Patent ID: 12224613

DETAILED DESCRIPTION

FIG.1is a diagram of a charging system100of an embodiment of the present invention. The charging system100includes a primary power source10, a power source controller PD, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a first port P1, and a second port P2. The primary power source10can receive the power input of the external power supply Vsrc, and the external power supply Vsrc can be a commercial AC power supply Vac or a battery pack DC power supply Vdc of a mobile charger. The primary power source10, for example, may include a flyback converter. If he external power supply Vsrc is an AC power supply Vac, the primary power source10receives instructions from the power source controller PD to convert the AC power supply Vac output to DC power of different voltages. However, the primary power source10of the embodiment is not limited to a flyback converter, but can include any converter well-known to those skilled in the art.

The first port P1can be selectively connected to the first device70, and the second port P2can be selectively connected to the second device72. The first device70and the second device72can be, for example, mobile phones, laptops or tablets. The power source controller PD includes an auxiliary power source20, a load detection circuit30, a first auxiliary power terminal40, and a second auxiliary power terminal50. The first auxiliary power terminal40and the second auxiliary power terminal50are both coupled to the auxiliary power source20. The auxiliary power source20can provide a first detection current through the first auxiliary power terminal40, and the auxiliary power source20can provide a second detection current through the second auxiliary power terminal50. The power source controller PD is coupled to the primary power source10. The first terminal of the first switch S1and the first terminal of the second switch S2are both coupled to the primary power source10. The first terminal of the third switch S3is coupled to the first auxiliary power terminal40. The first terminal of the fourth switch S4is coupled to the second auxiliary power terminal50. The control terminal of the first switch S1, the control terminal of the second switch S2, the control terminal of the third switch S3, and the control terminal of the fourth switch S4are coupled to the power source controller PD through different paths. The first port P1is coupled to the second terminal of the first switch S1and the second terminal of the third switch S3. The second port P2is coupled to the second terminal of the second switch S2and the second terminal of the fourth switch S4. The charging system100further includes a first current limiting device R1and a second current limiting device R2. The first current limiting device R1may be coupled between the first auxiliary power terminal40and the third switch S3to form a part of the first power path. The second current limiting device R2can be coupled between the second auxiliary power terminal50and the fourth switch S4to form a part of the second power path.

The power source controller PD, such as a USB Power Delivery control chip, can be used to control the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4, and also to manage the power transmission to the first port P1and the second port P2. The load detection circuit30is for detecting the variation of the first detection current and the second detection current to determine the connection status of the first port P1and/or the second port P2. In addition, in the embodiment, the first port P1may be an interface complied with the USB-PD specification, and the second port P2may be an interface not complied with the USB-PD specification. However, the charging system100of the present invention is not limited to including the first port P1being an interface complied with the USB-PD specification, and the second port P2being an interface not complied with the USB-PD specification. Any embodiment including at least one first port P1that complies with the USB-PD specification and the at least one second port P2that does not comply with the USB-PD specification, should be within the scope of this embodiment.

FIG.2Ais a flowchart of a method200for determining the coupling status and power supply of the charging system100. The method200includes the following steps:

S10: The power source controller PD turns off the first switch S1and the second switch S2, and turns on the third switch S3and the fourth switch S4. The auxiliary power source20provides the first detection current to the first port P1and the second detection current to the second port P2; the power source controller PD has a power profile; the power source controller PD can set the primary power source10according to the power profile, and the power profile includes a plurality of power capability options; the plurality of power capability options include the first power capability option and a plurality other power capability options; the first power capability option enables the output power of the primary power source10to be an acceptable charging power (for example, 5V) for most devices to be charged; the plurality of other power capability options are different from the first power capability option, and the plurality of other power capability options can enable the primary power source10to have different output powers (for example: 3.3V, 9V, 15V . . . ); if the first detection current increases from less than a threshold value to be greater than the threshold value, go to step S14; if the second detection current changes from less than the threshold value to be greater than the threshold value, go to step S16;

S14: The power source controller PD determines that the first port P1is connected to the first device70; the power source controller PD turns off the third switch S3and turns on the first switch S1, and the power source controller PD sets the primary power source10with the first power capability option making the first output power corresponding to the first power capability option; the primary power source10provides the first output power to the first device70through the first switch S1; go to step S20;

S16: The power source controller PD determines that the second port P2is connected to the second device72, the power source controller PD turns off the fourth switch S4and turns on the second switch S2, and the power source controller PD sets the primary power source10with the first power capability option making the second output power corresponding to the first power capability option; the primary power source10provides a second output power to the second device72through the second switch S2; go to step S22;

S20: The first device70handshakes with the power source controller PD through a signal line, and the power source controller PD provides the power profile to the first device70; after handshake communication between the two parties, the first device70provides the first device requested power capability option to the power source controller PD, the power profile including the first power capability option and a plurality of other power capability options; the first device requested power capability option may be the first power capability option or one of a plurality of other power capability options; and the power source controller PD uses the first device requested power capability option to set the primary power source10so as to change the first output power to a power corresponding to the selected power capability option; the primary power source10provides the first output power through the first switch S1to charge the first device70; go to step S24;

