Power supply circuit for independent control and monitoring of multi-battery charging

Abstract

Certain aspects of the present disclosure provide techniques and apparatus for powering, including battery charging. One example power supply circuit generally includes a switching regulator including an output node; a first battery node for coupling to a first battery; a second battery node for coupling to a second battery; a first switch coupled between an output node of the switching regulator and a first battery node; and a second switch coupled between the output node of the switching regulator and the second battery node. Such a power supply circuit may independently control and monitor charging of a plurality of independent batteries without using a plurality of chargers, may balance the batteries during discharging, and may operate without a current limiting switch.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. patent application No. 18 / 173,518, filed on February 23, 2023, which is hereby incorporated by reference. Technical Field

[0003] Certain aspects of the present disclosure relate generally to power circuits and, more particularly, to techniques and apparatus for independently controlling the charging and management of multiple independent batteries. Background Art

[0004] A voltage regulator ideally provides a constant direct current (DC) output voltage regardless of changes in load current or input voltage. Voltage regulators can be categorized as either linear or switching regulators. While linear regulators tend to be relatively compact, many applications can benefit from the increased efficiency of switching regulators. For example, a linear regulator can be implemented using a low-dropout (LDO) regulator. A switching regulator (also known as a "switching converter" or "switcher") can be implemented, for example, using a switch-mode power supply (SMPS), such as a buck converter, a boost converter, a buck-boost converter, or a charge pump.

[0005] For example, a buck converter is a type of SMPS that typically includes: (1) a high-side switch coupled between a relatively high voltage rail and a switching node, (2) a low-side switch coupled between the switching node and a relatively low voltage rail, and (3) an inductor coupled between the switching node and a load (e.g., represented by a shunt capacitive element). The high-side and low-side switches are typically implemented using transistors, although the low-side switch can also be implemented using a diode.

[0006] A charge pump is a type of SMPS (System-Modified Power Supply) typically consisting of at least one switching device, used to control the connection of a power supply voltage across a load via a capacitor. For example, in a voltage doubler (also known as a "multiply-by-two (X2) charge pump"), the charge pump circuit's capacitor can initially be connected across the power supply, charging the capacitor to the power supply voltage. The charge pump circuit can then be reconfigured to connect the capacitor in series with the power supply and the load, thereby doubling the voltage across the load. This two-stage cycle is repeated at the charge pump's switching frequency. Depending on the circuit topology, the charge pump can be used to multiply voltages by integers or fractional numbers.

[0007] A power management integrated circuit (PMIC) manages the power scheme of a host system and may include and / or control one or more voltage regulators (e.g., buck converters or charge pumps). PMICs are used in battery-operated devices such as mobile phones, tablets, laptops, and wearables to control the flow and direction of power within the device. The PMIC can perform various functions for the device, such as DC-to-DC conversion (e.g., using voltage regulators as described above), battery charging, source selection, voltage scaling, power sequencing, and more. Summary of the Invention

[0008] The systems, methods, and devices of the present disclosure each have multiple aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed in the appended claims, some features are briefly discussed below. After considering this discussion, and particularly after reading the section entitled "Detailed Description," one will understand how the features of the present disclosure provide the advantages described herein.

[0009] Certain aspects of the present disclosure provide a power supply circuit. The power supply circuit generally includes a switching regulator including an output node; a first battery node for coupling to a first battery; a second battery node for coupling to a second battery; a first switch coupled between the output node of the switching regulator and the first battery node; and a second switch coupled between the output node of the switching regulator and the second battery node.

[0010] Certain aspects of the present disclosure provide a power management integrated circuit (PMIC) including at least a portion of the above-mentioned power circuit.

[0011] Certain aspects of the present disclosure provide a battery charging circuit including the above power supply circuit.

[0012] Certain aspects of the present disclosure provide a device that generally includes a switching regulator including an output node, a first battery, a second battery, a first switch coupled between the output node of the switching regulator and the first battery, and a second switch coupled between the output node of the switching regulator and the second battery.

[0013] Certain aspects of the present disclosure relate to a method of providing power. The method generally includes converting a first voltage to a second voltage via a first switching regulator, charging a first battery from an output of the first switching regulator via a first switch, and charging a second battery from the output of the first switching regulator via a second switch, the second switch being different from the first switch.

[0014] To accomplish the foregoing and related objectives, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of but some of the various ways in which the principles of the various aspects may be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order that the manner in which the above-described features of the present disclosure may be understood in detail, a more particular description, briefly summarized above, may be had by reference to various aspects, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate only certain typical aspects of the disclosure and are therefore not to be considered limiting of its scope, as the description may admit to other equally effective aspects.

[0016] Figure 1 is a block diagram of an example device including a power management system, including a power management integrated circuit (PMIC) and a battery charging circuit, in which aspects of the present disclosure may be practiced.

[0017] Figure 2 is a circuit diagram of an example power supply circuit according to certain aspects of the present disclosure.

[0018] Figure 3A is a circuit diagram of an example power supply circuit capable of single charger charging according to certain aspects of the present disclosure, the example power supply circuit including a switch mode power supply (SMPS) circuit and multiple independently controlled charging paths.

[0019] Figures 3B to 3E is a circuit diagram of an example power supply circuit capable of parallel charging according to certain aspects of the present disclosure, which includes an SMPS circuit and multiple independently controlled charging paths.

[0020] Figure 3F is a circuit diagram of an example power supply circuit capable of charging two or more independent batteries including an SMPS circuit and two or more independently controlled charging paths, according to certain aspects of the present disclosure.

[0021] Figure 4 is a flow diagram of example operations for powering according to certain aspects of the present disclosure.

[0022] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0023] Certain aspects of the present disclosure provide techniques and apparatus for independently controlling the charging and management of multiple independent batteries using a power supply circuit that includes a switching regulator and multiple independently controlled and monitored charging paths. Such a power supply circuit can independently control and monitor the charging of multiple independent batteries without using multiple chargers and can balance the batteries during discharge. In some aspects, the power supply circuit can operate without impedance balancing circuitry (e.g., current limiting switches).

[0024] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms and should not be interpreted as being limited to any specific structure or function throughout the present disclosure. On the contrary, these aspects are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. Based on the teachings herein, it should be understood by those skilled in the art that, whether implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect of the present disclosure, the scope of the contents of the present disclosure is intended to cover any aspect disclosed herein. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method that uses other structures, functions, or structures and functions in addition to the various aspects of the present disclosure set forth herein or in addition to the various aspects of the present disclosure set forth herein to practice. It should be understood that any aspect of the disclosure disclosed herein can be embodied by one or more elements of the claims.

[0025] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects.

