CN114094854B - Power conversion system, control chip thereof and power supply control circuit - Google Patents
Power conversion system, control chip thereof and power supply control circuit Download PDFInfo
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- CN114094854B CN114094854B CN202111317466.0A CN202111317466A CN114094854B CN 114094854 B CN114094854 B CN 114094854B CN 202111317466 A CN202111317466 A CN 202111317466A CN 114094854 B CN114094854 B CN 114094854B
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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
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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
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
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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
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
- H02M3/1582—Buck-boost converters
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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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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention provides a power conversion system, a power supply control circuit and a control chip thereof. The power supply control circuit is used for supplying power to the control driving circuit, the control driving circuit is used for controlling a power device of the power conversion system, the power supply control circuit obtains power supply input voltage through an auxiliary winding coupled with the power conversion system, the power supply control circuit comprises a switch circuit and a linear circuit, and an output end of the switch circuit is compounded with an output end of the linear circuit and provides power supply voltage for supplying power to the control driving circuit. The power conversion system, the control chip and the power supply control circuit thereof can expand the output range of output voltage, simultaneously have reliable power supply and lower standby loss, and have higher power density and power efficiency.
Description
Technical Field
The invention relates to the field of electronics, in particular, but not exclusively, to a power conversion system, a control chip and a power supply control circuit thereof.
Background
Power converters are an indispensable component in electronic systems. As is well known, power converters include two main types, linear converters and switching power converters, which can be divided into isolated and non-isolated types in terms of conversion. In the case of a switching power supply, an isolated switching power supply converter is widely applicable, and has wide application in a telecommunication wireless network, an automobile and medical equipment because the isolated switching power supply converter can protect a load from high voltage impact and damage of an input bus. In various topologies of the isolated converter, the flyback converter (Flyback Converter) topology does not need an output filter inductor, so that the circuit structure is simple, the output is isolated, the cost is low, and the flyback converter has a high proportion in the application of terminal equipment. The isolated power conversion system is used in a power adapter for the USB-PD fast-charge protocol due to the advantages described above.
Fig. 1 shows a schematic diagram of an isolated flyback converter applied to a medium-small power adapter, and the isolated flyback converter is controlled by adopting secondary feedback SSR (Secondary Side Regulation), and is a main stream control architecture of the medium-small power adapter at present. Fig. 1 shows a widely used flyback conversion type power conversion system for converting Alternating Current (AC) into Direct Current (DC). The system comprises: full bridge rectification, a power controller, a transformer, a primary side power MOS switch and a current detection resistor, secondary rectification filtering and an isolated feedback compensation network. The power controller is used for controlling a power device MOS of the driving power conversion system so as to regulate the output voltage Vout. During the starting stage, the flyback conversion system generally takes electricity from a bus through a starting resistor Rst (shown in fig. 1) or a high-voltage starting Junction Field Effect Transistor (JFET) tube built in a chip, and is used for supplying power to a circuit in a power controller. After the start-up is finished, the auxiliary winding La (shown in FIG. 1) continuously supplies power to the power controller chip. However, the voltage of the auxiliary winding La is limited by the variation of the output voltage Vout, resulting in a variation of the supply voltage VDD of the flyback conversion system, approximately equal to (Na/Ns) Vout, where Na is the number of auxiliary winding turns and Ns is the number of secondary winding turns.
However, in the case of PD fast charging, the output voltage Vout required by the load provided by the power conversion system has a large variation range, such as for PD3.0, the output voltage Vout varies from 3V to 21V, thus requiring a large variation in the operating range of the supply voltage VDD. For example, when the minimum operating voltage of the supply voltage VDD is 10V, it means that the supply voltage VDD needs to be supplied with 10V even when the output voltage Vout is low, such as 3V, and accordingly, when the output voltage Vout is 21V, the supply voltage VDD may be as high as 70V, but a high supply voltage means that the withstand voltage requirement on the supply voltage pin VDD is high, and when the supply voltage VDD is high, the loss of the supply control circuit inside the chip is also large, and the heat generation is a large problem. In addition, in many applications, such as gallium nitride driving, it is desirable that the supply voltage be of a small or fixed value that does not vary with the auxiliary winding voltage.
In view of this, it is desirable to provide a new power supply control circuit for supplying power to the inside of the control chip of the power conversion system, so as to adapt to a larger variation range of the output voltage Vout in the PD fast charging situation.
Disclosure of Invention
At least in view of one or more problems in the background art, the present invention provides a power conversion system, a control chip thereof, and a power supply control circuit.
