CN114567155A - Power adapter, overcurrent protection circuit and electronic equipment - Google Patents
Power adapter, overcurrent protection circuit and electronic equipment Download PDFInfo
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- CN114567155A CN114567155A CN202210464115.0A CN202210464115A CN114567155A CN 114567155 A CN114567155 A CN 114567155A CN 202210464115 A CN202210464115 A CN 202210464115A CN 114567155 A CN114567155 A CN 114567155A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
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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 embodiment of the application provides a power adapter, an overcurrent protection circuit and electronic equipment, wherein a primary control chip in the power adapter is in isolated connection with a secondary protocol chip; the primary control chip comprises a main control circuit, the power circuit controls the primary control chip through the main control circuit, the secondary protocol chip comprises an overcurrent protection circuit, and the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit. This application gathers secondary opto-coupler current through the sampling sub-circuit in order to generate the detected signal, and control sub-circuit gathers secondary output voltage and primary input voltage in order to produce the detected signal threshold value, compares sub-circuit with detected signal and detected signal threshold value and compares, and anti-shake sub-circuit carries out anti-shake to the comparison result and detects, and protection sub-circuit generates first protection signal according to the comparison result that detects through anti-shake, and secondary agreement chip realizes overcurrent protection according to first protection signal.
Description
Technical Field
The application belongs to the technical field of circuit protection, and particularly relates to a power adapter, an overcurrent protection circuit and electronic equipment.
Background
Currently, a flyback converter in an existing high-power adapter is most widely applied to an existing adapter due to primary/secondary isolation, simple topology and mature technology. For the high-power adapter, the secondary protocol chip samples the output current through the secondary current sampling resistor and triggers corresponding protection when the output current is abnormal. However, when the secondary chip current sampling circuit fails, the output current can trigger protection only when reaching the current protection point of the primary control chip, but the output current protection point of the high input voltage and the low output voltage is significantly higher than the rated output current, which may cause that the system cannot be protected in time when abnormal, and may damage equipment or even cause danger when serious.
At present, a common method is to detect the switching frequency of the secondary synchronous rectifier, and when the switching frequency is reduced to a certain threshold and the voltage across the current sampling resistor is low, the system considers that the current sampling circuit has a fault and outputs an overcurrent to perform corresponding protection. However, in the prior art, when the primary enters the CCM mode, the switching frequency is a constant value, so that the frequency of the secondary synchronous rectifier tube is also a constant value, and at this time, the overcurrent cannot be detected by the method.
Disclosure of Invention
The embodiment of the application provides a power adapter, an overcurrent protection circuit and electronic equipment, so that overcurrent protection can be realized when the power adapter is in a CRM (critical conduction mode) mode and a CCM (continuous conduction mode) mode.
In a first aspect, an embodiment of the present application provides a power adapter, which includes a power circuit, a primary control chip, a secondary protocol chip, and an external compensation circuit, where the primary control chip is isolated from the secondary protocol chip by the external compensation circuit, the power circuit is connected to the primary control chip and the external compensation circuit, and the external compensation circuit is connected to the secondary protocol chip; the primary control chip comprises a main control circuit which controls the power circuit to output voltage, the secondary protocol chip comprises an overcurrent protection circuit, and the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current;
the control sub-circuit is used for acquiring a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
and the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result.
The anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of anti-shake detection and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to perform overcurrent protection.
In a second aspect, an embodiment of the present application provides an overcurrent protection circuit, which is applied to a power adapter, where the power adapter includes a power circuit, a primary control chip, a secondary protocol chip, and an external compensation circuit, the primary control chip is connected to the secondary protocol chip in an isolated manner through the external compensation circuit, the power circuit is connected to the primary control chip and the external compensation circuit, and the external compensation circuit is connected to the secondary protocol chip; the primary control chip comprises a main control circuit, the power circuit controls the power circuit through the main control circuit, and the secondary protocol chip comprises an overcurrent protection circuit;
the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current;
the control sub-circuit is used for acquiring a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
and the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result.
The anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of anti-shake detection and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to perform overcurrent protection.
In a third aspect, an embodiment of the present application provides an electronic device, including the power adapter according to the first aspect or the overcurrent protection circuit according to the second aspect.
