Seamless switching method between forward and reverse modes of the charger

Abstract

This invention provides a battery charger system and a method for operating it. [Solution] In system 100, controller 112 operates the battery charger implemented in voltage regulator 110 in forward mode. In forward mode, power is connected to the battery charger, power is supplied to the load 108, and the battery 102 is charged. The controller determines the expectation of power disconnection and, in response to the determination of the expectation, activates the reverse mode of the battery charger. When reverse mode is activated, power is supplied to the load and battery charging is interrupted while the power remains connected to the battery charger. The controller further determines at least one setting for the reverse mode of the battery charger.

Description

Technical Field

[0001] The present disclosure generally relates to semiconductor devices. More specifically, the present disclosure relates to a seamless switching operation between the reverse mode and the forward mode of a battery charger, more specifically operating the battery charger in the reverse mode anticipating the removal of an adapter.

Background Art

[0002] A device including a battery and an internal battery charger can be connected to a power adapter that supplies power from an external power source of the device. When the power adapter is connected to the device, the battery charger operates in the forward mode. Here, the power supplied from the power source is used to charge the battery and is also supplied to at least one load in the device. When the power adapter is disconnected from the device, the battery charger operates in the on-the-go (OTG) mode, that is, the reverse mode. Here, the battery supplies power to at least one load in the device.

Summary of the Invention

[0003] In one embodiment, generally, a method of operating a battery charger is provided. The method can include operating the battery charger in the forward mode. In the forward direction, a power source is connected to the battery charger, power is supplied to a load, and the battery is charged. The method can further include determining an anticipation of the removal of the power source. The method can further include activating the reverse mode of the battery charger in response to the determination of the anticipation. Here, when the reverse mode is activated, the power source remains connected to the battery charger, power is supplied to the load, and the charging of the battery is interrupted. The method also includes determining at least one setting in the reverse mode of the battery charger.

[0004] In one embodiment, a device for operating a battery charger is provided. The device may include a plurality of switches and a controller. The controller may be configured to control the plurality of switches to operate the battery charger in forward mode. In forward mode, a power supply is connected to the battery charger, power is supplied to the load, and the battery is charged. The controller may be further configured to determine an expectation of disconnecting the power supply. In response to the determination of the expectation, the controller may be further configured to activate the reverse mode of the battery charger. When reverse mode is activated, the power supply remains connected to the battery charger, power is supplied to the load, and battery charging is interrupted. The controller may be further configured to determine at least one setting for the reverse mode of the battery charger.

[0005] In one embodiment, a system for implementing battery charging is provided. The system may include a battery, a load, and a battery charger. The battery charger may be configured to operate in forward mode so that a power source can supply power to the load and charge the battery. In forward mode, the power source is connected to the battery charger. The battery charger is further configured to determine an expectation of disconnecting the power source. In response to the determination of the expectation, the battery charger is further configured to activate reverse mode. When reverse mode is activated, the power source remains connected to the battery charger, power is supplied to the load, and battery charging is interrupted. The battery charger is further configured to determine at least one setting for reverse mode of the battery charger.

[0006] The above summary is illustrative and not limiting in any sense. Further embodiments, features, and characteristics will become apparent by referring to the accompanying drawings and the following detailed description, in addition to the exemplary aspects, embodiments, and features described above. In the drawings, the same reference numerals indicate identical or functionally similar elements. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows the forward mode operation of a system that enables seamless switching between the forward and reverse modes of a charger in one embodiment. [Figure 2] This figure shows the reverse mode operation of the system shown in Figure 1, which enables seamless switching between the forward and reverse modes of the charger in one embodiment. [Figure 3] This figure shows the operation of the system in Figure 1 in one embodiment, where the reverse mode is activated in anticipation of adapter removal. [Figure 4] This is a flowchart of an exemplary process related to performing a transition from forward mode to reverse mode in one embodiment. [Figure 5] This figure shows the waveform of the signal resulting from the execution of the exemplary process shown in Figure 4 in one embodiment. [Figure 6] This is a flowchart of an exemplary process related to performing a transition from reverse mode to forward mode in one embodiment. [Figure 7] This figure shows the waveform of the signal resulting from the implementation of the exemplary process shown in Figure 6 in one embodiment. [Figure 8] This is a flowchart illustrating an exemplary process that enables seamless switching between the forward and reverse modes of a charger in one embodiment. [Modes for carrying out the invention]

[0008] The following description includes numerous specific details, including particular structures, components, materials, dimensions, processing steps, and techniques, to facilitate understanding of the various embodiments of the present application. However, those skilled in the art will understand that various embodiments of the present application can be realized without these specific details. In some cases, descriptions of known structures or processing steps are omitted to avoid obscuring the present application.

[0009] Figure 1 shows the forward mode operation of a system that can perform seamless switching between the forward and reverse modes of a charger in one embodiment. The system 100 shown in Figure 1 may be a battery charging system in a device, such as a desktop computer, laptop computer, tablet device, mobile phone including a smartphone, wearable device, robot, or other device including an internal battery pack (or battery), battery charger, and at least one load other than the battery pack. The system 100 may include at least one connector 106, at least one load 108, a voltage regulator 110, and a battery 102. In one embodiment, the voltage regulator 110 may implement a battery charger. In one embodiment, the connector 106 may be a port in a device implementing the system 100 for receiving power from an external power source 104. In one or more embodiments, the connector 106 may be various types of Universal Serial Bus (USB) ports. The load 108 may be a load in the system 100 that requires power to operate. For example, if system 100 is implemented in a computing device, load 108 could be a central processing unit (CPU), a microprocessor, a microcontroller, a network card, a graphics card, a memory controller, a wireless communication device, or other types of circuits and electronic components that require power to operate. Battery 102 could be a battery pack containing at least one battery.