According to one aspect of the present invention, a control chip for a power conversion system has a first pin for coupling to a first end of an inductor, and a second pin for coupling to a first capacitor and an auxiliary winding through a diode, the second pin for coupling to a second capacitor, the control chip comprising: the switching circuit comprises a switch, wherein a first end of the switch is coupled with the first pin, a second end of the switch is coupled with a first end of the rectifying tube, and a second end of the rectifying tube is coupled with the second pin; the linear circuit comprises a linear device, wherein a first end of the linear device is coupled with the first pin, and a second end of the linear device is coupled with the second pin; a selection control circuit for controlling the enable switch circuit or the linear circuit based on the voltage of the second end of the inductor or the voltage of the second pin; and the control driving circuit is provided with a power supply end and a signal output end, wherein the power supply end is coupled with the second pin, and the signal output end is used for driving a power device of the power supply conversion system.
In one embodiment, the inductor, the switch and the rectifying tube form a boost circuit, and the duty cycle of the boost circuit is preset fixed.
In one embodiment, the control chip further has a third pin for externally coupling to a control terminal of the power device, wherein the signal output terminal is coupled to the third pin.
According to another aspect of the present invention, a control chip for a power conversion system has a first pin for coupling to a first capacitor and an auxiliary winding through a diode, and a second pin for coupling to a second capacitor, the control chip comprising: the switching circuit comprises an inductor and a switch, wherein the first end of the inductor is coupled with the first end of the switch, the second end of the inductor is coupled with the first pin, the second end of the switch is coupled with the first end of the rectifying tube, and the second end of the rectifying tube is coupled with the second pin; the linear circuit comprises a linear device, wherein a first end of the linear device is coupled with a first pin or a first end of an inductor, and a second end of the linear device is coupled with a second pin; a selection control circuit for controlling the enable switch circuit or the linear circuit based on the voltage of the second end of the inductor; and the control driving circuit is provided with a power supply end and a signal output end, wherein the power supply end is coupled with the second pin, and the signal output end is used for driving a power device of the power supply conversion circuit.
According to a further aspect of the present invention, a power supply control circuit for a power conversion system is presented, the power supply control circuit being configured to supply power to a control driving circuit, the control driving circuit being configured to control a power device of the power conversion system, the power supply control circuit obtaining a power supply input voltage by coupling an auxiliary winding of the power conversion system, the power supply control circuit comprising a switching circuit and a linear circuit, an output of the switching circuit and an output of the linear circuit being combined and providing the power supply voltage for powering the control driving circuit.
In one embodiment, the power supply control circuit further comprises a selection control circuit selectively switching between the switching circuit and the linear circuit based on the power supply input voltage for enabling the switching circuit or the linear circuit.
In one embodiment, the switching circuit is a boost circuit, the boost circuit comprises an inductor, a switch and a rectifying tube, wherein a first end of the inductor is coupled with a first end of the switch and a first end of the rectifying tube, a second end of the inductor is coupled with an auxiliary winding through a diode, a second end of the switch is grounded, a second end of the rectifying tube is an output end of the switching circuit, when the power supply input voltage is lower than a preset threshold value, the boost circuit is enabled by the selection control circuit, the switch and the rectifying tube are alternately conducted, and a linear device in the linear circuit is turned off; when the power supply input voltage is higher than a preset threshold value, the selection control circuit enables the linear circuit, the booster circuit stops working, and the linear device is conducted.
In one embodiment, the boost circuit operates at a fixed duty cycle.
In one embodiment, the selection control circuit calculates a supply input voltage Vin, vin=vdd×doff based on the supply voltage VDD, where Doff is a duty cycle of the boost circuit, and selectively switches between the boost circuit and the linear circuit for enabling the boost circuit or the linear circuit based on the calculated supply input voltage.
In one embodiment, the selection control circuit includes: a voltage detection circuit for detecting a power supply voltage and providing a voltage detection signal; a calculation circuit that receives the voltage detection signal and the duty cycle signal, calculates a calculation signal that characterizes the power supply input voltage; a comparison circuit that compares the calculation signal with the threshold signal; and a switching control circuit that enables the switching circuit or the linear circuit based on a comparison result of the comparison circuit.
In one embodiment, the rectifier in the switching circuit and the linear device of the linear circuit multiplex the same switching device, selectively controlling the switching device to operate in a switching state or a linear state based on the supply input voltage.
According to a further aspect of the present invention, a power conversion system is presented, comprising a control chip or a power supply control circuit according to any of the above embodiments.
In one embodiment, the power conversion system is used in a power adapter of a PD fast charge protocol.
The power conversion system, the control chip and the power supply control circuit thereof can expand the output range of output voltage, simultaneously have reliable power supply and lower standby loss, and have higher power density and power efficiency.
