Adaptive tracking clamp for battery charging system

Abstract

The invention relates to adaptive tracking clamping of a battery charging system. An adaptive tracking clamp is used as an additional regulation loop for limiting offset, such as when transitioning from one regulation loop to another. The adaptive tracking clamp is dynamically positioned relative to the level of the regulation loop in control. In the case of a fast transient event, the loop which is initially in a control state will quickly improve the output demand, but will be limited by the self-adaptive tracking clamping level for the first time; at the second time, the adaptive tracking clamping algorithm incrementally increases the output demand until control is switched to another regulation loop.

Description

[0001] Claiming priority

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 582,796, entitled “Adaptive Tracking Clamp,” filed by Olivier Stéphane Simon Depuits et al. on September 14, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This document relates generally to, but is not limited to, battery charging systems. Background Art

[0004] Battery chargers are an essential part of the electronics industry, designed to replenish the power in batteries to fuel devices ranging from compact handheld devices to extended automotive systems. These chargers range from simple units that provide a steady DC power output to complex systems that dynamically adjust charging parameters based on real-time feedback from the battery. The core goal of a battery charger is to facilitate efficient and safe charging, thereby extending the life of the battery and optimizing its performance, while preventing potential hazards such as overcharging.

[0005] Power converters play an important role in these systems, especially in battery charger systems, for example, where they are responsible for not only supplying power to the battery, but also directly to the mobile device system when needed. These converters convert power from one form to another, adjusting the output to meet the specific voltage and current requirements of the battery and the device. This capability is critical in applications that require precise power management, from small consumer electronics to large industrial machinery and renewable energy systems.

[0006] The evolution of battery chargers and power converters has been significantly influenced by the growing emphasis on energy efficiency and the need to meet an expanding array of electronic devices with varying power requirements. Continuous advancements in this area are aimed at improving the efficiency, reliability, and safety of these systems. This involves integrating advanced adaptive power management technologies that can intelligently respond to varying load conditions and power requirements, thereby supporting the next generation of electronic devices and systems with greater complexity and environmental awareness. Summary of the invention

[0007] Among other things, the present disclosure describes an adaptive tracking clamp that acts as an additional loop to limit excursions (e.g., current overshoots), such as during transitions from one loop to another. The adaptive tracking clamp is dynamically positioned relative to the level of the regulation loop in control. In the event of a fast transient event, the loop that was initially in control will quickly increase the output demand, but will be limited by the adaptive tracking clamp level the first time; the second time, the adaptive tracking clamp algorithm will gradually increase the output demand until control is handed over to the other loop. Advantages include accuracy and speed. Accuracy is achieved because a fine regulation loop (e.g., an analog loop) still takes over control after a period of time. Speed ​​is achieved because the adaptive clamp takes control in the event of a fast transient event.

[0008] In some aspects, the present disclosure relates to a battery charging system, comprising: a power converter circuit coupled to a battery and a power source; a multi-channel regulation system coupled to the power converter circuit, the multi-channel regulation system being configured to generate an output demand signal representing an output demand current to the power conversion circuit; and an adaptive tracking clamp circuit coupled to the multi-channel regulation system, wherein the adaptive tracking clamp circuit is configured to generate a clamp level signal representing a limit of the output demand current to limit current overshoot, and wherein the clamp level signal is applied to the multi-channel regulation system.

[0009] In some aspects, the present disclosure relates to an adaptive tracking clamp circuit configured to be coupled to a multi-channel regulation system of a battery charging system, the adaptive tracking clamp circuit comprising: a digital control circuit configured to generate a clamp level signal representing a limit of an output demand current to limit current overshoot, wherein the clamp level signal is applied to the multi-channel regulation system; and a tracking system coupled to the digital control circuit, the tracking system configured to track the output current of the power converter circuit.

[0010] In some aspects, the present disclosure relates to a method for charging a battery, the method comprising: generating an output demand signal through a multi-channel regulation system, the output demand signal representing an output demand current applied to a power converter circuit coupled to the battery; and generating a clamping level signal representing a limit of the output demand current to limit current overshoot; and applying the clamping level signal to the multi-channel regulation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. The drawings generally illustrate, by way of example and not limitation, various embodiments discussed in this document.

[0012] Figure 1is a simplified block diagram of an example of a battery charging system.

[0013] Figure 2 is a simplified block diagram of an example of a battery charging system in which the various techniques of this disclosure may be implemented.

