MULTI-CONVERTER POWER SUPPLY

The multi-converter power supply has a first port, a second port, a second switching converter, one or more additional switching converters and an integrated control circuit. The first switching converter receives an input voltage and to convert the input voltage into a first output voltage. The second switching converter receives the input voltage and converts the input voltage into a second output voltage. The one or more additional switching converters are selectively activated. The integrated control circuit comprises a first pin, a second pin, one or more output pins, a load condition detect unit, a first switching control unit, a first power distribution control unit and a second power distribution control unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of CN application No. 202311266272.1, filed on Sep. 27, 2023, and incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to electronic circuits, and more particularly but not exclusively relates to multi-converter power supplies.

2. Description of Related Art

Conventional solutions for multiple output power delivery (PD) adapters typically employ a two-stage design to convert an input power to an expected output power. A first stage power converter (e.g., a flyback converter or an LLC resonant converter) can convert high voltage alternating current (AC) power to lower voltage direct current (DC) power. A second stage power converter (e.g., a buck converter) can convert power output from the first stage to different DC power to meet different requirements.

However, not all outputs need to be loaded at the same time, and power requirements of electronic devices can vary greatly during operation of the electronic devices. As the number or characteristics of a load changes, the power requirements also change. Multi-stage power converters capable of handling various power requirements may be difficult to design, expensive, and/or inefficient to implement, particularly when multi-stage converters have to meet different requirements in order to be compatible with each other.

SUMMARY OF THE INVENTION

It is one of the objects of the present invention to provide a multi-converter power supply.

One embodiment of the present invention discloses an integrated control circuit for a multi-converter power supply. The integrated control circuit has a first pin, a second pin, one or more output pins, a load condition detect unit, a first switching control unit, a first power distribution control unit and a second power distribution control unit. The first pin is used to receiving a mode signal. The mode signal controls the multi-converter power supply to operate in a first power supply mode or a second power supply mode. The second pin is used to receiving a first feedback signal representing a first output voltage provided by a first switching converter of the multi-converter power supply. The one or more output pins are used to provide one or more set signals. The load condition detect unit judges a load condition at a first port of the multi-converter power supply based on the first feedback signal. The first switching control unit is used to generate a first control signal based on the first feedback signal for controlling a first switch of the first switching converter. The first power distribution control unit is used to determine whether to activate a second switching converter of the multi-converter power supply based on the load condition when the multi-converter power supply operates in the first power supply mode. When the second switching converter is activated, the outputs of the second switching converter and the first switching converter are connected in parallel, and the second switching converter and the first switching converter operate interleaved with each other to provide power for the first port. The second power distribution control unit is used to determine whether to activate one or more additional switching converters of the multi-converter power supply based on the load condition when the multi-converter power supply operates in the first power supply mode. The second power distribution control unit is used to generate the one or more set signals. When the one or more additional switching converters are activated, the output terminals of the one or more additional switching converters are connected in parallel with output terminals of the first switching converter and the second switching converter to provide power to the first port.

Another embodiment of the present invention discloses a multi-converter power supply. The multi-converter power supply has a first port, a second port, a second switching converter, one or more additional switching converters and an integrated control circuit. The first switching converter receives an input voltage and to convert the input voltage into a first output voltage. The second switching converter receives the input voltage and converts the input voltage into a second output voltage. The one or more additional switching converters are selectively activated. The integrated control circuit has a first pin, a second pin, one or more output pins, a load condition detect unit, a first switching control unit, a first power distribution control unit and a second power distribution control unit. The first pin is used to receiving a mode signal. The mode signal controls the multi-converter power supply to operate in a first power supply mode or a second power supply mode. The second pin is used to receiving a first feedback signal representing a first output voltage. The one or more output pins are used to provide one or more set signals. The load condition detect unit is activated when the multi-converter power supply operates in the first power supply mode. The load condition detect unit judges a load condition at the first port based on the first feedback signal. The first switching control unit is used to generate a first control signal based on the first feedback signal for controlling a first switch of the first switching converter. The first power distribution control unit is used to determine whether to activate a second switching converter based on the load condition when the multi-converter power supply operates in the first power supply mode. When the second switching converter is activated, the outputs of the second switching converter and the first switching converter are connected in parallel, and the second switching converter and the first switching converter operate interleaved with each other to provide power for the first port. The second power distribution control unit is used to determine whether to activate one or more additional switching converters of the multi-converter power supply based on the load condition when the multi-converter power supply operates in the first power supply mode. The second power distribution control unit is further used to generate the one or more set signals. When the one or more additional switching converters are activated, output terminals of the one or more additional switching converters are connected in parallel with output terminals of the first switching converter and the second switching converter to provide power to the first port.

Yet another embodiment of the present invention discloses a control method for a multi-converter power supply. The control method includes receiving a mode signal, receiving a first feedback signal and determining a load condition at a first port of the multi-converter power supply based on a first feedback signal when the multi-converter power supply operates in the first power supply mode. The mode signal controls the multi-converter power supply to operate in a first power supply mode or a second power supply mode. The first feedback signal represents a first output voltage provided by a first switching converter of the multi-converter power supply. When a light load condition is detected, generating a first control signal based on the first feedback signal to control a first switching converter of the multi-converter power supply to provide power to the first port. When a medium load condition is detected, activating a second switching converter of the multi-converter power supply to perform power operation, wherein when the second switching converter is activated, outputs of the first switching converter and the second switching converter are connected in parallel, and the first switching converter and the second switching converter operate interleaved with each other to provide power for the first port. When a heavy load condition is detected, activating one or more additional switching converters to perform power operation, wherein when the one or more additional switching converters are activated, outputs of the additional switching converter, the first switching converter and the second switching converter are connected in parallel to provide power to the first port.