[0026] As used herein, the term "connected with" in various tenses of the verb "connect" may mean that element A is directly connected to element B, or that other elements may be connected between elements A and B (i.e., element A is indirectly connected to element B). In the context of electrical components, the term "connected" may also be used herein to mean that a wire, trace, or other conductive material is used to electrically connect elements A and B (as well as any components electrically connected between elements A and B).

[0027] Example device

[0028] It should be understood that various aspects of the present disclosure can be used in a variety of applications. Although the present disclosure is not limited in this respect, the circuits disclosed herein can be used in any of a variety of suitable devices, such as power supplies, battery charging circuits, or power management circuits in communication systems, video codecs, audio equipment such as music players and microphones, televisions, camera equipment, and test equipment such as oscilloscopes. Communication systems intended to be included within the scope of the present disclosure include, by way of example only, cellular wireless telephone communication systems, satellite communication systems, two-way radio communication systems, one-way pagers, two-way pagers, personal communication systems (PCS), personal digital assistants (PDAs), and the like.

[0029] Figure 1 An example device 100 is shown in which aspects of the present disclosure may be implemented. Device 100 may be a battery-operated device, such as a cellular phone, a PDA, a handheld device, a wireless device, a laptop computer, a tablet computer, a smartphone, an Internet of Things (IoT) device, a wearable device, etc. For certain aspects, device 100 may be a foldable device (e.g., a flip phone).

[0030] Device 100 may include a processor 104 that controls the operation of device 100. Processor 104 may also be referred to as a central processing unit (CPU). Memory 106, which may include read-only memory (ROM) and random access memory (RAM), provides instructions and data to processor 104. A portion of memory 106 may also include non-volatile random access memory (NVRAM). Processor 104 typically performs logical and arithmetic operations based on program instructions stored in memory 106.

[0031] In some aspects, the device 100 may also include a housing 108, which may include a transmitter 110 and a receiver 112 to allow for transmission and reception of data between the device 100 and a remote location. For some aspects, the transmitter 110 and the receiver 112 may be combined into a transceiver 114. One or more antennas 116 may be attached or otherwise coupled to the housing 108 and electrically connected to the transceiver 114. The device 100 may also include (not shown) multiple transmitters, multiple receivers, and / or multiple transceivers.

[0032] The device 100 may also include a signal detector 118, which may be used to detect and quantify the level of the signal received by the transceiver 114. The signal detector 118 may detect signal parameters such as total energy, energy per subcarrier per symbol, and power spectral density. The device 100 may also include a digital signal processor (DSP) 120 for processing signals.

[0033] Device 100 may also include a battery 122, which can be used to power various components of device 100 (e.g., when another power source (e.g., a wall adapter or wireless charger) is unavailable). Battery 122 may include a single cell or multiple cells connected in series and / or parallel. Device 100 may also include additional independent batteries (not shown). Each additional independent battery may include a single cell or multiple cells connected in series and / or parallel.

[0034] The device 100 may also include a power management system 123 for managing power from the battery 122 (one or more batteries), the wall adapter, and / or the wireless charger to the various components of the device 100. The power management system 123 may perform various functions of the device, such as DC-DC conversion, battery charging, power source selection, voltage scaling, power sequencing, source mode power, etc. In some aspects, the power management system 123 may include a power management integrated circuit (power management IC or PMIC) 124 and one or more power supply circuits, such as a battery charger 125, which may be controlled by the PMIC or logic associated with the battery charger. For some aspects, at least a portion of the one or more power supply circuits may be integrated into the PMIC 124. The PMIC 124 and / or the one or more power supply circuits may include at least a portion of a switch mode power supply (SMPS) circuit, which may be implemented by any of a variety of suitable switch mode power supply circuit topologies, such as a two-level buck converter, a three-level buck converter, a charge pump, or an adaptive combination power supply circuit (e.g., a step-down converter). Figure 2 The SMPS circuit 214 can be switched between operating in a buck converter mode and a charge pump mode, as described below.

[0035] The various components of device 100 can be coupled together via bus system 126, which may include a power bus, a control signal bus, and / or a status signal bus in addition to a data bus. Additionally or alternatively, various combinations of components of device 100 can be coupled together via one or more other suitable technologies.

[0036] Example Power Supply Circuit and Operation

[0037] As described above, the PMIC 124 and / or one or more power supply circuits (e.g., the battery charger 125) may include at least a portion of an SMPS circuit (e.g., a buck converter, a charge pump converter, or an adaptive combined power supply circuit capable of switching between these). The SMPS circuit may be a single-phase or multi-phase converter. In the case of an adaptive combined power supply circuit, two converter modes may be single-phase, two converter modes may be multi-phase, one converter mode may be single-phase and the other converter mode may be multi-phase or capable of switching between single-phase and multi-phase, or one converter mode may be multi-phase and the other converter mode may be capable of switching between single-phase and multi-phase.

[0038] Figure 2 FIG2 is a circuit diagram of an example power supply circuit 200 that can be used to charge one or more batteries. As shown, the power supply circuit 200 includes a power multiplexer 212 (labeled "PMUX"), a reverse current blocking transistor Q1 (also referred to as an overvoltage protection (OVP) field effect transistor (FET)), and an SMPS circuit 214 (e.g., an adaptive SMPS circuit).

[0039] The power multiplexer 212 can be configured to select between receiving power from, for example, (i) a universal serial bus (USB) port for connecting to a wall adapter and (ii) a wireless power port (neither of which is shown). The power multiplexer 212 can be implemented as a single-pole double-throw (SPDT) switch with two OVP FETs, and in this case, transistor Q1 can be eliminated.

[0040] In some aspects, the output of power multiplexer 212 can be coupled to an input voltage node 220 (labeled "VIN"). Input voltage node 220 can be coupled to the source of OVP FET Q1, and the drain of OVP FET Q1 can be coupled to a voltage node (labeled "MID") of SMPS circuit 214. The MID voltage node can serve as a power rail for SMPS circuit 214 and, in some cases, can alternatively be considered an input node of the SMPS circuit. In some cases, power multiplexer 212 and / or transistor Q1 can be removed.

[0041] For some aspects, the SMPS circuit 214 can have a two-level buck converter topology. For other aspects, the SMPS circuit 214 can have a single-phase three-level buck converter topology (e.g., Figure 2The power supply circuit 200 is shown in FIG. 1 , and may include a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, a flying capacitor Cfly, an inductor L1, and a load 210, represented here by a capacitor. To implement an adaptive SMPS circuit, a switch S1 may be added across the inductor L1 in a three-level buck converter topology. When switch S1 is closed, the adaptive SMPS circuit may function as a single-phase, divide-by-two (Div2) charge pump converter, as described below. In some aspects, switch S1 may be implemented using two back-to-back transistors.