[0014] Figure 3 A more detailed description Figure 2 A block diagram of an example of a battery charging system.

[0015] Figure 4 yes Figure 3 Example of a state diagram for a finite state machine.

[0016] Figure 5 A more detailed description Figure 2 Schematic diagram of an example of a multi-channel regulation system for a battery charging system.

[0017] Figure 6 is a flow chart of an example of a battery charging method. DETAILED DESCRIPTION

[0018] One approach to battery charging systems includes using a regulation system with multiple regulation channels or loops that control an output demand current. For example, a switch-mode charger for a lithium-ion battery may include regulation loops for battery voltage, battery current, system voltage, die temperature, input current, and output current. The regulation loop controls the switching inductor current demand (current mode regulation). There may be a first requirement for these loops to be accurate (meaning analog control loops or digital control loops with large resolution and stability compensation), and a second requirement for at least one of these loops to have a high bandwidth and at least another to have a low bandwidth.

[0019] The present inventors have recognized the need to avoid out-of-bounds demand excursions, such as current overshoots, which may occur following a fast transient event, resulting in a switch from a high bandwidth loop to a low bandwidth loop, while maintaining desired accuracy and stability requirements.

[0020] Among other things, the present disclosure describes an adaptive tracking clamp that acts as an additional loop to limit excursions (e.g., current overshoots), such as at a transition from one loop to another. The adaptive tracking clamp is dynamically positioned relative to the level of the regulation loop in control. In the event of a fast transient event, the loop that was initially in control will quickly increase the output demand, but will be limited by the adaptive tracking clamp level the first time; the second time, the adaptive tracking clamp algorithm will gradually increase the output demand until control is handed over to the other loop. Advantages include accuracy and speed. Accuracy is achieved because a fine regulation loop (e.g., an analog loop) still takes over control after a period of time. Speed ​​is achieved because the adaptive clamp controls in the event of a fast transient event.

[0021] Adaptive tracking clamping can be used for additional range limiting features. For example, in charger switch applications, this allows programmable maximum switch operating current and soft-start current ramp. The clamp level can be limited by predicting the minimum output demand level (current floor) while still avoiding exceeding the (current) limit. In charger applications, this helps maximize charging speed in the presence of frequent load transients. The up and down speeds of tracking can be programmed, which allows transient behavior to be customized to specific applications or scenarios. The system can be enabled / disabled by the application processor based on use case requirements. In charger applications, this can be used to prioritize input current limit vs. system current availability based on adapter type, operating mode, etc.

[0022] Figure 1 is a simplified block diagram of an example of a battery charging system 100. The battery charging system 100 includes a switch 102 coupled to a power source 104, such as a buck / boost power converter circuit, a regulated switched capacitor converter, or a hybrid switched capacitor converter circuit. The power source 104 can be coupled to the battery charging system 100 using, for example, a universal serial bus (USB) port.

[0023] The switch 102 uses the voltage from the power source 104 to charge the battery 106 (e.g., the battery of the mobile device 108) via the transistor 112 (Qbatt), and also provides the system voltage to the system 110 (e.g., the system of the mobile device 108). In some examples, the battery 106 can be a lithium-ion battery. The switch 102 can also be used in reverse as a boost converter to provide power to the USB port to supply accessories or wireless chargers. In some examples, the switch 102 can be directly connected to the battery 106.

[0024] When a valid adapter is present, switch 102 opens and provides current to battery 106 and system 110. Switch 102 acts as a power converter and adheres to the following rules during the charging process: 1) Charge the battery according to a constant current (CC) or 2) constant voltage (CV) setting, 3) Maintain the system (SYS) voltage, 4) Keep the input charge current (Ichgin) below the current limit (INLIM), and 5) Maintain the die temperature (Tdie). Each goal is controlled by a separate regulation loop with its own parameters such as bandwidth, gain, etc. Switching from one regulation loop to another is not an immediate action.

[0025] When the switch 102 is regulating and there is a system current transient, the switch 102 reacts within a certain time according to the regulation loop in control. During the constant current or constant voltage period, the switch 102 increases its input current in response to the additional current required. This continues until another regulation loop takes over control. During this time, the amount by which the input current is increased depends on the required output power. The inventors have recognized that a problem to be solved is that the input current may temporarily exceed the current limit setting. Once the input current regulation loop begins to control, the input current will be regulated to the target current limit even if the system current remains high and the battery 106 provides additional current.