These and other features of the present invention will be readily apparent to persons of ordinary skill in the art upon reading the entirety of this disclosure, which comprises the accompanying drawings and claims.

DETAILED DESCRIPTION OF THE INVENTION

Reference to “one embodiment”, “an embodiment”, “an example” or “examples” means: certain features, structures, or characteristics are contained in at least one embodiment of the present invention. These “one embodiment”, “an embodiment”, “an example” and “examples” are not necessarily directed to the same embodiment or example. Furthermore, the features, structures, or characteristics may be combined in one or more embodiments or examples. In addition, it should be noted that the drawings are provided for illustration, and are not necessarily to scale. And when an element is described as “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there could exist one or more intermediate elements. In contrast, when an element is referred to as “directly connected” or “directly coupled” to another element, there is no intermediate element. When a signal is described as “equal to” another signal, it is substantially identical to the other signal.

FIG.1schematically illustrates a circuit diagram of a multi-converter power supply100in accordance with an embodiment of the present invention. In an embodiment shown inFIG.1, the multi-converter power supply100has only three ports (USBC1-USBC3) for output. In the other embodiments, the multi-converter power supply100includes additional output(s) and/or output(s) other than USB ports.

In the embodiment shown inFIG.1, the multi-converter power supply100includes a first switching converter101, a second switching converter102, a third switching converter201, a first port USBC1, a second port USBC2, a third port USBC3, an integrated control circuit103, a third controller11, a load switch104, a load switch106, a power delivery (PD) controller105and a power delivery controller107.

As shown inFIG.1, the first switching converter101has a first input terminal, a second input terminal, a first output terminal OUT1, and a second output terminal OUT2. The first input terminal and the second input terminal of the first switching converter101are coupled across an input capacitor Cin respectively to receive an input voltage Vin. The first switching converter101converts the input voltage Vin to a first output voltage Vo1and provides the first output voltage Vo1to the first output terminal OUT1and the second output terminal OUT2. The second switching converter102has a first input terminal, a second input terminal, a third output terminal OUT3and a fourth output terminal OUT4. The first input terminal and the second input terminal of the second switching converter102are coupled across the input capacitor Cin respectively to receive the input voltage Vin. The second switching converter102converts the input voltage Vin to a second output voltage Vo2and provides the second output voltage Vo2to the third output terminal OUT3and the fourth output terminal OUT4. The second output terminal OUT2is coupled to the fourth output terminal OUT4and grounded together.

The third switching converter201has a first input terminal, a second input terminal, a fifth output terminal OUT5and a sixth output terminal OUT6. The first input terminal and the second input terminal of the third switching converter201are coupled across the input capacitor Cin respectively to receive the input voltage Vin. The third switching converter201converts the input voltage Vin into a third output voltage Vo3and provides the third output voltage Vo3to the fifth output terminal OUT5and the sixth output terminal OUT6. In one embodiment, the sixth output terminal OUT6is coupled to the fourth output terminal OUT4and grounded together. The third switching converter201is controlled by the third controller11.

In one embodiment, the input capacitor Cin is configured to receive a high voltage input. In some embodiments, the high voltage input is an alternating current (AC) input, such as a line voltage. In the other embodiments, the high voltage input is a high voltage direct current (DC) input, such as an EMI filtered and rectified line voltage.

In order to filter ripple and stabilize the output voltage, both output terminals of the first switching converter101, the second switching converter102and the third switching converter201are coupled to an output capacitor respectively. As shown inFIG.1, an output capacitor Co1is coupled between the first output terminal OUT1and the second output terminal OUT2of the first switching converter101to receive the first output voltage Vo1. An output capacitor Co2is coupled between the third output terminal OUT3and the fourth output terminal OUT4of the second switching converter102to receive the second output voltage Vo2. An output capacitor Co3is coupled between the fifth output terminal OUT5and the sixth output terminal OUT6of the third switching converter201to receive the third output voltage Vo3. Considering factors such as capacity, price and volume, the output capacitors are generally made of electrolytic capacitors, such as aluminum electrolytic capacitors.

The first port USBC1has a bus terminal BUS1and a ground terminal RTN1, and the bus terminal BUS1receives a first voltage V1and the ground terminal RTN1is coupled to ground. The second port USBC2has a bus terminal BUS2and a ground terminal RTN2, and the bus terminal BUS2receives a second voltage V2and the ground terminal RTN2is coupled to ground. The third port USBC3has a bus terminal BUS3and a ground terminal RTN3, and the bus terminal BUS3receives a third voltage V3, and the ground terminal RTN3is coupled to ground. In one embodiment, all of the first port USBC1, the second port USBC2and the third port USBC3are Type-C ports.

In some cases, at least one port is not connected to an external electronic device. In one embodiment, only the first port USBC1is coupled to a first electronic device, the second port USBC2is disconnected from a second electronic device111, and the third port USBC3is also disconnected from a third electronic device112. For example, as shown inFIG.1, the connection of the second port USBC2and the second electronic device111, the connection of the third port USBC3and the third electronic device112are indicated by dashed lines. In another embodiment, the first port USBC1is coupled to the first electronic device110, the second port USBC2is coupled to the second electronic device111, and the third port USBC3is disconnected from the third electronic device112.