[0042] Transistor Q3 may be coupled to transistor Q2 via a first node (labeled "CFH" for a flying capacitor high node), transistor Q4 may be coupled to transistor Q3 via a second node (labeled "VSW" for a voltage switch node), and transistor Q5 may be coupled to transistor Q4 via a third node (labeled "CFL" for a flying capacitor low node). For certain aspects, transistors Q2 through Q5 may be implemented as n-type metal oxide semiconductor (NMOS) transistors, such as Figure 2 As shown. In this case, the drain of transistor Q3 can be coupled to the source of transistor Q2, the drain of transistor Q4 can be coupled to the source of transistor Q3, and the drain of transistor Q5 can be coupled to the source of transistor Q4. The source of transistor Q5 can be coupled to a reference potential node 218 (e.g., electrical ground) of the power supply circuit 200. The flying capacitor element Cfly can have a first terminal coupled to the first node and a second terminal coupled to the third node. The inductive element L1 can have a first terminal coupled to the second node and a second terminal coupled to the output voltage node 216 (labeled "VOUT", which may also be referred to as "VPH_PWR" or "VPH") and the load 210.

[0043] Control logic 201 can control the operation of SMPS circuit 214 and other aspects of power supply circuit 200. For example, control logic 201 can control the operation of transistors Q2 through Q5 via output signals to the inputs of respective gate drivers 202, 204, 206, and 208. The outputs of gate drivers 202, 204, 206, and 208 are coupled to the corresponding gates of transistors Q2 through Q5. During operation of the adaptive SMPS circuit (or three-level buck converter), control logic 201 can cycle through four different phases, which can differ depending on whether the duty cycle is less than 50% or greater than 50%.

[0044] First, the operation of an adaptive SMPS circuit with a duty cycle less than 50% will be described. In the first phase (referred to as the "charging phase"), transistors Q2 and Q4 are enabled, while transistors Q3 and Q5 are disabled, charging the flying capacitor element Cfly and energizing the inductor element L1. In the second phase (referred to as the "holding phase"), transistor Q2 is disabled and transistor Q5 is enabled, coupling the VSW node to the reference potential node. The flying capacitor element Cfly is disconnected (e.g., one of the Cfly terminals is floating), and the inductor element L1 is de-energized. In the third phase (referred to as the "discharging phase"), transistors Q3 and Q5 are enabled, while transistor Q4 is disabled, discharging the flying capacitor element Cfly and energizing the inductor element L1. In the fourth phase (also referred to as the "holding phase"), transistor Q4 is enabled and transistor Q3 is disabled, disconnecting the flying capacitor element Cfly and de-energizing the inductor element L1.

[0045] The operation of the adaptive SMPS circuit with a duty cycle greater than 50% is similar in the first and third phases, which have the same transistor configuration. However, in the second phase (referred to as the "hold phase") following the first phase, transistor Q4 is deactivated and transistor Q3 is activated, coupling the VSW node to the MID node, disconnecting the flying capacitor element Cfly, and energizing the inductor element L1. Similarly, in the fourth phase (also referred to as the "hold phase") with a duty cycle greater than 50%, transistor Q2 is activated and transistor Q5 is deactivated, disconnecting the flying capacitor element Cfly and energizing the inductor element L1.

[0046] In addition, the control logic 201 may have a control signal ( Figure 2 (not shown) This control signal is configured to control the operation of switch S1 and selectively enable a divide-by-two (Div2) charge pump operation. For certain aspects, when this control signal is logic low, switch S1 is open, and the power supply circuit 200 operates as a three-level buck converter using inductive element L1. When this control signal is logic high in certain aspects, switch S1 is closed, thereby shorting inductive element L1 and effectively removing inductive element L1 from the circuit, allowing the adaptive SMPS circuit to operate as a Div2 charge pump. Control logic 201 can be configured to automatically control the operation of switch S1 (e.g., via the logic level of the control signal) based on the output current (also referred to as "load current") and / or input current of the adaptive SMPS circuit.

[0047] Example power supply circuit for multiple battery charging

[0048] Many portable devices may use multiple independent batteries. In some cases, such as foldable and flip phones and Internet of Things (IoT) devices, the multiple independent batteries include cells of varying capacities (asymmetric cells), which often presents challenges for charging, monitoring, and balancing the batteries. At least some multi-battery charging implementations are complex and expensive (in terms of cost and area) and can lead to performance issues. For example, some multi-battery charging implementations use multiple individual charging circuits and impedance balancing circuits (e.g., current-limiting switches) to balance the cells (e.g., to prevent one cell from charging or discharging faster than another).

[0049] Certain aspects of the present disclosure provide techniques and apparatus for charging multiple independent batteries using a power supply circuit that includes a switch-mode power supply (SMPS) and independently controlled and monitored charging paths. Such a power supply circuit can control and monitor the charging of multiple independent batteries without the use of multiple chargers. For example, the power supply circuit can include an independently controlled charging path for each battery, each charging path having a switch (e.g., a battery FET) to provide charging control. In some aspects, the power supply circuit can operate without impedance balancing circuitry (e.g., a current-limiting switch). In this way, certain aspects can support independent control of the charging, monitoring, and balancing of multiple independent batteries (e.g., any number m of cells in series and any number n of batteries in parallel per battery (mSnP), such as one cell per battery and any number n of batteries in parallel (1SnP)), regardless of whether the batteries have different capacities), while significantly reducing cost and complexity. Such a power supply circuit can also provide independent monitoring of the individual state of charge of each battery.

[0050] Figure 3A is a circuit diagram of an example power supply circuit 300A according to certain aspects of the present disclosure, which includes a switching regulator (e.g., SMPS circuit 214) as a single charger and independently controlled charging paths (e.g., charging paths 360, 362). For certain aspects, the power supply circuit 300A can include the power multiplexer 212, the OVP FET Q1, and the SMPS circuit 214 (or another suitable SMPS circuit). The power supply circuit 300A can also include a load 306 (e.g., labeled "VPH LOAD"), a first switch (e.g., implemented by one or more transistors QBAT1), a second switch (e.g., implemented by one or more transistors QBAT2), a first battery 304 (BAT1), a second battery 302 (BAT2), a first sensing resistive element R SNS1 , the second sensing resistor element R SNS2and a balancing resistive element Rb. For certain aspects, the batteries 302, 304 may be external to an integrated circuit (IC) (eg, a PMIC), while at least a portion of the switching regulator and switch (implemented by transistors QBAT1 and QBAT2) may be internal to the IC. SNS1 and R SNS2 The sensing resistor element R may be internal or external to the IC, or one sensing resistor element may be internal and the other external. SNS1 and R SNS2 One or both of may be eliminated, and the on-resistance of the corresponding transistors QBAT1 and / or QBAT2 may be used as a current sensing resistor.