[0010] The voltage regulator 110 may include a controller 112, an inductor L, and a switching circuit having switches Q1, Q2, Q3, and Q4. The switches Q1, Q2, Q3, and Q4 may be metal-oxide-semiconductor field-effect transistors (MOSFETs). The switches Q1, Q2, Q3, and Q4 are arranged in a full-bridge configuration. The voltage regulator 110 may be a bidirectional switching converter configured to convert or regulate a voltage VBUS to a system voltage VSYS or battery voltage VBAT in the forward direction (e.g., from connector 106 to battery 102) and to convert or regulate VBAT to VBUS in the reverse direction (e.g., from battery 102 to connector 106). The voltage VBUS may be the voltage at the node between the load 108 and the voltage regulator 110.

[0011] The controller 112 may be, for example, a microcontroller, an analog controller, or dedicated analog hardware. The controller 112 may further include electronic components, including a processor, logic circuits, a digital-to-analog converter (DAC), a comparator, a mixer, an amplifier, and various other electronic components. The controller 112 may also include memory devices, such as registers, configured to store various predefined reference values ​​and thresholds that may be required to operate the system 100. The controller 112 may be configured to generate control signals for controlling various aspects of the system 100. For example, the controller 112 may be configured to control switches Q1, Q2, Q3, and Q4 based on various control loops, such as a voltage control loop and a current control loop. For example, the controller 112 may monitor VBUS and adjust VBUS to a target voltage level.

[0012] In one or more embodiments, the controller 112 may be configured to operate the system 100 in forward mode and reverse mode or on-the-go (OTG) mode. Figure 1 shows operation in forward mode. Reverse mode is described in detail below. When the system 100 is operating in forward mode, the controller 112 can receive an adapter connection power signal ACOK indicating whether voltage has been detected at connector 106. ACOK may be asserted (e.g., logic high) when power supply 104 is connected to the system 100, for example when connector 106 is closed or activated, and when power supply 104 supplies adapter power through connected connector 106. When ACOK is asserted, the controller 112 can control switches Q1, Q2, Q3, and Q4 to operate the system 100 in forward mode. As shown in Figure 1, in forward mode, current IADP may flow from connected power supply 104, be distributed to load 108 as current ILOAD, and be distributed to battery 102 as current IBAT. Therefore, in forward mode, the power supply 104 can support both VBUS for the load 108 and VBAT for the battery 102.

[0013] If the adapter power is not detected at connector 106, ACOK is deasserted (e.g., logic low), and the controller 112 can control switches Q1, Q2, Q3, and Q4 to operate system 100 in reverse mode or OTG mode. In one embodiment, ACOK may be deasserted when connector 106 is opened (e.g., because power supply 104 is disconnected). Also in some embodiments, the adapter power may remain at connector 106 for a relatively short period. This causes the ACOK signal to be deasserted immediately after connector 106 is opened. As shown in Figure 2, in reverse mode, power supply 104 no longer supplies IADP, and current IBAT can flow from battery 102 to load 108 as reverse current IREV. Thus, in reverse mode, battery 102 can support VBUS for load 108.

[0014] In one embodiment, if the power supply 104 is disconnected from the system 100 during forward mode, forward mode is disabled and the IADP may stop supporting the load 108. The VBUS may drop to a lower level or even to zero until the controller 112 activates reverse mode and the VBAT can support the VBUS. However, various delays may occur between the disconnection of the power supply and the activation of reverse mode. These delays may cause the VBUS to remain relatively low, and possibly at zero volts for an undesirable amount of time, during which the load 108 cannot operate normally without power. One delay may be the OTG start debounce, or the start time of reverse mode. This can be pre-programmed to a fixed time value, which can be the shortest available start delay (e.g., 7.5 milliseconds (ms)). Another delay may be the delay between the VBUS voltage dropping to zero and the ACOK deassertion occurring. This is variable and may be approximately 26 ms depending on the system. Furthermore, even when reverse mode is activated, another delay may occur between the activation of reverse mode and the controller 112 beginning to switch Q1, Q2, Q3, and Q4 to convert IBAT to IREV. This delay can be approximately 8 ms in some systems. In some embodiments, with power supply 104 disconnected, capacitors (not shown) connected to the drain terminals of Q1 and Q3 can be discharged before activating reverse mode to support VBUS. However, the charge that can be stored in these capacitors is limited and may be insufficient to support VBUS over the entire duration of the delay.

[0015] To reduce or eliminate VBUS downtime (e.g., VBUS drop or zero volts), the controller 112 may be configured to enable reverse mode with the power supply 104 connected and the connector 106 closed, as shown in Figure 3. When reverse mode is enabled with the power supply 104 connected, the IADP continues to support the VBUS, and the IADP can be supplied to the load 108 as an ILOAD. Furthermore, the step of enabling reverse mode with the power supply 104 connected includes a step of preventing the IADP from flowing to the battery 102, such as by interrupting the charging of the battery 102. In one embodiment, the controller 112 may prevent the IADP from flowing to the battery 102 by turning off switches Q1 and Q3 or stopping switches Q1, Q2, Q3, and Q4. Furthermore, in the activated reverse mode shown in Figure 3, the controller 112 can configure various settings for the system 100 in reverse mode, such as setting the voltage VOTG in reverse mode to a specific value and disabling overvoltage protection in reverse mode. The settings in reverse mode enable the controller 112 to switch switches Q1, Q2, Q3, and Q4 in reverse mode. In one or more embodiments, the system 100 can implement various hardware and / or software mechanisms to anticipate the removal of the power supply 104 from the system 100. Based on this expectation, the controller 112 may be configured to enable reverse mode before the actual removal of the power supply 104. Note that enabling reverse mode and operating in reverse mode may be different operations. Enabling reverse mode may include the steps of interrupting the charging of the battery 102 while the power supply 104 remains connected and supporting the VBUS, and determining the settings in reverse mode. On the other hand, operating in reverse mode may involve actually switching switches Q1, Q2, Q3, and Q4 so that the battery 102 supports the VBUS while the power supply 104 is disconnected.