It can be seen that, in the embodiment of the present application, a sampling sub-circuit collects a secondary optocoupler current to generate a detection signal, a control sub-circuit collects a secondary output voltage and a primary input voltage to generate a detection signal threshold, a comparison sub-circuit compares the detection signal with the detection signal threshold to obtain a comparison result, an anti-jitter sub-circuit performs anti-jitter detection on the comparison result, a protection sub-circuit generates a first protection signal according to the comparison result passing through anti-jitter detection, and sends the first protection signal to a main control unit of a secondary protocol chip, and the secondary protocol chip implements overcurrent protection according to the first protection signal. Therefore, the power adapter can realize overcurrent protection by detecting the current flowing through the secondary optocoupler in both CRM and CCM modes.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an overcurrent protection circuit according to an embodiment of the present application;
fig. 2 is a circuit diagram of an overcurrent protection circuit according to an embodiment of the present application;
FIG. 3 is a schematic structural diagram of a power adapter provided in an embodiment of the present application;
fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The terms "first," "second," and the like in the description and claims of the present application and in the above-described drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, system, article, or apparatus.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
The embodiment of the application provides an overcurrent protection circuit, so that overcurrent protection can be realized in both a CCM (charge-coupled device) mode and a CRM (customer relationship management) mode in a power adapter, and a system architecture related to the embodiment of the application is introduced below.
Referring to fig. 1, the present application provides an overcurrent protection circuit 31, which is applied to a power adapter, where the power adapter further includes a power circuit 10, a primary control chip 20, a secondary protocol chip 30, and an external compensation circuit 40, the primary control chip 20 is isolated from the secondary protocol chip 30 by the external compensation circuit 40, the power circuit 10 is connected to the primary control chip 20 and the external compensation circuit 40, and the external compensation circuit 40 is connected to the secondary protocol chip 30; the primary control chip 20 comprises a main control circuit 21, the main control circuit 21 controls the power circuit 10 to output voltage, and the secondary protocol chip 30 comprises an overcurrent protection circuit 31;
the over-current protection circuit 31 comprises a sampling sub-circuit 310, a control sub-circuit 320, a comparison sub-circuit 330, an anti-shake sub-circuit 340 and a protection sub-circuit 350;
the sampling sub-circuit 310 is configured to collect a secondary optocoupler current IF of the external compensation circuit 40, and generate a detection signal according to the secondary optocoupler current IF;
the control sub-circuit 320 is configured to collect a secondary output voltage Vout and a primary input voltage Vbulk, and generate a detection signal threshold according to the secondary output voltage Vout and the primary input voltage Vbulk;
the comparison sub-circuit 330 is configured to compare the detection signal with the detection signal threshold to obtain a comparison result.
The anti-shake sub-circuit 340 is configured to perform anti-shake detection on the comparison result;
the protection sub-circuit 350 is configured to generate a first protection signal or a second protection signal according to the comparison result of the anti-shake detection, and send the first protection signal or the second protection signal to the main control unit of the secondary protocol chip 30, where the first protection signal is used to instruct the secondary protocol chip 30 to perform overcurrent protection.
By way of example, the specific structure of the over-current protection circuit 31 is not limited to the form of the sampling sub-circuit 310, the control sub-circuit 320, the comparison sub-circuit 330, the anti-shake sub-circuit 340 and the protection sub-circuit 350. The sampling sub-circuit 310, the control sub-circuit 320, the comparison sub-circuit 330, the anti-shake sub-circuit 340 and the protection sub-circuit 350 may also use other existing circuit structures, and only the functions to be realized in this embodiment need to be realized.
In the specific implementation, in this embodiment, first, the sampling sub-circuit 310 collects a secondary optocoupler current IF to generate a detection signal, the control sub-circuit 320 collects a secondary output voltage Vout and a primary input voltage Vbulk to generate a detection signal threshold, the comparison sub-circuit 330 compares the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit 340 performs anti-shake detection on the comparison result, the protection sub-circuit 350 generates a first protection signal according to the comparison result passing the anti-shake detection, and sends the first protection signal to the main control unit of the secondary protocol chip 30, and the secondary protocol chip 30 implements overcurrent protection according to the first protection signal. Therefore, overcurrent protection can be realized by detecting the current flowing through the secondary optocoupler OptoB in both CRM and CCM modes of the power adapter.