The power delivery controller105is coupled to the first port USBC1and the second port USBC2. In response to a load information received from the first port USBC1and the second port USBC2, the power delivery controller105determines the multi-converter power supply100operate in a first power supply mode or a second power supply mode, and provides a mode signal MS. In one embodiment, when only the first port USBC1is coupled to the first electronic device110and neither the second port USBC2nor the third port USBC3is coupled to the electronic device, the integrated control circuit103controls the multi-converter power supply100to operate in the first power supply mode. In another embodiment, when all ports are floating, i.e. no load, the integrated control circuit103controls the multi-converter power supply100to operate in the first power supply mode. When the first port USBC1is coupled to the first electronic device110and the second port USBC2is coupled to the second electronic device111, the integrated control circuit103controls the multi-converter power supply100to operate in the second power supply mode.

The power delivery controller105is configured to control selection switches Q1and Q2and the load switch104. The power delivery controller105detects power requirements of respective ports USBC1and USBC2and customizes power outputs of the respective ports USBC1and USBC2. In this manner, various power requirements for different numbers of loads are met. The selection switch Q1is coupled between the first output terminal OUT1and the bus terminal BUS1, and the selection switch Q2is coupled between the third output terminal OUT3and the bus terminal BUS2. The power delivery controller105controls the selection switch Q1and the selection switch Q2based on the power supply mode and the power requirements. The power delivery controller105is further configured to provide a first feedback signal VFB1representing the first output voltage Vo1and a second feedback signal VFB2representing the second output voltage Vo2.

The power delivery controller107is coupled to the power delivery controller105and the third port USBC3, and determines the multi-converter power supply100operates in the first power supply mode or the second power supply mode, or another power supply mode in response to the load information received from each port. The power delivery controller107is configured to control a selection switch Q3and the load switch106. The power delivery controller107also provides a third feedback signal VFB3representing the third output voltage Vo3.

The first switching converter101and the second switching converter102could have the same topology. In one embodiment, both the first switching converter101and the second switching converter102are flyback converters. Both the first switching converter101and the second switching converter102are controlled by the integrated control circuit103. In one embodiment, the integrated control circuit103provides a first control signal CTRL1and a second control signal CTRL2to control a first switch of the first switching converter101and a second switch of the second switching converter102respectively. In another embodiment, the integrated control circuit103is integrated on the same chip with the first switch and the second switch.

In the embodiment shown inFIG.1, the integrated control circuit103includes a first switching control circuit1031, a load condition detect unit1032, a first power distribution control unit1033, a second power distribution control unit1034and a plurality of pins. In the integrated control circuit103, the plurality of pins include a first feedback pin FB1, a second feedback pin FB2, a mode indicating pin OCH, a first drive pin DRV1, a first current sense pin CS1, a second drive pin DRV2, a second current sense pin CS2, first output pin Sync1and a second output pin Sync2. The first feedback pin FB1is coupled to the power delivery controller105and receives the first feedback signal VFB1representing the first output voltage Vo1. The second feedback pin FB2is coupled to the power delivery controller105and receives the second feedback signal VFB2representing the second output voltage Vo2. The mode indicating pin OCH is coupled to the power delivery controller105as well and receives the mode signal MS controlling the multi-converter power supply100to operate in the first power supply mode or the second power supply mode.

In the embodiment shown inFIG.1, the first switching control unit1031generates the first control signal CTRL1based on the first feedback signal VFB1to control the first switch of the first switching converter101. The selection switch Q1coupled between the first output terminal OUT1and the bus terminal BUS1is turned on, and the first switching converter101supplies power to the first port USBC1.

When the multi-converter power supply100operates in the first power supply mode, the load condition detect unit1032is activated. The load condition detect unit1032judges a load condition of the first electronic device110coupled to the first port USBC1based on the first feedback signal VFB1. In one embodiment, the load condition detect unit1032compares the first feedback signal VFB1with a first feedback threshold Vth_1and a second feedback threshold Vth_2, and provides a first condition signal ST1and a second condition signal ST2at output terminals of the load condition detect unit1032. When the first condition signal ST1is logic low level, the first electronic device110is in the light load condition or no load is coupled to the first port USBC1. When the first condition signal ST1is logic high level, the first electronic device110is in the medium load condition. When the second condition signal ST2changes from logic low level to logic high level, the first electronic device110is in the heavy load condition.

In one embodiment, if the current required by the first electronic device110is less than the first current threshold, it indicates that the first electronic device110is in the light load condition or no load condition. If the current required by the first electronic device110is greater than the first current threshold and less than the second current threshold, it indicates that the first electronic device110is in the medium load condition. And if the current required by the first electronic device110is greater than the second feedback threshold, it indicates that the first electronic device110is in the heavy load condition. Herein, the first current threshold is less than the second current threshold.

When the multi-converter power supply100operates in the first power supply mode, the first power distribution control unit1033determines whether to activate the second switching converter102for power operation based on the load condition of the first electronic device110. When the multi-converter power supply100operates in the first power supply mode and the first electronic device110is in the medium load condition or the heavy load condition, the load switch104coupled between the first output terminal OUT1and the third output terminal OUT3is turned on, and the second switching converter102is activated. In this case, both the first output terminal OUT1and the third output terminal OUT3are coupled to the bus terminal BUS1of the first port USBC1. The integrated control circuit103controls the first switching converter101and the second switching converter102to operate interleaved with each other based on the first feedback signal VFB1. So that the first switching converter101and the second switching converter102provide power to the first port USBC1together. Thereby providing double current load capability to the first electronic device110.

