Power management device including multiple input ports and associated system and method

Abstract

The invention relates to a power management device including multiple input ports and associated systems and methods. A power management device includes a first input port configured to be electrically coupled to an energy source, a second input port configured to be electrically coupled to a capacitor, a first output port configured to be electrically coupled to a first load, and a direct current-direct current (DC-DC) converter. The DC-DC converter is configured to: (a) charge the capacitor from energy of the energy source; and (b) providing energy to the first output port at least partially using the energy stored in the capacitor. The energy source includes, for example, a battery.

Description

Technical Field

[0001] The present disclosure relates to power management devices including multiple input ports and associated systems and methods. Background Art

[0002] Batteries are often used to provide power to electronic devices such as mobile electronic devices. It is often desirable for mobile electronic devices to have a small form factor. Therefore, batteries in mobile electronic devices often need to have a small form factor. Summary of the invention

[0003] In one embodiment, a power management device including multiple input ports includes: (a) a first input port configured to be electrically coupled to an energy source; (b) a second input port configured to be electrically coupled to a first capacitor; (c) a first output port configured to be electrically coupled to a first load; and (d) a direct current-to-direct current (DC-DC) converter configured to: (i) charge the first capacitor using energy from the energy source; and (ii) provide energy to the first output port at least partially using energy stored in the first capacitor.

[0004] In one embodiment, a method for providing power to one or more loads using a power management device includes: (a) using an inductor of a first direct current to direct current (DC-DC) converter to charge a first capacitor using energy from an energy source; (b) using the inductor of the first DC-DC converter to provide energy to a first load from energy stored in the first capacitor; and (c) using the inductor of the first DC-DC converter to transfer energy stored in a second capacitor to the first capacitor, the second capacitor being electrically coupled to the first load.

[0005] In one embodiment, an electrical system includes: (a) an energy source, (b) a first capacitor, (c) a first load, and (d) a power management device. The power management device includes: (i) a first input port electrically coupled to the energy source; (ii) a second input port electrically coupled to the first capacitor; (iii) a first output port electrically coupled to the first load; and (iv) a direct current-to-direct current (DC-DC) converter configured to: (a) charge the first capacitor from energy from the energy source; and (b) provide energy to the first load using at least in part the energy stored in the first capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 is the electrical model of a battery.

[0007] Figure 2A yes Figure 1 An example graph of the current in a battery versus time.

[0008] Figure 2B yes Figure 1 An example graph of the voltage in a battery versus time.

[0009] Figure 3 is a block diagram of an electrical system including a power management device according to an embodiment.

[0010] Figure 4 is the input energy transfer mode Figure 3 Block diagram of the electrical system.

[0011] Figure 5 is the output energy transfer mode Figure 3 Block diagram of the electrical system.

[0012] Figure 6 yes Figure 3 A block diagram of an electrical system showing an alternative output energy transfer mode.

[0013] Figure 7 is a diagram showing the discharge energy transfer mode Figure 3 Block diagram of the electrical system.

[0014] Figure 8 is another discharge energy transfer mode. Figure 3 Block diagram of the electrical system.

[0015] Fig. 9 yes Figure 3 Schematic diagram of one possible embodiment of a DC-DC converter of a power management device.

[0016] Fig.10 Included are five graphs illustrating one example of a controller that generates control signals to cause Fig. 9 The buck-boost converter operates in input energy transfer mode.

[0017] Fig.11 Included are five graphs illustrating another example of a controller that generates control signals to cause Fig. 9 The buck-boost converter operates in input energy transfer mode.

[0018] Fig.12 Included are five graphs illustrating additional examples of a controller that generates control signals to cause Fig. 9 The buck-boost converter operates in input energy transfer mode.

[0019] Fig.13 Included are five graphs illustrating one example of a controller that generates control signals to cause Fig. 9The buck-boost converter is operated in an output energy transfer mode.

[0020] Fig.14 Included are five graphs illustrating an example of a controller that generates control signals to cause Fig. 9 The buck-boost converter is operated in a discharge energy transfer mode.

[0021] Fig.15 Included are five graphs illustrating one example of a controller that generates control signals to cause Fig. 9 The buck-boost converter is operated in a discharge energy transfer mode.

[0022] Fig.16 Included are five graphs illustrating yet another example of a controller that generates control signals to cause Fig. 9 The buck-boost converter operates in input energy transfer mode.

[0023] Fig.17 Included are five graphs illustrating yet another example of a controller that generates control signals to cause Fig. 9 The buck-boost converter is operated in an output energy transfer mode.

[0024] Fig.18 It is shown Figure 3 A state diagram of an example of how a DC-DC converter of a power management device transitions between energy transfer modes.

[0025] Fig.19 Including showing Fig.18 The state diagram of Figure 3 Three graphs of an example of the operation of an electrical system.

[0026] Fig. 20 Shows Fig.18 An alternative embodiment of a state diagram.

[0027] Fig.21 Including showing Fig. 20 The state diagram of Figure 3 Three graphs of an example of the operation of an electrical system. DETAILED DESCRIPTION

[0028] Batteries with small form factors, such as microbatteries, can be used in size-sensitive applications, such as wearable electronic device applications and Internet of Things (IoT) applications. Examples of batteries that can have small form factors include, but are not limited to, silver oxide batteries, lithium thionyl chloride batteries, lithium manganese dioxide batteries, and zinc-air batteries. However, batteries with small form factors typically exhibit high impedance and low specific power, which can be problematic in some applications.

[0029] For example, mobile electronic devices increasingly have large peak electrical loads. For example, health wearable electronic devices that implement photoplethysmography (PPG) can have a peak load of 250 milliamps (mA) or more, and motors in wearable drug delivery pumps can have a peak load of more than 800mA. As another example, Internet of Things (IoT) devices including narrowband (Nb) radios can have a peak load of more than 800mA. If the battery has a high impedance, this high peak load may cause the battery voltage to drop excessively.