In this embodiment, the sampling sub-circuit collects a secondary optocoupler current to generate a detection signal, the control sub-circuit collects a secondary output voltage Vout and a primary input voltage Vbulk to generate a detection signal threshold, the comparison sub-circuit compares the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit performs anti-shake detection on the comparison result, the protection sub-circuit generates a first protection signal according to the comparison result passing the anti-shake detection and sends the first protection signal to the main control unit of the secondary protocol chip, and the secondary protocol chip implements overcurrent protection according to the first protection signal.
In one possible embodiment, the sampling sub-circuit 310 includes a secondary output feedback control unit 311 and a mirror current unit 312; the secondary output feedback control unit 311 is configured to adjust a secondary optocoupler current IF to obtain the secondary output voltage Vout; the mirror current unit 312 is configured to generate a mirror current of the secondary optocoupler current IF, and generate a corresponding detection signal according to the mirror current and a voltage and a resistance inside the secondary protocol chip.
In a specific implementation, as shown in fig. 2, the output voltage Vout of the power circuit 10 is divided by a certain proportion to obtain the divided voltage Vdiv, and the divided voltage Vdiv and the reference voltage source Vref control the current flowing through the MOS transistor by controlling the output of the operational amplifier, so as to adjust the magnitude of the secondary optocoupler current IF to realize feedback adjustment of the output. The mirror current unit 312 mirrors the secondary optocoupler current IF, and converts the secondary optocoupler current IF into the detection signal Vce through the internal voltage and the resistance of the chip.
In the embodiment, the sampling of the secondary output current is realized by sampling the secondary optocoupler current IF, so as to provide a detection signal for subsequent overcurrent judgment.
In one possible embodiment, as shown in fig. 2, the secondary output feedback control unit 311 includes a first MOS transistor Q1, an error amplifier EA, and a reference voltage source Vref, a gate of the first MOS transistor Q1 is connected to the output terminal of the error amplifier EA, a drain of the first MOS transistor Q1 is connected to the output terminal of the secondary optical coupler OptoB, a source of the first MOS transistor Q1 is connected to the mirror current unit 312, a non-inverting input terminal of the error amplifier EA is connected to the Vdiv voltage, an inverting input terminal of the error amplifier EA is connected to the positive electrode of the reference voltage source Vref, and a negative electrode of the reference voltage source Vref is connected to the signal ground.
In specific implementation, the voltage Vdiv is obtained by dividing the output voltage Vout according to a certain proportion, the error amplifier EA controls the current flowing through the MOS transistor to adjust the secondary optocoupler current IF, which reflects the secondary output condition, and the secondary optocoupler current IF is converted into the detection signal Vce inside the chip after being mirrored by the mirror current unit 312.
It can be seen that in this embodiment, sampling of the secondary output current is realized by sampling the secondary optocoupler current IF, so as to provide a sampling current for subsequent overcurrent protection.
In one possible embodiment, as shown in fig. 2, the mirror current unit 312 includes a first transistor Q2, a second transistor Q3, and a first resistor R1; the collector of the first triode Q2 is connected with the secondary output feedback control unit, the base of the first triode and the base of the second triode Q3, the collector of the second triode Q3 is connected with one end of the first resistor R1 and the comparator circuit 330, the other end of the first resistor R1 is connected with the internal voltage, and the emitter of the first triode Q2 and the emitter of the second triode Q3 are both connected with the signal ground.
In a specific implementation, the first transistor Q2 and the second transistor Q3 form a mirror circuit, and the currents of the two collectors of the first transistor Q2 and the second transistor Q3 are the same (i.e., Imos1= Imos 2). After the first triode receives the detection current, the value of Imos2 can be known, and therefore the value of the detection signal Vce can be obtained. And then comparing with the detection signal threshold value to determine whether overcurrent protection is needed.
The following is a separate description of specific circuit principles.