When the multi-converter power supply100operates in the first power supply mode, the second power distribution control unit1034determines whether to further activate the third switching converter201for power operation based on the load condition, and generates a first set signal SET1. The first set signal SET1is provided to the first output pin Sync1to activate the third switching converter201. When the third switching converter201is activated, the load switch106coupled between the third output terminal OUT3and the fifth output terminal OUT5is turned on by the power delivery controller107. The outputs of the activated third switching converter201are in parallel with the outputs of the first switching converter101and the second switching converter102. The first switching converter101, the second switching converter102, and the third switching converter201provide higher power and stronger load current capability together for the first port USBC1.

When the multi-converter power supply100operates in the second power supply mode, the load switch104coupled between the first output terminal OUT1and the third output terminal OUT3is turned off, the load switch106coupled between the third output terminal OUT3and the fifth output terminal OUT5is turned off, the selection switch Q1coupled between the first output terminal OUT1and the bus terminal BUS1remained on, and the selection switch Q2coupled between the third output terminal OUT3and the bus terminal BUS2is turned on. In such an embodiment, the third output terminal OUT3is decoupled from the bus terminal BUS1and the first output terminal OUT1, and then coupled to the bus terminal BUS2of the second port USBC2, the fifth output terminal OUT5is decoupled from the bus terminal BUS1and the third output terminal OUT3. When the multi-converter power supply100operates in the second power supply mode, the first switching control unit1031controls the first switching converter101to provide the first output voltage Vo1based on the first feedback signal VFB1to power the first electronic device110. The first output voltage Vo1is provided as the first voltage V1supplied to the first port USBC1. At the same time, the first power distribution control unit1033controls the second switching converter102to provide the second output voltage Vo2based on the second feedback signal VFB2. The second output voltage Vo2is provided as the second voltage V2supplied to the second port USBC2. The second power distribution control unit1034is deactivated when the multi-converter power supply100operates in the second power supply mode, in this case the first set signal SET1of the third switching converter201is zero.

The third controller11is used for controlling the third switching converter201. The third controller11has a switching control circuit1011and a plurality of pins, the plurality of pins includes a synchronization pin Sync, a feedback pin FB, a drive pin DRV and a current sense pin CS. The synchronization pin Sync is coupled to the first output pin Sync1corresponding to the integrated control circuit103, and receives the corresponding first set signal SET1when the multi-converter power supply100operates in the first power supply mode and the first electronic device110is in the heavy load condition. The feedback pin FB is coupled to the power delivery controller107and receives the third feedback signal VFB3representing the third output voltage Vo3. The switching control circuit1101provides a third control signal CTRLS1to the drive pin DRV based on the first set signal SET1or the third feedback signal VFB3to control a power switch of the third switching converter201. When the switching control circuit1101receives a normal first set signal SET1, the switching control circuit1101generates the third control signal CTRLS1based on the first set signal SET1to control the third switching converter201to supply power to the first port USBC1. If the first set signal SET1is not received within a preset time period, it indicates that the third switching converter201is not activated by the integrated control circuit103. Subsequently, when the switching control circuit1101detects that the third feedback signal VFB3changes from logic high level to logic low level, it indicates that the third port USBC3needs to be powered by the third switching converter201. In this case, the third switching converter201generates the third control signal CTRLS1based on the third feedback signal VFB3, the selection switch Q3is turned on, and the third switching converter201supplies power to the third port USBC3.

According to an embodiment of the present invention, in order to meet the change in the power requirements, when the multi-converter power supply100operates in the first power supply mode, the integrated control circuit103may self-regulate the power provided by the multi-converter power supply in a way that increases or decreases the number of the switching converters performing the power operation. Under no load or light load, only the first switching converter101in the multi-converter power supply100is under power operation to transfer energy to a load.

FIG.2schematically illustrates a circuit diagram of a multi-converter power supply100A in accordance with an embodiment of the present invention. Compared to the multi-converter power supply100shown inFIG.1, the multi-converter power supply100A shown inFIG.2further comprises a fourth switching converter202, a fourth controller12, a load switch108, a power delivery controller109and a fourth port USBC4. In one embodiment, the first port USBC1is coupled to the first electronic device110, the second port USBC2is coupled to the second electronic device111, the third port USBC3is coupled to the third electronic device112, and the fourth port USBC4is coupled to a fourth electronic device113.

The fourth switching converter202has a first input terminal, a second input terminal, a seventh output terminal OUT7and an eighth output terminal OUT8. The first input terminal and the second input terminal of the fourth switching converter202are coupled across the input capacitor Cin to receive the input voltage Vin. The fourth switching converter202converts the input voltage Vin into a fourth output voltage Vo4and provides the fourth output voltage Vo4to the seventh output terminal OUT7and the eighth output terminal OUT8. The fourth switching converter202is controlled by the fourth controller12. The output capacitor Co4is coupled between the seventh output terminal OUT7and the eighth output terminal OUT8of the fourth switching converter202to receive the fourth output voltage Vo4.