[0026] Figure 2 is a simplified block diagram of an example of a battery charging system 100 that may implement various techniques of the present disclosure. Figure 1 As in , battery charging system 100 is coupled to battery 106 and system 110 (eg, a system of mobile device 108).

[0027] The battery charging system 100 includes a power converter circuit 202, which may be similar to Figure 1 The switch 102 is a buck / boost converter. The power converter circuit 202 is coupled to the battery 106 and the power source 104. The battery charging system 100 also includes a multi-channel regulation system 204. The multi-channel regulation system 204 is configured to generate an output demand signal 206, for example, representing an output demand current, based on one or more sensed parameters (such as battery voltage, battery current, system voltage, die temperature, input current, and output current). The output demand signal 206 is applied to the power converter circuit 202.

[0028] The multi-channel regulation system 204 includes multiple regulation channels (also referred to as regulation loops), including channels for battery voltage, battery current, system voltage, die temperature, input current, and input voltage. The regulation channels control the inductor current demand (current mode regulation) of the power converter circuit 202. One or more of the regulation channels have a high bandwidth, while one or more of the regulation channels have a low bandwidth.

[0029] According to the present invention, the battery charging system 100 also includes an adaptive tracking clamp circuit 208 coupled to the multi-channel regulation system 204. The adaptive tracking clamp circuit 208 is configured to generate a clamp level signal 210, which represents a limit of the output demand signal 206, such as an output demand current, which is applied to the multi-channel regulation system 204 to limit current overshoot. The adaptive tracking clamp circuit 208 of the present disclosure acts as an additional regulation channel to limit or avoid demand excursions beyond limits (e.g., current overshoot) after a fast transient event, resulting in a transition from a high bandwidth loop to a low bandwidth loop while maintaining accuracy and stability requirements. The adaptive tracking clamp circuit 208 dynamically positions its output relative to the level of the regulation channel in control by stepping up and down. In the case of a fast transient event, the adaptive tracking clamp circuit 208 will temporarily control the output demand and manage the transition from the originally controlled loop to the other loop without an out-of-limit demand excursion.

[0030] The adaptive tracking clamp circuit 208 can be used for other range limiting features. For example, in a charger switch application, the adaptive tracking clamp circuit 208 allows programmable maximum switch operating current, soft start current ramp, etc.

[0031] In some examples, the clamp level signal 210 is bounded on the low side by predicting the minimum level of output demand (e.g., current floor) while still avoiding exceeding the limit (e.g., current limit). In charger switching applications, this helps maximize charging speed under frequent load transient conditions.

[0032] In some examples, the up and down speed of the tracking can be programmed by the user. This allows the transient behavior to be customized according to the application or scenario.

[0033] The adaptive tracking clamp circuit 208 can be enabled / disabled by the application processor based on the use case requirements. For example, in a charger switch application, this can be used to prioritize input current limit vs. system current availability based on adapter type, operating mode, etc.

[0034] Figure 3 A more detailed description Figure 2 1 is a block diagram of an example of a battery charging system 100. The multi-channel regulation system 204 is configured to generate an output demand signal 206, for example, representing an output demand current applied to the power converter circuit 202. The output demand signal 206 is based on one or more sensed parameters, such as battery voltage, battery current, system voltage, die temperature, input current, and output current.

[0035] The multi-channel regulation system 204 includes multiple regulation channels (also referred to as "regulation loops") for one or more sensed parameters of the mobile device, such as battery voltage, battery current, system voltage, die temperature, input current, and output current. When the power converter circuit 202 is in current mode regulation, the regulation channels control its inductor current demand. The multi-channel regulation system 204 includes a first regulation channel 300 ("regulation loop 1"), a second regulation channel 302, and so on, through the nth regulation channel 304 ("regulation loop n"). In some examples, the multi-channel regulation system 204 includes only two regulation channels.

[0036] Each conditioning channel is configured to generate a corresponding output that is applied to the selector circuit 308. For example, the first conditioning channel 300 generates a first output signal ("conditioning level 1"), the second conditioning channel 302 generates a second output signal ("conditioning level 2"), and so on, the nth conditioning channel 304 generates an nth output signal ("conditioning level n").