Fig. 1 is a schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the present application, and the diagram includes a power circuit 10, a primary control chip 20, a secondary protocol chip 30, and an external compensation circuit 40. The principle of the invention is to detect the secondary optocoupler current IF, i.e. the current flowing through the MOSFET inside the secondary protocol chip 30, to detect the output current, so that the output current threshold can be set to realize the required overcurrent protection.
Taking the overcurrent protection circuit shown in fig. 2 as an example, the method of detecting the pin current Imos1 of the secondary protocol chip 30 and generating the corresponding detection signal Vce is not limited to this. In this circuit, Vout is set by the secondary protocol chip 30, Vbulk is obtained by detecting a voltage value V = Vout + Vbulk/n when the synchronous rectifier Q4 of the power circuit is turned off in the reverse direction, Imos2 is Imos1= Imos2 which is a mirror image of a current Imos1 flowing into the pin of the secondary protocol chip 30, and thus Vce = VDD-Imos 1R 1 can be obtained, where VDD is a voltage inside the secondary protocol chip and R1 is a resistance inside the secondary protocol chip 30. The control sub-circuit 320 of the secondary protocol chip 30 sets a corresponding detection signal threshold Vth according to Vout and Vbulk (the method for generating the detection signal Vth is described later), and sends the detection signal threshold Vth to a "-" terminal of a comparator Comp1, and sends Vce to a "+" terminal of a comparator Comp1, and when the output current Io increases, VCS rises, VFB (i.e., VFB _ open in fig. 2) rises, the primary optocoupler current Ice decreases, the secondary optocoupler current IF decreases, Imos1 and Imos2 decrease, and Vce rises. Therefore, when the output current is too large, resulting in too small Imos1, and Vce exceeds the detection signal threshold Vth, if the state is not released within a certain time, the secondary protocol chip 30 will set the signal of the protection sub-circuit 350 high, and then the secondary protocol chip 30 can use the signal alone as current-limiting protection or combine with other internal signals to complete the actually required current-limiting protection, for example, after setting the output current threshold, when the signal of the protection sub-circuit 350 is high, the secondary protocol chip 30 directly performs current-limiting protection on the output, or when the protection sub-circuit 350 is high and the current detected by the secondary chip through the sampling resistor is less than the set threshold, the secondary protocol chip 30 determines that the secondary sampling resistor is short-circuited to perform current-limiting protection on the output, and the protection measure can also be set according to requirements, for example, the path power tube Q5 or the pull-down optical coupler is turned off.
For the CRM mode, the output current Io is related to the secondary optocoupler current IF by:
- (formula 1)
For the CCM mode, the output current Io is related to the secondary optocoupler current IF by:
- (formula 2)
Therefore, for the CRM or CCM mode, when the system parameter, the input voltage Vbulk and the output voltage Vout are known, the secondary optocoupler current IF-protection corresponding to the output current limit value Io-protection can be obtained according to formula 1 or formula 2, and since IF = Imos1= Imos2 and Vce = VDD-Imos2 × R1, the Vce-protection obtained under the output current limit value Io-protection is the detection signal threshold Vth. When the output current Io exceeds the current limiting value Io-protection, the detection signal Vce exceeds the detection signal threshold Vth to trigger the corresponding overcurrent protection.
Referring to fig. 2 and fig. 3, the present application further provides a power adapter 100, which includes a power circuit 10, a primary control chip 20, a secondary protocol chip 30, and an external compensation circuit 40, wherein the primary control chip 20 is isolated from the secondary protocol chip 30 by the external compensation circuit 40, the power circuit 10 is connected to the primary control chip 20 and the external compensation circuit 40, and the external compensation circuit 40 is connected to the secondary protocol chip 30; the primary control chip 20 comprises a main control circuit 21 which controls the power circuit 10 to output voltage, the secondary protocol chip 30 comprises an overcurrent protection circuit 31, and the overcurrent protection circuit 31 comprises a sampling sub-circuit 310, a control sub-circuit 320, a comparison sub-circuit 330, an anti-shake sub-circuit 340 and a protection sub-circuit 350;
the sampling sub-circuit 310 is configured to collect a secondary optocoupler current IF output by the external compensation circuit 40, and generate a detection signal according to the secondary optocoupler current IF;
the control sub-circuit 320 is configured to collect a secondary output voltage Vout and a primary input voltage Vbulk of the power circuit 10, and generate a detection signal threshold according to the secondary output voltage Vout and the primary input voltage Vbulk;
the comparison sub-circuit 330 is configured to compare the detection signal with the detection signal threshold to obtain a comparison result.
