Charging device

Abstract

A charging device is provided. A first sensing circuit senses a first DC voltage provided by a first DC voltage generating circuit and generates a first sense voltage. A second sensing circuit senses a second DC voltage provided by a second DC voltage generating circuit and generates a second sense voltage. A first current balancing circuit adjusts a first feedback signal provided by a first optocoupler and a second feedback signal provided by a second optocoupler based on the first sense voltage and the second sense voltage.

Description

Technical Field

[0001] This invention relates to an electronic device, and more particularly to a charging device. Prior Technology

[0002] Commonly available dual universal bus C-type (USB Type-C) chargers can achieve different output voltages for the two output ports by setting up one AC-DC converter and two DC-DC converters, or by setting up two AC-DC converters. Although these two methods can meet the output power requirements, they have problems such as excessive system size, unbalanced output current, and high output voltage ripple. Summary of the Invention

[0003] This invention provides a charging device that can reduce system size while achieving balanced output current and low output voltage ripple.

[0004] The charging device of the present invention includes a first DC voltage generating circuit, a second DC voltage generating circuit, a first sensing circuit, a second sensing circuit, a connection switch, a switch control circuit, a first current balancing circuit, a first voltage regulator, a second voltage regulator, a first optocoupler, and a second optocoupler. The first DC voltage generating circuit provides a first DC voltage to a first output port of a power supply device through a first power transmission path. The second DC voltage generating circuit provides a second DC voltage to a second output port of the power supply device through a second power transmission path. The first sensing circuit is coupled to the first DC voltage generating circuit and senses the first DC voltage to generate a first sense voltage. The second sensing circuit is coupled to the second DC voltage generating circuit and senses the second DC voltage to generate a second sense voltage. The connection switch is coupled between the first power transmission path and the second power transmission path. The first voltage regulator is coupled to the first sensing circuit. The second voltage regulator is coupled to the second sensing circuit. The first optocoupler is coupled to the first voltage regulator, and the first voltage regulator controls the first optocoupler to provide a first feedback signal to the first DC voltage generating circuit based on the first sense voltage, thereby controlling the first DC voltage generating circuit to generate the first DC voltage. The second optocoupler is coupled to the second voltage regulator. The second voltage regulator controls the second optocoupler to provide a second feedback signal to the second DC voltage generating circuit based on the second sensed voltage, so as to control the second DC voltage generating circuit to generate a second DC voltage. The first current balancing circuit adjusts at least one of the first feedback signal and the second feedback signal based on at least one of the first sensed voltage and the second sensed voltage.

[0005] In one embodiment of the present invention, the first current balancing circuit adjusts the first feedback signal and the second feedback signal according to the first sensing voltage and the second sensing voltage.

[0006] In one embodiment of the present invention, the charging device further includes a switch control circuit, a first output switch, and a second output switch. The switch control circuit is coupled to the switches and controls the on / off state of the switches. The first output switch is coupled between a first DC voltage generating circuit and a first output port, and the control terminal of the first output switch is coupled to the switch control circuit. The second output switch is coupled between a second DC voltage generating circuit and a second output port, and the control terminal of the second output switch is coupled to the switch control circuit. The switch control circuit controls the first and second output switches to be turned on or off.

[0007] In one embodiment of the present invention, the first output switch is a first output transistor, the second output switch is a second output transistor, and the first output transistor and the second output transistor are P-type transistors or N-type transistors.

[0008] In one embodiment of the present invention, the first DC voltage generating circuit and the second DC voltage generating circuit described above are AC-DC conversion circuits. The charging device further includes a first voltage regulator, a second voltage regulator, a first optocoupler, and a second optocoupler. The first voltage regulator is coupled to a first sensing circuit. The second voltage regulator is coupled to a second sensing circuit. The first optocoupler is coupled to the first voltage regulator and a first current balancing circuit. The first voltage regulator controls the first optocoupler to provide a first feedback signal to the first DC voltage generating circuit based on the first sensing voltage, so as to control the first DC voltage generating circuit to generate a first DC voltage. The second optocoupler is coupled to the second voltage regulator and the first current balancing circuit. The second voltage regulator controls the second optocoupler to provide a second feedback signal to the second DC voltage generating circuit based on the second sensing voltage, so as to control the second DC voltage generating circuit to generate a second DC voltage. The first current balancing circuit adjusts the first feedback signal and the second feedback signal based on the first sensing voltage and the second sensing voltage.