S22: The second device72handshakes with the power source controller PD through a signal line; the second device72provides the second device requested power capability option to the power source controller PD; the power profile including the first power capability option and a plurality of other power capability options; the second device requested power capability option may be the first power capability option or one of a plurality of other power capability options; after handshake communication between the two parties, the power source controller PD uses the second device requested power capability option to set the primary power source10so as to change the second output power to a power corresponding to the selected power capability option; the primary power source10provides the second output power through the second switch S2to charge the second device72;

S24: Determine whether the first device70has been removed from the first port P1, or the second device72has been removed from the second port P2; if yes, go to step S26; if no, go to step S10; and

S26: The primary power source10stops charging; go to step S10.

In step S24, the charging system100can detect whether the first device70has been removed from the first port P1, or whether the second device72has been removed from the second port P2. In step S26, the power source controller PD can control the corresponding switch to make the primary power source10stop charging to the interface that has been disconnected, and go to step S10to detect whether a device has been connected to the interface.

In step S24, assuming that the first device70is the only device connected to the charging system100, and the first device70has not been removed from the first port P1, it would go to step S10to detect whether there is another device connected to the other interface. If no other device is connected to the other interface (for example, the second detection current is maintained at less than the threshold value), the first device70would be charged with the power capability option selected in step S20; if in step S10, another device is connected to the other interface (for example, the second detection current is changed to greater than the threshold value), the method500inFIG.4should be used to find the most proper power capability option. The method500is used when the first port P1and the second port P2are respectively coupled to different devices. InFIG.2A, steps S20and S22describe detail procedures of the handshake communication between the first device70and the second device72, and the power source controller PD.

FIG.2Bis a flowchart of a method300for determining the coupling status and power supply of the charging system100. The method300includes the following steps:

S11: The power source controller PD turns off the first switch S1and the second switch S2and turns on the third switch S3and the fourth switch S4; the auxiliary power source20provides the first detection current to the first port P1and the second detection current to the second port P2; and

S32: When the first detection current is less than the threshold value, the power source controller PD maintains the first switch S1to be off and the third switch S3to be on, and maintains the first auxiliary power terminal40to provide the first detection current through the third switch S3; return to step S11.

FIG.2Cis a flowchart of a method400for determining the coupling status and power supply of the charging system100. The method400includes the following steps:

S11: The power source controller PD turns off the first switch S1and the second switch S2and turns on the third switch S3and the fourth switch S4; the auxiliary power source20provides the first detection current to the first port P1and the second detection current to the second port P2; and

S42: When the second detection current is less than the threshold value, the power source controller PD maintains the second switch S2to be off and the fourth switch S4to be on, and maintains the second auxiliary power terminal42to provide the second detection current through the fourth switch S4; return to step S11.

In the embodiment, the output power may be according to USB-PD specification, for example, 5V, 9V or 15V. The first device and the second device can be any device that uses USB to charge, such as mobile phones, digital cameras, external storage peripherals, laptops, displays, etc.

If the first detection current is less than the threshold value, for example 0.5 mA, the load detection circuit30can determine that a first wire60connected to the first port P1is floating, and the power source controller PD maintains the first switch S1to be off and the third switch S3to be on. The first detection current is provided by the first auxiliary power terminal40through the third switch S3. When the first detection current is greater than the threshold value, the load detection circuit30can determine that the first port P1is coupled to the first device70, and the power source controller PD is triggered to turn off the third switch S3, and turn on the first switch S1. The power source controller PD sets the primary power source10with the first power capability option, so that the primary power source10provides a first output power, such as 5V, to the first device70through the first switch S1. In this way, the primary power source10can provide output power through the first switch S1only when the first wire60connected to the first port P1is coupled to the first device70.

FIGS.3A-3Dare diagrams of charging current for determining the coupling status of the charging system100. In the embodiment, the method using the load detection circuit30to determine the coupling status of the first port P1is as follows.

As shown inFIG.3A, if the first detection current is greater than 0 mA and less than 2 mA, such as 0.5 mA, it can be determined that the first wire60connected to the first port P1is a floating active wire. The first wire60continues to consume the lower current 0.5 mA. The active wire in this case refers to, for example, a charging wire with power-consuming components such as LED indicators or integrated circuits.

As shown inFIG.3B, if the first detection current is substantially maintained at 0 mA, it can be determined that the first port P1is not connected to any wire or the first wire60is a floating passive wire. The passive wire in this case refers to, for example, a charging wire without a power-consuming component.

As shown inFIG.3C, if the first detection current rises from less than 2 mA (for example, 1 mA) to more than 100 mA (for example, LA), it can be determined that the first wire60connected to the first port P1is an active wire coupled to the first device70.