The anti-shake sub-circuit 340 is configured to perform anti-shake detection on the comparison result;
the protection sub-circuit 350 is configured to generate a first protection signal or a second protection signal according to the comparison result of the anti-shake detection, and send the first protection signal or the second protection signal to the main control unit of the secondary protocol chip 30, where the first protection signal is used to instruct the secondary protocol chip 30 to perform overcurrent protection.
For example, the power adapter 100 may be a mobile power adapter 100, or may also be a power adapter 100 of a device such as an electric vehicle, and the overcurrent protection circuit 31 applied in this embodiment is a range to be protected by this application, and is not limited thereto.
Furthermore, since the overcurrent protection circuit 31 has been described in detail above, it is again not to be limited exclusively.
It can be seen that, in this embodiment of the application, first, the sampling sub-circuit 310 collects the secondary optocoupler current IF to generate a detection signal, the control sub-circuit collects the secondary output voltage Vout and the primary input voltage Vbulk to generate a detection signal threshold, the comparison sub-circuit 330 compares the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit 340 performs anti-shake detection on the comparison result, the protection sub-circuit 350 generates a first protection signal according to the comparison result passing the anti-shake detection, and sends the first protection signal to the main control unit of the secondary protocol chip 30, and the secondary protocol chip 30 implements overcurrent protection according to the first protection signal. This enables overcurrent protection to be achieved in both CRM and CCM modes of the power adapter 100 by detecting the current IF flowing through the secondary optocoupler OptoB.
In one possible embodiment, the sampling sub-circuit 310 includes a secondary output feedback control unit 311 and a mirror current unit 312; the secondary output feedback control unit 311 is configured to adjust a secondary optocoupler current IF to obtain the output voltage; the mirror current unit 312 is configured to generate a mirror current of the secondary optocoupler current IF, and generate a corresponding detection signal according to the mirror current and a voltage and a resistance inside the secondary protocol chip.
In one possible embodiment, the secondary output feedback control unit 311 includes a first MOS transistor Q1, an error amplifier EA, and a reference voltage source Vref, a gate of the first MOS transistor Q1 is connected to an output terminal of the error amplifier EA, a drain of the first MOS transistor Q1 is connected to an output terminal of the secondary optical coupler OptoB in the external compensation circuit 40, a source of the first MOS transistor Q1 is connected to the mirror current unit 312, a non-inverting input terminal of the error amplifier EA is connected to the Vdiv voltage, an inverting input terminal of the error amplifier EA is connected to a positive electrode of the reference voltage source Vref, and a negative electrode of the reference voltage source Vref is connected to a signal ground.
In one possible embodiment, the mirror current unit 312 includes a first transistor Q2, a second transistor Q3, and a first resistor R1;
the collector of the first triode Q2 is connected with the secondary output feedback control unit, the base of the first triode and the base of the second triode Q3, the collector of the second triode Q3 is connected with one end of the first resistor R1 and the comparator circuit 330, the other end of the first resistor R1 is connected with the internal voltage, and the emitter of the first triode Q2 and the emitter of the second triode Q3 are both connected with the signal ground.
In one possible embodiment, the protection mode of the overcurrent protection comprises pulling down a primary side optical coupler or turning off a path MOS tube to cut off a power supply loop.
In this embodiment, the sampling sub-circuit collects a secondary optocoupler current to generate a detection signal, the control sub-circuit collects a secondary output voltage Vout and a primary input voltage Vbulk to generate a detection signal threshold, the comparison sub-circuit compares the detection signal with the detection signal threshold to obtain a comparison result, the anti-shake sub-circuit performs anti-shake detection on the comparison result, the protection sub-circuit generates a first protection signal according to the comparison result passing the anti-shake detection and sends the first protection signal to the main control unit of the secondary protocol chip, and the secondary protocol chip implements overcurrent protection according to the first protection signal.