[0051] The load 306 may be similar to Figure 2 Load 306 may represent a device (eg, a power supply rail VPH = VOUT) that is internally powered by a switching regulator (eg, having a power rail VPH = VOUT). Figure 1 The load 306 may be coupled (in parallel) to the reference potential node 218 .

[0052] In certain aspects, the first battery 304 and / or the second battery 302 can represent a single-cell (1S) battery, a two-cell series (2S) battery, or two or more stacked cells in a battery (eg, a multi-cell series battery). Figure 3A The charging architecture shown in Figure 3 represents a 1S2P configuration. In some cases, first battery 304 and second battery 302 can be symmetrical batteries with the same capacity (and size). In other cases, first battery 304 and second battery 302 can be asymmetrical batteries, each having a different capacity (and size). For example, power circuit 300A can be included in a foldable device, which can include a first portion connected to a second portion via a hinge. In this example, the first portion of the foldable device can include first battery 304, and the second portion of the foldable device can include second battery 302.

[0053] In some aspects, the output voltage node 216 of the SMPS circuit 214 can be coupled to transistor QBAT1, transistor QBAT2, and load 306. In some aspects, one or more of transistors QBAT1 and QBAT2 can be bidirectional switches, each implemented using one or more transistors. In some cases, for example, transistors QBAT1 and / or QBAT2 can be implemented using back-to-back transistors or body-switchable transistors. The gates of the QBAT1 and QBAT2 transistors can be controlled by logic circuits (e.g., Figure 2 The control logic 201 or Figure 3A other logic not shown).

[0054] In certain aspects, transistor QBAT1 can be coupled to first battery 304 via a first battery voltage node 340 (labeled "VBAT1"), and transistor QBAT2 can be coupled to second battery 302 via a second battery voltage node 330 (labeled "VBAT2"). First battery 304 can be coupled to a first sensing resistive element R via another first battery voltage node 342 (e.g., coupled to the negative terminal of first battery 304). SNS1 , and the second battery 302 may be coupled to the second sensing resistive element R via another second battery voltage node 332 (eg, coupled to the negative terminal of the second battery 302 ). SNS2 The first sensing resistive element R SNS1 and the second sensing resistive element R SNS2 The resistors 304 and 302 may be used as sense resistors to measure the current through the first battery 304 and the second battery 302, respectively.

[0055] When the batteries 302, 304 are external to an IC with other circuits of the power supply circuit 300A, the IC can include a positive first battery port (e.g., a pin) coupled to the first battery voltage node 340 and the positive terminal of the first battery 304. In some cases, the IC can include a negative first battery port coupled to another first battery voltage node 342, the first sensing resistive element R SNS1 and the negative terminal of the first battery 304. Additionally or alternatively, the IC can include a positive second battery port coupled to the second battery voltage node 330 and the positive terminal of the second battery 302. In some cases, the IC can include a negative second battery port coupled to another second battery voltage node 332, a sensing resistive element R SNS2 and the negative terminal of the second battery 302. The sensing resistive element R SNS1 and R SNS2 may be coupled to a reference potential node 218 .

[0056] In certain aspects, the positive terminals of the first battery 304 and the second battery 302 can be coupled together via a balancing resistive element Rb. In some cases, for example, the balancing resistive element Rb can be implemented as a 100Ω resistor. The balancing resistive element Rb can be internal to the IC (coupled between the first battery voltage node 340 and the second battery voltage node 330), or can be external to the IC. The balancing resistive element Rb can be used to balance the two batteries during charging or when the device is powered off and the batteries 302, 304 begin to discharge.

[0057] According to certain aspects, power supply circuit 300A can charge both first battery 304 and second battery 302 via two independently controlled charging paths 360 and 362 (via SMPS circuit 214). For example, electrical power received from a wall adapter or wireless charger at power multiplexer 212 can be converted by SMPS circuit 214 and used to independently charge first battery 304 (e.g., via charging path 362) and second battery 302 (e.g., charging path 360). For example, current from output voltage node 216 can be routed via transistor QBAT1 in charging path 362 to first battery voltage node 340 for charging first battery 304. Similarly, current from output voltage node 216 can be routed via transistor QBAT2 in charging path 360 to second battery voltage node 330 for charging second battery 302. In certain aspects, transistor QBAT1 can be configured to independently control and monitor the charging of first battery 304 (via charging path 362 ), and transistor QBAT2 can be configured to independently control and monitor the charging of second battery 302 (via charging path 360 ).

[0058] Having one or more transistors (e.g., transistor QBAT1 or QBAT2) in each charging path can allow for independent charge control of the batteries, including trickle charging, pre-charging, constant current (CC), constant voltage (CV), and / or termination charging. In some aspects, independently monitoring the charging of multiple independent batteries can include independently monitoring the charge levels in the batteries via these transistors. Additionally or alternatively, independently monitoring the charging of multiple independent batteries can include independent current sensing, battery measurement, and / or current limit regulation of the batteries (aggregate or individual). The presence of one or more transistors in each charging path can eliminate the need for impedance balancing circuits (e.g., current limit switches) between the multiple independent batteries, as the transistors in each charging path can be used to perform current limit regulation. For example, power supply circuit 300A may lack a current limit switch between first battery 304 and second battery 302.

[0059] Certain aspects of the present disclosure may also provide flexibility in battery charge termination (e.g., battery charge termination may be dependent on the current of a single battery, the total current of multiple batteries, or the battery state of charge (SOC)). Independent charge path switches (e.g., transistors QBAT1 and QBAT2) may be internal (integrated into the PMIC), or one or more switches may be external to the PMIC. The battery temperature may be independently monitored, and based on the sensed battery temperature, appropriate action may be taken via the independent charge path switches (e.g., charging may be paused, charging voltage and / or current may be reduced, etc.). For example, when the temperature of the second battery 302 is too high, transistor QBAT2 may be effectively disconnected, or the charge current may be incrementally reduced.

[0060] According to certain aspects, power circuit 300A can charge a single battery (e.g., first battery 304) using a single charger. For example, second battery 302 may have been disconnected and / or removed from power circuit 300A. In this 1S1P configuration, transistor QBAT2 can function as a bypass switch (e.g., a bypass FET). When only a single battery is connected, power circuit 300A can enable powering up of a device (e.g., device 100) while also preventing overcharging of the single connected battery.

[0061] In some cases, it may be desirable to charge multiple independent batteries using parallel charging to speed up charging (e.g., when the batteries have a higher power level). In an exemplary parallel charging solution, a primary charger (e.g., SMPS circuit 214) can charge multiple independent batteries (e.g., first battery 304 and second battery 302) and provide power itself, or it can be connected in parallel with one or more auxiliary chargers. For example, each auxiliary charger can be implemented as a switched capacitor converter (e.g., a divide-by-two (Div2) or divide-by-three (Div3) charge pump (CP)) or a switched mode power supply (SMPS) topology using an inductor (e.g., a buck converter). CP converters can provide a more efficient alternative to buck converters.

