding L1 and the auxiliary winding L2.
The peripheral circuit 12 is electrically connected to the primary winding L1 and the auxiliary winding L2, and the peripheral circuit 12 may at least include a Start up circuit (Start up circuit) for generating a power supply voltage Vcc, which is not limited by the invention.
Further, as shown in fig. 2, the output rectifying module 13 includes a transistor Q2 and a load capacitor C1. One end of the transistor Q2 is electrically connected to the other end of the secondary winding Ls, the other end of the transistor Q2 is electrically connected to a secondary ground terminal SGND, and a gate terminal of the transistor Q2 is configured to receive a control signal SGate, wherein the transistor Q2 determines whether to turn on one end and the other end thereof according to the control signal SGate. In this embodiment, the transistor Q2 is used as a synchronous rectification switch to replace a rectification diode, for example: schottky diodes and other diodes having low forward voltage and fast recovery characteristics, and the invention is not limited thereto. Two ends of the load capacitor C1 are electrically connected to one end of the secondary winding Ls and the secondary ground SGND, respectively, so as to provide the output voltage Vo to the load and reduce the ripple of the output voltage Vo.
Further, referring to fig. 2, the switch module 20 includes a transistor Q1, one end of the transistor Q1 is electrically connected to the other end of the primary winding L1, the other end of the transistor Q1 is electrically connected to the primary ground PGND, and a gate end of the transistor Q1 is configured to receive the control signal PGate, wherein the transistor Q1 determines whether to turn on one end and the other end thereof according to the control signal PGate. Therefore, the switch module 20 can control the time and frequency of the output power of the transformer 11, and further control and adjust the output voltage Vo.
In one embodiment, the transistor Q1 and the transistor Q2 may be implemented by bipolar transistors (bipolar transistors), field effect transistors (field effect transistors), Insulated Gate Bipolar Transistors (IGBTs), etc., and the invention is not limited thereto.
Further, referring to fig. 2, in this embodiment, the digital isolation coupling module 30 is implemented as a digital optical coupling module, which includes a light emitting diode D1, a photodiode PD, a logic circuit LC, a transistor T1, and a transistor T2.
One end of the led D1 is connected to a secondary power source (e.g., the secondary ground SGN D), and the other end of the led D1 is configured to receive the digital control signal Cs output by the control module 40, so that the led D1 can emit light (i.e., an optical signal corresponding to a binary signal) according to a voltage difference between the secondary power source and the digital control signal Cs (i.e., a binary signal).
The photodiode module PD is electrically connected to the logic circuit LC, and is configured to sense light of the light emitting diode D1, generate a corresponding light sensing signal Ss, and transmit the light sensing signal Ss to the logic circuit LC, thereby achieving an isolation (i.e., no conductor (resistivity <0.01ohm-m) is connected, and the photodiode module PD and the light emitting diode D1 are insulated from each other (leakage current <10mA), and are resistant to high voltage (breakdown voltage >40V)) and coupled (transmit signals).
The logic circuit LC is electrically connected to the photodiode module PD, the transistor T1 and the transistor T2, and is configured to receive the light sensing signal Ss and generate a control signal G1 and a control signal G2 for controlling the transistor T1 and the transistor T2 according to the light sensing signal Ss.
In one embodiment, when the switching converter circuit 100 is just powered on, the logic circuit LC has not received the light sensing signal Ss, and the logic circuit LC is configured to automatically generate the control signal G1 and the control signal G2.
In one embodiment, when the switching converter circuit 100 is just powered on, the logic circuit LC has not received the light sensing signal Ss, and the logic circuit LC may generate the control signal G1 and the control signal G2 according to an external signal (not shown).
In one embodiment, the logic circuit LC determines whether to restart according to the light sensing signal Ss. Further, the logic circuit LC determines whether the light sensing signal Ss is interrupted (for example, when the switching conversion circuit 100 is powered on for a period of time, the logic circuit LC determines that the time for not receiving the light sensing signal Ss exceeds 0.1 second, the logic circuit LC determines that the light sensing signal Ss is interrupted), and when the logic circuit LC determines that the light sensing signal Ss is interrupted, the switching conversion circuit is restarted.