[0030] For example, Figure 1 is an electrical model of the battery 100. The battery 100 is Figure 1 The battery 100 is modeled by a voltage source 102 and an impedance element 104 electrically coupled in series between a first battery output node 106 and a second battery output node 108. The battery 100 has a battery voltage V between the second battery output node 108 and the first battery output node 106. bat , and the battery 100 has a current I flowing between the first battery output node 106 and the second battery output node 108 bat The voltage source 102 is a voltage source having a voltage amplitude V as a function of the state of charge (SOC) of the battery 100. th The impedance element 104 has an impedance R which is also a function of the charge state of the battery 100. th Voltage V bat With current I bat The relationship between can be expressed in the following formula 1.

[0031] V bat =V th (SOC)-I bat ·R th (SOC) (Formula 1)

[0032] It is obvious from Formula 1 that the battery voltage V bat With the impedance R t The increase of current I bat Therefore, if R th large, the large peak current load may cause the battery voltage V bat For example, Figure 2A and 2B Graphs 200 and 202 are graphs 200 and 202, respectively, which together illustrate an example of the operation of battery 100 when subjected to a large peak current load. Graph 200 is a graph of current I bat Graph 202 is a graph of voltage V versus time. bat Graphs 200 and 202 have a common time base. Current Ibat Initially has the magnitude of I1, but the current I bat At time t1, the current jumps to the magnitude of I2 in a short time in response to the peak load. The current spike at time t1 causes the voltage V bat The amplitude of V3 drops to that of V1 instantly, and the voltage V bat Then it rebounds to the amplitude of V3. If the load powered by the battery 100 has a minimum operating voltage of V2, then at time t1 the battery voltage V bat The drop in current will cause the voltage supplied to the load to exceed the specification, possibly causing improper operation of the load. Therefore, the high impedance of the battery in the electronic device may cause improper operation of the electronic device when the battery is subjected to a large peak load. In addition, some types of batteries may be damaged by excessive peak current.

[0033] Disclosed herein is a power management device and associated systems and methods that at least partially overcome the above-mentioned problems. A specific embodiment of the new power management device includes two input ports, which are configured to be electrically coupled to an energy source and a capacitor, respectively, and the capacitor is used to buffer the energy source from a large peak load, thereby reducing the energy source voltage drop and potential energy source damage caused by the large peak load. The energy source includes, for example, a battery. In addition, certain embodiments of the new power management device include multiple output ports, so that the power management device can power multiple loads. In addition, some embodiments can quickly transfer charge from the capacitance of the load to the capacitor for later use, thereby being able to quickly change the size of the load voltage while saving energy. In addition, some embodiments of the new power management device use a single DC-DC converter, such as a single buck-boost converter, to meet all energy transfer requirements, thereby promoting miniaturization, low cost and high efficiency of the power management device.

[0034] Figure 3 3 is a block diagram of an electrical system 300 including a power management device 302, an energy source 304, a capacitor 306, N loads 308, and N capacitors 310, where N is an integer greater than or equal to 1. In this document, a specific instance of an item may be referred to by using a number in parentheses (e.g., load 308(1)), while a number without parentheses refers to any such item (e.g., load 308). Although Figure 3N is depicted as being greater than 1, but it should be understood that N can be equal to 1. The power management device 302 is an embodiment of the new power management device disclosed herein, and includes a first input port 312, a second input port 314, and N output ports 316. The first input port 312 is configured to be electrically coupled to the energy source 304, and the second input port 314 is configured to be electrically coupled to the capacitor 306. Therefore, the energy source 304 is electrically coupled between the first input port 312 and the reference node 318, and the capacitor 306 is electrically coupled between the second input port 314 and the reference node 318. The reference node 318 is described as a ground node, such as a ground node or a chassis ground node. However, it should be understood that the reference node 318 does not need to be a ground node, and the reference node 318 can be at a different potential than the ground or the chassis ground. In some embodiments, the first input port 312, the second input port 314, and the output port 316 are discrete components, such as integrated circuit pins, integrated circuit solder balls or pads, electrical terminals, etc. In some other embodiments, first input port 312, second input port 314, and output port 316 are respective electrical nodes that optionally surround a plurality of electrical conductors.

[0035] Energy source 304 is, for example, a battery, such as a micro battery. In certain embodiments, energy source 304 is a silver oxide battery, a lithium thionyl chloride battery, a lithium manganese dioxide battery, or a zinc-air battery. For example, energy source 304 may include one or more coin cells or button cells. However, energy source 304 is not limited to batteries. For example, energy source 304 may be replaced by a photovoltaic device, a thermoelectric generator (TEG), a micro generator, a super capacitor, etc. In certain embodiments, energy source 304 has a maximum current capability less than the maximum peak current requirement of one or more loads 308. Energy source 304 may be replaced by a plurality of energy sources electrically coupled in series and / or in parallel, so as to achieve an energy source capacitance higher than the energy source capacity actually achieved using a single energy source and / or to achieve an energy source voltage higher than the energy source voltage actually obtained using a single energy source. In an embodiment including a plurality of energy sources, each energy source does not need to have the same configuration. In addition, capacitor 306 may be replaced by a plurality of capacitors electrically coupled in series and / or in parallel, so as to achieve a higher capacitor rated voltage and / or a larger capacitance value than actually achieved using a single capacitor. One or more capacitors (not shown) are optionally electrically coupled in parallel with energy source 304 .

[0036] Each output port 316 is configured to be electrically coupled to a corresponding load 308. Thus, each load 308 is electrically coupled between the corresponding output port 316 and the reference node 318. In addition, each capacitor 310 is electrically coupled between the corresponding output port 316 and the reference node 318, so that each capacitor 310 is electrically coupled to the corresponding load 308. Examples of loads 308 include, but are not limited to, loads of mobile electronic devices, such as wearable health devices, wearable medical devices, Internet of Things devices, mobile information technology devices, mobile communication devices, etc. Each load 308 need not have the same configuration.