[0009] In one embodiment of the present invention, the first output switch is a first output transistor, the second output switch is a second output transistor, and the first output transistor and the second output transistor are P-type transistors or N-type transistors.

[0010] In one embodiment of the present invention, the first current balancing circuit includes a first comparator, a first transistor, a first switch, a second comparator, a second transistor, a second switch, and a control circuit. The first input terminal and the second input terminal of the first comparator are respectively coupled to a first sensing circuit and a second sensing circuit to receive a first sense voltage and a second sense voltage. The first transistor is coupled between a first optocoupler and ground. The first switch is coupled between the output terminal of the first comparator and the control terminal of the first transistor. The first input terminal and the second input terminal of the second comparator are respectively coupled to a second sensing circuit and a first sensing circuit to receive a second sense voltage and a first sense voltage. The second transistor is coupled between a second optocoupler and ground. The second switch is coupled between the output terminal of the second comparator and the control terminal of the second transistor. The control circuit controls the conduction state of the first switch and the second switch.

[0011] In one embodiment of the present invention, the first sensing circuit includes a first sensing resistor and a first amplification circuit. The first end and the second end of the first sensing resistor are respectively coupled to the output terminal and the first output port of the first DC voltage generating circuit. The first amplification circuit is coupled to the first sensing resistor and generates a first sensing voltage based on the voltage across the first sensing resistor.

[0012] In one embodiment of the present invention, the first amplification circuit includes a third comparator, a first resistor, and a second resistor. The positive and negative input terminals of the third comparator are respectively coupled to the first and second terminals of the first sensing resistor, and the output terminal of the third comparator outputs a first sensing voltage. The first resistor is coupled between the second terminal of the first sensing resistor and the negative input terminal of the third comparator. The second resistor is coupled between the negative input terminal and the output terminal of the third comparator.

[0013] In one embodiment of the present invention, the second sensing circuit includes a second sensing resistor and a second amplification circuit. The first and second terminals of the second sensing resistor are respectively coupled to the output terminal and the second output port of the second DC voltage generating circuit. The second amplification circuit is coupled to the second sensing resistor and generates a second sensing voltage based on the voltage across the second sensing resistor.

[0014] In one embodiment of the present invention, the second amplification circuit includes a fourth comparator, a third resistor, and a third resistor. The positive and negative input terminals of the fourth comparator are respectively coupled to the first and second terminals of the second sensing resistor, and the output terminal of the fourth comparator outputs a second sensing voltage. The third resistor is coupled between the second terminal of the second sensing resistor and the negative input terminal of the fourth comparator. The fourth resistor is coupled between the negative input terminal and the output terminal of the fourth comparator.

[0015] In one embodiment of the present invention, the charging device further includes a second current balancing circuit. The first current balancing circuit adjusts a first feedback signal based on a first sensing voltage and a minimum sensing voltage. The second current balancing circuit adjusts a second feedback signal based on a second sensing voltage and a minimum sensing voltage, wherein the lower of the first and second sensing voltages is used as the minimum sensing voltage.

[0016] In one embodiment of the present invention, the first output port and the second output port are Universal Sequence Bus Type C connection ports.

[0017] The present invention also provides a charging device, comprising a first DC voltage generating circuit, a second DC voltage generating circuit, a first sensing circuit, a second sensing circuit, a connection switch, a switch control circuit, a first current balancing circuit, a first output switch, and a second output switch. The first DC voltage generating circuit provides a first DC voltage to a first output port of a power supply device via a first power transmission path. The second DC voltage generating circuit provides a second DC voltage to a second output port of the power supply device via a second power transmission path. The first sensing circuit is coupled to the first DC voltage generating circuit and senses the first DC voltage to generate a first sense voltage. The second sensing circuit is coupled to the second DC voltage generating circuit and senses the second DC voltage to generate a second sense voltage. The connection switch is coupled between the first power transmission path and the second power transmission path. The switch control circuit is coupled to the connection switch and controls the on / off state of the connection switch. The first current balancing circuit is coupled to the first sensing circuit and the second sensing circuit. The first output switch is coupled between the first DC voltage generating circuit and the first output port, and the control terminal of the first output switch is coupled to the switch control circuit and the first current balancing circuit. The second output switch is coupled between the second DC voltage generating circuit and the second output port. The control terminal of the second output switch is coupled to the switch control circuit and the first current balancing circuit. The switch control circuit controls the first output switch and the second output switch to open or close. The first current balancing circuit controls the conduction degree of the first output switch and the second output switch according to the first sensing voltage and the second sensing voltage, so as to adjust the first output current and the second output current.