[0016] In one embodiment, controller 112 can receive an adapter removal signal ADPR that encodes and / or indicates at least one parameter value. Controller 112 can use the encoded parameter value in the ADPR signal to determine whether the power supply 104 is expected to be removed, and if it is expected that the power supply 104 will be removed, controller 112 can be triggered to activate reverse mode before the power supply 104 is actually removed. A description of the parameter values ​​that can be encoded in the ADPR signal is provided in more detail below. Since reverse mode is activated before the power supply 104 is removed, and the settings in reverse mode prepare controller 112 to perform the switch in reverse mode, when the power supply 104 is removed, the operation of system 100 can be switched from forward mode to reverse mode without delay, without controller 112 determining the settings in reverse mode after the power supply 104 is removed.

[0017] Figure 4 is a flowchart of an exemplary process related to performing a transition from forward mode to reverse mode in one embodiment. The description of Figure 4 can be made by referring to the components shown in Figures 1 to 3. The process 400 shown in Figure 4 may be performed by the controller 112 of the system 100. The start block 402 of process 400 may occur when the system 100 is operating in forward mode and the power supply 104 supports both VBUS and VBAT. Block 404 may be performed periodically to check whether adapter removal is expected. The adapter may be, for example, the connector 106 shown in Figures 1 to 3. Also in this disclosure, adapter removal may refer to disconnecting or removing the power supply 104 from the system 100. Various hardware and / or software can be implemented to monitor specific parameters or signals related to the power supply 104 in order to detect whether adapter removal is expected in block 404. Furthermore, in some embodiments, the period from the start to the completion of adapter removal may provide sufficient time for the controller 112 to anticipate the completion of adapter removal. For example, controller 112 can detect the start of adapter removal and anticipate that the adapter can be completely removed in a period of, for example, milliseconds (ms). If controller 112 does not anticipate adapter removal (404: NO), process 400 remains in block 404 and can continuously determine whether adapter removal is anticipated. If controller 112 determines that adapter removal is anticipated (404: YES), process 400 can proceed to block 406.

[0018] In one embodiment, the input voltage and / or current (e.g., IADP) from the power supply 104 may be continuously monitored by the controller 112. If a relatively large drop occurs in the input voltage and / or current, an ADPR signal is asserted, and the controller 112 can determine the expectation of adapter removal based on the assertion of the ADPR signal. In another embodiment, the power supply 104 may be configured to communicate with the controller 112 using a communication protocol such as USB Power Delivery (USB-PD). The power supply 104 may communicate information such as changes in the status of the power supply 104 or requests for changes in the power level, and based on this information (which may be encoded in the ADPR signal), the controller 112 can determine the expectation of adapter removal. In another embodiment, the connector 106 may be a barrel adapter, and the system 100 may include a mechanical switch for detecting whether the barrel adapter is being removed. The start of barrel adapter removal releases the mechanical switch and asserts the ADPR signal, and based on the assertion of the ADPR signal, the controller 112 can detect the release and expect that the barrel adapter will soon be completely removed. In another embodiment, the system 100 may include a detection circuit formed by various sensors for sensing whether the adapter has begun to be unplugged. The ADPR signal can encode sensor data from the sensors, and the controller 112 can use the sensor data encoded in the ADPR signal to determine when the adapter will be unplugged. In another embodiment, the ADPR signal is asserted when the battery 102 is fully charged, and the controller 112 can anticipate the adapter being unplugged because the user unplugs the adapter when the battery 102 is fully charged. In another embodiment, the ADPR signal is asserted when the adapter temperature rises above a predetermined temperature threshold, such as a temperature that causes an interruption in charging the battery 102, and the controller 112 can anticipate the adapter being unplugged because the user unplugs the adapter when charging is interrupted and the temperature is too high.In another embodiment, the system 100 may be part of the robot, the power supply 104 may be part of the docking station, and the robot may assert the ADPR signal in anticipation of moving away from the docking station.

[0019] In block 406, the controller 112 can determine a value for the reverse mode voltage or OTG mode voltage VOTG. In one embodiment, the controller 112 can set VOTG to be less than the supply voltage, such as the voltage of the adapter or the voltage of the power supplied by the power supply 104, or a voltage measured or sensed by various mechanisms within the system 100. In one embodiment, a memory device (e.g., a register) of the controller 112 can store a predetermined value for VOTG, and the controller 112 can load the predetermined VOTG in block 406. For example, the predetermined value for VOTG could be the minimum voltage required to support the load 108. In another embodiment, a memory device (e.g., a register) of the controller 112 can store a predetermined offset, and the controller 112 can determine VOTG by subtracting the predetermined offset from the supply voltage. For example, if the predetermined offset is 4 volts (V) and the supply voltage is 48V, the controller 112 can determine that VOTG is 44V (e.g., 48V - 4V = 44V). In another embodiment, system 100 may be a USB Type-C power delivery (USB-CPD) system, where a negotiated value for the voltage VBUS is queryable. Controller 112 can determine VOTG by subtracting a predetermined offset from the negotiated VBUS. For example, if the predetermined offset is 4 volts (V) and the negotiated VBUS is 36V, controller 112 can determine that VOTG is 32V (e.g., 36V - 4V = 32V).