[0037] The power management device 302 also includes a direct current to direct current (DC-DC) converter 320 and a controller 322. The DC-DC converter 320 is electrically coupled to the first input port 312, the second input port 314, and each output port 316. A specific embodiment of the DC-DC converter 320 includes a single inductor 324, which is composed of Figure 3 The inductor symbol in is shown symbolically for energy transfer between ports 312, 314 and 316, as described below. In certain embodiments, DC-DC converter 320 includes one or more of a buck-boost converter, a buck-boost converter, a buck converter and a boost converter. Although DC-DC converter 320 is described as a single component, DC-DC converter 320 can be implemented by multiple sub-components that do not need to be packaged together. For example, in a specific embodiment, inductor 324 is packaged separately from other components of DC-DC converter 320.

[0038] Controller 322 is communicatively coupled 326 to DC-DC converter 320, and controller 322 at least partially controls the operation of DC-DC converter 320. Controller 322 is formed, for example, by analog electronic circuits and / or digital electronic circuits. Although controller 322 is depicted as a discrete component, controller 322 can alternatively be partially or completely combined with one or more other components. For example, in some alternative embodiments, controller 322 is at least partially combined with DC-DC converter 320. In addition, controller 322 can be implemented by multiple sub-components that do not need to be packaged together. In addition, controller 322 can also be partially or completely outside power management device 302.

[0039] The controller 322 is optionally further communicatively coupled to one or more of the first input port 312, the second input port 314, and the output port 316, for example, to obtain voltage and / or current measurements at one or more of the above ports. For example, in some embodiments, the controller 322 is configured to obtain (a) a voltage at the first input port 312, for example, a voltage V across the energy source 304; es, (b) current flowing through the first input port 312, for example, the current I flowing between the energy source 304 and the first input port 312 es , (c) the voltage at the first output port 314, for example, the voltage V across the capacitor 306 T , (d) a current flowing through the second input port 314, for example, a current I flowing between the second input port 314 and the capacitor 306 T , (e) the voltage at each output port 316, e.g., the corresponding voltage V across each load 308 L , (f) the current at each output port 316, e.g., the corresponding current I flowing between each output port 316 and the parallel combination of the corresponding load 308 and capacitor 310 L For the sake of explanation, Figure 3 Not shown are optional communication connections between the controller 322 and one or more of the first input port 312 , the second input port 314 , and the output port 316 .

[0040] The power management device 302 may also include a current limiting circuit 328 configured to limit the current I flowing between the energy source 304 and the first input port 312 to es The magnitude of the current I is limited to a predetermined maximum value. The optional current limiting circuit 328 (when present) is electrically coupled between the first input port 312 and the DC-DC converter 320, so that the first input port 312 is electrically coupled to the DC-DC converter 320 via the current limiting circuit 328. In some other embodiments, the DC-DC converter 320 is configured to limit the current I to a predetermined maximum value without using the current limiting circuit 328. es The size of is limited to a predetermined maximum value, and the current limiting circuit 328 is omitted accordingly.

[0041] The controller 322 is configured to cause the DC-DC converter 320 to operate in one or more possible energy transfer modes, such as depending on the needs of the electrical system 300. Figure 4-8 Discussed are several example energy transfer modes of the DC-DC converter 320 in the power management device 302. However, it should be understood that the DC-DC converter 320 need not be able to support all of the example energy transfer modes. In addition, the DC-DC converter 320 can be configured to support alternative and / or additional energy transfer modes without departing from the scope of this document.

[0042] Figure 4 is a block diagram of the electrical system 300, showing an example in which the controller 322 operates the DC-DC converter 320 in an input energy transfer mode 402, wherein the energy transfer path is Figure 4314, where the DC-DC converter 320 transfers energy from the first input port 312 to the second input port 314. Therefore, the capacitor 306 is charged by the energy of the energy source 304 in the input energy transfer mode 402 of the DC-DC converter 320. In a specific embodiment, the controller 322 controls the DC-DC converter 320 so that the capacitor 306 is charged to a voltage having a voltage greater than the energy source voltage V es A larger voltage V T , to facilitate large energy storage in capacitor 306 without requiring a large capacitance value for capacitor 306. In particular, the energy E stored in capacitor 306 is governed by Equation 2, where C T is the capacitance of capacitor 306. As can be seen from Formula 2, increasing the voltage V T The magnitude of causes the energy stored in capacitor 306 to increase exponentially at a given capacitance value of capacitor 306.

[0043]

[0044] Current I es The magnitude of is limited, for example, by the current limiting circuit 328 and / or by the operation of the DC-DC converter 320 in the input energy transfer mode 402 of the DC-DC converter 320. Therefore, in certain embodiments, the energy source 304 is not subjected to large peak currents, which promotes the energy source voltage V es stable value and long life of energy source 304.

[0045] Figure 5 is a block diagram of electrical system 300, illustrating an example in which controller 322 causes DC-DC converter 320 to operate in output energy transfer mode 502(1), wherein the energy transfer path is Figure 5 6(1), where the DC-DC converter 320 transfers energy from the second input port 314 to the output port 316(1). Thus, in the output energy transfer mode 502(1) of the DC-DC converter 320, the DC-DC converter 320 provides electrical power to the load 308(1) from the energy stored in the capacitor 306. It should be understood that the load 308(1) is indirectly powered by the energy source 304. In particular, as described above, the capacitor 306 is charged by the energy of the energy source 304 in the first energy transfer mode 402 of the DC-DC converter 320, and the load 308(1) is subsequently powered by the energy stored in the capacitor 306 in the output energy transfer mode 502(1) of the DC-DC converter 320. Thus, the capacitor 306 electrically buffers the energy source 304 from the load 308, thereby preventing the energy source 304 from being affected by the large peak current drawn by the load 308.

[0046] The DC-DC converter 320 is configured to support a corresponding output energy transfer mode 502 for each output port 316 of the power management device 302, wherein the DC-DC converter 320 transfers energy from the second input port 314 to the corresponding output port 316 of the output energy transfer mode 502. For example, Figure 6 is a block diagram of an electrical system 300 illustrating an example of a controller 322 that causes a DC-DC converter 320 to operate in an output energy transfer mode 502 (N) in which the energy transfer path is in an output energy transfer mode 502 (N). Figure 6 306 (N), where the DC-DC converter 320 transfers energy from the second input port 314 to the output port 316 (N). Therefore, when the DC-DC converter 320 operates in the output energy transfer mode 502 (N), the DC-DC converter 320 provides electrical power to the load 308 (N) from the energy stored in the capacitor 306.