[0037] In current mode control, the battery charging system 100 uses regulation channels to control the inductor current of the inductor of the power converter circuit 202. These regulation channels attempt to regulate different sensed parameters of the system, such as the battery voltage. During the charging of the battery 106, the battery current may need to be regulated. Therefore, depending on the type of battery and the customer's application, the user may want to charge faster or slower to avoid damaging the battery or to extend the battery life. In current mode control, the output signal of the corresponding regulation channel represents the target inductor current (peak, average, or valley), where the minimum value is the selected target for the power converter circuit 202. In some examples, four regulation channels can be used to regulate more than four variables of the mobile device, such as six or more variables.

[0038] The selector circuit 308 is configured to receive the output signals of the regulation channels of the multi-channel regulation system 204. In addition, the selector circuit 308 is configured to receive the clamp level signal 210 ("MAXVAL") generated by the adaptive tracking clamp circuit 208 and applied to the multi-channel regulation system 204. The clamp level signal 210 represents the limit of the output demand current, as shown by the output demand signal 206, and is used to limit excursions such as current overshoot. The clamp level signal 210 allows the reaction of the power converter circuit 202 to be clamped. The clamp level signal 210 acts as another regulation channel. The selector circuit 308 selects a minimum value from the received regulation channel output signals and the clamp level signal 210, wherein the minimum value represents the minimum current requirement of the power converter circuit 202. The clamp level signal 210 represents the absolute maximum value of the minimum value selected by the selector circuit 308.

[0039] In some examples, adaptive tracking clamp circuit 208 is configured to limit current overshoot during a transition between first regulation channel 300 and second regulation channel 302 of multi-channel regulation system 204 .

[0040] The adaptive tracking clamp circuit 208 includes a digital control circuit 310 configured to generate a clamp level signal 210 and a tracking system 312 coupled to the digital control circuit 310. The tracking system is configured to track an output demand current of the power converter circuit, such as the current represented by the output demand signal 206. The adaptive tracking clamp circuit 208 attempts to limit excursions, such as by generating a clamp level signal 210 that is higher than the actual output current. The actual output current will vary over time, so the tracking system 312 tracks it up and down.

[0041] The adaptive tracking clamp circuit 208 also includes a clamping digital-to-analog converter 314, which is coupled to the output of the digital control circuit 310 and is configured to generate the clamping level signal 210. The clamping digital-to-analog converter 314 generates the clamping level signal 210 according to the digital code 318 generated by the digital control circuit 310, which is applied to the multi-channel adjustment system 204, particularly the selector circuit 308.

[0042] Tracking system 312 includes tracking digital-to-analog converter 316 configured to receive digital code 338, which in some examples is digital code 318 from digital control circuit 310 plus an offset generated by offset circuit 336. Tracking system 312 also includes amplifier circuit 320 for comparing output 324 of tracking digital-to-analog converter 316 to output demand signal 206 (e.g., actual buck current level), which is used to adjust digital code 318 to achieve tracking.

[0043] Amplifier circuit 320 includes a first input 322, e.g., an inverting input, coupled to an output 324 (“tracking level”) of tracking digital-to-analog converter 316, and a second input 326, e.g., a non-inverting input, configured to receive a representation of the current produced by power converter circuit 202, i.e., output demand signal 206. An output signal 328 of amplifier circuit 320 is applied to digital control circuit 310, and digital control circuit 310 is configured to adjust digital code 318 based on output signal 328 of amplifier circuit 320. In some examples, amplifier circuit 320 is in an open-loop configuration.

[0044] The digital control circuit 310 is configured to generate a digital code 318 that represents the clamp level signal 210 and is based on a minimum level of the output demand current. In some examples, the digital control circuit 310 is configured to generate a minimum level of the output demand current that will limit the operating range based on one or more parameters that affect the input-to-output conversion of the power converter circuit, while still ensuring that the target input current is not exceeded. The parameters may include programmable input current limit, peak or valley operating mode, programmable inductance value, and / or programmable switching frequency. The digital control circuit 310 receives various inputs from the system and takes different actions to control the value of the clamp level signal 210. By using these inputs, the adaptive tracking clamp circuit 208 can maximize the available current serving the system 110, can maximize the charging current, and can reduce the charging time.