[0020] In one embodiment, process 400 can proceed from block 406 to block 408. In another embodiment, block 406 may be part of block 408. In block 408, controller 112 can configure the system 100 in reverse mode or OTG mode. If block 406 is part of block 408, the configuration in reverse mode may include determining the VOTG in block 406. The configuration in block 408 may include disabling overvoltage protection in reverse mode or OTG mode, determining the VOTG, or other configurations for operating the system 100 in reverse mode. For example, overvoltage protection in reverse mode may generate a fault if the VBUS exceeds the VOTG determined in block 406, and if a fault exists, reverse mode cannot be enabled. Therefore, in one embodiment, in order to enable reverse mode as shown in Figure 3, overvoltage protection in reverse mode must be turned off because block 406 has determined that the VOTG is below the supply voltage. In the reverse mode shown in Figure 3, power supply 104 continues to support VBUS at its supply voltage. By disabling overvoltage protection in reverse mode, power supply 104 can support VBUS without interrupting in response to the activation of reverse mode.

[0021] Process 400 can proceed from block 408 to block 410. At block 410, the controller 112 can complete the activation of the reverse mode shown in FIG. 3. In one embodiment, blocks 406 and 408 can be part of block 410 such that activating the reverse mode includes determining the settings in the reverse mode. In one embodiment, to activate the reverse mode at block 410, the controller 112 can deactivate the forward mode by interrupting the regulation of VBUS or VBAT. In another embodiment, the controller 112 can deactivate the forward mode by turning off switches Q1 and Q3. When the forward mode is deactivated, the controller 112 can activate the reverse mode. When the reverse mode is activated, IADP does not flow towards the battery 102, and while the charging of the battery 102 is paused, the power supply 104 can continue to support VBUS. Also, when the reverse mode is activated, since VOTG has already been determined at block 406 and various configurations have already been executed at block 408, the controller 112 is ready to start switching switches Q1, Q2, Q3, and Q4 to achieve VOTG when the power supply 104 is disconnected.

[0022] Process 400 can proceed from block 410 to block 412. In block 412, controller 112 starts a timer that elapses after a predetermined time T (T is programmable). Controller 112 can wait with power supply 104 disconnected (e.g., ACOK low) or until the timer has elapsed. If power supply 104 remains connected after the timer has elapsed or expired (e.g., ACOK high) (412: NO), process 400 can return to block 404. Here, system 100 operates again in forward mode and can wait for another signal indicating the expectation of adapter removal. The timer can prevent system 100 from enabling reverse mode for an undesirable amount of time. For example, enabling reverse mode could prevent battery 102 from charging, so if reverse mode is enabled for too long, battery 102 may remain uncharged for an undesirable amount of time. Also, in block 404, the signal detected to anticipate adapter removal could be a false positive. For example, the controller 112 may determine that the power supply 104 may be disconnected once the battery 102 is fully charged, and can proceed to execute blocks 406, 408, and 410. After block 410, if the power supply 104 remains connected for a relatively long period, the controller 112 requires a trigger to resume normal operation (e.g., forward mode). Therefore, a waiting period of a predetermined time T can provide a trigger for the controller 112 to resume normal operation if the adapter's expectation in block 404 was a false positive.

[0023] If the power supply 104 is disconnected before the elapse of a predetermined time T (412: YES), the process 400 can proceed to block 414. Here, the controller 112 can switch Q1, Q2, Q3, and Q4 based on the settings in block 408 and supply VBUS using VOTG determined in block 406, thereby operating the system 100 in the reverse mode or OTG mode. In one embodiment, in block 414, the controller 112 can activate overvoltage protection to prevent BUS from exceeding the VOTG determined in block 406. As a result of executing the process 400, the voltage VBUS may be maintained at a minimum voltage such as VOTG during the transition from the forward mode to the reverse mode. Also, the power to the load 108 can be maintained without interruption.

[0024] Figure 5 shows the waveforms of signals resulting from the execution of the exemplary process in Figure 4 in one embodiment. The explanation of Figure 5 can be made by referring to the components shown in Figures 1 to 4. Figure 5 shows several signal waveforms 500. System 100 may operate in forward mode before signal event 502 (e.g., blocks 402 and 404 of process 400). Signal event 502 may occur while system 100 is operating in forward mode. Signal event 502 may be an assertion of the ADPR signal. Assertion of the ADPR signal (block 404: YES) causes controller 112 to anticipate the removal of the adapter (or the power supply 104). Assertion of the ADPR signal allows controller 112 to determine VOTG and set reverse mode (blocks 406, 408 in Figure 4). Once the setup in reverse mode is complete, the controller 112 can force the ACOK signal low (e.g., deassert it), as shown in signal event 504, to indicate that forward mode is disabled and reverse mode is enabled (block 410). Referring to Figure 5, when the ACOK signal is deasserted, the IFWD current drops to zero because battery charging is disabled. The IADP current decreases because IADP only supports ILOAD. Also, when the ACOK signal is deasserted, the VBUS may rise slightly, as shown in signal event 506, due to the reduced load from the cessation of switching (battery charging). For example, if the supply voltage is 48V and VOTG is 44V, the overvoltage protection threshold in reverse mode can be set to ±2V so that VBUS does not exceed 46V when system 100 is in OTG mode or reverse mode. If overvoltage protection is disabled, the 48V supply voltage can continue to support VBUS without triggering overvoltage protection that would interfere with operation in reverse mode.