Drawings
The accompanying drawings are included to provide a further understanding of the invention, and together with the description serve to explain the embodiments of the invention, and do not constitute a limitation of the invention.
FIG. 1 shows a schematic diagram of an isolated flyback converter;
FIG. 2 shows a schematic diagram of a power conversion system according to an embodiment of the invention;
FIG. 3 shows a schematic diagram of a control chip for a power conversion system according to an embodiment of the invention;
FIG. 4 shows a schematic diagram of a power supply control circuit according to an embodiment of the invention;
FIG. 5 illustrates a linear circuit embodiment according to an embodiment of the invention;
FIG. 6 shows a schematic diagram of a control chip according to an embodiment of the invention;
fig. 7 shows a schematic diagram of a power supply control circuit according to an embodiment of the invention.
Detailed Description
For a further understanding of the present invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are merely intended to illustrate further features and advantages of the invention, and are not limiting of the claims of the invention.
The description of this section is intended to be illustrative of only a few exemplary embodiments and the invention is not to be limited in scope by the description of the embodiments. Combinations of the different embodiments, and alternatives of features from the same or similar prior art means and embodiments are also within the scope of the description and protection of the invention.
"coupled" or "connected" in the specification includes both direct and indirect connections. An indirect connection is a connection via an intermediary, such as a connection via an electrically conductive medium, such as a conductor, where the electrically conductive medium may contain parasitic inductance or parasitic capacitance, or may be a connection via an intermediary circuit or component described in the embodiments of the specification; indirect connections may also include connections through other active or passive devices, such as through circuits or components such as switches, signal amplification circuits, follower circuits, and the like, that may perform the same or similar functions. "plurality" or "multiple" means two or more.
Fig. 2 shows a schematic diagram of a power conversion system according to an embodiment of the invention. In the illustrated embodiment, the power conversion system is an isolated flyback power conversion system that includes primary and secondary side circuits, isolated by a transformer, where the primary side circuit has a primary winding Lp and a power device Q1. The power device Q1 may be any suitable power device for performing a switching action or regulating the output voltage Vout of the power conversion system via a controlled degree of conduction. In one embodiment, the power device Q1 includes a Metal Oxide Semiconductor Field Effect Transistor (MOSFET). In another embodiment, the power device Q1 includes a power transistor. In one embodiment, the power device Q1 comprises a gallium nitride (GaN) power tube. The secondary circuit has a secondary winding Ls and a rectifier tube Do. Based on the control of the power device Q1, the power conversion system converts the input bus voltage Vbus input to the primary circuit into an output voltage Vout at the output of the secondary circuit for driving the load. In one embodiment, the output voltage Vout is a voltage source that meets the USB-PD fast charge protocol, and the power conversion system is used in a PD fast charge source adapter. The power conversion system further includes an auxiliary winding La, a first capacitor C1, a second capacitor C2, a diode D1, a control drive circuit 22 for controlling the power device Q1, and a power supply control circuit 21 for supplying power to the control drive circuit 22. The power supply control circuit 21 obtains a power supply input voltage Vin by coupling the auxiliary winding La. Wherein the first end of the auxiliary winding La is coupled to the anode of the first diode D1, the second end of the auxiliary winding La is grounded GND, and the cathode of the diode D1 is coupled to the power supply input end of the power supply control circuit 21 and the first end of the first capacitor C1, and the second end of the first capacitor C1 is grounded GND. The voltage Vin across the first capacitor C1 is a supply input voltage provided by the auxiliary winding La for providing a voltage source to the supply control circuit 21. The voltage Vin may also be used to input a feedback signal for controlling the driving circuit 22. One end of the second capacitor C2 is coupled to the output end of the power supply control circuit 21, and the other end is grounded, and the second capacitor C2 is used for providing the power supply voltage VDD.