[0062] Figures 3B to 3E is a circuit diagram of an example power supply circuit capable of parallel charging according to certain aspects of the present disclosure, the example power supply circuit including a primary charger (e.g., SMPS circuit 214) and one or more auxiliary chargers having multiple independently controlled charging paths (e.g., charging paths 360, 362).

[0063] Figure 3B The power supply circuit 300B can be similar to Figure 3AThe power supply circuit 300A is similar to the power supply circuit 300A, but also includes a CP 308 and a CP 310 as auxiliary chargers for parallel charging. Each of the CPs 308 and 310 can be implemented as a Div2 charge pump, a Div4 charge pump, or a charge pump with any other suitable voltage conversion. The CP 308 can have an input coupled to the input voltage node 220 and an output coupled to the second battery voltage node 330, and the CP 310 can have an input coupled to the input voltage node 320 and an output coupled to the first battery voltage node 340. The design of the power supply circuit 300B may be desirable when the first battery 304 and the second battery 302 are substantially symmetrical (e.g., not too asymmetrical) due to lower power conduction losses.

[0064] As described above, transistor QBAT2 may be implemented as back-to-back transistors QBAT2A and QBAT2B, as shown, but may alternatively be implemented as bulk-switchable transistors. The gates of transistors QBAT2A and QBAT2B may be driven by logic circuitry, as described above.

[0065] During parallel charging, electrical power received at the power multiplexer 212, for example, from a wall adapter or wireless charger, can be converted by the SMPS circuit 214 and used to independently charge the first battery 304 (e.g., via charging path 362) and the second battery 302 (e.g., charging path 360). In addition to charging path 362, when the CP 310 is enabled, electrical power from the power multiplexer 212 can also be converted by the CP 310 and used to charge the first battery 304 in parallel with the SMPS circuit 214. Furthermore, in addition to charging path 360, when the CP 308 is enabled, electrical power from the power multiplexer 212 can also be converted by the CP 308 and used to charge the second battery 302 in parallel with the SMPS circuit 214.

[0066] Figure 3C The power supply circuit 300C can be similar to Figure 3A The power supply circuit 300A is similar to the power supply circuit 300A, except that a CP 312 is added as an auxiliary charger for parallel charging. The CP 312 can be implemented as a Div2 charge pump, a Div4 charge pump, or a charge pump with any other suitable voltage conversion. The CP 312 can have an input coupled to the input voltage node 220 and an output coupled to the output voltage node 216.

[0067] Sensing a resistive element (e.g., element R SNS1 and R SNS2 ) is optional in the power supply circuit 300C and can be removed from the power supply circuit 300C. The power supply circuit 300C does not include the element R SNS1 and RSNS2 In this case, the on-resistance of transistor QBAT1 can be used as a sense resistor for the first battery 304, and the on-resistance of transistor QBAT2 can be used as a sense resistor for the second battery 302. In addition, due to the design of a single charge pump and the connection method of CP 312, the power supply circuit 300C can also have fewer wires or traces passing through the hinge of the foldable device (compared to Figure 3B and Figure 3D (Compared with other parallel charging topologies in the power supply circuits 300B and 300D).

[0068] As described above, transistor QBAT2 may be implemented as back-to-back transistors QBAT2A and QBAT2B. Figure 3C 2A and QBAT2B are shown, but may alternatively be implemented as bulk switchable transistors. The gates of transistors QBAT2A and QBAT2B may be driven by logic circuitry, as described above.

[0069] During parallel charging, electrical power received at the power multiplexer 212, for example, from a wall adapter or wireless charger, can be converted by the SMPS circuit 214 and used to independently charge the first battery 304 (e.g., via charging path 362) and the second battery 302 (e.g., via charging path 360). Additionally, when the CP 312 is enabled, electrical power from the power multiplexer 212 can also be converted by the CP 312 and used to independently charge the first battery 304 (e.g., via charging path 362) and the second battery 302 (e.g., via charging path 360).

[0070] Figure 3D The power supply circuit 300D can be similar to Figure 3A The power supply circuit 300A is not shown, but may also include CP 314 and CP 316 as auxiliary chargers for parallel charging. Each of CP 314, 316 may be implemented as a Div2 charge pump, a Div4 charge pump, or a charge pump with any other suitable voltage conversion. CP 314 may have an input coupled to input voltage node 220 and an output coupled to output voltage node 216, and CP 316 may have an input coupled to input voltage node 22 and an output coupled to first battery voltage node 340. When the first battery 304 and the second battery 302 are very asymmetric (with Figure 3A and Figure 3B The design of power supply circuit 300D may be desirable when comparing power supply circuits 300A, 300B. For example, in addition to SMPS circuit 214, first battery 304 may have a much larger capacity than second battery 302 and may benefit from being charged by both CP 314 and CP 316. Power supply circuit 300D may have a larger capacity than second battery 302. Figure 3CThe power supply circuit 300C has lower conduction power loss and higher efficiency.

[0071] In some aspects, the power supply circuit 300D may not include a sensing resistive element R SNS2 Instead, the on-resistance of transistors QBAT2A and / or QBAT2B may be used as a current sensing resistor for the second battery 302 .

[0072] During parallel charging, electrical power received at the power multiplexer 212, for example, from a wall adapter or wireless charger, can be converted by the SMPS circuit 214 and used to independently charge the first battery 304 (e.g., via charging path 362) and the second battery 302 (e.g., via charging path 360). Furthermore, when the CP 314 is enabled, electrical power from the power multiplexer 212 can also be converted by the CP 314 and used to independently charge the first battery 304 (e.g., via charging path 362) and the second battery 302 (e.g., via charging path 360). Furthermore, when the CP 316 is enabled, electrical power from the power multiplexer 212 can be converted by the CP 316 and used to charge the first battery 304 in parallel with the SMPS circuit 214 (and in parallel with the CP 314 when both CPs 314, 316 are enabled).

[0073] Figure 3E The power supply circuit 300E can be similar to Figure 3A The power supply circuit 300A is not shown in FIG. 3 , but may also include CP 318 and CP 320 as auxiliary chargers for parallel charging. Each of CP 318 and 320 may be implemented as a Div2 charge pump, a Div4 charge pump, or a charge pump with any other suitable voltage conversion. CP 318 may have an input coupled to input voltage node 220 and an output coupled to output voltage node 216, and CP 320 may have an input coupled to input voltage node 22 and an output coupled to second battery voltage node 330. When the first battery 304 and the second battery 302 are very asymmetric (with Figure 3A and Figure 3B The design of the power supply circuit 300E may be desirable when comparing the power supply circuits 300A, 300B of FIG. 2 . For example, the second battery 302 may have a much larger capacity than the first battery 304 and thus benefit from being charged by both the CP 318 and the CP 320 in addition to the SMPS circuit 214. The power supply circuit 300E may have a larger capacity than the first battery 304. Figure 3C The power supply circuit 300C has lower conduction power loss and higher efficiency.