[0025] In one embodiment, when reverse mode is enabled, the controller 112 can maintain at least the VOTG setting voltage at the VBUS node. The OTGPG (OTG Power Good) signal can indicate that OTG mode or reverse mode is enabled and the voltage is within an acceptable regulation window. If overvoltage protection is disabled, there is no upper limit to the regulation window, so the OTGPG can indicate that reverse mode is enabled and ready. When the power supply 104 is disconnected, in event 510, the VBUS voltage drops to 44V, at which point the controller 112 can switch Q1, Q2, Q3, and Q4 to maintain VBUS at 44V. In one embodiment, the system 100 may include a voltage sensing circuit configured to sense a reverse voltage, and the controller 112 can use the output from the voltage sensing circuit to determine whether the reverse voltage has reached a determined VOTG.

[0026] In the example shown in Figure 5, power supply 104 can be removed within a predetermined time T. When power supply 104 is removed, VBUS drops, as shown in signal event 510. Because the reverse mode is ready before power supply 104 is removed (e.g., signal event 508), when power supply 104 is removed, controller 112 can operate system 100 in reverse mode or OTG mode, and VBUS can drop to VOTG instead of dropping to zero. For example, between signal events 504 and 506 and signal event 508, VBUS can be 48V because it is supported by power supply 104. If VOTG is determined to be 44V, after signal event 508, VBUS can drop to 44V. Furthermore, once reverse mode is activated, controller 112, or another component outside controller 112, can deassert the ADPR signal. Thus, the transition from forward mode to reverse mode can be performed seamlessly, and the operation of load 108 can be supported without interruption.

[0027] Figure 6 is a flowchart of an exemplary process related to performing a transition from reverse mode to forward mode in one embodiment. The explanation of Figure 6 can be made by referring to the components shown in Figures 1 to 5. The process 600 shown in Figure 6 may be executed by the controller 112 of system 100. The start block 602 of process 600 may occur when system 100 is operating in reverse mode or OTG mode, VBAT supports VBUS, and power supply 104 is not connected (e.g., connector 106 is open). In one embodiment, the controller 112 may execute process 600 after reverse mode is enabled in block 414.

[0028] Block 604 may be run periodically to check whether power supply 104 is plugged in. Various hardware and / or software can be implemented in block 604 to monitor specific parameters or signals associated with power supply 104 in order to detect whether power supply 104 is plugged in. In one embodiment, controller 112 may monitor VBUS. If VBUS increases above VOTG in reverse mode, controller 112 can determine that power supply 104 is plugged in. In another embodiment, system 100 may be a USB Type-C power supply (USB-CPD) system, and the voltage VBUS is queryable at a negotiated value. Controller 112 may monitor VBUS in reverse mode, and if VBUS is at the negotiated VBUS, controller 112 can determine that power supply 104 is plugged in. In one embodiment, the controller 112 can determine if the VOTG in reverse mode (block 406 in Figure 4) is lower than the negotiated VBUS so that it can determine whether the power supply 104 is plugged in using the negotiated VBUS. If the power supply 104 is not plugged in (604: NO), the process 600 can remain in block 604 and continue to determine whether the power supply 104 is plugged in. If the power supply 104 is plugged in (604: YES), the process 600 can proceed to block 606. In block 606, the controller 112 can disable reverse mode or OTG mode and enable forward mode.

[0029] In one embodiment, to prevent VBUS from dropping to an undesirable voltage level, such as the minimum voltage required by the load 108, when transitioning from reverse mode to forward mode, the controller 112 may maintain the operating mode in reverse mode until the power supply 104 is connected in block 606. In block 606, the controller 112 determines the settings for forward mode and prepares to change the switching patterns of switches Q1, Q2, Q3, and Q4 to implement forward mode. Once the controller 112 has completed the settings for forward mode, the OTG enable (OTGEN) may be deasserted to disable reverse mode and enable forward mode. After enabling forward mode in block 606, the controller 112 may execute process 400.

[0030] Figure 7 shows the waveforms of signals resulting from the execution of the exemplary process of Figure 6 in one embodiment. The explanation of Figure 7 can be made by referring to the components shown in Figures 1 to 6. Figure 7 shows several signal waveforms 700. System 100 may operate in reverse mode or OTG mode before signal event 702 (e.g., blocks 602 and 604 of process 600). Signal event 702 may be a rise in VBUS indicating that power supply 104 has been plugged in (block 604: YES). In response to detecting the plugging in of power supply, controller 112 may maintain the activation of reverse mode, as shown in Figure 7. The IFWD, which supplies current from the voltage regulator 110 to the load 108 while operating in reverse mode, stops supplying current at event 702, the IADP increases and supplies power to the load 108, and the VBUS is supported. However, since forward mode is still disabled, the IFWD does not supply power to battery 102.

[0031] The controller 112 can determine the settings in forward mode, such as by changing the switching patterns of switches Q1, Q2, Q3, and Q4 to implement forward mode. Once the controller 112 has completed the settings in forward mode, the OTG enable (OTGEN) signal may be deasserted to disable reverse mode and enable forward mode. Furthermore, the system 100 may wait until the adapter power supplied from the power supply 104 stabilizes before operating in forward mode. As shown in Figure 7, after the OTGEN signal deassers 704, the ACOK signal asserts 706. In response to the assertion of the ACOK signal, IFWD and IADP can be further increased to operate the system 100 in forward mode. Also, since the power supply 104 supports both VBUS and battery 102 charging in forward mode, the signal event 708 on VBUS can be slightly reduced. Since the reverse mode remains active for a while after the power supply 104 is inserted, the VBUS can be supported by IADP while the controller 112 sets the parameters for the forward mode, and the VBUS does not drop to undesirable voltage levels such as the minimum voltage required by the zero-volt load 108. Thus, the transition from reverse mode to forward mode can be performed seamlessly, and the operation of the load 108 can be supported without interruption.