[0018] In one embodiment of the present invention, the first DC voltage generating circuit and the second DC voltage generating circuit described above are AC-DC conversion circuits. The charging device further includes a first voltage regulator, a second voltage regulator, a first optocoupler, and a second optocoupler. The first voltage regulator is coupled to a first sensing circuit. The second voltage regulator is coupled to a second sensing circuit. The first optocoupler is coupled to the first voltage regulator and a first current balancing circuit. The first voltage regulator controls the first optocoupler to provide a first feedback signal to the first DC voltage generating circuit based on the first sensing voltage, so as to control the first DC voltage generating circuit to generate a first DC voltage. The second optocoupler is coupled to the second voltage regulator and the first current balancing circuit. The second voltage regulator controls the second optocoupler to provide a second feedback signal to the second DC voltage generating circuit based on the second sensing voltage, so as to control the second DC voltage generating circuit to generate a second DC voltage. The first current balancing circuit adjusts the first feedback signal and the second feedback signal based on the first sensing voltage and the second sensing voltage.

[0019] In one embodiment of the present invention, the first output switch is a first output transistor, the second output switch is a second output transistor, and the first output transistor and the second output transistor are P-type transistors or N-type transistors.

[0020] In one embodiment of the present invention, the first output port and the second output port are Universal Sequence Bus Type C connection ports.

[0021] Based on the above, the first sensing circuit of this embodiment can sense the first DC voltage provided by the first DC voltage generating circuit and generate a first sensing voltage, the second sensing circuit can sense the second DC voltage provided by the second DC voltage generating circuit and generate a second sensing voltage, and the first current balancing circuit can adjust the first feedback signal provided by the first optocoupler and the second feedback signal provided by the second optocoupler according to the first sensing voltage and the second sensing voltage, so as to avoid the voltage regulator independently controlling the corresponding DC voltage generating circuit, which would lead to an imbalance in the output current provided by the DC voltage generating circuit and a problem of high output voltage ripple caused by unstable output current.

[0022] To make the above features and advantages of the present invention more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings for detailed explanation. Simple Explanation of the Diagram

[0023] Figure 1 is a schematic diagram of a charging device according to an embodiment of the present invention. Figure 2 is a schematic diagram of a sensing circuit and a current balancing circuit according to an embodiment of the present invention. Figures 3 to 5 are schematic diagrams of a charging device according to an embodiment of the present invention. Implementation

[0024] Figure 1 is a schematic diagram of a charging device according to an embodiment of the present invention. The charging device includes DC voltage generating circuits DG1 and DG2, sensing circuits SC1 and SC2, voltage regulators SR1 and SR2, optocouplers D1 and D2, a current balancing circuit CB1, a switch control circuit CTR1, a connection switch SWC1, and output switches SWO1 and SWO2. The DC voltage generating circuit DG1 is coupled to the output port P1 via a first power transmission path PTH1. The sensing circuit SC1 is coupled to the output terminal of the DC voltage generating circuit DG1. The output switch SWO1 is coupled between the sensing circuit SC1 and the output port P1, and the control terminal of the output switch SWO1 is coupled to the switch control circuit CTR1. Similarly, the DC voltage generating circuit DG2 is coupled to the output port P2 via a second power transmission path PTH2. The sensing circuit SC2 is coupled to the output terminal of the DC voltage generating circuit DG2. The output switch SWO2 is coupled between the sensing circuit SC2 and the output port P2, and the control terminal of the output switch SWO2 is coupled to the switch control circuit CTR1. Output ports P1 and P2 can be, for example, general-purpose sequential bus type C ports, but are not limited thereto. Connector switch SWC1 is coupled between the first power transmission path PTH1 and the second power transmission path PTH2, and the control terminal of connector switch SWC1 is coupled to switch control circuit CTR1. Voltage regulator SR1 is coupled to sensing circuit SC1 and optocoupler D1; current balancing circuit CB1 is coupled to sensing circuits SC1 and SC2 and optocouplers D1 and D2; voltage regulator SR2 is coupled to sensing circuit SC2 and optocoupler D2. Voltage regulators SR1 and SR2 can be, for example, shunt regulators, but are not limited thereto.