The power supply control circuit 21 includes a switch circuit 211 and a linear circuit 212. Wherein the switching circuit 211 comprises a switch K and an inductance L1. Preferably, the switching circuit 211 comprises a Boost (Boost) circuit, including an inductor L1 coupled to the auxiliary winding La through a diode D1, a switch K coupled to a first end of the inductor L1, and a rectifying tube coupled to the first end of the inductor L1 and the switch K, wherein the other end of the rectifying tube is used as an output end of the switching circuit 211. In other embodiments, the switching circuit 211 may also include a Buck-boost (Buck-boost) circuit or other type of switching circuit. The linear circuit 212 includes a linear device, wherein a first end of the linear device is also coupled to the auxiliary winding La through a diode D1. The output of the switching circuit 211 and the output of the linear circuit 212 are combined to provide the supply voltage VDD. An output of the switching circuit 211 may be coupled directly to an output of the linear circuit 212 at a first end of the second capacitor C2 for providing the supply voltage VDD. The output of the switching circuit 211 and the output of the linear circuit 212 may also each be coupled to the compound circuit and provide the supply voltage VDD through the output of the compound circuit. In one embodiment, the composite circuit includes two switching tubes, wherein the input ends of the two switching tubes are respectively coupled to the output end of the linear circuit and the output end of the switching circuit, the output ends of the two switching tubes are coupled to the output end of the power supply control circuit, and the control ends of the two switching tubes are respectively coupled to the output end of the selection control circuit. When the output voltage Vout is low, the supply input voltage Vin is also low, and the selective switch boost circuit 211 operates to make the supply voltage VDD higher than the supply input voltage Vin, and supply power to the control drive circuit 22 after boosting. When the output voltage Vout is high, the supply input voltage Vin is also high, and the enable linear circuit 212 is selected to make the supply voltage VDD lower than the supply input voltage Vin, and supply power to the control driving circuit 22 after the voltage is reduced. Thus, the power supply voltage VDD can be limited to a reasonable range regardless of the variation of the output voltage Vout, and the output range of the output voltage Vout can be expanded.
In one embodiment, the power supply control circuit 21 and the control driving circuit 22 are fabricated in one control chip 20, and the control chip 20 is integrated as one electronic package through a packaging process. In another embodiment, the inductor L1 is fabricated as a peripheral circuit outside the control chip, and the other components of the power supply control circuit 21 and the control driving circuit 22 are fabricated in the same control chip. In one embodiment, the power device Q1 is also integrated in the control chip.
The control driving circuit 22 is supplied with power by the power supply voltage VDD supplied from the power supply control circuit 21. The control driving circuit 22 outputs a control driving signal GATE for controlling the power device Q1, thereby regulating the output voltage Vout of the power conversion system.
The illustrated power conversion system is a flyback voltage converter structure, and in other embodiments, the power conversion system can also use other topologies, such as a forward voltage converter, a Buck voltage converter, etc., for example, an auxiliary winding is coupled to obtain an auxiliary voltage source through the inductance of the transformer and the Buck circuit.
Fig. 3 shows a schematic diagram of a control chip 30 for a power conversion system according to an embodiment of the invention. The control chip 30 is coupled to the inductor L1, and is coupled to the first capacitor C1, the diode D1 and the auxiliary winding La through the inductor L1. The auxiliary winding La is rectified by a diode D1 and filtered by a capacitor C1 to provide a supply input voltage Vin, which is further coupled to the SW port of the chip 30 by an inductor L1. The control chip 30 includes a power supply control circuit 31 and a control drive circuit 32, the auxiliary winding La supplies power to the power supply control circuit 31, and a power supply voltage VDD is generated by the power supply control circuit 31 based on a power supply input voltage Vin for supplying power to the control drive circuit 32. The power supply control circuit 31 includes a boost circuit 311, a linear circuit (LDO) 312, and a selection control circuit 313, wherein the selection control circuit 313 selects one of the boost circuit 311 and the linear circuit 312 to operate according to a power supply input voltage Vin, i.e., determines whether the power supply voltage VDD is in a boost control power supply mode or a linear circuit power supply mode by the power supply input voltage Vin. The chip 30 performs a combined power supply control of a switching boost control power supply and a linear circuit power supply to the power supply voltage VDD through the external inductor L1. In the illustrated embodiment, the boost circuit 311 operates with a fixed duty cycle Doff, and the selection control circuit 313 detects the supply voltage VDD, calculates the supply input voltage Vin based on the supply voltage VDD, where vin=vdd×doff, and enables the boost circuit 311 or the linear circuit 312 according to the calculated supply input voltage Vin. In one embodiment, the duty cycle of the boost circuit is preset fixed, its value follows a preset curve, and there is a certain functional relationship between the supply input voltage Vin and the supply voltage VDD, and the functional relationship may be a nonlinear relationship. In the linear circuit operating state, the selection control circuit 313 may switch to the boost mode when the supply voltage VDD is less than a predetermined threshold, and the boost circuit 311 operates. In another embodiment, the selection control circuit 313 directly acquires the value of the power supply input voltage Vin, selects one of the booster circuit 311 and the linear circuit 312 to operate based on the directly detected power supply input voltage Vin, and realizes switching control of the switch circuit 311 and the linear circuit 312. The power supply input voltage Vin rectified and filtered by the auxiliary winding La is obtained through a preset duty ratio mode or direct detection, so that the working range of the boost mode is effectively controlled, normal operation can be ensured under the condition that the power supply input voltage Vin provided by the auxiliary winding La is low, such as no-load operation, and the circuit is simple to control, so that standby loss is reduced. The control driving circuit 32 has a power supply terminal and a signal output terminal, wherein the power supply terminal is coupled to the output terminal of the power supply control circuit 31 and the pin VDD, so that the power supply control circuit 31 supplies power to the control driving circuit 32. The signal output terminal provides an output driving signal GATE. Specifically, the control driving circuit 32 includes a control circuit for generating a pulse width modulation signal PWM and a driving circuit for amplifying the PWM signal for outputting a driving signal GATE to drive the power device. The control circuit and the drive circuit are supplied with a supply voltage VDD supplied from a supply control circuit 31. By selecting the switching circuit 311 or the linear circuit 312 to operate at different supply input voltages Vin, the supply voltage VDD can be limited to a reasonable range within a wider supply input voltage Vin range, so as to provide a suitable supply voltage VDD to the control driving circuit 32, thereby realizing effective driving of the power device for realizing a wider range of output voltage regulation of the power conversion system. Meanwhile, the control chip 30 has fewer peripheral elements, simple circuit, low standby loss and higher power density and power efficiency.