[0047] Figure 7 is a block diagram of an electrical system 300 illustrating an example of a controller 322 that causes a DC-DC converter 320 to operate in a discharge energy transfer mode 702(1) in which the energy transfer path is Figure 7 , where DC-DC converter 320 transfers energy from output port 316(1) to second input port 314. Thus, DC-DC converter 320 transfers energy stored in capacitor 310(1) to capacitor 306, thereby causing capacitor 310(1) to at least partially discharge when DC-DC converter 320 operates in discharge energy transfer mode 702(1). For example, if it is necessary to quickly reduce voltage V L (1), such as during dynamic voltage scaling (DVS), it may be desirable to discharge capacitor 310(1). It will be appreciated that transferring energy from capacitor 310(1) to capacitor 306 enables the energy to be subsequently used to power one or more loads 308, thereby improving the energy efficiency of electrical system 300. In some embodiments, energy source 304 does not tolerate being reverse powered or charged, i.e., energy source 304 does not tolerate current I having a negative polarity. es In such an embodiment, energy from capacitor 310 cannot be returned to energy source 304, which makes it particularly beneficial to store energy obtained from discharging capacitor 310 in capacitor 306, as energy would otherwise need to be dissipated.

[0048] The DC-DC converter 320 is configured to support a corresponding discharge energy mode 702 for each output port 316 of the power management device 302, wherein energy is transferred from the output port 316 to the second input port 314. For example, Figure 8is a block diagram of the electrical system 300 showing an example of a controller 322 that causes the DC-DC converter 320 to operate in a discharge energy transfer mode 702 (N) in which the energy transfer path is Figure 8 306, where the DC-DC converter 320 transfers energy from the output port 316 (N) to the capacitor 306. Thus, the DC-DC converter 320 transfers the energy stored in the capacitor 310 (N) to the capacitor 306, thereby at least partially discharging the capacitor 310 (N) when the DC-DC converter 320 operates in the discharge energy transfer mode 702 (N).

[0049] It should be understood that the above Figure 4-8 The energy transfer modes discussed use a single power converter, namely the DC-DC converter 320, to transfer energy between ports. In addition, each of the above energy transfer modes uses a common inductor, namely the inductor 324 of the DC-DC converter 320, to transfer energy between ports. For example, the inductor 324 of the DC-DC converter 320 is used to transfer energy from the first input port 312 to the second input port 314 in the input energy transfer mode 402, the inductor 324 of the DC-DC converter 320 is used to transfer energy from the second input port 314 to the output port 316 in the output energy transfer mode 502, and the inductor 324 in the DC-DC converter 320 is used to transfer energy from the output port 316 to the third input port 314 in the discharge energy transfer mode 702. This use of a single power converter for the above energy transfer modes improves efficiency by eliminating the power losses associated with using multiple power converters to transfer energy between ports. Furthermore, the ability of the power management device 302 to transfer energy between ports using a single power converter (ie, DC-DC converter 320 ) facilitates the small size and low cost of the power management device 302 .

[0050] The controller 322 is configured to cause the DC-DC converter 320 to operate in one of the input energy transfer mode 402, the output energy transfer mode 502, and the discharge energy transfer mode 702, for example, based on one or more parameters of the electrical system 300. In some embodiments, the controller 322 is configured to (a) respond to the voltage V T falls below a predetermined minimum voltage value causing the DC-DC converter 320 to operate in the input energy transfer mode 402, and (b) in response to (1) the voltage V TThe DC-DC converter 320 discontinues operation in the input energy transfer mode 402 when the load voltage V ... L drops below a predetermined load threshold voltage value, causing the DC-DC converter 320 to operate in the output power transfer mode 502, and (b) in response to (1) the load voltage V L The controller 322 is configured to stop the DC-DC converter 320 from operating in the output power delivery mode 502 in response to (a) a load current I associated with the output power delivery mode 502 rising above a predetermined maximum load voltage value or (b) a maximum allowed time period for operating in the output power delivery mode 502 expiring. In addition, in some embodiments, the controller 322 is configured to (a) respond to the load current I associated with the output power delivery mode 502 L The DC-DC converter 320 operates in the output power transfer mode 502 in response to the increase of the load current I L The DC-DC converter 320 stops operating in the output power transfer mode 502. In addition, in some embodiments, the controller 322 operates the DC-DC converter 320 in the discharge energy transfer mode 702 in response to a signal indicating a decrease in the desired voltage at the output port 316 corresponding to the discharge energy transfer mode 702.

[0051] Some embodiments of the controller 322 are configured to cause the DC-DC converter 320 to switch rapidly between energy transfer modes. For example, certain embodiments of the controller 322 are configured to cause the DC-DC converter 320 to repeatedly switch between the input energy transfer mode 402 and one or more output energy transfer modes 502 in order to simultaneously regulate the voltage V under light load conditions of the electrical system 300. T and one or more load voltages V L Additionally, certain embodiments of the controller 322 are configured to give priority to the output energy transfer mode 502 over the input energy transfer mode 402 to promote the load voltage V L and / or load current I L In addition, some embodiments of the controller 322 are configured to cause the DC-DC converter 320 to operate in two or more output energy transfer modes 502 simultaneously, i.e., to transfer energy from the second input port 314 to two or more output ports 316 simultaneously, for example, if the two or more output ports 316 are at a common voltage V LFurthermore, certain embodiments of the controller 322 are configured to cause the DC-DC converter 320 to operate in two or more discharge energy transfer modes 702 simultaneously, i.e., to transfer energy from two or more output ports 316 to the second input port 314 simultaneously, for example, if the two or more output ports 316 are at a common voltage V L Next operation.

[0052] Fig. 9 900 is a schematic diagram of a buck-boost converter 900, which is a DC-DC converter 320 ( Figure 3 However, it should be understood that the DC-DC converter 320 may be implemented in other ways without departing from the scope of this document.