Referring to fig. 4, the present application further provides an electronic device 1 including the power adapter or the over-current protection circuit as described above. The electronic device 1 may be any device that needs a power adapter or the overcurrent protection circuit described above, such as a mobile phone, a computer, a television, an electric vehicle, and the like, which is not limited to the above. Since the power adapter and the over-current protection circuit have been described in detail above, they are not described in detail herein.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications can be easily made by those skilled in the art without departing from the spirit and scope of the present invention, and it is within the scope of the present invention to include different functions, combination of implementation steps, software and hardware implementations.
Claims (10)
1. A power adapter is characterized by comprising a power circuit, a primary control chip, a secondary protocol chip and an external compensation circuit, wherein the primary control chip is connected with the secondary protocol chip in an isolated mode through the external compensation circuit; the primary control chip comprises a main control circuit, and the main control circuit controls the power circuit to output voltage; the secondary protocol chip comprises an overcurrent protection circuit, and the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current;
the control sub-circuit is used for acquiring a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result;
the anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of anti-shake detection and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to perform overcurrent protection.
2. The power adapter as claimed in claim 1, wherein the sampling sub-circuit comprises a secondary output feedback control unit and a mirror current unit;
the secondary output feedback control unit is used for adjusting the current of the secondary optocoupler to obtain the secondary output voltage;
and the mirror current unit is used for generating a mirror current of the secondary optocoupler current and generating a corresponding detection signal according to the mirror current and the voltage and the resistance in the secondary protocol chip.
3. The power adapter as claimed in claim 2 wherein the external compensation circuit comprises a secondary optocoupler configured to output a secondary optocoupler current;
the secondary output feedback control unit comprises a first MOS tube, an error amplifier and a reference voltage source, the grid electrode of the first MOS tube is connected with the output end of the error amplifier, the drain electrode of the first MOS tube is connected with the output end of the secondary optical coupler, the source electrode of the first MOS tube is connected with the mirror current unit, the positive phase input end of the error amplifier is connected with the Vdiv voltage, the reverse phase input end of the error amplifier is connected with the anode of the reference voltage source, and the cathode of the reference voltage source is connected with the signal ground.
4. The power adapter as claimed in claim 2, wherein the mirror current unit comprises a first transistor, a second transistor and a first resistor;
the collector of the first triode is connected with the secondary output feedback control unit, the base of the first triode and the base of the second triode, the collector of the second triode is connected with one end of the first resistor and the comparator circuit, the other end of the first resistor is connected with the internal voltage VDD, and the emitter of the first triode and the emitter of the second triode are both connected with a signal ground.
5. The power adapter as claimed in claim 4, wherein the protection mode of the over-current protection includes pulling down a primary side optical coupler or turning off a path MOS tube to cut off a power supply loop.
6. The overcurrent protection circuit is applied to a power adapter, the power adapter comprises a power circuit, a primary control chip, a secondary protocol chip and an external compensation circuit, the primary control chip is in isolated connection with the secondary protocol chip through the external compensation circuit, the power circuit is connected with the primary control chip and the external compensation circuit, and the external compensation circuit is connected with the secondary protocol chip; the primary control chip comprises a main control circuit which controls the power circuit to output voltage, and the secondary protocol chip comprises an overcurrent protection circuit;
the overcurrent protection circuit comprises a sampling sub-circuit, a control sub-circuit, a comparison sub-circuit, an anti-shake sub-circuit and a protection sub-circuit;
the sampling sub-circuit is used for collecting secondary optocoupler current output by the external compensation circuit and generating a detection signal according to the secondary optocoupler current
The control sub-circuit is used for acquiring a secondary output voltage and a primary input voltage of the power circuit and generating a detection signal threshold according to the secondary output voltage and the primary input voltage;
the comparison sub-circuit is used for comparing the detection signal with the detection signal threshold value to obtain a comparison result;
the anti-shake sub-circuit is used for carrying out anti-shake detection on the comparison result;
the protection sub-circuit is used for generating a first protection signal or a second protection signal according to a comparison result of anti-shake detection and sending the first protection signal or the second protection signal to a main control unit of a secondary protocol chip, wherein the first protection signal is used for indicating the secondary protocol chip to perform overcurrent protection.