[0025] The DC voltage generating circuits DG1 and DG2 can be, for example, AC-DC conversion circuits. DG1 and DG2 can perform AC-DC conversion to generate DC voltages VCC1 and VCC2 respectively for output ports P1 and P2. Sensing circuits SC1 and SC2 can detect DC voltages VCC1 and VCC2 and generate sensing voltages V1 and V2 respectively, as shown in Figure 1. Sensing circuit SC1 can, for example, include a sensing resistor Rsense1 and an amplifier circuit A1. The first and second terminals of the sensing resistor Rsense1 are coupled to the output terminal of the DC voltage generating circuit DG1 and the output port P1, respectively. The amplifier circuit A1 is coupled to the sensing resistor Rsense1 and can generate the sensing voltage V1 based on the voltage across the sensing resistor Rsense1. Similarly, the sensing circuit SC2 includes a sensing resistor Rsense2 and an amplifier circuit A2. The first and second ends of the sensing resistor Rsense2 are respectively coupled to the output terminal and output port P2 of the DC voltage generating circuit DG2. The amplifier circuit A2 is coupled to the sensing resistor Rsense2 and can generate a sensing voltage V2 based on the voltage across the sensing resistor Rsense2.

[0026] The switch control circuit CTR1 can control the conduction states of the connection switch SWC1, output switches SWO1 and SWO2, so that the output current on the first power transmission path PTH1 and the second power transmission path PTH2 is directed to output ports P1 and P2 respectively, or the output current on the first power transmission path PTH1 and the second power transmission path PTH2 is directed to one of output ports P1 and P2. For example, the switch control circuit CTR1 can control the connection switch SWC1 and output switch SWO1 to be on and the output switch SWO2 to be off, so that the output current on the first power transmission path PTH1 and the second power transmission path PTH2 is concentrated and flows to output port P1, thereby increasing the charging power of output port P1. In addition, the switch control circuit CTR1 can also control the connection switch SWC1 to be off and control the output switches SWO1 and SWO2 to be on, so that the output current provided by the DC voltage generating circuits DG1 and DG2 flows to output ports P1 and P2 respectively.

[0027] The voltage regulator SR1 controls the optocoupler D1 to provide a first feedback signal to the DC voltage generating circuit DG1 based on the voltage divider resistor between the sensed voltage V1 and the DC voltage VCC1, thereby controlling the DC voltage generating circuit DG1 to generate the DC voltage VCC1. The sensed voltage V1 reflects the current state on the first power transmission path PTH1, and the voltage divider resistor of VCC1 reflects the state of the DC voltage VCC1. For example, the first feedback signal can be provided to the pulse width modulation (PWM) control circuit on the primary side of the transformer of the DC voltage generating circuit DG1, so that the PWM control circuit adjusts the duty cycle of the PWM signal provided to the switch connected to the primary winding according to the first feedback signal, thereby adjusting the DC voltage VCC1. Similarly, the voltage regulator SR2 controls the optocoupler D2 to provide a second feedback signal to the DC voltage generating circuit DG2 based on the voltage divider resistor between the sensed voltage V2 and the DC voltage VCC2, thereby controlling the DC voltage generating circuit DG2 to generate the DC voltage VCC2.

[0028] In addition, the current balancing circuit CB1 can adjust the first feedback signal and the second feedback signal according to the sensing voltage V1 and the sensing voltage V2. This can avoid the problem of unbalanced output current provided by DC voltage generating circuits DG1 and DG2 and high output voltage ripple caused by the independent control of DC voltage generating circuits DG1 and DG2 by voltage regulators SR1 and SR2, respectively.