[0032] Figure 8 is a flowchart illustrating an example of a process that can achieve seamless switching between the forward and reverse modes of a charger in one embodiment. The process 800 shown in Figure 8 can refer to the components shown in Figures 1 to 7. The process 800 may include one or more operations, actions, or functions represented by one or more blocks 802, 804, 806, and / or 808. Although shown in the figure as individual blocks, various blocks can be divided into additional blocks, combined into fewer blocks, omitted, executed in different orders, or executed in parallel, depending on the desired application.

[0033] Process 800 may be carried out by a controller of the battery charging system, such as the controller 112 described herein. Process 800 can begin in block 802, in which the controller can operate the battery charger in forward mode, in which a power supply is connected to the battery charger, power is supplied to the load, and the battery is charged. Process 800 can proceed from block 802 to block 804, in which the controller can determine when to expect to disconnect the power supply.

[0034] Process 800 can proceed from block 804 to at least one of block 806 and block 808. In block 806, the controller can enable the reverse mode of the battery charger in response to the determination of the expectation. When reverse mode is enabled, power is supplied to the load and battery charging is interrupted, while the power supply remains connected to the battery charger. In block 808, the controller can determine at least one setting for the reverse mode of the battery charger.

[0035] In one embodiment, the controller can determine at least one setting by determining the reverse voltage in reverse mode, where the reverse voltage is below the power supply voltage. In one embodiment, the controller can determine at least one setting by disabling overvoltage protection in reverse mode.

[0036] In one embodiment, the controller can detect power disconnection (e.g., actual disconnection) when reverse mode is enabled. In response to detecting power disconnection when reverse mode is enabled, the controller can operate the battery charger in reverse mode using at least one setting so that the battery can supply power to the load.

[0037] In one embodiment, the controller can detect the insertion of power when the battery charger is operating in reverse mode. In response to the detection of the insertion, the controller can maintain the operating mode of the battery charger in reverse mode, determine at least one setting in the forward mode of the battery charger, disable the reverse mode, and operate the battery charger in reverse mode.

[0038] In one embodiment, in response to the determination of the prediction, the controller may activate a timer to wait for a predetermined time. The controller may detect the disconnection of the power supply within the predetermined time. In response to the detection of the disconnection of the power supply within the predetermined time, the controller may operate the battery charger in reverse mode using at least one setting.

[0039] In one embodiment, in response to the determination of the prediction, the controller may activate a timer to wait for a predetermined time. The controller may detect that the power supply remains connected to the battery charger after the predetermined time has elapsed. In response to the detection that the power supply remains connected to the battery charger after the predetermined time has elapsed, the controller may maintain the operating mode of the battery charger in forward mode.

[0040] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, segment, or part thereof of instructions containing one or more executable instructions for realizing a specified logical function. In some alternative implementations, the functions shown in the blocks may occur in a different order than shown in the figures. For example, two blocks shown consecutively may actually be realized substantially simultaneously, or, depending on the functions involved, may be realized in the reverse order in some cases. It should also be noted that each block in the block diagram and / or flowchart, and combinations thereof, may be realized by a special-purpose hardware-based system that performs a specified function or operation, or a special-purpose combination of hardware and computer instructions. [Note] Note 1: A method for operating a battery charger, comprising: operating the battery charger in forward mode, in which a power supply is connected to the battery charger, power is supplied to a load, and the battery is charged; determining an expectation of power supply disconnection; in response to the determination of the expectation, enabling the reverse mode of the battery charger, in which, when the reverse mode is enabled, power is supplied to a load, and battery charging is interrupted, while the power supply remains connected to the battery charger; and determining at least one setting for the reverse mode of the battery charger in response to the determination of the expectation.

[0041] Note 2: The method according to Appendix 1, further comprising the steps of detecting a power disconnection while reverse mode is enabled, and, in response to the detection of a power disconnection while reverse mode is enabled, operating the battery charger in reverse mode with at least one setting so that the battery supplies power to a load.

[0042] Note 3: The step of determining at least one setting includes the step of determining the reverse voltage in reverse mode, wherein the reverse voltage is below the voltage of the power supply, as described in Appendix 1 or 2.

[0043] Note 4: The method described in any one of the appendices 1 to 3, wherein the step of determining at least one setting includes the step of disabling overvoltage protection in reverse mode.

[0044] Note 5: The method according to any one of the appendices 1 to 4, further comprising the steps of: detecting the insertion of power when the battery charger is operating in reverse mode; in response to the detection of the insertion, maintaining the operating mode of the battery charger in reverse mode and determining at least one setting for the forward mode of the battery charger; disabling the reverse mode; and operating the battery charger in forward mode.

[0045] Note 6: The method according to any one of the appendices 1 to 5, further comprising: starting a timer to wait for a predetermined time in response to a prediction being determined; detecting a power disconnection within the predetermined time; and operating the battery charger in reverse mode using at least one setting in response to the detection of a power disconnection within the predetermined time.

[0046] Note 7: The method according to any one of the appendices 1 to 6, further comprising: starting a timer to wait for a predetermined time in response to a prediction being determined; detecting that the power supply remains connected to the battery charger after the predetermined time has elapsed; and, in response to detecting that the power supply remains connected to the battery charger after the predetermined time has elapsed, disabling the reverse mode and operating the battery charger in the forward mode.

[0047] Note 8: A device comprising a plurality of switches and a controller, wherein the controller is configured to control the plurality of switches to operate a battery charger in forward mode, in which a power supply is connected to the battery charger, power is supplied to a load, and the battery is charged; the controller is configured to determine an expected disconnection of the power supply and, in response to the determination of such an expectation, activate the reverse mode of the battery charger; when the reverse mode is activated, power is supplied to a load, and battery charging is interrupted, while the power supply remains connected to the battery charger; and the controller is configured to determine at least one setting for the reverse mode of the battery charger.