7. The overcurrent protection circuit of claim 6, wherein the sampling sub-circuit comprises a secondary output feedback control unit and a mirror current unit;
the secondary output feedback control unit is used for adjusting the current of the secondary optocoupler to obtain the secondary output voltage;
and the mirror current unit is used for generating mirror current of the secondary optocoupler current and generating corresponding detection signals according to the mirror current and voltage and resistance voltage in the secondary protocol chip.
8. The overcurrent protection circuit of claim 7, wherein the external compensation circuit comprises a secondary optocoupler configured to output a secondary optocoupler current; the secondary output feedback control unit comprises a first MOS tube, an error amplifier and a reference voltage source, the grid electrode of the first MOS tube is connected with the output end of the error amplifier, the drain electrode of the first MOS tube is connected with the output end of the secondary optical coupler, the source electrode of the first MOS tube is connected with the mirror current unit, the positive phase input end of the error amplifier is connected with the Vdiv voltage, the reverse phase input end of the error amplifier is connected with the anode of the reference voltage source, and the cathode of the reference voltage source is connected with the signal ground.
9. The overcurrent protection circuit of claim 8, wherein the mirror current unit comprises a first transistor, a second transistor, and a first resistor;
the collector of the first triode is connected with the secondary output feedback control unit, the base of the first triode and the base of the second triode, the collector of the second triode is connected with one end of the first resistor and the comparator circuit, the other end of the first resistor is connected with internal voltage, and the emitter of the first triode and the emitter of the second triode are both connected with a signal ground.
10. An electronic device comprising a power adapter according to any one of claims 1-5 or an overcurrent protection circuit according to any one of claims 6-9.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210464115.0A CN114567155B (en) | 2022-04-29 | 2022-04-29 | Power adapter, overcurrent protection circuit and electronic equipment |
| CN202211007976.2A CN117013495A (en) | 2022-04-29 | 2022-04-29 | Overcurrent protection circuit, related power adapter and electronic equipment |
| PCT/CN2023/089793 WO2023207789A1 (en) | 2022-04-29 | 2023-04-21 | Power adapter, over-current protection circuit, and electronic device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210464115.0A CN114567155B (en) | 2022-04-29 | 2022-04-29 | Power adapter, overcurrent protection circuit and electronic equipment |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211007976.2A Division CN117013495A (en) | 2022-04-29 | 2022-04-29 | Overcurrent protection circuit, related power adapter and electronic equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114567155A true CN114567155A (en) | 2022-05-31 |
| CN114567155B CN114567155B (en) | 2022-07-08 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211007976.2A Pending CN117013495A (en) | 2022-04-29 | 2022-04-29 | Overcurrent protection circuit, related power adapter and electronic equipment |
| CN202210464115.0A Active CN114567155B (en) | 2022-04-29 | 2022-04-29 | Power adapter, overcurrent protection circuit and electronic equipment |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211007976.2A Pending CN117013495A (en) | 2022-04-29 | 2022-04-29 | Overcurrent protection circuit, related power adapter and electronic equipment |
Country Status (2)
| Country | Link |
|---|---|
| CN (2) | CN117013495A (en) |
| WO (1) | WO2023207789A1 (en) |
Cited By (3)
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| WO2023207789A1 (en) * | 2022-04-29 | 2023-11-02 | 深圳英集芯科技股份有限公司 | Power adapter, over-current protection circuit, and electronic device |
| CN117578359A (en) * | 2024-01-11 | 2024-02-20 | 深圳市新源鑫电器有限公司 | Automatic over-temperature and over-voltage protection device and method for power adapter |
| CN117578359B (en) * | 2024-01-11 | 2024-04-26 | 深圳市新源鑫电器有限公司 | Automatic over-temperature and over-voltage protection device and method for power adapter |
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| CN117578359B (en) * | 2024-01-11 | 2024-04-26 | 深圳市新源鑫电器有限公司 | Automatic over-temperature and over-voltage protection device and method for power adapter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117013495A (en) | 2023-11-07 |
| WO2023207789A1 (en) | 2023-11-02 |
| CN114567155B (en) | 2022-07-08 |
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