[0029] In detail, the implementation of the current balancing circuit CB1 and the amplifier circuits A1 and A2 can be shown in Figure 2. The current balancing circuit CB1 may include comparators CMP1 and CMP2, transistors M1 and M2, switches SW1 and SW2, and control circuit 202. The positive and negative input terminals of comparator CMP1 are coupled to the output terminals of amplifier circuits A1 and A2, respectively. The positive and negative input terminals of comparator CMP2 are coupled to the output terminals of amplifier circuits A2 and A1, respectively. Switch SW1 is coupled between the output terminal of comparator CMP1 and the control terminal of transistor M1. Switch SW2 is coupled between the output terminal of comparator CMP2 and the control terminal of transistor M2. Transistor M1 is coupled between optocoupler D1 and ground. Transistor M2 is coupled between optocoupler D2 and ground. Control circuit 202 is coupled to the control terminals of switches SW1 and SW2.

[0030] Comparators CMP1 and CMP2 compare sensed voltages V1 and V2 respectively, and control the conduction states of transistors M1 and M2 based on the comparison results to adjust the first and second feedback signals provided by optocouplers D1 and D2. Control circuit 202 can determine whether to allow current balancing circuit CB1 to adjust the first and second feedback signals by controlling the opening and closing of switches SW1 and SW2. In this embodiment, since the positive and negative input terminals of comparator CMP1 are coupled to the output terminals of amplifier circuits A1 and A2 respectively, and the positive and negative input terminals of comparator CMP2 are coupled to the output terminals of amplifier circuits A2 and A1 respectively, the optocoupler current corresponding to higher output current or voltage will be increased, while the optocoupler current corresponding to lower output current or voltage will remain unchanged. For example, if the DC voltage VCC1 is greater than the DC voltage VCC2 or the output current ICC1 is greater than the output current ICC2, the optocoupler current of optocoupler D1 will be increased, while the optocoupler current of optocoupler D2 will remain unchanged. In this way, the DC voltage generating circuit DG1 can reduce the DC voltage VCC1 it provides according to the first feedback signal, and adjust the voltages VBUS1 and VBUS2 to be the same, so as to achieve current sharing and low output voltage ripple.

[0031] It is worth noting that in this embodiment, current sharing and low output voltage ripple are achieved by reducing the relatively high DC voltage VCC1 and the relatively high output current ICC1, but this is not a limitation. In other embodiments, current sharing and low output voltage ripple can also be achieved by increasing the relatively low DC voltage VCC2 and the relatively low output current ICC2. For example, the positive and negative input terminals of comparator CMP1 can be coupled to the output terminals of amplifier circuits A2 and A1 respectively, and the positive and negative input terminals of comparator CMP2 can be coupled to the output terminals of amplifier circuits A1 and A2 respectively. That is, the coupling objects of the positive and negative input terminals of comparators CMP1 and CMP2 can be reversed, thereby increasing the DC voltage VCC2 and the output current ICC2 to achieve current sharing and low output voltage ripple.

[0032] In detail, the amplifier circuit A1 can be as shown in Figure 2, including comparator CMP3, resistor R1 and R2. However, in other embodiments, other current amplifier circuits can be used to implement amplifier circuits A1 and A2, and it is not limited to this embodiment. The positive input terminal of comparator CMP3 is coupled to the first terminal of sensing resistor Rsense1. Resistor R1 is coupled between the negative input terminal of comparator CMP3 and the second terminal of sensing resistor Rsense1. Resistor R2 is coupled between the negative input terminal and the output terminal of comparator CMP3. The output terminal of comparator CMP3 is coupled to voltage regulator SR1, the positive input terminal of comparator CMP1 and the negative input terminal of comparator CMP2. Similarly, amplifier circuit A2 may include comparator CMP4, resistors R3 and R4. The positive input terminal of comparator CMP4 is coupled to the first terminal of sensing resistor Rsense2. Resistor R3 is coupled between the negative input terminal of comparator CMP4 and the second terminal of sensing resistor Rsense2. Resistor R4 is coupled between the negative input terminal and the output terminal of comparator CMP4. The output terminal of comparator CMP4 is coupled to regulator SR2, the negative input terminal of comparator CMP1, and the positive input terminal of comparator CMP2.