[0045] The digital control circuit 310 includes a finite state machine 330 having a tracking state and a control state. The finite state machine 330 receives various system feedback parameters, such as the state of the power converter circuit 202, such as buck or boost, regulation channel control state, and / or input current undershoot, and determines whether to increase or decrease the clamp level signal 210 and the speed or slowness of the increase or decrease to dynamically adapt to these conditions. The finite state machine 330 uses the system feedback parameters, such as which regulation channel is controlled, and begins adjusting the clamp level. If the regulation channel is not in control, the finite state machine 330 moves from the control state back to the tracking state.

[0046] The digital control circuit 310 also includes an up / down counter circuit 332 and a dynamic lower limit arithmetic circuit 334. The dynamic lower limit arithmetic circuit 334 helps the battery charging system 100 deliver as much current as possible as quickly as possible without exceeding the input current limit. The dynamic lower limit arithmetic circuit 334 also helps avoid system voltage collapse at startup and improves settling time by limiting the ramp-up time of the clamp level signal 210 ("MAXVAL").

[0047] In some examples, the dynamic lower limit arithmetic circuit 334 can set the lower limit of the clamp level signal 210 to just below the expected buck current at full load under input current limit control. The dynamic lower limit arithmetic circuit 334 can update the lower limit level based on various inputs, such as programmable input current limit, peak or valley operation mode, programmable inductor value, and / or programmable switching frequency. In this way, the dynamic lower limit arithmetic circuit 334 provides a predicted dynamic lower limit.

[0048] The up / down counter circuit 332 receives the output of the dynamic lower limit arithmetic circuit 334, the output of the finite state machine 330, and the output signal 328 of the amplifier circuit 320, and in response generates a digital code 318. The digital code 318 is applied to the clamping digital-to-analog converter 314 and to the tracking digital-to-analog converter 316 through the offset circuit 336.

[0049] If the demand for one of the regulation channels is below the clamp level signal 210 ("MAXVAL"), indicating that the particular channel is in control, the clamp level signal 210 is set to track the minimum value if the minimum value is greater than the lower limit value, otherwise, the clamp level signal 210 is set to the lower limit value. The clamp level signal 210 tracks the minimum value plus the headroom value in the steady state. The clamp level signal 210 clamps the minimum value during fast transient increase events and then gradually increases until the appropriate regulation channel regains control.

[0050] In some examples, the speed of the adaptive tracking clamp circuit can be programmed by a user. For example, the adaptive tracking clamp circuit 208 includes a register 340 coupled to the digital control circuit 310. The register 340 stores speed information programmed by the user. In some examples, the register 340 is programmed using a serial communication protocol such as an inter-integrated circuit (I2C).

[0051] Figure 4 yes Figure 3 4. The finite state machine 330 includes four states: an idle state 402, a buck stop state 404, a buck tracking state 406, and a buck control state 408. In the idle state 402, the clamp level signal 210 ("MAXVAL") is not controlled by the finite state machine 330.

[0052] Finite state machine 330 may move from idle state 402 to buck stop state 404. In buck stop state 404, which is a tracking state, adaptive tracking clamp circuit 208 is not actively controlling output demand, but rather attempts to closely track current. In this state, clamp level signal 210 ("MAXVAL") is under control of finite state machine 330. The response of adaptive tracking clamp circuit 208 is designed to be highly responsive, decreasing quickly to align with any decrease in output current level, e.g., having a time base short enough to track to the fastest regulation loop. Conversely, increases in current are managed more slowly, e.g., having a time base long enough to allow the slowest regulation loop to stabilize. This prevents the system from reacting to sudden spikes in current, and instead chooses to dampen to effectively manage such increases.

[0053] The finite state machine 330 may move from the buck stop state 404 to the buck control state 408, during which the clamp level signal 210 ("MAXVAL") is in control. In the buck control state 408, the adaptive tracking clamp circuit 208 takes the active control role, and the clamp level signal 210 ("MAXVAL") is not controlled by the finite state machine 330. This ensures that the current level does not decrease, but is allowed to gradually increase, with a time base long enough to allow the slowest regulation loop to stabilize. The buck control state 408 continues until another regulation channel in the system signals a need to reduce current, at which time control is switched to that regulation channel. The finite state machine 330 may move from the buck control state 408 back to the buck stop state 404, during which the clamp level signal 210 ("MAXVAL") is not controlled.