[0074] In some aspects, the power supply circuit 300E may not include a sensing resistive element R SNS1Instead, the on-resistance of transistor QBAT1 may be used as a current sensing resistor for the first battery 304 .

[0075] During parallel charging, electrical power received at the power multiplexer 212, for example, from a wall adapter or wireless charger, can be converted by the SMPS circuit 214 and used to independently charge the first battery 304 (e.g., via charging path 362) and the second battery 302 (e.g., via charging path 360), as described above. Furthermore, when the CP 318 is enabled, electrical power from the power multiplexer 212 can also be converted by the CP 318 and used to independently charge the first battery 304 (e.g., via charging path 362) and the second battery 302 (e.g., via charging path 360). Furthermore, when the CP 320 is enabled, electrical power from the power multiplexer 212 can be converted by the CP 320 and used to charge the second battery 302 in parallel with the SMPS circuit 214 (and in parallel with the CP 318 when both CPs 318, 320 are enabled).

[0076] Figure 3F FIG2 is a circuit diagram of an example power supply circuit (e.g., power supply circuit 300F) capable of charging two or more independent batteries according to certain aspects of the present disclosure. The power supply circuit includes an SMPS circuit (e.g., SMPS circuit 214) and multiple independent charging paths (e.g., charging paths 360, 362, 364). In some cases, it may be desirable for a device to have more than two batteries coupled in parallel. Figure 3F The power supply circuit 300F can be similar to Figure 3A The power supply circuit 300A may also include a third switch (implemented by one or more transistors QBAT3) for independently controlling the third battery 322, the third sensing resistive element R SNS3 and the charging of the second balancing resistive element Rbx. In some aspects, transistor QBAT3 can be a bidirectional switch implemented using transistors. For example, transistor QBAT3 can be implemented using back-to-back transistors or body-switchable transistors. The gate of transistor QBAT3 can be controlled by logic circuits (e.g., Figure 2 The control logic 201 or Figure 3F other logic not shown) as described above.

[0077] In this case, the output voltage node 216 of the SMPS circuit 214 may also be coupled to the transistor QBAT3. Transistor QBAT3 may be coupled to the positive terminal of the third battery 322 (for coupling to the port of the second battery 322) via a third battery voltage node 350 (labeled "VBAT3"). The negative terminal of the third battery 322 (or its port) may be coupled to a third sensing resistive element RSNS3 via another third battery voltage node 352. The third sensing resistive element RSNS3 may be configured to measure the current through the third battery 322 and may be coupled to the reference potential node 218, as shown. The third sensing resistive element RSNS3 may be internal to an integrated circuit (IC) (e.g., a PMIC) that includes at least a portion of the power supply circuit 300F, or external to such an IC. For example, the IC may include a port coupled to the third battery voltage node 350 for coupling to the positive terminal of the third battery. In some cases, the IC may include another port that may be coupled to another third battery voltage node 352 to couple to the negative terminal of the third battery 322, or may be coupled to the reference potential node 218 to couple to an external third sensing resistive element R SNS3 In some aspects, the third battery 322 and the second battery 302 can be coupled together via a second balancing resistive element Rbx. In some cases, for example, the second balancing resistive element Rb can be implemented as a 100Ω resistor. In some aspects, a third balancing resistive element (not shown) can be added between the first battery voltage node 340 and the third battery voltage node 350. The third sensing resistive element R SNS3 , the second balancing resistive element Rbx and / or the third balancing resistive element may be external or internal to the IC (eg, PMIC).

[0078] According to certain aspects, the power supply circuit 300F can charge the third battery 322 in addition to the first battery 304 and the second battery 302 via three independently controlled charging paths (using a single charger). The charging paths 360, 362 are described above with respect to Figure 3A The electric power converted by the SMPS circuit 214 can also be used to charge the third battery 322 (e.g., via the charging path 364). For example, the current from the SMPS circuit 214 can be routed from the output voltage node 216 to the third battery voltage node 350 via the transistor QBAT3. In some aspects, the transistor QBAT3 can be configured to independently control and monitor the charging of the third battery 322 (via the charging path 364), as described above (e.g., with respect to FIG. Figure 3A ).

[0079] Example Operation

[0080] Figure 4 is a flow chart of example operations 400 for powering according to certain aspects of the present disclosure. Operations 400 may be performed by a power supply circuit (e.g., Figures 3A to 3F The power supply circuits 300A to 300F) are implemented.

[0081] At block 402, operations may begin with a first switching regulator (e.g., SMPS circuit 214) converting a first voltage (e.g., input voltage VIN or MID) to a second voltage (output voltage VOUT or VPH). At block 404, a power supply circuit charges a first battery (e.g., first battery 304) from the output of the first switching regulator (e.g., output voltage node 216) via a first switch (e.g., transistor QBAT1). At block 406, the power supply circuit charges a second battery (e.g., second battery 302) from the output of the first switching regulator via a second switch (e.g., transistor QBAT2). The second switch is different from the first switch.

[0082] According to certain aspects, operation 400 also includes charging a third battery (eg, third battery 322) from the output of the first switching regulator via a third switch (eg, transistor QBAT3). In this case, the third switch can be different from the second switch and / or different from the first switch.

[0083] According to certain aspects, operation 400 also includes converting the first voltage to a second voltage via a second switching regulator (e.g., CP 312, 314, or 318). In this case, the output of the first switching regulator can be coupled to the second switching regulator. For certain aspects, operation 400 also includes converting the first voltage to a third voltage via a third switching regulator (e.g., CP 316 or 320). In some cases, operation 400 can also include charging the first battery from the output of the third switching regulator (e.g., as described above with respect to Figure 3D As described above). At block 404, such charging of the first battery from the output of the third switching regulator may occur while the first battery is being charged from the output of the first switching regulator via the first switch. In other cases, operations 400 may also include charging the second battery from the output of the third switching regulator (e.g., as described above with respect to Figure 3E At block 406, charging of the third battery from the output of the third switching regulator may occur while the second battery is being charged from the output of the first switching regulator via the second switch.

[0084] According to certain aspects, operations 400 also include converting the first voltage to a third voltage via a second switching regulator (e.g., CP 310), and charging the first battery from the output of the second switching regulator. This charging of the first battery from the output of the second switching regulator can occur while the first battery is being charged from the output of the first switching regulator via the first switch. According to certain aspects, operations 400 can also include converting the first voltage to a fourth voltage via a third switching regulator (e.g., CP 308), and charging the second battery from the output of the third switching regulator. This charging of the third battery from the output of the third switching regulator can occur while the second battery is being charged from the output of the first switching regulator via the second switch.