[0048] Note 9: The apparatus as described in Appendix 8, wherein the controller detects when the power supply is disconnected while reverse mode is enabled, and in response to the detection of the power supply disconnection while reverse mode is enabled, controls several switches to operate the battery charger in reverse mode using at least one setting, thereby configuring the battery to supply power to the load.

[0049] Note 10: • To determine at least one setting, the controller is configured to determine the reverse voltage in reverse mode, where the reverse voltage is below the power supply voltage, as described in Appendix 8 or 9 of the device.

[0050] Note 11: The device described in any one of the appendices 8 to 10, wherein the controller is configured to disable overvoltage protection in reverse mode in order to determine at least one setting.

[0051] Note 12: The device as described in any one of Annexes 8 to 11, wherein the controller is configured to detect power insertion in reverse mode, and in response to the detection of insertion, maintain the operating mode of the battery charger in reverse mode, determine at least one setting in the forward mode of the battery charger, disable reverse mode, and operate the battery charger in reverse mode.

[0052] Note 13: The device as described in any one of the appendices 8 to 12, wherein the controller is configured to activate a timer to wait for a predetermined time in response to a prediction being made, to detect power disconnection within the predetermined time, and to operate the battery charger in reverse mode in response to the detection of power disconnection within the predetermined time.

[0053] Note 14: The device as described in any one of the appendices 8 to 13, wherein the controller is configured to activate a timer to wait for a predetermined time in response to a prediction being determined, to detect after the predetermined time that the power supply remains connected to the battery charger, and in response to the detection that the power supply remains connected to the battery charger after the predetermined time, to disable the reverse mode and operate the battery charger in the forward mode.

[0054] Note 15: A system comprising a battery, a load, and a battery charger, wherein the battery charger is configured to operate in forward mode such that a power supply provides power to the load and the battery is charged, in which case the power supply is connected to the battery charger, the battery charger is configured to determine an expectation of disconnecting the power supply, the battery charger is configured to activate reverse mode in response to the determination of the expectation, when reverse mode is activated, power is supplied to the load and battery charging is interrupted while the power supply remains connected to the battery charger, and the battery charger is configured to determine at least one setting in reverse mode in response to the determination of the expectation.

[0055] Note 16: The system as described in Appendix 15, wherein the battery charger detects power disconnection when reverse mode is enabled, and in response to the detection of power disconnection when reverse mode is enabled, controls several switches to operate the battery charger in reverse mode using at least one setting so that the battery can supply power to the load.

[0056] Note 17: • To determine at least one setting, the battery charger is configured to determine the reverse voltage in reverse mode, where the reverse voltage is below the power supply voltage, as described in Appendix 15 or 16 of the system.

[0057] Note 18: The system described in any one of Appendix 15 to 17, wherein the battery charger is configured to detect power insertion in reverse mode, and in response to the detection of insertion, maintain the operating mode of the battery charger in reverse mode, determine at least one setting in the forward mode of the battery charger, disable reverse mode, and operate the battery charger in reverse mode.

[0058] Note 19: The system described in any one of Appendix 15 to 18, wherein the battery charger is configured to activate a timer to wait for a predetermined time in response to a prediction being made, to detect power disconnection within the predetermined time, and to operate the battery charger in reverse mode in response to the detection of power disconnection within the predetermined time.

[0059] Note 20: The system described in any one of Appendix 15 to 19, wherein the battery charger is configured to activate a timer to wait for a predetermined time in response to a prediction being made, to detect after the predetermined time that the power supply remains connected to the battery charger, and in response to the detection that the power supply remains connected to the battery charger after the predetermined time, the reverse mode is disabled and the system operates in the forward mode.

[0060] The terms used herein are used solely to describe specific embodiments and are not intended to limit the invention. Unless otherwise specified, singular terms used herein are also intended to include plural forms. Furthermore, the term “equipped with” as used herein defines the presence of the described features, integers, steps, actions, elements, and / or components, but does not exclude the presence or addition of one or more features, integers, steps, actions, elements, components, and / or groups thereof.

[0061] All means or steps and corresponding structures, materials, operations, and their equivalents described in the appended claims are intended to encompass any structures, materials, or operations for achieving a function in combination with other elements specifically described. The description of the disclosed embodiments of the present invention is provided for illustrative and explanatory purposes, but is not intended to be exhaustive or to limit oneself to the disclosed forms. It will be apparent to those skilled in the art that many modifications and variations can be applied without departing from the scope and spirit of the invention. The embodiments described above have been selected and described in order to best illustrate the principles and practical applications of the present invention, and so that those skilled in the art may understand the invention in terms of various embodiments with various modifications to suit the specific applications under consideration.

Claims

1. A method for operating a battery charger, A step of operating the battery charger in forward mode, wherein in forward mode, a power supply is connected to the battery charger, power is supplied to the load, and the battery is charged. A step of determining the expected removal of the power supply, In response to the determination of the aforementioned prediction, the step of enabling the reverse mode of the battery charger, wherein when the reverse mode is enabled, the power supply remains connected to the battery charger, the power is supplied to the load, and the charging of the battery is interrupted. In response to the determination of the aforementioned prediction, the steps include determining at least one setting for the battery charger in the reverse mode, Methods that include...

2. The steps include detecting the removal of the power supply when the reverse mode is enabled, In response to the detection of the power supply being disconnected while the reverse mode is enabled, the battery charger is operated in the reverse mode using the at least one setting so that the battery supplies power to the load. The method according to claim 1, further comprising:

3. The method according to claim 1, wherein the step of determining the at least one setting includes the step of determining the reverse voltage in the reverse mode, wherein the reverse voltage is less than the voltage of the power supply.