[0054] From the Buck Stop state 404, the finite state machine 330 may also move to the Buck Tracking state 406. The Buck Tracking state 406 may be used to smooth the transition when the current setting needs to be adjusted. For example, if the user sets a higher current level on the adapter input, the system avoids abrupt changes by smoothly ramping up to the new setting ("MAXVAL") of the clamp level signal 210. This gradual approach may prevent system glitches and avoid false detection of load step events, which may occur if the system misinterprets a normal increase in input current as an anomaly. In the Buck Tracking state 406, the adaptive tracking clamp circuit 208 may adjust upward rapidly, such as at a rate of one step per multiple of the fastest adjustment cycle time base, until it approaches a set limit. When approaching that limit, the system transitions back to the Buck Stop state 404 to slow down the ramping process ("MAXVAL") of the clamp level signal 210, thereby allowing any potential overshoot or system load steps to be carefully managed.

[0055] By using these techniques, the ramp rate clamp level signal 210 ("MAXVAL") is adjustable. The ramp rate can be asymmetric, in that the ramp up rate can be different than the ramp down rate. In addition, the clamp level signal 210 ("MAXVAL") can be adaptive based on various conditions, including whether the clamp level signal 210 or the regulation loop is in control, and based on the control history, such as which regulation loop has recently taken control.

[0056] In some examples, the ramp-down rate ("MAXVAL") of the clamp level signal 210 is a fast ramp, such as by tracking a fast regulation channel within a given time after the regulation loop takes control. In other examples, the ramp-down rate is a slow ramp to avoid mode switching oscillations.

[0057] In some examples, the ramp-up speed ("MAXVAL") of the clamp level signal 210 depends on the controlled regulation channel and the distance from the target value. When the regulation loop is in control, the adaptive tracking clamp circuit 208 uses a "target proximity detector" to select between a fast or slow ramp-up speed. When further away from the target value, the adaptive tracking clamp circuit 208 selects a fast ramp-up speed that maximizes the available current. When approaching the target value, the adaptive tracking clamp circuit 208 selects a slow ramp-up speed, which helps minimize the risk of overshoot. When the clamp level signal 210 ("MAXVAL") is in control, the adaptive tracking clamp circuit 208 selects a slow ramp-up speed, which helps limit overshoot.

[0058] Figure 5 A more detailed description Figure 2 Schematic diagram of an example of a multi-channel regulation system 204 of a battery charging system 100. Figure 5 As shown, the digital control circuit 310 of the adaptive tracking clamp circuit 208 generates an n-bit digital code 318, which is applied to the clamping digital-to-analog converter 314 and converted into the clamping level signal 210 ("MAXVAL"). In response, the clamping digital-to-analog converter 314 generates differential analog signals, such as MAXVAL+ and MAXVAL-, both of which are applied to the selector circuit 308. In addition, the differential analog signals MAXVAL+ and MAXVAL- are fed back to the tracking system 312 of the adaptive tracking clamp circuit 208.

[0059] Figure 5 The illustrated multi-channel regulation system 204 includes four regulation channels, namely a first regulation channel 500, a second regulation channel 502, a third regulation channel 504, and a fourth regulation channel 506. Each regulation channel includes an integrator, such as the integrator 508 of the first regulation channel 500. Each regulation channel includes a digital-to-analog converter, such as the digital-to-analog converter 510 of the first regulation channel 500, to program a target voltage or current.

[0060] Each regulation channel includes a positive clamp, such as positive clamp 512 of first regulation channel 500, which is used by the uncontrolled regulation channel. Each regulation channel includes a negative clamp, such as negative clamp 514 of first regulation channel 500, which is used by the regulation channel to avoid reverse operation.

[0061] Each regulation channel is configured to receive voltage feedback or current feedback. For a voltage regulation channel, such as the first regulation channel 500, the regulation channel includes a voltage scaler 516. For a current regulation channel, a current sense amplifier may be used.

[0062] In addition, the regulation channel may include an error amplifier stage, a transconductance stage (open loop) for the voltage regulation channel, or an amplifier stage (closed loop) for the current regulation channel.

[0063] Each regulation channel generates a positive voltage signal and a negative voltage signal that are applied to the selector circuit 308. For example, the first regulation channel 500 generates a positive voltage signal at node 518 and a negative voltage signal at node 520. The selector circuit 308 then selects the minimum value between the signal provided by the regulation channel and the clamp level signal 210.

[0064] Figure 6 6 is a flow chart of an example of a battery charging method. At block 602, method 600 generates an output demand signal by a multi-channel regulation system, the output demand signal representing an output demand current applied to a power converter circuit coupled to a battery. For example, multi-channel regulation system 204 generates output demand signal 206 applied to power converter circuit 202.