[0085] Example aspects

[0086] In addition to the above aspects, specific combinations of the aspects are also within the scope of the present disclosure, some of which are as follows:

[0087] Aspect 1: A power supply circuit comprising: a switching regulator including an output node; a first battery node for coupling to a first battery; a second battery node for coupling to a second battery; a first switch coupled between the output node of the switching regulator and the first battery node; and a second switch coupled between the output node of the switching regulator and the second battery node.

[0088] Aspect 2: The power supply circuit according to aspect 1, wherein the first switch and the second switch are bidirectional switches implemented using transistors.

[0089] Aspect 3: The power supply circuit according to aspect 1 or 2, wherein at least one of the first switch or the second switch comprises back-to-back transistors.

[0090] Aspect 4: The power supply circuit according to any one of aspects 1 to 3, wherein at least one of the first switch or the second switch comprises a body-switchable transistor.

[0091] Aspect 5: The power supply circuit according to any one of aspects 1 to 4, further comprising a first sensing resistive element for coupling to the first battery.

[0092] Aspect 6: The power supply circuit according to Aspect 5 further includes: a reference potential node for the power supply circuit; and a third battery node, wherein the first battery node is used to couple to the first terminal of the first battery, wherein the third battery node is used to couple to the second terminal of the second battery, and wherein the first sensing resistive element is coupled between the third battery node and the reference potential node.

[0093] Aspect 7: The power supply circuit according to aspect 5 or 6, further comprising a second sensing resistive element for coupling to the second battery.

[0094] Aspect 8: The power supply circuit according to Aspect 7 further includes: a reference potential node for the power supply circuit; a third battery node, wherein the first battery node is used to couple to the first terminal of the first battery, wherein the third battery node is used to couple to the second terminal of the second battery, and wherein the first sensing resistive element is coupled between the third battery node and the reference potential node; and a fourth battery node, wherein the second battery node is used to couple to the first terminal of the second battery, wherein the fourth battery node is used to couple to the second terminal of the first battery, and wherein the second sensing resistive element is coupled between the fourth battery node and the reference potential node.

[0095] Aspect 9: The power supply circuit according to any one of aspects 1 to 8, further comprising a resistive element coupled between the first battery node and the second battery node.

[0096] Aspect 10: The power circuit according to any one of aspects 1 to 9, wherein the power circuit lacks a current limiting switch coupled between the first battery node and the second battery node.

[0097] Aspect 11: The power supply circuit according to any one of Aspects 1 to 10 further includes a first charge pump, the first charge pump including a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the output node of the switching regulator.

[0098] Aspect 12: The power supply circuit according to Aspect 11, further comprising a second charge pump, the second charge pump comprising a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the first battery port.

[0099] Aspect 13: The power supply circuit according to Aspect 11, further comprising a second charge pump, the second charge pump comprising a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the second battery port.

[0100] Aspect 14: The power supply circuit according to any one of aspects 1 to 10, further comprising a first charge pump, the first charge pump comprising a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the first battery port.

[0101] Aspect 15: The power supply circuit according to Aspect 14, further comprising a second charge pump, the second charge pump comprising a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the second battery port.

[0102] Aspect 16: The power supply circuit according to any one of Aspects 1 to 15, wherein the switching regulator comprises a three-level buck converter, and the three-level buck converter is selectively configurable as a divide-by-two charge pump.

[0103] Aspect 17: A power supply circuit according to Aspect 16, wherein: the three-level buck converter includes an inductive element coupled to the output node of the switching regulator and a switch coupled in parallel with the inductive element; the three-level buck converter is configured to operate in a buck converter mode when the switch is disconnected; and the three-level buck converter is configured to operate in a charge pump mode when the switch is closed.

[0104] Aspect 18. The power supply circuit according to any one of aspects 1 to 15, wherein the switching regulator comprises a two-level buck converter.

[0105] Aspect 19: An integrated circuit (IC) for power management, the integrated circuit comprising the power circuit of any one of aspects 1 to 18.

[0106] Aspect 20: The IC according to Aspect 19 further includes: a first port coupled to the first battery node, the first port configured to be coupled to the first battery; and a second port coupled to the second battery node, the second port configured to be coupled to the second battery.

[0107] Aspect 21: The IC of aspect 19 or 20, wherein the first switch and the second switch are internal to the IC.

[0108] Aspect 22: A device comprising: a switching regulator, the switching regulator including an output node; a first battery; a second battery; a first switch coupled between the output node of the switching regulator and the first battery; and a second switch coupled between the output node of the switching regulator and the second battery.

[0109] Aspect 23: The device of aspect 22, wherein the device is foldable, wherein a first portion of the device is coupled to a second portion of the device by a hinge, wherein a first battery is disposed in the first portion, and wherein a second battery is disposed in the second portion.

[0110] Aspect 24: The apparatus of aspect 22 or 23, further comprising a resistive element coupled between the first battery and the second battery.

[0111] Aspect 25: The apparatus of aspect 24, wherein at least a portion of the switching regulator, the first switch, and the second switch are implemented in an integrated circuit (IC), and wherein the resistive element is external to the IC.

[0112] Aspect 26: The device of any one of aspects 22 to 25, wherein the capacity of the first battery is different from the capacity of the second battery.

[0113] Aspect 27: The device according to any one of aspects 22 to 26, wherein the second switch is configured to control charging of the second battery independently of charging control of the first battery by the first switch.

[0114] Aspect 28: A power supply method, comprising: converting a first voltage to a second voltage by a first switching regulator; charging a first battery from an output of the first switching regulator via a first switch; and charging a second battery from the output of the first switching regulator via a second switch, the second switch being different from the first switch.

[0115] Aspect 29: The method of aspect 28, further comprising charging a third battery from the output of the first switching regulator via a third switch, the third switch being different from the second switch and the first switch.

[0116] Aspect 30: The method of aspect 28 or 29, further comprising converting the first voltage to the second voltage via a second switching regulator, wherein the output of the first switching regulator is coupled to the third switching regulator.

[0117] Aspect 31: The method according to Aspect 30 further includes: converting the first voltage into a third voltage via a third switching regulator; and charging the first battery from the output of the third switching regulator while charging the first battery from the output of the first switching regulator via the first switch.

[0118] Aspect 32: The method according to Aspect 30 further includes: converting the first voltage into a third voltage via a third switching regulator; and charging the second battery from the output of the third switching regulator while charging the second battery from the output of the first switching regulator via the second switch.

[0119] Aspect 33: The method according to Aspect 28 or 29 further includes: converting the first voltage into a third voltage via a second switching regulator; and charging the first battery from the output of the second switching regulator while charging the first battery from the output of the first switching regulator via the first switch.