[0033] The sensing voltages V1 and V2 can be calculated using the following equations (1) and (2). (1) (2)

[0034] The output currents ICC1 and ICC2 can be adjusted by changing the ratios of R1 to R3, R2 to R4, or Rsense1 to Rsense2. For example, when R1 / R3 = N and V1 = V2 is achieved through the current balancing circuit CB1, the output current ICC1 is N times the output current ICC2. When R2 / R4 = 1 / N and V1 = V2 is achieved through the current balancing circuit CB1, the output current ICC1 is N times the output current ICC2. When Rsense1 / Rsense2 = 1 / N and V1 = V2 is achieved through the current balancing circuit CB1, the output current ICC1 is N times the output current ICC2.

[0035] It is worth noting that the above embodiments are illustrated using the example of a charging device including two DC voltage generating circuits DG1 and DG2. However, in other embodiments, the charging device may include more DC voltage generating circuits and is not limited to the above embodiments. For example, as shown in FIG3, the charging device may include n DC voltage generating circuits DG1~DGn and corresponding circuit elements (e.g., sensing circuits SC1~SCn, voltage regulators SR1~SRn, current balancing circuits CB1~CBn, optocouplers D1~Dn, switch control circuits SWC1~SWCm, and switch control circuits CTR1~CTRm, etc.), where n is a positive integer greater than 2 and m is a positive integer greater than 1. The detailed implementation of the sensing circuits SC1~SCn, voltage regulators SR1~SRn, optocouplers D1~Dn, switch control circuits SWC1~SWCm, and switch control circuits CTR1~CTRm is similar to that in the embodiments of FIG1 and 2, and will not be repeated here. The main difference between the current balancing circuits CB1~CBn in this embodiment and the current balancing circuit CB1 in the embodiment of Figure 1 is that the current balancing circuits CB1~CBn adjust the feedback signals provided by the optocouplers D1~Dn according to the sensing voltages V1~Vn and the lowest sensing voltage VL provided by the corresponding sensing circuits SC1~SCn (that is, the two input terminals of the comparators CMP1 and CMP2 in each current balancing circuit CB1~CBn are changed to receive the sensing voltages provided by the corresponding sensing circuits and the lowest sensing voltage VL), so as to achieve the purpose of current sharing and low output voltage ripple. The lowest sensing voltage VL is the sensing voltage with the lowest voltage value among the sensing voltages V1~Vn. In addition, the switch control circuits CTR1~CTRm can control the conduction state of the switch control circuits SWC1~SWCm respectively, so as to transmit the current on different power transmission paths to a specific output port (such as the output port P1 in Figure 3).

[0036] Figure 4 is a schematic diagram of a charging device according to another embodiment of the present invention. The main difference between this embodiment and the charging device of Figure 1 is that the output switches SWO1 and SWO2 of the embodiment of Figure 1 are implemented using output transistors MO1 and MO2 in this embodiment (in some embodiments, the output switches SWO1 and SWO2 of Figure 1 can also be implemented using output transistors MO1 and MO2 in this embodiment). Furthermore, the current balancing circuit CB1 of this embodiment is also coupled to the control terminals of the output transistors MO1 and MO2. The current balancing circuit CB1 can control the conduction level of transistors MO1 and MO2 based on the sensed voltages V1 and V2 to adjust the output current flowing to output ports P2 and P2 through the first power transmission path PTH1 and the second power transmission path PTH2. For example, it can reduce the current value of the output current with a higher current value or increase the current value of the output current with a lower current value to achieve current sharing and low output voltage ripple. The transistors MO1 and MO2 can be, for example, N-type transistors or P-type transistors. Furthermore, in some embodiments, the current balancing circuit CB1 of the embodiment in FIG4 can also adjust the first feedback signal and the second feedback signal according to the sensing voltage V1 and the sensing voltage V2, as in the embodiments in FIG1 and 2.

[0037] Figure 5 is a schematic diagram of a charging device according to another embodiment of the present invention. The main difference between this embodiment and the embodiment in Figure 4 is that the DC voltage generating circuits DG1 and DG2 are DC voltage sources. That is, the DC voltage generating circuits DG1 and DG2 do not need to perform AC-DC conversion. The charging device does not include voltage regulators SR1 and SR2 and optocouplers D1 and D2. The current balancing circuit CB1 can control the conduction degree of transistors MO1 and MO2 according to the sensed voltages V1 and V2 to achieve current sharing and low output voltage ripple.