In the illustrated embodiment, the control chip 30 has a first pin SW, a second pin VDD, a third pin GATE and a ground pin GND. Of course, the control chip 30 may also have other pins, such as a feedback pin for receiving a current feedback signal or other feedback signals, etc. The first pin SW is coupled to the first end of the inductor L1, and the second end of the inductor L1 is coupled to the first end of the capacitor C1 and the cathode of the diode D1. The anode of the diode D1 is coupled to the first end of the auxiliary winding La. The second end of the auxiliary winding La and the second end of the capacitor C1 are grounded GND. The first pin SW is coupled to the power supply control circuit 31. Of course, the inductor L1 may also be part of the power supply control circuit, or part of the switching circuit 311 in the power supply control circuit. The first pin SW is for receiving a supply input voltage source from the auxiliary winding La. The second pin VDD is coupled to the second capacitor C2, and is coupled to the output end of the power supply control circuit 31 to supply the power supply voltage to the control driving circuit. The third pin GATE is used to drive the power device. In one embodiment, the control chip 30 is fabricated in an electronic package, which may have one or more dies inside. In another embodiment, the control chip 30 is fabricated on a semiconductor substrate.
In another embodiment, the power device may also be integrated within the control chip 30.
Fig. 4 shows a schematic diagram of a power supply control circuit according to an embodiment of the invention. The power supply control circuit includes a switching circuit 41 and a linear circuit 42, wherein the switching circuit 41 includes a switch K and a rectifying switch T1, and constitutes a booster circuit together with an inductance L1. The switch K and the rectifying tube T1 can adopt devices such as MOSFET or triode. The rectifier tube T1 may be replaced by a diode. The first end of the inductor L1 is coupled to the first end of the switch K and the first end of the rectifying switch T1, the second end of the inductor L1 is coupled to the auxiliary winding La through the diode D1, the second end of the switch K is grounded GND, and the second end of the rectifying switch T1 is used as the output end of the switching circuit 41. When K is turned on, the first end SW of the inductor L1 is pulled to ground, the inductor L1 is charged, and when K is turned off, the rectifier T1 is turned on, the inductor L1 charges the second capacitor C2, and if the boost circuit is controlled to operate in a Continuous Current Mode (CCM) or a critical conduction mode (BCM), there are:
Vin*Ton/L＝(VDD-Vin)*Toff/L
the simplification is as follows: vin= (1-Don) vdd=doff VDD
Where L is the inductance of the external inductance L1 and Ton and Toff are the on and off times of the boost controlled switch K, respectively. Doff is the duty cycle of the boost switch OFF time OFF. In a preferred embodiment Doff is a fixed value. The value of Vin can be obtained by detecting the supply voltage VDD. By setting a fixed duty ratio, the switching circuit does not need feedback and a compensation loop, thereby greatly simplifying system control and reducing standby power consumption.
The linear circuit 42 includes a linear device T3, and the linear device T3 may also be a MOSFET, a triode, or the like, and operate in a linear region. In the illustrated embodiment, the first terminal of the linear device T3 is coupled to the node SW, i.e. the first terminal of the inductor L1, and the second terminal of the linear device T3 is coupled together as the output terminal of the linear circuit 42 and the output terminal of the switching circuit 41, and is commonly coupled to the first terminal of the second capacitor C2 for providing the supply voltage VDD to the control driving circuit. When the selection control circuit enables the linear circuit 42 and simultaneously disables the switching circuit 41, the inductor L1 may be regarded as a conducting wire for transmitting the rectified and filtered supply input voltage Vin transmitted by the auxiliary winding La to the linear circuit 42, and after being converted by the linear circuit 42, the supply voltage VDD is provided at the first end of the second capacitor C2.