[0120] Aspect 34: The method according to Aspect 33 further includes: converting the first voltage into a fourth voltage via a third switching regulator; and charging the second battery from the output of the third switching regulator, while charging the second battery from the output of the first switching regulator via the second switch.

[0121] Other considerations

[0122] The various operations of the above methods may be performed by any suitable components capable of performing the corresponding functions. Such components may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors. Generally, where operations are illustrated in a figure, these operations may have corresponding corresponding components plus functional components with similar numbering.

[0123] As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, database, or another data structure), deciding, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Furthermore, "determining" may include resolving, selecting, choosing, establishing, and the like.

[0124] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to encompass: a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other order of a, b, and c).

[0125] The methods disclosed herein include one or more steps or actions for implementing the methods. Method steps and / or actions may be interchangeable with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0126] It should be understood that the claims are not limited to the precise configuration and components described above, and that various modifications, changes, and variations may be made in the arrangement, operation, and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A power supply circuit comprising: a switching regulator including an output node; a first battery node for coupling to a first battery; a second battery node for coupling to a second battery; a first switch coupled between the output node of the switching regulator and the first battery node; as well as The second switch is coupled between the output node of the switching regulator and the second battery node.

2. The power supply circuit according to claim 1, wherein The first switch and the second switch are bidirectional switches implemented using transistors.

3. The power supply circuit according to claim 1, wherein At least one of the first switch or the second switch includes back-to-back transistors.

4. The power supply circuit according to claim 1, wherein At least one of the first switch or the second switch includes a body-switchable transistor. 5 . The power supply circuit of claim 1 , further comprising a first sensing resistive element for coupling to the first battery.

6. The power supply circuit according to claim 5, further comprising: a reference potential node for said power circuit; as well as a third battery node, wherein the first battery node is for coupling to a first terminal of the first battery, wherein the third battery node is for coupling to a second terminal of the first battery, and wherein the first sensing resistive element is coupled between the third battery node and the reference potential node.

7. The power supply circuit of claim 5, further comprising a second sensing resistive element for coupling to the second battery.

8. The power supply circuit according to claim 7, further comprising: a reference potential node for said power circuit; a third battery node, wherein the first battery node is for coupling to a first terminal of the first battery, wherein the third battery node is for coupling to a second terminal of the first battery, and wherein the first sensing resistive element is coupled between the third battery node and the reference potential node; as well as a fourth battery node, wherein the second battery node is for coupling to a first terminal of the second battery, wherein the fourth battery node is for coupling to a second terminal of the second battery, and wherein the second sensing resistive element is coupled between the fourth battery node and the reference potential node.

9. The power supply circuit of claim 1, further comprising a resistive element coupled between the first battery node and the second battery node.

10. The power supply circuit according to claim 1, wherein The power circuit lacks a current limiting switch coupled between the first battery node and the second battery node. 11 . The power supply circuit of claim 1 , further comprising a first charge pump including a first terminal coupled to an input node of the switching regulator and a second terminal coupled to the output node of the switching regulator. 12 . The power supply circuit of claim 11 , further comprising a second charge pump including a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the first battery node. 13 . The power supply circuit of claim 11 , further comprising a second charge pump including a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the second battery node.

14. The power supply circuit of claim 1, further comprising a first charge pump including a first terminal coupled to an input node of the switching regulator and a second terminal coupled to the first battery node. 15 . The power supply circuit of claim 14 , further comprising a second charge pump including a first terminal coupled to the input node of the switching regulator and a second terminal coupled to the second battery node.

16. The power supply circuit according to claim 1, wherein The switching regulator includes a three-level buck converter that is selectively configured as a divide-by-two charge pump.

17. The power supply circuit according to claim 16, wherein: The three-level buck converter includes an inductive element coupled to the output node of the switching regulator and a switch coupled in parallel with the inductive element; The three-level buck converter is configured to operate in a buck converter mode when the switch is open; and The three-level buck converter is configured to operate in a charge pump mode when the switch is closed.

18. The power supply circuit according to claim 1, wherein The switching regulator includes a two-level buck converter.

19. An integrated circuit (IC) for power management, the IC comprising the power circuit of claim 1.

20. The IC of claim 19, further comprising: a first port coupled to the first battery node, the first port being configured to be coupled to the first battery; as well as The second port is coupled to the second battery node, and the second port is configured to be coupled to the second battery.

21. The IC of claim 19, wherein: The first switch and the second switch are inside the IC.

22. A device comprising: a switching regulator, the switching regulator comprising an output node; First battery; Second battery; a first switch coupled between the output node of the switching regulator and the first battery; as well as The second switch is coupled between the output node of the switching regulator and the second battery.

23. The apparatus of claim 22, wherein: The device is foldable, wherein a first portion of the device is coupled to a second portion of the device by a hinge, wherein the first battery is disposed in the first portion, and wherein the second battery is disposed in the second portion.

24. The device of claim 22, further comprising a resistive element coupled between the first battery and the second battery.

25. The apparatus of claim 24, wherein: At least a portion of the switching regulator, the first switch, and the second switch are implemented in an integrated circuit (IC), and wherein the resistive element is external to the IC.

26. The apparatus of claim 22, wherein: A capacity of the first battery is different from a capacity of the second battery.

27. The apparatus of claim 22, wherein: The second switch is configured to control charging of the second battery independently of charging control of the first battery by the first switch.

28. A power supply method, comprising: converting the first voltage into a second voltage via a first switching regulator; charging a first battery from an output of the first switching regulator via a first switch; as well as A second battery is charged from the output of the first switching regulator via a second switch, the second switch being different from the first switch.

29. The method of claim 28, further comprising charging a third battery from the output of the first switching regulator via a third switch, the third switch being different from the second switch and the first switch.

30. The method of claim 28, further comprising converting the first voltage to the second voltage via a second switching regulator, wherein the output of the first switching regulator is coupled to an output of the second switching regulator.

31. The method of claim 30, further comprising: converting the first voltage into a third voltage via a third switching regulator; as well as The first battery is charged from an output of the third switching regulator, while the first battery is simultaneously charged from the output of the first switching regulator via the first switch.

32. The method of claim 30, further comprising: converting the first voltage into a third voltage via a third switching regulator; as well as The second battery is charged from the output of the third switching regulator, while the second battery is simultaneously charged from the output of the first switching regulator via the second switch.

33. The method of claim 28, further comprising: converting the first voltage into a third voltage via a second switching regulator; as well as The first battery is charged from an output of the second switching regulator, while the first battery is simultaneously charged from the output of the first switching regulator via the first switch.

34. The method of claim 33, further comprising: converting the first voltage into a fourth voltage via a third switching regulator; as well as The second battery is charged from the output of the third switching regulator, while the second battery is simultaneously charged from the output of the first switching regulator via the second switch.

Images