[0038] In summary, the sensing circuit of this embodiment can sense the DC voltage provided by the DC voltage generating circuit to generate a sensing voltage. The current balancing circuit can adjust the feedback signal provided by the optocoupler based on the sensing voltages provided by the two sensing circuits, thereby adjusting the output voltage provided by the DC voltage generating circuit. This achieves output current balance and low output voltage ripple while reducing system size. In some embodiments, the current balancing circuit can also control the conduction degree of the output switches on the first power transmission path and the second power transmission path based on the sensing voltages provided by the two sensing circuits, thereby achieving output current balance and low output voltage ripple while reducing system size.

[0039] DG1~DGn: DC voltage generation circuit SC1~SCn: Sensing circuits SR1~SRn: Voltage regulators D1~Dn: Optical couplers CB1~CBn: Current balancing circuit CTR1~CTRm: Switch control circuit SWC1~SWCm: Connecting switches SWO1, SWO2: Output switches PTH1: First power transmission path PTH2: Second power transmission path P1, P2: Output ports VCC1, VCC2: DC voltage V1, V2: Sensing voltage Rsense1~Rsensen: Sensing resistor A1~An: Amplifier circuit VBUS1, VBUS2: Voltage CMP1~CMP4: Comparators M1, M2: Transistors SW1, SW2: Switches 202: Control Circuit ICC1, ICC2: Output current R1~R4: Resistors VL: Minimum sensing voltage MO1, MO2: Output transistors

Claims

1. A charging device, comprising: A first DC voltage generating circuit provides a first DC voltage to a first output port of a power supply device through a first power transmission path. A second DC voltage generating circuit provides a second DC voltage to a second output port of the power supply device via a second power transmission path; a first sensing circuit coupled to the first DC voltage generating circuit senses the first DC voltage and generates a first sensing voltage; a second sensing circuit coupled to the second DC voltage generating circuit senses the second DC voltage and generates a second sensing voltage; a connection switch coupled between the first power transmission path and the second power transmission path; a first current balancing circuit; a first voltage regulator coupled to the first sensing circuit; and a second voltage regulator coupled to the second sensing circuit. A first optocoupler is coupled to the first voltage regulator, the first voltage regulator controlling the first optocoupler to provide a first feedback signal to the first DC voltage generating circuit based on the first sensed voltage, so as to control the first DC voltage generating circuit to generate the first DC voltage; and a second optocoupler is coupled to the second voltage regulator, the second voltage regulator controlling the second optocoupler to provide a second feedback signal to the second DC voltage generating circuit based on the second sensed voltage, so as to control the second DC voltage generating circuit to generate the second DC voltage; and a first current balancing circuit adjusts at least one of the first feedback signal and the second feedback signal based on at least one of the first sensed voltage and the second sensed voltage.

2. The charging device as claimed in claim 1, wherein the first current balancing circuit adjusts the first feedback signal and the second feedback signal based on the first sense voltage and the second sense voltage.

3. The charging device as claimed in claim 1, further comprising: A switch control circuit is coupled to the connection switch to control the on / off state of the connection switch; A first output switch is coupled between the first DC voltage generating circuit and the first output port, and the control terminal of the first output switch is coupled to the switch control circuit. And a second output switch, coupled between the second DC voltage generating circuit and the second output port, the control terminal of the second output switch is coupled to the switch control circuit, and the switch control circuit controls the first output switch and the second output switch to be turned on or off.

4. The charging device as claimed in claim 3, wherein the first output switch is a first output transistor, the second output switch is a second output transistor, and the first output transistor and the second output transistor are P-type transistors or N-type transistors.

5. The charging device as claimed in claim 1, wherein the first current balancing circuit comprises: A first comparator, with its first input terminal and second input terminal respectively coupled to the first sensing circuit and the second sensing circuit, to receive the first sense voltage and the second sense voltage; a first transistor, coupled between the first optocoupler and a ground; a first switch, coupled between the output terminal of the first comparator and the control terminal of the first transistor; a second comparator, with its first input terminal and second input terminal respectively coupled to the second sensing circuit and the first sensing circuit, to receive the second sense voltage and the first sense voltage; a second transistor, coupled between the second optocoupler and the ground; a second switch, coupled between the output terminal of the second comparator and the control terminal of the second transistor; And a control circuit to control the conduction state of the first switch and the second switch.