The power supply control circuit further includes a voltage detection circuit 43, a calculation circuit 44, a comparison circuit 45, and a switching control circuit 46. Wherein the voltage detection circuit 43 comprises a voltage divider circuit consisting of resistors R1 and R2, the voltage detection circuit providing a voltage detection signal representative of the supply voltage VDD. The calculation circuit 44 receives the voltage detection signal and the duty cycle signal Doff, and calculates a calculation signal V1 representing the power supply input voltage Vin based on the duty cycle Doff and the voltage detection signal. The comparison circuit 45 compares the calculated calculation signal V1 with the threshold signal Vref1, and controls the switching control circuit 46 to enable the switching circuit 41 or the linear circuit 42 according to the comparison result. When the power supply input voltage Vin is calculated to be lower than a certain value, the calculation signal V1 is lower than the threshold signal Vref1, and the selection control circuit enables the step-up circuit to control the switch K and the rectifying tube T1 to work in an alternate switch state. The supply voltage is raised to be greater than the supply input voltage Vin. When Vin is calculated to be higher than a certain value, the calculation signal V1 is higher than the threshold signal Vref1, and the power supply mode is switched to the LDO, so that the linear circuit is enabled, the linear control circuit 47 is enabled, the booster circuit is stopped, and the linear device is turned on. The linear control circuit 47 may be a closed-loop negative feedback control circuit including voltage dividing resistors R3 and R4, and an error amplifier EA for error amplifying the divided voltage of VDD with the reference signal Vref 2. In another embodiment, the linear circuit 42 may also employ a regulated tube voltage control scheme as shown in fig. 5.
Through the control, the range of the power supply voltage can be effectively controlled, so that the standby loss in no-load is reduced, and the range of the output voltage of the power conversion system is widened.
Fig. 5 shows an embodiment of a linear circuit according to an embodiment of the invention. The linear device in the linear circuit adopts a triode and adopts a voltage stabilizing tube to realize the control of the power supply voltage VDD.
Fig. 6 shows a schematic diagram of a control chip 60 according to an embodiment of the invention. In this embodiment, the inductor L1 coupled to the cathode of the diode D1 and the first capacitor C1 is fabricated inside the control chip 60. In contrast to the embodiment of fig. 3, the first pin Vin of the control chip 60 is directly coupled to the cathode of the diode D1. The connection manner of the inductor L1 and other components of the power supply control circuit may be the connection manner of fig. 4, where a first end of the inductor L1 is coupled to a first end of the switch K and a first end of the linear device T2, and a second end of the inductor L1 is externally coupled to a cathode of the diode D1. In another embodiment, the first terminal of the inductor L1 is coupled to the first terminal of the switch K, the second terminal of the inductor L1 is coupled to the cathode of the diode D1, and the first terminal of the linear device is coupled to the pair. By arranging the inductor L1 inside the control chip 60, reasonable power supply voltage can be provided under the condition of meeting large-range output voltage, the system power consumption is reduced, peripheral devices are reduced, the system volume is reduced, and the system integration level is improved.
Fig. 7 shows a schematic diagram of a power supply control circuit 70 according to an embodiment of the invention. In this embodiment, the switching circuit and the linear circuit of the power supply control circuit 70 share one switching device T3, so that the selection control circuit 71 is enabled when detecting that the power supply input voltage Vin is low (first time period), the switching enable signal EN1 is enabled, the switching device T3 is controlled to operate in a switching state by the switching signal CT1, the switching device K and the switching device T3 are alternately turned on, and the inductor L1, the switching device T3 and the switching device K constitute a boost circuit for making the power supply voltage VDD higher than the power supply input voltage Vin. The switching signal CT1 may be a square wave signal with alternating positive and negative levels. When the selection control circuit 71 detects that the supply input voltage Vin is high (second time period), the second enable signal EN2 is active, the control signal CT2 controls the switching device T3 to operate in a linear state, the switch K is turned off, the inductor L1 is degraded to the effect of the wire, and the supply voltage VDD is lower than the supply input voltage Vin by controlling the conduction degree of the linear device T3. CT2 may be a signal provided by the linear control circuit 47 of fig. 4. Therefore, the output range of the power supply voltage VDD is limited in a larger output voltage range, and the control driving circuit in the control chip can avoid the lower loss caused by the power supply of the higher power supply voltage when the power supply conversion system has high output voltage, so that the efficiency of the power supply conversion system is improved, and meanwhile, the control driving circuit has enough power supply voltage to realize driving when the power supply conversion system has low output voltage.