The fourth port USBC4has a bus terminal BUS4and a ground terminal RTN4. The bus terminal BUS4receives the fourth voltage V4and the ground terminal RTN1is coupled to ground. The power delivery controller109is coupled to the fourth port USBC4and the power delivery controller107to provide a fourth feedback signal VFB4representing the fourth output voltage Vo4in response to load information received at each port. The power delivery controller109is configured to control a selection switch Q4and the load switch108.

The fourth controller12has substantially the same structure as the third controller11shown inFIG.1, differing merely in that a synchronization pin Sync of the fourth controller12is coupled to the second output pin Sync2of the integrated control circuit103to receive a second set signal SET2. A switching control circuit of the fourth controller12generates a fourth control signal CTRLS2based on the second set signal SET2or a fourth feedback signal VFB4representing the fourth output voltage Vo4to control the power switch.

FIG.3schematically illustrates a circuit diagram of a multi-converter power supply100B in accordance with an embodiment of the present invention. Compared to the multi-converter power supply100shown inFIG.1, the multi-converter power supply100B shown inFIG.3further includes a first isolated delivery path31, a second isolated delivery path32, a third isolated delivery path33, and a fourth isolated delivery path34.

The isolated delivery paths are required when detection of the first power supply mode and the second power supply mode, and detection of the respective output voltage occur on a secondary side of the switching converter. In some embodiments, the isolated delivery path may include an optocoupler, a transformer, a capacitive isolation device, or any other suitable electrical isolation device.

In the embodiment shown inFIG.3, the first feedback pin FB1of the integrated control circuit103receives the first feedback signal VFB1via the first isolated delivery path31. The first feedback signal VFB1is an error amplifying signal of the first output voltage Vo1. Specifically, the first isolated delivery path31includes a feedback resistor Rfb1, a photocoupler OC1, and a three-terminal adjustable voltage regulator device (not shown). In one embodiment, the three-terminal adjustable voltage regulator device is integrated within the power delivery controller105. The photocoupler OC1comprises a photosensitive diode and a photosensitive transistor. The photosensitive diode has an anode and a cathode, the anode is coupled to the first output terminal OUT1via the feedback resistor Rfb1, and the cathode is coupled to one terminal of the power delivery controller105. When the multi-converter power supply100B operates in the first power supply mode or the second power supply mode, the power delivery controller105converts the error amplifying signal of the first output voltage Vo1to a current flowing through the photosensitive diode. The photosensitive transistor is coupled between the first feedback pin FB1of the integrated control circuit103and the second input terminal of the first switching converter101. The photosensitive transistor provides the first feedback signal VFB1in response to the current flowing through the photosensitive diode, the first feedback signal VFB1is input to the integrated control circuit103to control an operation of the integrated control circuit103.

Similarly, when the multi-converter power supply100B operates in the second power supply mode, the second feedback pin FB2of the integrated control circuit103receives the second feedback signal VFB2via the second isolated delivery path32. The second feedback signal VFB2is an error amplifying signal of the second output voltage Vo2. Specifically, the second isolated delivery path32includes a feedback resistor Rfb2, a photocoupler OC2, and a three-terminal adjustable voltage regulator device (integrated within the power delivery controller105as well). The photocoupler OC2also comprises a photosensitive diode and a photosensitive transistor. When the multi-converter power supply100B operates in the second power supply mode, the power delivery controller105provides the error amplifying signal of the second output voltage Vo2to the second feedback pin FB2of the integrated control circuit103, the second feedback signal VFB2is input to the switching control circuit109to control the operation thereof.

The mode indicating pin OCH of the integrated control circuit103receives the mode signal MS controlling the multi-converter power supply100B to operate in the first power supply mode or the second power supply mode via the third isolated delivery path33. In the embodiment shown inFIG.3, the mode signal MS is related to the first output voltage Vo1. In other embodiments, the mode signal MS may be provided to the integrated control circuit103by other ways. Specifically, the third isolated delivery path33includes a feedback resistor Rfb3, a photocoupler OC3, and the three-terminal adjustable voltage regulator device (also integrated within the power delivery controller105). When the multi-converter power supply100B operates in the first power supply mode or the second power supply mode, the power delivery controller105provides a signal related to the first output voltage Vo1to the mode indicating pin OCH of the integrated control circuit103, and the signal is input to the integrated control circuit103to control the operation of the integrated control circuit103.

Similarly, the feedback pin FB of the third controller11receives the third feedback signal VFB3representing the third output voltage Vo3via the fourth isolated delivery path34. The fourth isolated delivery path34includes a feedback resistor Rfb4, a photocoupler OC4, and a three-terminal adjustable voltage regulator device (integrated within the power delivery controller107). When the multi-converter power supply100B operates in the first power supply mode, the third feedback signal VFB3remains logic high level. When the third feedback signal VFB3changes from logic high level to logic low level, it indicates that the third port USBC3needs to be powered by the third switching converter201.

FIG.4schematically illustrates a circuit diagram of a multi-converter power supply100C in accordance with an embodiment of the present invention. The multi-converter power supply100C includes a first switching converter101A, a second switching converter102A, a third switching converter201A, a first port USBC1, a second port USBC2, a third port USBC3, and an integrated control circuit103A. In the embodiment shown inFIG.4, each of a first switching converter101A, a second switching converter102A and a third switching converter201A are flyback circuits. And the first switching converter101A comprises a switch S1, a transformer T1and a diode D1, the second switching converter102A comprises a switch S2, a transformer T2and a diode D2, and the third switching converter201A comprises a switch S3, a transformer T3and a diode D3.