6. The charging device as claimed in claim 5, wherein the first sensing circuit comprises: A first sensing resistor, the first end of which is coupled to the output terminal of the first DC voltage generating circuit and the first output port, respectively. And a first amplifier circuit coupled to the first sensing resistor, generating the first sensing voltage based on the voltage across the first sensing resistor.

7. The charging device as claimed in claim 6, wherein the first amplification circuit comprises: A third comparator, whose positive and negative input terminals are respectively coupled to the first and second terminals of the first sensing resistor, and whose output terminal outputs the first sensing voltage; A first resistor is coupled between the second terminal of the first sensing resistor and the negative input terminal of the third comparator; And a second resistor, coupled between the negative input and output of the third comparator.

8. The charging device as claimed in claim 5, wherein the second sensing circuit comprises: A second sensing resistor, the first end of which is coupled to the output terminal of the second DC voltage generating circuit and the second output port, respectively. And a second amplifier circuit coupled to the second sensing resistor, which generates the second sensing voltage based on the voltage across the second sensing resistor.

9. The charging device as claimed in claim 8, wherein the second amplification circuit comprises: A fourth comparator, whose positive and negative input terminals are respectively coupled to the first and second terminals of the second sensing resistor, and whose output terminal outputs the second sensing voltage; a third resistor, coupled between the second terminal of the second sensing resistor and the negative input terminal of the fourth comparator; And a fourth resistor, coupled between the negative input and output of the fourth comparator.

10. The charging device as claimed in claim 1, further comprising: A second current balancing circuit is provided, wherein the first current balancing circuit adjusts the first feedback signal based on the first sensing voltage and a minimum sensing voltage, and the second current balancing circuit adjusts the second feedback signal based on the second sensing voltage and the minimum sensing voltage, wherein the lowest sensing voltage among the first sensing voltage and the second sensing voltage is used as the minimum sensing voltage.

11. The charging device as claimed in claim 1, wherein the first output port and the second output port are Universal Sequence Bus Type C connectors.

12. A charging device, comprising: A first DC voltage generating circuit provides a first DC voltage to a first output port of a power supply device through a first power transmission path. A second DC voltage generating circuit provides a second DC voltage to a second output port of the power supply device via a second power transmission path; a first sensing circuit coupled to the first DC voltage generating circuit senses the first DC voltage and generates a first sensing voltage; a second sensing circuit coupled to the second DC voltage generating circuit senses the second DC voltage and generates a second sensing voltage; a connection switch coupled between the first power transmission path and the second power transmission path; a switch control circuit coupled to the connection switch and controls the on / off state of the connection switch; a first current balancing circuit coupled to the first sensing circuit and the second sensing circuit; a first output switch coupled between the first DC voltage generating circuit and the first output port, the control terminal of the first output switch being coupled to the switch control circuit and the first current balancing circuit; A second output switch is coupled between the second DC voltage generating circuit and the second output port. The control terminal of the second output switch is coupled to the switch control circuit and the first current balancing circuit. The switch control circuit controls the first output switch and the second output switch to be turned on or off. The first current balancing circuit controls the conduction degree of the first output switch and the second output switch according to the first sensing voltage and the second sensing voltage, so as to adjust the first output current flowing to the first output port and the second output current flowing to the second output port; a first voltage regulator is coupled to the first sensing circuit; a second voltage regulator is coupled to the second sensing circuit. A first optocoupler is coupled to the first voltage regulator and the first current balancing circuit. The first voltage regulator controls the first optocoupler to provide a first feedback signal to the first DC voltage generating circuit based on the first sensed voltage, so as to control the first DC voltage generating circuit to generate the first DC voltage. A second optocoupler is coupled to the second voltage regulator and the first current balancing circuit. The second voltage regulator controls the second optocoupler to provide a second feedback signal to the second DC voltage generating circuit based on the second sensed voltage, so as to control the second DC voltage generating circuit to generate the second DC voltage. The first current balancing circuit adjusts the first feedback signal and the second feedback signal based on the first sensed voltage and the second sensed voltage.

13. The charging device as claimed in claim 12, wherein the first output switch is a first output transistor, the second output switch is a second output transistor, and the first output transistor and the second output transistor are P-type transistors or N-type transistors.

14. The charging device as claimed in claim 12, wherein the first output port and the second output port are Universal Sequence Bus Type C connectors.

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