One end of the transistor T1 receives a power supply voltage Vcc, the other end of the transistor T1 is configured to output the control signal PGate, and the gate end of the transistor T1 is configured to receive the control signal G1, wherein the transistor T1 determines whether to turn on one end and the other end thereof according to the control signal G1.
One end of the transistor T2 is electrically connected to the other end of the transistor T1, the other end of the transistor T2 is electrically connected to the primary side ground PGND, and the gate of the transistor T2 is configured to receive the control signal G2, wherein the transistor T2 determines whether to turn on one end and the other end thereof according to the control signal G1.
In the embodiment, the transistors T1 and T2 may be implemented by one of an N-type transistor and a P-type transistor, for example, the transistor T1 may be a P-type transistor, and the transistor T2 may be an N-type transistor, and the invention is not limited thereto.
In one embodiment, when the transistor T1 is implemented as one of an N-type transistor and a P-type transistor, and the transistor T2 is implemented as the other of an N-type transistor and a P-type transistor, the control signal G1 and the control signal G2 may be substantially the same.
Thereby, the logic circuit LC may control the transistors T1 and T2 to be turned on or off by the control signal G1 and the control signal G2 to generate the control signal PGate.
Further, referring to fig. 2, the control module 40 is configured to receive the output voltage Vo and the sensing voltage Vsen, and accordingly generate the control signal SGat e for controlling the transistor Q2 and the digital control signal Cs for controlling the light emitting diode D1.
In one embodiment, the control module 40 may be a PWM control module, and the invention is not limited thereto.
Further, the operation of the power conversion circuit 100 controlled by the secondary side will be described below with reference to the schematic timing diagram of fig. 3.
Referring to fig. 2 and fig. 3, first, taking flyback as an example, at time Ta, on the primary side of the transformer 11, the digital control signal Cs is converted from an enable voltage level to a disable voltage level (high voltage level to low voltage level), meanwhile, the control signal PGate controlling the transistor Q1 is changed from an enabled voltage level to a disabled voltage level (high voltage level is changed to low voltage level), the transistor Q1 is turned off, on the secondary side of the transformer 11, the sensing voltage Vsen Is lower than the reference voltage, so the control signal SGate of the transistor Q2 Is converted from the disable voltage level to the enable voltage level (low voltage level Is converted to high voltage level), the transistor Q2 Is turned on, a loop Is formed between two ends of the secondary winding L s, a secondary current Is generated, and the load capacitor C1 starts to be charged.
Between time Ta and time Tb, the secondary-side current Is decreases with time in a substantially linear manner, and the sensing voltage Vsen increases as the secondary-side current Is decreases. At time Tb, the secondary-side current Is stops.
At a time point Tc, when the sensing voltage Vsen reaches a peak (high voltage level), the control module 40 detects a time point (i.e., the time point Tc) of a turning point of the sensing voltage Vsen, at which the digital control signal Cs is converted from a disable voltage level to an enable voltage level (low voltage level is converted to high voltage level), and at the same time, the control signal PGate is controlled to be converted from a disable voltage level to an enable voltage level (low voltage level is converted to high voltage level), the transistor Q1 is turned on to generate a primary side current Ip, the control signal SGate is maintained at the disable voltage level (low voltage level) on the secondary side of the transformer 11, the transistor Q2 is turned off, and the control signal SGate at the disable voltage level is used to prevent the transistor Q2 from malfunctioning, wherein, in the present embodiment, the control module is a Quasi-resonance mode (Quasi-resonance mode, QR mode) and turns on the transistor Q1 by essentially detecting the point in time at which the coil voltage (i.e., the sense voltage Vsen) turns back on the transformer 11. In this way, a voltage conversion process is completed.
In one embodiment, the reference voltage is, for example, -50 millivolts, and the invention is not limited thereto.
In summary, in the present invention, the digital control signal Cs generated by the control module 40 is matched with the digital isolation coupling module 30 driven by a digital signal, so that the control signal PGa te can control the transistor Q1 according to the synchronous converted voltage level of the digital control signal Cs, and the transformer module 10 can precisely adjust the output voltage Vo, thereby achieving the purpose of improving the control precision.
The above description is only an example of the present invention, and is not intended to limit the scope of the present invention.