The description and applications of the present invention herein are illustrative and are not intended to limit the scope of the invention to the embodiments described above. The relevant descriptions of effects, advantages and the like in the description may not be presented in practical experimental examples due to uncertainty of specific condition parameters or influence of other factors, and the relevant descriptions of effects, advantages and the like are not used for limiting the scope of the invention. Variations and modifications of the embodiments disclosed herein are possible, and alternatives and equivalents of the various components of the embodiments are known to those of ordinary skill in the art. It will be clear to those skilled in the art that the present invention may be embodied in other forms, structures, arrangements, proportions, and with other assemblies, materials, and components, without departing from the spirit or essential characteristics thereof. Other variations and modifications of the embodiments disclosed herein may be made without departing from the scope and spirit of the invention.
Claims (14)
1. A control chip for a power conversion system having a first pin for coupling to a first end of an inductor and a second pin for coupling to a first capacitor and to an auxiliary winding via a diode, the second pin for coupling to a second capacitor, the control chip comprising:
the switching circuit comprises a switch and a rectifying tube, wherein the first end of the switch is coupled with the first pin, the second end of the switch is coupled with the first end of the rectifying tube, and the second end of the rectifying tube is coupled with the second pin;
the linear circuit comprises a linear device, wherein a first end of the linear device is coupled with the first pin, and a second end of the linear device is coupled with the second pin;
a selection control circuit for controlling the enable switch circuit or the linear circuit based on the voltage of the second end of the inductor or the voltage of the second pin; and
the control driving circuit is provided with a power supply end and a signal output end, wherein the power supply end is coupled with the second pin, and the signal output end is used for driving a power device of the power conversion system.
2. The control chip of claim 1, wherein the inductor, the switch and the rectifier form a boost circuit, and a duty cycle of the boost circuit is preset fixed.
3. The control chip of claim 1, further comprising a third pin for externally coupling to a control terminal of the power device, wherein the signal output terminal of the control driving circuit is coupled to the third pin.
4. A control chip for a power conversion system having a first pin for coupling to a first capacitor and an auxiliary winding through a diode and a second pin for coupling to a second capacitor, the control chip comprising:
the switching circuit comprises an inductor, a switch and a rectifying tube, wherein the first end of the inductor is coupled with the first end of the switch, the second end of the inductor is coupled with the first pin, the second end of the switch is coupled with the first end of the rectifying tube, and the second end of the rectifying tube is coupled with the second pin;
the linear circuit comprises a linear device, wherein a first end of the linear device is coupled with a first pin or a first end of an inductor, and a second end of the linear device is coupled with a second pin;
a selection control circuit for controlling the enable switch circuit or the linear circuit based on the voltage of the second end of the inductor; and
the control driving circuit is provided with a power supply end and a signal output end, wherein the power supply end of the control driving circuit is coupled with the second pin, and the signal output end of the control driving circuit is used for driving a power device of the power supply conversion circuit.
5. The control chip of any one of claims 1-4, wherein the rectifier tube and the linear device share the same switching device, the selection control circuit enables the switching circuit to operate in a switching state during a first time period, the switching device and the switching device are alternately turned on, and the inductor, the switching device and the switching device form a boost circuit; in a second time period, the selection control circuit enables the linear circuit, the switching device operates in a linear state, and the switch is turned off.
6. A power conversion system comprising a control chip as claimed in any one of claims 1-4.
7. A power supply control circuit for a power conversion system, wherein the power supply control circuit is used for supplying power to a control driving circuit, the control driving circuit is used for controlling a power device of the power conversion system, the power supply control circuit obtains a power supply input voltage through an auxiliary winding coupled with the power conversion system, the power supply control circuit comprises a switch circuit and a linear circuit, and an output end of the switch circuit and an output end of the linear circuit are combined and provide power supply voltage for supplying power to the control driving circuit; the power supply control circuit further includes a selection control circuit selectively switching between the switching circuit and the linear circuit based on the power supply input voltage for enabling the switching circuit or the linear circuit, wherein the switching circuit is a boost circuit.
8. The power supply control circuit of claim 7, wherein the boost circuit comprises an inductor, a switch and a rectifier tube, wherein a first end of the inductor is coupled to a first end of the switch and a first end of the rectifier tube, a second end of the inductor is coupled to the auxiliary winding through a diode, a second end of the switch is grounded, a second end of the rectifier tube is an output end of the switch circuit, the select control circuit enables the boost circuit when the power supply input voltage is lower than a preset threshold value, the switch and the rectifier tube are alternately turned on, and a linear device in the linear circuit is turned off; when the power supply input voltage is higher than a preset threshold value, the selection control circuit enables the linear circuit, the booster circuit stops working, and the linear device is conducted.