[0053] Buck-boost converter 900 includes input capacitor 902, switch device 904, switch device 906, switch device 908, switch device 910, N switch devices 912, and inductor 914. Inductor 914 is inductor 324 ( Figure 3 ) embodiment. Switching devices 904, 906, 908, 912 and 913 are respectively controlled by controller 322 ( Fig. 9 In some embodiments, each of the switch devices 904, 906, 908, 912 and 912 includes one or more transistors, and each of the switch devices 906, 908, 912 and 912 optionally also includes a driving circuit for driving one or more transistors.

[0054] The input capacitor 902 is electrically coupled between the first input port 312 and the reference node 318, and the switch device 904 is electrically coupled between the first input port 312 and the first switch node 916. The switch device 906 is electrically coupled between the first switch node 916 and the reference node 318, and the inductor 914 is electrically coupled between the first switch node 916 and the second switch node 918. The switch device 908 is electrically coupled between the second switch node 918 and the reference node 318, and the switch device 910 is electrically coupled between the second switch node 918 and the second input port 314. Each switch device 912 is electrically coupled between the first switch node 916 and a corresponding output port 316.

[0055] Controller 322 is configured to generate control signals Φ1, Φ2, Φ3, Φ4, and Φ5 to control the operation of buck-boost converter 900, such as to cause buck-boost converter 900 to operate in one of input energy transfer mode 402, one or more output energy transfer modes 502, and one or more discharge energy transfer modes 702. In some embodiments, controller 322 uses a voltage mode control technique or a current mode control technique to adjust one or more parameters of electrical system 300. Examples of possible parameters that may be adjusted by controller 322 include, for example, voltage V T 、Current I T , voltage V L and current I L The controller 322 may adjust the voltage V in the input energy transfer mode 402. T and / or current I T In addition, the controller 322 may regulate each voltage V in the respective output energy transfer mode 502. L and / or current I L For example, the controller 322 may adjust the voltage V in the output energy transfer mode 502 ( 1 ). L (1), and the controller 322 can adjust the voltage V in the output energy transfer mode 502 (N) L (N). In addition, the controller 322 can adjust each voltage V in the respective discharge energy transfer mode 702. L and / or current I L For example, the controller 322 may adjust the voltage V in the discharge energy transfer mode 702 ( 1 ). L (1), and the controller 322 can adjust the voltage V in the discharge energy transfer mode 702 (N) L (N).

[0056] Each switching device 904-912 of the buck-boost converter 900 is not necessarily used in every energy transfer mode. For example, in some embodiments, the switching device 912 remains in its off state in the input energy transfer mode 402. As another example, in some embodiments, the switching device 904 remains in its off state in any output energy transfer mode 502 and in any discharge energy transfer mode 702. Figure 10-17 Discussed are several examples of how the controller 322 generates control signals Φ1, Φ2, Φ3, Φ4, and Φ5 to control the operation of the buck-boost converter 900. However, it should be understood that the buck-boost converter 900 is not limited to operating according to Figure 10-17 to operate with the example.

[0057] Figure 10-17Each of the assumptions in (a) asserting the control signal when the control signal is in a logic high state, (b) operating the switching device in its on-state (conductive state) when the corresponding control signal of the switching device is asserted, and (c) operating the switching device in its off-state (non-conductive state) when the corresponding control signal of the switching device is de-asserted. For example, in Figure 10-17 In the example of , when in a logic high state, the control signal Φ2 is asserted, the switch device 906 operates in its on state when the control signal Φ2 is asserted, and when the control signal Φ2 is deasserted, the switch device 906 operates in its off state. However, without departing from the scope of this document, the control signal can have other polarities and the switch device can respond to the control signal in other ways.

[0058] Fig.10 Graphs 1000, 1002, 1004, 1006, and 1008 are included, which illustrate an example of the controller 322 generating control signals Φ1, Φ2, Φ3, and Φ4 to operate the buck-boost converter 900 in the input energy transfer mode 402. The switching devices 912 are maintained in their off state in the input energy transfer mode 402, so that Fig.10 The control signal Φ5 is not shown. Graph 1000 shows the relationship between the control signal Φ1 and time, graph 1002 shows the relationship between the controller signal Φ2 and time, graph 1004 shows the relationship between the control signal Φ3 and time, graph 1006 shows the relationship between the controller signal Φ4 and time, and graph 1008 shows the inductor current I ind The relationship between Figures 1000-1008 has a common time base. The controller 322 has a period T a , and in Fig.10 In the example, each cycle T a It is divided into four stages: P1 a 、P2 a 、P3 a and P4 a The controller 322 determines the period T a The relative duration of the phases, for example, to adjust one or more parameters of the electrical system 300. a , switching devices 904 and 908 are in their on-states, and switching devices 906 and 910 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V es , inductor current I ind The inductor 914 is charged by the energy from the energy source 304. a, switching devices 904 and 910 are in their on-states, and switching devices 906 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V bat -V T .exist Fig.10 In the example, the voltage V es Greater than voltage V T , so the current I ind In phase P2 a The upward slope continues, although at a slower rate than in phase P1. a Medium slow. In stage P2 a In phase P3, inductor 914 continues to be charged by energy from energy source 304 and transfers energy to capacitor 306. a , switching devices 906 and 910 are in their on-states, and switching devices 904 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to -V T , and the inductor current I ind Slope downward, e.g. to zero, e.g. Fig.10 As shown. In stage P3 a In phase P4, inductor 914 continues to deliver energy to capacitor 306, but inductor 914 is not charged from energy source 304. a In the phase P4, the switching devices 906 and 908 are in their on-states, and the switching devices 904 and 910 are in their off-states, so that the inductor 914 is short-circuited. a The purpose is, for example, to provide time for the controller 322 to obtain and / or process data.