When the multi-converter power supply100C operates in the first power supply mode, only the first port USBC1is coupled to the first electronic device110or no load is coupled to each port. In response to the multi-converter power supply100C operating in the first power supply mode, each converter of the multi-converter power supply100C is configured to different operating modes depending on power levels required by the load. Specifically, when the first electronic device110is in the light load condition or no-load condition, only the first switching converter101is under power operation, and the second switching converter102is not under power operation. When the first electronic device110is in the medium load condition, the first switching converter101and the second switching converter102are reconfigured, so that their outputs are connected in series and the first switching converter101and the second switching converter102can operate interleaved with each other to provide double current load capability to the first electronic device110. Therefore, the power supply requirements of the medium power load condition can be met. When the first electronic device110is in the heavy load condition, more switching converters, for example, the third switching converter201and/or the fourth switching converter202are further activated. The outputs of the third switching converter201and the fourth switching converter202operate in a way that their outputs are connected in parallel to provide increased load capacity. In other embodiments, more converters other than the third switching converter201and the fourth switching converter202may be further activated to provide power to a load coupled to the first port USBC1.

However, when the second port USBC2is coupled to the second electronic device111, the multi-converter power supply100C is reconfigured, so that the outputs of the switching converters are connected in parallel, the inputs of the switching converters are independent from each other. Thereby, respective output voltages are provided for the first electronic device110, the second electronic device111and even the third electronic device112(when the third port USBC3is coupled to the third electronic device112). So that the power supply requirements of multiple loads can be met.

Although the switching converters in the embodiment ofFIG.4are all exemplified by flyback circuits, it will be understood by those skilled in the art that this is not intended to limit the present invention. The switching converters of the present invention may also be implemented using any other suitable topology, such as FORWARD, LLC resonant converter, AHB, and BUCK-BOOST, and the switches therein may also be implemented using any suitable controllable semiconductor device.

FIG.5schematically illustrates a circuit diagram of an integrated control circuit103B in accordance with an embodiment of the present invention. As shown inFIG.5, the integrated control circuit103B includes a first switching control unit1031A, a load condition detect unit1032A, a first power distribution control unit1033A, and a second power distribution control unit1034A.

In the embodiment shown inFIG.5, the first switching control unit1031A includes a modulation signal generating circuit131, a first comparison circuit132, a second comparison circuit133, and a first logic circuit134.

The modulation signal generating circuit131is used to generate a modulation signal VM. In one embodiment, the modulation signal VM is a sawtooth wave signal. The first comparison circuit132has a first input terminal, a second input terminal and an output terminal. The first input terminal of the first comparison circuit132is coupled to the first feedback pin FB1to receive the first feedback signal VFB1, the second input terminal of the first comparison circuit132is coupled to the modulation signal generating circuit131to receive the modulation signal VM. Based on the first feedback signal VFB1and the modulation signal VM, the first comparison circuit132generates a comparison signal PFM1at its output terminal to control turn-on of the switch S1shown inFIG.4.

The second comparison circuit133has a first input terminal, a second input terminal and an output terminal. The first input terminal of the second comparison circuit133receives a first current sense signal representing the current flowing through the switch S1, the second input terminal of the second comparison circuit133receives a threshold signal lpk_ref1. Based on the first current sense signal and the threshold signal lpk_ref1, the second comparison circuit133generates a comparison signal PR at its output terminal to control turn-off of the switch S1. In one embodiment, the first threshold signal lpk_ref1is related to the first feedback signal VFB1. The integrated control circuit103B further comprises a first current threshold generating circuit130coupled to the first feedback pin FB1, the first current threshold generating circuit130generates the first threshold signal lpk_ref1based on the first feedback signal VFB1.

The first logic circuit134has a first input terminal, a second input terminal and an output terminal. The first input terminal of the first logic circuit134is coupled to the first comparison circuit132to receive the comparison signal PFM1, the second input terminal of the first logic circuit134is coupled to the second comparison circuit133to receive the comparison signal PR. Based on the comparison signal PFM1and the second comparison signal PR, the first logic circuit134generates the control signal CTRL1of the switch S1at its output terminal, the control signal CTRL1is output at the first driving terminal DRV1.

When the multi-converter power supply operates in the first power supply mode, the load condition detect unit1032A is activated and configured to compare the first feedback signal VFB1with the first feedback threshold Vth_1and the second feedback threshold Vth_2to judge the load condition of the first electronic device110coupled to the first port USBC1. And then the load condition detect unit1032A provides the first condition signal ST1and the second condition signal ST2respectively. In the embodiment shown inFIG.5, the load condition detect unit1032A comprises a first threshold comparison circuit121and a second threshold comparison circuit122.

The first threshold comparison circuit121has a first input terminal, a second input terminal and an output terminal. The first input terminal of the first threshold comparison circuit121receives the first feedback signal VFB1varies with the load, the second input terminal of the first threshold comparison circuit121receives the first feedback threshold Vth_1. Based on the first feedback signal VFB1and the first feedback threshold Vth_1, the first feedback comparison circuit121generates the first condition signal ST1at its output terminal to determine whether to activate the second switching converter102A when the multi-converter power supply operates in the first power supply mode. The second threshold comparison circuit122has a first input terminal, a second input terminal and an output terminal. The first input terminal of the second threshold comparison circuit122receives the first feedback signal VFB1, the second input terminal of the second threshold comparison circuit122receives the second feedback threshold Vth_2. Based on the first feedback signal VFB1and the second feedback threshold Vth_2, the second feedback comparison circuit122generates the second condition signal ST2at its output terminal to determine whether to activate the third switching converter201A, and whether to provide the first set signal SET1and the second set signal SET2when the multi-converter power supply operates in the first power supply mode.