[0065] At block 604, the method 600 generates a clamp level signal representing a limit of the output demand current to limit current overshoot. For example, the adaptive tracking clamp circuit 208 generates a clamp level signal 210 representing a limit of the output demand current. Figure 2 The output demand signal 206 is limited.

[0066] At block 606, method 600 applies the clamp level signal to the multi-channel regulation system. For example, Figure 2 The adaptive tracking clamp circuit 208 applies a clamp level signal 210 to the multi-channel regulation system 204 .

[0067] In some examples, method 600 includes receiving a clamp level signal and signals corresponding to channels of a multi-channel regulation system and selecting a minimum value, such as by selector circuit 308 .

[0068] In some examples, method 600 includes receiving a digital code, receiving a representation of a current generated by the power converter circuit, and adjusting the digital code based on an output of the amplifier circuit, such as by using tracking system 312 and digital control circuit 310 .

[0069] The method 600 may include additional actions related to the functions described above.

[0070] Various annotations

[0071] Each non-limiting claim or example described herein may stand alone or in various permutations or combinations with one or more of the other examples.

[0072] The above detailed description includes references to the accompanying drawings that form a part of the detailed description. The accompanying drawings illustrate specific embodiments in which the present invention can be practiced by way of illustration. These embodiments are also referred to as "examples" herein. These examples may include elements other than those shown or described. However, the inventors also contemplate examples that only provide the shown or described elements. In addition, the inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more claims thereof), whether with respect to a specific example (or another one or more claims thereof), or with respect to other examples shown or described herein (or one or more claims thereof).

[0073] In the event of an inconsistency in usage between this document and any document incorporated by reference, the usage in this document shall control.

[0074] In this document, as is common in patent documents, the terms "a" or "an" are used to include one or more, independent of any other instance or usage of "at least one" or "one or more." In this document, the term "or" is used to refer to a non-exclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise noted. In this document, the terms "including" and "wherein" are used as synonyms for the respective terms "comprising" and "wherein." Furthermore, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, apparatus, article, composition, formulation, or method that includes additional elements in addition to the elements listed after such terms in a claim is still deemed to fall within the scope of the claim. Furthermore, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0075] The method examples described herein may be implemented at least in part by a machine or computer. Some examples may include a computer-readable medium or a machine-readable medium encoded with instructions, which may be operable to configure an electronic device to perform the method described in the above examples. The implementation of this method may include code, such as microcode, assembly language code, high-level language code, etc. Such code may include computer-readable instructions for performing various methods. The code may form part of a computer program product. In addition, in one example, the code may be tangibly stored on one or more volatile, non-transient or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media may include, but are not limited to, a hard disk, a removable disk, a removable optical disk (e.g., an optical disk and a digital video disk), a cassette, a memory card or a memory stick, a random access memory (RAM), a read-only memory (ROM), etc.

[0076] The above description is intended to be illustrative rather than limiting. For example, the above examples (or one or more claims thereof) may be used in combination with each other. Other embodiments may be used, such as by a person of ordinary skill in the art after reading the above description. The abstract is provided to comply with the provisions of Section 1.72 (b) of Chapter 37 of the Code of Federal Regulations, so that the reader can quickly determine the nature of the technical disclosure. The premise of submitting this document is that this document shall not be used to interpret or limit the scope or meaning of the claims. In addition, in the above detailed description, various features may be combined together to simplify the disclosure. This should not be interpreted as meaning that unclaimed public features are essential to any claim. On the contrary, the subject matter of the present invention may lie in the partial features of a particular disclosed embodiment. Therefore, the following claims are incorporated into the detailed description as examples or embodiments, each claim exists independently as a separate embodiment, and it is conceivable that these embodiments can be combined with each other in various combinations or arrangements. The scope of the present invention should be determined with reference to the attached claims and the full scope of equivalents enjoyed by these claims.

Claims

1. A battery charging system comprising: a power converter circuit coupled to the battery and the power source; a multi-channel regulation system coupled to the power converter circuit, the multi-channel regulation system configured to generate an output demand signal indicative of an output demand current to the power conversion circuit; and An adaptive tracking clamp circuit is coupled to the multi-channel regulation system, wherein the adaptive tracking clamp circuit is configured to generate a clamp level signal representing a limit of the output demand current to limit current overshoot, and wherein the clamp level signal is applied to the multi-channel regulation system.