As shown inFIG.3D, if the first detection current rises from substantially 0 mA to greater than 100 mA, for example, 1A, it can be determined that the first wire60connected to the first port P1is a passive wire and is coupled to the first device70. Using the load detection circuit30to determine the coupling status of the second port P2is similar and will not be repeated here.

FIG.4is a flowchart of a handshaking communication method500for the first device70, the second device72and the power source controller PD. The method500includes the following steps:

S501: Determine whether the second device72is coupled to the second port P2; if yes, go to step S554; if no, go to step S505;

S503: Determine whether the first device70is coupled to the first port P1; if yes, go to step S554; if no, go to step S507;

S505: The first device70communicates with the power source controller PD through a signal line, and the power source controller PD provides a power profile to the first device70; after handshake communication between the two parties, the first device70selects a power capability option from the power profile, and the power source controller PD sets the primary power source10according to the selected power capability option; the first output power is updated to correspond to the selected power capability option, and the primary power source10provides the first output power through the first switch S1to charge the first device70; go to step S24;

S507: The second device72communicates with the power source controller PD through a signal line, and the second device72provides the power source controller PD with a second device requested power capability option; the power source controller PD sets the primary power source10according to the second device requested power capability option and updates the second output power to correspond to the second device requested power capability option; the primary power source10provides the second output power through the second switch S2to charge the second device72; go to step S24;

S554: When a plurality of devices are connected to the charging system100, apply the first power capability option to set the primary power source10to output the power corresponding to the first power capability option, for example, 5V; this avoids interrupting the charging process of the original device, and avoids damaging the newly connected device;

S556: The first switch S1and the second switch S2are both turned on; the primary power source10provides the power corresponding to the first power capability option to the first device70through the first switch S1, and the primary power source10provides the power corresponding to the first power capability option to the second device72through the second switch S2;

S558: The second device72communicates with the power source controller PD, and the second device72provides the power source controller PD with the second device requested power capability option;

S560: The first device70communicates with the power source controller PD; the power source controller PD sends a modified power profile to the first device70; the modified power profile includes the first power capability option and the second device requested power capability option provided by the second device72;

S564: Determine whether the first device70can accept the second device requested power capability option corresponding to the second device72? If yes, go to step S566; if no, go to step S568;

S566: The power source controller PD sets the primary power source10according to the second device requested power capability option corresponding to the second device72; the primary power source10provides the power corresponding to the second device requested power capability option through the first switch S1and the second switch S2respectively to the first device70and the second device72; go to step S24;

S568: According to the factory or user settings of the charging system100, the power source controller PD determines whether to fast charge the first device70, to fast charge the second device72, or to charge both with a lower voltage; if the power source controller PD determines to fast charge the first device70, go to step S570; if the power source controller PD determines to fast charge the second device72, go to step S572; otherwise, go to step S574;

S570: The power source controller PD turns off the second switch S2; the first device70communicates with the power source controller PD through the signal line, and the power source controller PD provides the power profile in step S505to the first device70; after handshake communication between the two parties, the first device70selects a power capability option from the power profile in step S505, and the power source controller PD then sets the primary power source10according to the selected power capability option; the first output power is updated to the power corresponding to the selected power capability option; the primary power source10provides the first output power through the first switch S1to fast charge the first device70; go to step S24;

S572: The power source controller PD turns off the first switch S1and sets the primary power source10according to the second device requested power capability option provided by the second device72; the second output power is updated to the power corresponding to the second device requested power capability option provided by the second device72; the primary power source10provides the second output power through the second switch S2to fast charge the second device72; go to step S24; and

S574: The power source controller PD sets the primary power source10with the first power capability option to output the power corresponding to the first power capability option for example, 5V, to the first device70and the second device72; the fast charging capability is discarded, but the plurality of devices connected to the charging system100can continue to be charged simultaneously; go to step S24.

In step566, when the power source controller PD intends to update the original power capability option (for example, 5V) with another power capability option corresponding to a higher voltage (for example, 12V), before updating, the power source controller PD can perform the following safety check steps.

(1) Check that the secondary power paths (third switch S3and fourth switch S4) corresponding to the first port P1and the second port P2that are currently connected to the devices are both turned off, and the corresponding primary power paths (the first switch S1and the second switch S2) are turned on, so as to avoid unnecessary power loss at the secondary power paths.

(2) If the charging system100includes a third interface that is not yet coupled to any device, the power source controller PD would first check to confirm that a fifth switch on the primary power path corresponding to the third interface has been turned off; when a third device is later coupled to the third interface, this can prevent a higher voltage corresponding to another power capability option damaging the third device.

In summary, the charging system and method for the universal serial bus of the present invention can simultaneously detect whether the charging wires coupled to a plurality of USB charging interfaces are floating, and enable a plurality of USB charging interfaces to provide higher output powers simultaneously in a low-cost manner. This overcomes the incompatibility or abnormal operation of various multi-port charging technologies, and achieves energy saving and full use of the advantages of fast charging provided by USB Power Delivery.

Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.