[0059] Fig.11 Another example is shown where the controller 322 generates the control signals Φ1 , Φ2 , Φ3 , and Φ4 to cause the buck-boost converter 900 to operate in the input energy transfer mode 402 . Fig.11 Including similar to Fig.10 1000, 1002, 1004, 1006 and 1008 of the graphs 1100, 1102, 1104, 1106 and 1108 of the graphs ... b , and in Fig.11 In the example, each cycle T b It is divided into four stages: P1 b 、P2 b 、P3 b and P4 b The controller 322 determines the period T bThe relative duration of the phases, for example, to adjust one or more parameters of the electrical system 300. b , switching devices 904 and 908 are in their on-states, and switching devices 906 and 910 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V es , and the inductor 914 is charged by the energy from the energy source 304. In phase P2 b , switching devices 904 and 910 are in their on-states, and switching devices 906 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V es –V T However, with Fig.10 Compared to the example, the voltage V es Less than Fig.11 The voltage V in the example T , so the current I ind In phase P2 b Inductor 914 is in phase P2 b Energy is delivered to capacitor 306. In phase P3 b , switching devices 906 and 910 are in their on-states, and switching devices 904 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to -V T , and inductor 914 continues to deliver energy to capacitor 306. In phase P4 a In the phase P4, the switching devices 906 and 908 are in their on-states, and the switching devices 904 and 910 are in their off-states, so that the inductor 914 is short-circuited. b The purpose is, for example, to provide time for the controller 322 to obtain and / or process data.

[0060] Fig.12 Additional examples are shown of the controller 322 generating the control signals Φ1 , Φ2 , Φ3 , and Φ4 to cause the buck-boost converter 900 to operate in the input energy transfer mode 402 . Fig.12 Including similar to Fig.10 1000, 1002, 1004, 1006 and 1008. The controller 322 has a period T c , and in Fig.12 In the example, each cycle T c It is divided into four stages: P1 c 、P2 c 、P3 cand P4 c The controller 322 determines the relative durations of the phases of the period Tc, for example, to adjust one or more parameters of the electrical system 300. In phase P1 c , switching devices 904 and 908 are in their on-states, and switching devices 906 and 910 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V es , and the inductor 914 is charged by the energy from the energy source 304. In phase P2 c , switching devices 904 and 910 are in their on-states, and switching devices 906 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V bat –V T However, with Fig.10 and Fig.11 Compared to the example, the voltage V es equal Fig.11 The voltage V in the example T , so the current I ind In phase P2 c Inductor 914 is flat in phase P2 c Energy is delivered to capacitor 306. In phase P3 c , switching devices 906 and 910 are in their on-states, and switching devices 904 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to -V T , and inductor 914 continues to deliver energy to capacitor 306. In phase P4 c In the embodiment of the present invention, switching devices 906 and 908 are in their on-states, and switching devices 904 and 910 are in their off-states, so that inductor 914 is short-circuited. c The purpose is, for example, to provide the controller 322 with time to obtain and / or process data.

[0061] Fig.13 Graphs 1300, 1302, 1304, 1306, and 1308 are included that illustrate one example of a controller 322 that generates control signals Φ4, Φ3, Φ2, and Φ5 (1) to cause the buck-boost converter 900 to operate in the output energy transfer mode 502 (1), wherein the buck-boost converter 900 transfers energy from the second input port 314 to the output port 316 (1). The switch device 904 remains in its off state in the output energy transfer mode 502 (1), and thus the control signal Φ1 is in the off state. Fig.13In addition, in embodiments where N is greater than 1, in output energy transfer mode 502(1), all switching devices 912 except switching device 912(1) also remain in their off state. Fig.13 Control signals Φ5 other than control signal Φ5(1) are not shown.

[0062] Graph 1300 shows the relationship between control signal Φ4 and time, graph 1302 shows the relationship between control signal Φ3 and time, graph 1304 shows the relationship between control signal Φ2 and time, graph 1306 shows the relationship between control signal Φ5(1) and time, and graph 1308 shows the inductor current I ind The relationship between the graphs 1300-1308 and time. The controller 322 has a switching period T d , and in Fig.13 In the example, each cycle T d It is divided into four stages: P1 d 、P2 d 、P3 d and P4 d The controller 322 determines the period T d The relative duration of the phases, for example, to adjust one or more parameters of the electrical system 300. It should be noted that Fig.13 In the example, the inductor current I ind is negative due to the direction of energy flow in output energy transfer mode 502 ( 1 ), ie, energy flows out of capacitor 306 rather than into capacitor 306 in output energy transfer mode 502 ( 1 ).

[0063] In phase P1 d , switching devices 910 and 906 are in their on-states, and switching devices 908 and 912(1) are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to -V T , inductor current I ind The inductor 914 is charged by the energy from the capacitor 306. d , switching devices 910 and 912(1) are in their on-states, and switching devices 908 and 906 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L (1) -V T .exist Fig.13 In the example, the voltage V T Greater than voltage V L (1), so the current I ind In phase P2d The downward slope continues, although at a faster rate than in phase P1. d Medium slow. In stage P2 d , inductor 914 continues to be charged by energy from capacitor 306 and delivers energy to output port 316 (1). However, it will be appreciated that if voltage V L (1) On the contrary, it is greater than the voltage V T , then in stage P2 d In the case of ind will slope up instead of down. In addition, if the voltage V T Equal to voltage V L (1), then the inductor current I ind In phase P2 d In phase P3 d , switching devices 908 and 912(1) are in their on-states, and switching devices 910 and 906 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L (1), and the current I ind Inductor 914 continues to deliver energy to output port 316(1), but in phase P3 d In the phase P4, the inductor 914 is not charged from the capacitor 306. d In the embodiment of the present invention, switching devices 906 and 908 are in their on-states, and switching devices 910 and 912 (1) are in their off-states, so that inductor 914 is short-circuited. d The purpose is to ensure that the inductor 914 provides time for the controller 322 to obtain and / or process data, for example.

[0064] Fig.13 The example of can make the buck-boost converter 900 operate in another output energy conversion mode 502 by switching the control signal Φ5(1) to another control signal Φ5. For example, Fig.13 The example of may be modified to cause the buck-boost converter 900 to operate in the output energy transfer mode 502 (N) by exchanging the control signal Φ5 (1) for the control signal Φ5 (N).