2. The battery charging system of claim 1 , wherein the adaptive tracking clamp circuit configured to generate the clamp level signal is configured to limit current overshoot during a transition between a first regulation channel and a second regulation channel of the multi-channel regulation system. 3 . The battery charging system of claim 1 , wherein the multi-channel regulation system is configured to generate the output demand signal based on one or more sensed parameters.

4. The battery charging system of claim 1 , wherein the adaptive tracking clamp circuit comprises: A digital control circuit configured to generate the clamping level signal; and A tracking system is coupled to the digital control circuit, the tracking system being configured to track an output current of the power converter circuit.

5. The battery charging system according to claim 4, comprising: a clamping digital-to-analog converter coupled to the output of the digital control circuit and configured to generate the clamping level signal; and The selector circuit is configured to receive the clamp level signal and the signals corresponding to the channels of the multi-channel regulation system and select the minimum value.

6. The battery charging system of claim 5, wherein the tracking system comprises: a tracking digital-to-analog converter configured to receive a digital code; an amplifier circuit having a first input coupled to the output of the tracking digital-to-analog converter and a second input configured to receive a representation of the current generated by the power converter circuit, wherein the output of the amplifier circuit is coupled to the digital control circuit, and wherein the digital control circuit is configured to adjust the digital code based on the output of the amplifier circuit.

7. The battery charging system of claim 6, wherein the amplifier circuit is in an open loop configuration.

8. The battery charging system of claim 4, wherein the digital control circuit is configured to generate a minimum level of the output demand current, and wherein the digital control circuit is configured to generate a digital code representing the clamping level signal based on the minimum level of the output demand current.

9. The battery charging system of claim 8, wherein the digital control circuit is configured to generate the minimum level of the output demand current based on one or more parameters affecting input-to-output conversion of the power converter circuit.

10. The battery charging system of claim 9, wherein the one or more parameters are selected from programmable input current limit, peak or valley operation mode, programmable inductor value, and programmable switching frequency.

11. The battery charging system of claim 4, wherein the digital control circuit comprises a finite state machine, the finite state machine comprising a tracking state and a control state.

12. The battery charging system of claim 1, wherein a speed of the adaptive tracking clamp circuit is programmable by a user.

13. An adaptive tracking clamp circuit configured to be coupled to a multi-channel regulation system of a battery charging system, the adaptive tracking clamp circuit comprising: a digital control circuit configured to generate a clamping level signal representing a limit of an output demand current to limit current overshoot, wherein the clamping level signal is applied to the multi-channel regulation system; and A tracking system is coupled to the digital control circuit, the tracking system being configured to track an output current of the power converter circuit.

14. The adaptive tracking clamp circuit according to claim 13, comprising: The clamping digital-to-analog converter is coupled to the output of the digital control circuit and is configured to generate the clamping level signal.

15. The adaptive tracking clamp circuit of claim 13, wherein the digital control circuit comprises a finite state machine including a tracking state and a control state.

16. The adaptive tracking clamp circuit of claim 13, wherein the tracking system comprises: a tracking digital-to-analog converter configured to receive a digital code; an amplifier circuit having a first input coupled to the output of the tracking digital-to-analog converter and a second input configured to receive a representation of the current generated by the power converter circuit, wherein the output of the amplifier circuit is coupled to the digital control circuit, and wherein the digital control circuit is configured to adjust the digital code based on the output of the amplifier circuit.

17. The adaptive tracking clamp circuit of claim 16, wherein the digital control circuit is configured to generate a minimum level of the output demand current, and wherein the digital control circuit is arranged to generate a digital code representing the clamp level signal based on the minimum level of the output demand current.

18. A method for charging a battery, the method comprising: generating, by a multi-channel regulation system, an output demand signal representing an output demand current applied to a power converter circuit coupled to a battery; and generating a clamping level signal representing a limit of the output demand current to limit current overshoot; and The clamp level signal is applied to the multi-channel regulation system.

19. The method according to claim 18, comprising: The clamp level signal and signals corresponding to channels of the multi-channel regulation system are received and a minimum value is selected.

20. The method according to claim 18, comprising: Receive digital code; receiving a representation of a current generated by the power converter circuit; and The digital code is adjusted based on an output of the amplifier circuit.

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