The first power distribution control unit1033A includes a third comparison circuit135, a phase shift control circuit136, a logic selection circuit137, a fourth comparison circuit138, and a second logic circuit139.

The third comparison circuit135has a first input terminal, a second input terminal and an output terminal. The first input terminal of the third comparison circuit135is coupled to the second feedback pin FB2to receive the second feedback signal VFB2, the second input terminal of the third comparison circuit135is coupled to the modulation signal generating circuit131to receive the modulation signal VM. Based on the second feedback signal VFB2and the modulation signal VM, the third comparison circuit135generates a comparison signal PFM2at its output terminal to control turn-on of the switch S2when the multi-converter power supply operates in the second power supply mode.

The phase shift control circuit136receives the first control signal CTRL1, performs phase shifting based on the first control signal CTRL1, and generates a phase shift control signal CTRLD to control the turn-on of the switch S2when the multi-converter power supply operates in the first power supply mode and the first electronic device110is in the medium load condition. The time period required for the switch S1to perform a complete switching action can be defined as one period. The phase shift control circuit136may turn on the switch S2a half period after the switch S1is turned on.

The logic selection circuit137is coupled to the mode indicating pin OCH for receiving the mode signal MS controlling the multi-converter power supply to operate in the first power supply mode or the second power supply mode. The logic selection circuit137is further coupled to the load condition detect unit1032A for receiving the first condition signal ST1. Furthermore, based on the mode signal MS and the first condition signal ST1, the logic selection circuit137sets the phase shift control signal CTRLD output by the phase shift control circuit136or the comparison signal PFM2output by the third comparison circuit135as a conduction control signal FS. In the embodiment shown inFIG.5, the logic selection circuit137includes AND gate circuits AND1and AND2and an OR gate circuit OR1. Persons of ordinary skill in the art should appreciate that the logic selection circuit137may have any other circuit element or structure as long as functionality of the present invention can be implemented.

The fourth comparison circuit138has a first input terminal, a second input terminal and an output terminal. The first input terminal of the fourth comparison circuit138receives a second current sense signal characterizing a current flowing through the switch S2, the second input terminal of the fourth comparison circuit138receives a second threshold signal lpk_ref2. Based on the second current sense signal and the second threshold signal lpk_ref2, the fourth comparison circuit138generates a comparison signal FR at its output terminal to control the turn-off of the switch S2.

In the embodiment shown inFIG.5, the integrated control circuit103B further includes a second current threshold generating circuit140and a selection circuit143. The second current threshold generating circuit140is coupled to the second feedback pin FB2to receive the second feedback signal VFB2and to provide a threshold signal lpk_ref0at its output terminal. The selection circuit143has a first input terminal, a second input terminal and an output terminal. The first input terminal of the selection circuit143is coupled to the second current threshold generating circuit140to receive the threshold signal lpk_ref0, the second input terminal of the selection circuit143is coupled to the output terminal of the first current threshold generating circuit130to receive the first threshold signal lpk_ref0. Based on the mode signal MS, the selection circuit143selects the threshold signal lpk_ref0or the first threshold signal lpk_ref1as the second threshold signal lpk_ref2, and provides the second threshold signal lpk_ref2to the output terminal of the selection circuit143. When the multi-converter power supply operates in the first power supply mode, the second threshold signal lpk_ref2is the same as the first threshold signal Ipk_ref1. When the multi-converter power supply operates in the second power supply mode, the second threshold signal lpk_ref2is related to the second feedback signal VFB2and generated by the second current threshold generating circuit140based on the second feedback signal VFB2. To maintain system stability, the second comparison circuit133and the fourth comparison circuit138often introduced with slope compensation signals, such as signals RAMP1and RAMP2shown inFIG.5. The principles associated with slope compensation are well known to those skilled in the art and will not be described in detail herein.

The second logic circuit139has a first input terminal, a second input terminal and an output terminal. The first input terminal of the second logic circuit139is coupled to the logic selection circuit137to receive the selected conduction control signal FS, the second input terminal of the second logic circuit139is coupled to the fourth comparison circuit138to receive the comparison signal FR. Based on the conduction control signal FS and the comparison signal FR, the second logic circuit139generates the second control signal CTRL2at its output terminal to control turn-on and turn-off of the switch S2.

In another embodiment, the logic selection circuit137and the second logic circuit139may be disposed in the same logic circuit. When the multi-converter power supply operates in the first power supply mode and the first electronic device110is in the light load condition, the switch S2remained off. When the multi-converter power supply operates in the first power supply mode and the first electronic device110is in the medium load condition or the heavy load condition, the second control signal CTRL2is generated based on the phase shift control signal CTRLD and the comparison signal FR. When the multi-converter power supply operates in the second power supply mode, the second control signal CTRL2is generated based on the comparison signal PFM2and the comparison signal FR.