[0065] Fig.14Graphs 1400, 1402, 1404, 1406, and 1408 are included, which illustrate an example of controller 322 generating control signals Φ4, Φ3, Φ2, and Φ5 (1) to cause buck-boost converter 900 to operate in discharge energy transfer mode 702 (1), wherein buck-boost converter 900 transfers energy from output port 316 (1) to second input port 314. Switching device 904 remains in its off state in discharge energy transfer mode 702 (1), and thus control signal Φ1 is not present. Fig.14 In addition, in embodiments where N is greater than 1, in discharge energy transfer mode 702 (1), all switching devices 912 except switching device 912 (1) also remain in their off state. Fig.14 Control signals Φ5 other than control signal Φ5(1) are not shown.

[0066] Graph 1400 shows the relationship between control signal Φ4 and time, graph 1402 shows the relationship between control signal Φ3 and time, graph 1404 shows the relationship between control signal Φ2 and time, graph 1406 shows the relationship between control signal Φ5(1) and time, and graph 1408 shows the relationship between inductor current I ind The relationship between the controller 322 and the time. Figures 1400-1408 have a common time base. The controller 322 has a switching period T e , and in Fig.14 In the example, each cycle T e It is divided into three stages: P1 e 、P2 e and P3 e . Fig.14 The example does not include the inductor current I ind The controller 322 determines the period T e The relative durations of the phases, for example, to adjust one or more parameters of the electrical system 300 .

[0067] In phase P1 e , switching devices 910 and 906 are in their on-states, and switching devices 908 and 912(1) are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to -V T , inductor current I ind The voltage of the capacitor 306 is charged by the energy from the inductor 914. e , switching devices 910 and 912(1) are in their on-states, and switching devices 908 and 906 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L(1) -V T .exist Fig.14 In the example, the voltage V T Greater than voltage V L (1), so the current I ind In phase P2 e The downward slope continues, although at a faster rate than in phase P1. e Inductor 914 is in phase P2 e In phase P3, energy is continuously delivered to capacitor 306 and energy is received from capacitor 310(1). e , switching devices 908 and 912(1) are in their on-states, and switching devices 910 and 906 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L (1), and the current I ind The upward ramp causes inductor 914 to be charged with energy from capacitor 310(1).

[0068] Fig.15 Graphs 1500, 1502, 1504, 1506, and 1508 are included that illustrate another example of controller 322 generating control signals Φ5(1), Φ2, Φ3, and Φ4 to cause buck-boost converter 900 to operate in discharge energy transfer mode 702(1), wherein buck-boost converter 900 transfers energy from output port 316(1) to second input port 314. Switching device 904 remains in its off state in output energy transfer mode 702(1), and thus control signal Φ1 is not present. Fig.15 In addition, in embodiments where N is greater than 1, in discharge energy transfer mode 702 (1), all switching devices 912 except switching device 912 (1) also remain in their off state. Fig.15 Control signals Φ5 other than control signal Φ5(1) are not shown.

[0069] Graph 1500 shows the relationship between control signal Φ5(1) and time, graph 1502 shows the relationship between control signal Φ2 and time, graph 1504 shows the relationship between control signal Φ3 and time, graph 1506 shows the relationship between control signal Φ4 and time, and graph 1508 shows the relationship between inductor current I ind The relationship between Figures 1500-1508 has a common time base. The controller 322 has a period T f , and in Fig.15 In the example, each cycle T f It is divided into four stages: P1 f 、P2 f 、P3f and P4 f The controller 322 determines the period T f The relative duration of the phases, for example, to adjust one or more parameters of the electrical system 300. f , switching devices 912(1) and 908 are in their on-states, and switching devices 906 and 910 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L (1), inductor current I ind The voltage at the input terminal 914 is ramped upward, and the inductor 914 is charged by the energy from the capacitor 310(1). f , switching devices 912(1) and 910 are in their on-states, and switching devices 906 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L (1) -V T .exist Fig.15 In the example, the voltage V L (1) Greater than voltage V T , so the current I ind In phase P2 f The upward slope continues, although at a slower rate than in phase P1. f Inductor 914 is in phase P2 f 310(1) continues to be charged by energy from capacitor 310(1) and transfers energy to capacitor 306. However, it will be appreciated that if voltage V L (1) is smaller than the voltage V T , then the inductor current I ind In phase P2 f In addition, if the voltage V T Equal to voltage V L (1), then the inductor current I ind In phase P2 f In phase P3 f , switching devices 906 and 910 are in their on-states, and switching devices 912(1) and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to -V T In phase P3 f In phase P4, inductor 914 continues to deliver energy to capacitor 306, but inductor 914 does not charge from load capacitor 310(1). fIn the embodiment of the present invention, switching devices 906 and 908 are in their on-states, and switching devices 912(1) and 910 are in their off-states, so that inductor 914 is short-circuited. f The purpose is, for example, to provide the controller 322 with time to obtain and / or process data.

[0070] Fig.14 and Fig.15 The example of can make the buck-boost converter 900 operate in another discharge energy conversion mode 702 by exchanging the control signal Φ5(1) with another control signal Φ5. For example, Fig.15 The example of may be modified to operate the buck-boost converter 900 in the discharge energy transfer mode 702 (N) by exchanging the control signal Φ5 (1) for another control signal Φ5 (N).

[0071] Figure 10-15 The example can be modified, for example, by omitting one or more phases per cycle, adding one or more phases per cycle, changing the inductor current I ind characteristics (for example, making the inductor voltage I ind Continuous, so that the resistor current I ind Discontinuous, making the current meter current I ind change direction, etc.). For example, in Figure 10-15 In some alternative embodiments of the example, the third phase is omitted, for example, when the voltage at the port receiving energy is greater than the voltage at the port providing energy. Fig.16 Additional examples are shown of the controller 322 generating the control signals Φ1 , Φ2 , Φ3 , and Φ4 to cause the buck-boost converter 900 to operate in the input energy transfer mode 402 . Fig.16 An example similar to Fig.11 , but omits the third stage. Fig.16 Including similar to Fig.10 Graphs 1600 , 1602 , 1604 , 1606 and 1608 of graphs 1000 , 1002 , 1004 , 1006 and 1008 .