9. The power supply control circuit of claim 8, wherein the boost circuit operates at a fixed duty cycle.
10. The power supply control circuit according to claim 9, wherein the selection control circuit calculates the power supply input voltage Vin, vin=vdd, doff, which is a duty ratio of the step-up circuit, based on the power supply voltage VDD, and selectively switches between the step-up circuit and the linear circuit for enabling the step-up circuit or the linear circuit based on the calculated power supply input voltage.
11. The power supply control circuit of claim 7, wherein the selection control circuit comprises:
a voltage detection circuit for detecting a power supply voltage and providing a voltage detection signal;
a calculation circuit that receives the voltage detection signal and the duty cycle signal, calculates a calculation signal that characterizes the power supply input voltage;
a comparison circuit that compares the calculation signal with the threshold signal; and
and a switching control circuit that enables the switching circuit or the linear circuit based on a comparison result of the comparison circuit.
12. The power supply control circuit of claim 7, wherein the rectifier tube in the switching circuit and the linear device of the linear circuit multiplex the same switching device, the switching device being selectively controlled to operate in either a switching state or a linear state based on the power supply input voltage.
13. A power conversion system comprising a power supply control circuit as claimed in any one of claims 7 to 12, a power device and an auxiliary winding.
14. The power conversion system of claim 13, used in a power adapter of a PD fast charge protocol.
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| CN202111317466.0A CN114094854B (en) | 2021-11-09 | 2021-11-09 | Power conversion system, control chip thereof and power supply control circuit |
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| CN115967258B (en) * | 2023-02-21 | 2023-05-23 | 恩赛半导体(成都)有限公司 | Power supply circuit, power supply system and electronic device |
| CN116742974B (en) * | 2023-08-08 | 2023-10-20 | 无锡硅动力微电子股份有限公司 | Control circuit and method for detecting and supplying input voltage of switching power supply |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101668369A (en) * | 2009-10-01 | 2010-03-10 | 英飞特电子（杭州）有限公司 | High-efficiency constant-current LED driver |
| JP2013038882A (en) * | 2011-08-05 | 2013-02-21 | Panasonic Corp | Control method for two-converter type power supply unit and power supply unit |
| CN103023337A (en) * | 2013-01-11 | 2013-04-03 | 聚辰半导体(上海)有限公司 | Power circuit of switching power converter |
| CN103280995A (en) * | 2013-05-29 | 2013-09-04 | 中国电子科技集团公司第二十四研究所 | Quasi-resonance converter synchronous rectification circuit |
| JP2018064398A (en) * | 2016-10-13 | 2018-04-19 | 富士電機株式会社 | Switching power supply unit |
| CN111431386A (en) * | 2020-05-29 | 2020-07-17 | 上海南芯半导体科技有限公司 | Control method and control circuit for auxiliary power supply |
| CN112054657A (en) * | 2020-09-04 | 2020-12-08 | 昂宝电子（上海）有限公司 | Pulse width modulation control chip and power supply conversion system |
| CN112865546A (en) * | 2021-03-11 | 2021-05-28 | 佛山市南海赛威科技技术有限公司 | Power converter and power supply control method and power supply control chip thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10291113B2 (en) * | 2017-07-05 | 2019-05-14 | Richtek Technology Corporation | Flyback power converter circuit and primary side controller circuit thereof |
-
2021
- 2021-11-09 CN CN202111317466.0A patent/CN114094854B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101668369A (en) * | 2009-10-01 | 2010-03-10 | 英飞特电子（杭州）有限公司 | High-efficiency constant-current LED driver |
| JP2013038882A (en) * | 2011-08-05 | 2013-02-21 | Panasonic Corp | Control method for two-converter type power supply unit and power supply unit |
| CN103023337A (en) * | 2013-01-11 | 2013-04-03 | 聚辰半导体(上海)有限公司 | Power circuit of switching power converter |
| CN103280995A (en) * | 2013-05-29 | 2013-09-04 | 中国电子科技集团公司第二十四研究所 | Quasi-resonance converter synchronous rectification circuit |
| JP2018064398A (en) * | 2016-10-13 | 2018-04-19 | 富士電機株式会社 | Switching power supply unit |
| CN111431386A (en) * | 2020-05-29 | 2020-07-17 | 上海南芯半导体科技有限公司 | Control method and control circuit for auxiliary power supply |
| CN112054657A (en) * | 2020-09-04 | 2020-12-08 | 昂宝电子（上海）有限公司 | Pulse width modulation control chip and power supply conversion system |
| CN112865546A (en) * | 2021-03-11 | 2021-05-28 | 佛山市南海赛威科技技术有限公司 | Power converter and power supply control method and power supply control chip thereof |
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