Claims (13)

1. A switching type conversion circuit controlled by a secondary side is characterized by comprising:
a transformer module for outputting an output voltage;
the switch module is electrically connected with the voltage transformation module;
the digital isolation coupling module is electrically connected with the switch module; and
a control module electrically connected with the transformer module and the digital isolation coupling module,
and is configured to receive the output voltage and,
the control module directly transmits a control signal to the switch module through the digital isolation coupling module according to the change of the output voltage so as to regulate and control the output voltage.
2. The switched mode converter circuit of claim 1, wherein said control module receives said output voltage and a sensed voltage on a secondary side of a transformer of said transformer module and generates a digital control signal therefrom.
3. The switched-mode conversion circuit of claim 2, wherein the digital control signal comprises a PWM control signal and a PDM control signal.
4. The switched mode conversion circuit of claim 2, wherein the control signal is synchronized with the digital control signal.
5. The switched mode conversion circuit of claim 2, wherein the control signal is synchronized with the sense voltage.
6. The switched mode conversion circuit of claim 2, wherein the digital isolation coupling module is a digital optical coupling module.
7. The switched-mode conversion circuit of claim 6, wherein the digital isolation coupling module comprises:
the light emitting diode is electrically connected with the control module and used for receiving the digital control signal;
the photodiode module is optically coupled with the light emitting diode and generates a light sensing signal;
a logic circuit electrically connected to the photodiode module and receiving the light sensing signal,
and generating a first control signal and a second control signal;
a first transistor, one end of which is used for receiving a power voltage, a gate terminal of which is electrically connected with the logic circuit and receives the first control signal, and the first transistor is determined to be switched on or switched off according to the first control signal; and
and one end of the second transistor is electrically connected with the other end of the first transistor and used for outputting the control signal, a gate terminal of the second transistor is electrically connected with the logic circuit and used for receiving the second control signal, and the second transistor is switched on or switched off according to the second control signal.
8. The switched-mode switching circuit of claim 7, wherein the logic circuit is configured to automatically generate the first control signal and the second control signal.
9. The switched-mode switching circuit of claim 7, wherein the logic circuit is configured to generate the first control signal and the second control signal according to an external signal.
10. The switching converter circuit of claim 7, wherein the logic circuit is configured to determine whether to restart according to a state of the light sensing signal.
11. The switching converter circuit of claim 1, wherein the switch module comprises a transistor, one end of the transistor is electrically connected to the primary side of the transformer, a gate terminal of the transistor is electrically connected to the digital isolation coupling module and receives the control signal, and the other end of the transistor is electrically connected to a primary side ground terminal of the transformer.
12. The switched mode power converter circuit of claim 11, wherein said transistors are bipolar transistors, field effect transistors and insulated gate bipolar transistors.
13. The switching converter circuit of claim 1, wherein the switching converter circuit comprises a load capacitor electrically connected to the transformer.
CN202011373776.XA 2020-11-30 2020-11-30 Switching type conversion circuit controlled by secondary side Pending CN114583983A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011373776.XA CN114583983A (en) 2020-11-30 2020-11-30 Switching type conversion circuit controlled by secondary side

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011373776.XA CN114583983A (en) 2020-11-30 2020-11-30 Switching type conversion circuit controlled by secondary side

Publications (1)

Publication Number Publication Date
CN114583983A true CN114583983A (en) 2022-06-03

Family

ID=81767145

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011373776.XA Pending CN114583983A (en) 2020-11-30 2020-11-30 Switching type conversion circuit controlled by secondary side

Country Status (1)

Country Link
CN (1) CN114583983A (en)

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