In response to the multi-converter power supply operating in the second power supply mode, the second power distribution control unit1034A is deactivated. In one embodiment, the second power distribution control unit1034A includes a first synchronization control unit141. When the multi-converter power supply operates in the first power supply mode and the first electronic device110is in the light load condition or the medium load condition, the first synchronization control unit141remains the first set signal SET1at zero, in other word, the first synchronization control unit141remains the first set signal SET1with a first status. When the multi-converter power supply operates in the first power supply mode and the first electronic device110is in the heavy load condition, the first synchronization control unit141provides the first set signal SET1(in other word, the first synchronization control unit141provides the first set signal SET1with a second status) to the first output pin Sync1of the integrated control circuit103B based on the first control signal CTRL1. In the embodiment shown inFIG.5, the first synchronization control unit141comprises a one-shot circuit1411receiving rising edge of the first control signal CTRL1and an AND gate circuit AND3.

In another embodiment, the second power distribution control unit1034A further includes a second synchronization control unit142. When the multi-converter power supply operates in the first power supply mode and the first electronic device110is in the light load condition or the medium load condition, the second set signal SET2remained at zero, in other word, the second synchronization control unit142remains the second set signal SET2with a first status. When the multi-converter power supply operates in the first power supply mode and the first electronic device110is in the heavy load condition, the second synchronization control unit142provides the second set signal SET2(in other word, the second synchronization control unit142provides the second set signal SET2with a second status) to the second output pin Sync2of the integrated control circuit103B based on the second control signal CTRL2. In the embodiment shown inFIG.5, the second synchronization control unit142comprises a one-shot circuit1421receiving rising edge of the second control signal CTRL1and an AND gate AND4.

FIG.6schematically illustrates a flowchart of a control method for a multi-converter power supply in accordance with an embodiment of the present invention. The multi-converter power supply includes a first port and a second port for supplying power to a single load or multiple loads, a first switching converter and a second switching converter and one or more other switching converters (i.e., one or more additional converters) that might be activated. The first switching converter converts an input voltage to a first output voltage and the second switching converter converts the input voltage to a second output voltage. The control method comprises steps401to408.

At the step401, receiving a mode signal controlling the multi-converter power supply to operate in a first power supply mode or a second power supply mode. In one embodiment, the mode signal is provided by a power delivery controller coupled to the first port and the second port. In one embodiment, when the multi-converter power supply operates in the first power supply mode, only the first port is coupled to the first electronic device or none of the ports are coupled to the electronic device(s) (i.e., no load). When the multi-converter power supply operates in the second power supply mode, the first port is coupled to the first electronic device while the second port is coupled to the second electronic device.

At the step402, receiving a first feedback signal representing the first output voltage. In one embodiment, a first feedback signal is provided by the power delivery controller coupled to the first port and the second port.

In response to the multi-converter power supply operating in the first power supply mode, the control method entering steps403to406.

At the step403, when the multi-converter power supply operates in the first power supply mode, determining a load condition of the first electronic device based on the first feedback signal. The first feedback signal is a signal that varies with the load.

At the step404, when the first electronic device is in the no load condition, or the light load condition, generating a first control signal based on the first feedback signal to control the first switching converter to provide power to the first port.

At the step405, when the first electronic device is in the medium load condition, activating the second switching converter for power operation. Outputs of the first switching converter and the second switching converter are connected in parallel, and the first switching converter and the second switching converter operate interleaved with each other to provide power to the first port.

At the step406, when the first electronic device is in the heavy load condition, further activating one or more other switching converters (i.e., one or more additional switching converters) for power operation. Outputs of the activated one or more additional switching converters are connected in parallel with the outputs of the first switching converter and the second switching converter to provide power to the first port.

In response to the multi-converter power supply operating in the second power supply mode, the control method entering steps407to408.

At the step407, generating the first control signal based on the first feedback signal to control the first switching converter, in order to provide power to the first port.

At the step408, receiving a second feedback signal representing the second output voltage, and generating a second control signal based on the second feedback signal to control a second switch of the second switching converter, the second switching converter is configured to provide power to the second port.

In one embodiment, a method of generating a second control signal for controlling a second switching converter comprises: phase-shifting a first control signal to generate a phase shift control signal; generating a third comparison signal based on a modulation signal and a second feedback signal; generating a fourth comparison signal based on a second current sense signal characterizing a current flowing through the second switch and a second threshold signal; and remaining the second switch off when a multi-converter power supply operates in a first power supply mode and a first electronic device is in the light load condition, generating the second control signal based on the phase shift control signal and the fourth comparison signal when the multi-converter power supply operates in the first power supply mode and the first electronic device is in the medium load condition or the heavy load condition, generating the second control signal based on the third comparison signal and the fourth comparison signal when the multi-converter power supply operates in the second power supply mode.

In another embodiment, a set signal is remained at zero (in other word, the set signal is remained with a first status) when a multi-converter power supply operates in a first power mode and a first electronic device is in a light load condition or medium load condition; the set signal is remained at zero (in other word, the set signal is remained with the first status) when the multi-converter power supply operates in a second power supply mode; and providing the set signal based on a first control signal or a second control signal when the multi-converter power supply operates in the first power mode and the first electronic device is in the heavy load condition, in this case, the set signal is in a second status.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. It should be understood, of course, the foregoing disclosure relates only to a preferred embodiment (or embodiments) of the invention and that numerous modifications may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims. Various modifications are contemplated and they obviously will be resorted to by those skilled in the art without departing from the spirit and the scope of the invention as hereinafter defined by the appended claims as only a preferred embodiment(s) thereof has been disclosed.