4. The method according to claim 1, wherein the step of determining the at least one setting includes the step of disabling overvoltage protection in the reverse mode.

5. The steps include detecting the insertion of the power supply when the battery charger is operating in the reverse mode, In response to detecting the aforementioned insertion, Maintain the operating mode of the battery charger in the reverse mode, Determine the at least one setting in the forward mode of the battery charger, The aforementioned reverse mode is disabled, The steps include operating the battery charger in the forward mode, The method according to claim 1, further comprising:

6. In response to the determination of the aforementioned prediction, the steps include starting a timer to wait for a predetermined time, A step of detecting the removal of the power supply within the predetermined time, In response to detecting the removal of the power supply within the predetermined time, the battery charger is operated in the reverse mode using at least one setting. The method according to claim 1, further comprising:

7. In response to the determination of the aforementioned prediction, the steps include starting a timer to wait for a predetermined time, The steps include detecting that the power supply remains connected to the battery charger after a predetermined time has elapsed, In response to detecting that the power supply remains connected to the battery charger after the predetermined time has elapsed, the steps include disabling the reverse mode and operating the battery charger in the forward mode, The method according to claim 1, further comprising:

8. A device comprising multiple switches and a controller, The controller is configured to control the plurality of switches to operate the battery charger in forward mode, in which the power supply is connected to the battery charger, power is supplied to the load, and the battery is charged. The controller is configured to determine the expected removal of the power supply, The controller is configured to enable the reverse mode of the battery charger in response to the determination of the prediction, and when the reverse mode is enabled, the power is supplied to the load and the charging of the battery is interrupted, while the power supply remains connected to the battery charger. The controller is configured to determine at least one setting for the battery charger in the reverse mode in response to the determination of the prediction. Device.

9. The aforementioned controller, When the reverse mode is enabled, the power supply is detected to be disconnected. In response to detection of the power supply being disconnected while the reverse mode is enabled, the plurality of switches are controlled to operate the battery charger in the reverse mode using at least one setting, so that the battery supplies power to the load. The apparatus according to claim 8.

10. The apparatus according to claim 8, wherein, in order to determine the at least one setting, the controller is configured to determine a reverse voltage in the reverse mode, the reverse voltage being lower than the voltage of the power supply.

11. The apparatus according to claim 8, wherein the controller is configured to disable overvoltage protection in the reverse mode in order to determine the at least one setting.

12. The controller is configured to detect the insertion of the power supply in the reverse mode, The controller, in response to detecting the insertion, Maintain the operating mode of the battery charger in the reverse mode, Determine the at least one setting in the forward mode of the battery charger, The aforementioned reverse mode is disabled, The battery charger is configured to operate in the reverse mode described above. The apparatus according to claim 8.

13. The aforementioned controller, In response to the determination of the aforementioned prediction, a timer is started to wait for a predetermined period of time. The power supply is detected to be removed within the predetermined time period. The battery charger is configured to operate in reverse mode in response to the detection of the power supply being removed within the predetermined time period. The apparatus according to claim 8.

14. The aforementioned controller, In response to the determination of the aforementioned prediction, a timer is started to wait for a predetermined period of time. After the predetermined time has elapsed, it is detected that the power supply remains connected to the battery charger. In response to detecting that the power supply remains connected to the battery charger after a predetermined time has elapsed, the system is configured to disable the reverse mode and operate the battery charger in the forward mode. The apparatus according to claim 8.

15. A system comprising a battery, a load, and a battery charger, The battery charger is configured to operate in forward mode such that the power supply provides power to the load and the battery is charged, and in forward mode the power supply is connected to the battery charger, The battery charger is configured to determine the expected removal of the power supply, The battery charger is configured to activate reverse mode in response to the determination of the prediction, and when reverse mode is activated, the power is supplied to the load and battery charging is interrupted while the power supply remains connected to the battery charger. The battery charger is configured to determine at least one setting in the reverse mode of the battery charger in response to the determination of the prediction. system.

16. The aforementioned battery charger, When the reverse mode is enabled, the power supply is detected to be disconnected. In response to the detection of the power supply being removed while the reverse mode is enabled, a plurality of switches are controlled to operate the battery charger in the reverse mode using at least one setting, so that the battery supplies power to the load. The system according to claim 15.

17. The system according to claim 15, wherein, in order to determine the at least one setting, the battery charger is configured to determine a reverse voltage in the reverse mode, the reverse voltage being lower than the voltage of the power supply.

18. The battery charger is configured to detect the insertion of the power supply in the reverse mode, The battery charger, in response to detecting the insertion, Maintain the operating mode of the battery charger in the reverse mode, Determine the at least one setting in the forward mode of the battery charger, The aforementioned reverse mode is disabled, The battery charger is configured to operate in the reverse mode described above. The system according to claim 15.

19. The aforementioned battery charger, In response to the determination of the aforementioned prediction, a timer is started to wait for a predetermined period of time. The power supply is detected to be removed within the predetermined time period. The battery charger is configured to operate in reverse mode in response to the detection of the power supply being removed within the predetermined time period. The system according to claim 15.

20. The aforementioned battery charger, In response to the determination of the aforementioned prediction, a timer is started to wait for a predetermined period of time. After the predetermined time has elapsed, it is detected that the power supply remains connected to the battery charger. In response to detecting that the power supply remains connected to the battery charger after a predetermined time has elapsed, the system is configured to disable the reverse mode and operate in the forward mode. The system according to claim 15.

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