[0072] The controller 322 has a period T g , and in Fig.16 In the example, each cycle T g It is divided into three stages: P1 g 、P2 g and P4 g The controller 322 determines the period T g The relative duration of the phases, for example, to adjust one or more parameters of the electrical system 300. g, switching devices 904 and 908 are in their on-states, and switching devices 906 and 910 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V es , and the inductor 914 is charged by the energy from the energy source 304. In phase P2 g , switching devices 904 and 910 are in their on-states, and switching devices 906 and 908 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V es –V T Voltage V es Less than Fig.16 The voltage V in the example T , so the current I ind In phase P2 b Inductor 914 is in phase P2. g Energy is delivered to capacitor 306. Fig.16 There is no example similar to stage P3 b ( Fig.11 ) stage. On the contrary, Fig.16 The example immediately starts from stage P2 g Proceed to stage P4 g , where switching devices 906 and 908 are in their on-states and switching devices 904 and 910 are in their off-states, shorting inductor 914. Therefore, Fig.16 Phase P4 g Similar to Fig.11 Phase P4 b .

[0073] As another example of a possible modification to the above example, the fourth stage in which the inductor 914 is short-circuited may be omitted, for example, when the inductor current I ind Continuous case. For example, Fig.17 shows the omission of the fourth stage Fig.13 In particular, Fig.17 Graphs 1700, 1702, 1704, 1706, and 1708 are included, which illustrate another example of the controller 322 generating control signals Φ4, Φ3, Φ2, and Φ5 (1) to cause the buck-boost converter 900 to operate in the output energy transfer mode 502 (1), wherein the buck-boost converter 900 transfers energy from the second input port 314 to the output port 316 (1). The switch device 904 remains in its off state in the output energy transfer mode 502 (1), and thus the control signal Φ1 is not in the output energy transfer mode 502 (1). Fig.17In addition, in the embodiment where N is greater than 1, in the output energy transfer mode 502 (1), all switching devices 912 except the switching device 912 (1) also remain in their off state. Fig.17 Control signals Φ5 other than control signal Φ5(1) are not shown.

[0074] Graph 1700 shows the relationship between control signal Φ4 and time, graph 1702 shows the relationship between control signal Φ3 and time, graph 1704 shows the relationship between control signal Φ2 and time, graph 1706 shows the relationship between control signal Φ5(1) and time, and graph 1708 shows the inductor current I ind The relationship between the controller 322 and the time. The diagrams 1700-1708 have a common time base. The controller 322 has a switching period T h , and in Fig.17 In the example, each cycle T h It is divided into three stages: P1 h 、P2 h and P3 h The controller 322 determines the period T h The relative duration of the phases, for example, to adjust one or more parameters of the electrical system 300. It should be noted that Fig.17 In the example, the inductor current I ind is continuous.

[0075] In phase P1 h , switching devices 910 and 906 are in their on-states, and switching devices 908 and 912(1) are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to -V T , inductor current I ind The inductor 914 is charged by the energy from the capacitor 306. h , switching devices 910 and 912(1) are in their on-states, and switching devices 908 and 906 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L (1) -V T .exist Fig.14 In the example, the voltage V T Greater than voltage V L (1), so the current I ind In phase P2 h The downward slope continues, although at a faster rate than in phase P1. h Medium slow. In stage P2 h, inductor 914 continues to be charged by energy from capacitor 306 and delivers energy to output port 316 (1). However, it will be appreciated that if voltage V L (1) On the contrary, it is greater than the voltage V T , then the inductor current I ind In phase P2 h In addition, if the voltage V T Equal to voltage V L (1), then the inductor current I ind In phase P2 h In phase P3 h , switching devices 908 and 912(1) are in their on-states, and switching devices 910 and 906 are in their off-states. Therefore, the voltage V across inductor 914 is ind Equal to V L (1), and the current I ind Inductor 914 continues to deliver energy to output port 316(1), but in phase P3 h , inductor 914 is not charged from capacitor 306 .

[0076] Reference again Figure 3 In certain embodiments, controller 322 is configured to cause DC-DC converter 320 to switch between energy transfer modes at least in part in response to a magnitude of a voltage and / or current at a port of power management device 302 exceeding a threshold. For example, Fig.18 1 is a state diagram 1800 illustrating how some embodiments of controller 322 cause DC-DC converter 320 to transition between output energy transfer mode 502(1) and input energy transfer mode 402. State diagram 1800 includes two states of DC-DC converter 320, namely, state 1802 in which DC-DC converter 320 operates in output energy transfer mode 502(1) to convert voltage V L (1) Adjust to V ref1 , and state 1804, in which the DC-DC converter 320 operates in the input energy transfer mode 402 to regulate the voltage V T To V ref2 Two state decisions A and B are associated with state 1802, where state decision A has a higher priority than state decision B, such as Fig.18 As shown, state decision A has priority "1" and state decision B has priority "2". Therefore, whenever the voltage V L (1) Less than V ref1 , DC-DC converter 320 remains in output energy transfer mode 502(1). On the other hand, if VL (1) Not less than V ref1 , and the voltage V T Less than V ref2 , the DC-DC converter 320 switches from the output energy transfer mode 502 ( 1 ) to the input energy transfer mode 402 , as shown in the state diagram 1800 .

[0077] In addition, two state decisions C and D are associated with state 1804, where state decision C has a higher priority than state decision D, as shown in FIG. Fig.18 As shown, state decision C has priority "1" and state decision D has priority "2". Therefore, whenever the voltage V L (1) Less than V ref1 , DC-DC converter 320 switches from input energy transfer mode 402 to output energy transfer mode 502 (1). On the other hand, if V L (1) Not less than V ref1 , and the voltage V T Less than V ref2 , the DC-DC converter 320 remains in the input energy transfer mode 402 , as shown in the state diagram 1800 .

[0078] Although state diagram 1800 only addresses transitions between output energy transfer mode 502(1) and input energy transfer mode 402, state diagram 1800 may be modified to address transitions between input energy transfer mode 402 and one or more other output energy transfer modes 502. Additionally, two or more output energy transfer modes 502 may be prioritized. Furthermore, state diagram 1800 may be modified to further include one or more transitions into or out of discharge energy transfer mode 702.

[0079] Reference again Figure 3 In certain embodiments, DC-DC converter 320 can only transfer energy between two ports at a time. Differently, in these embodiments, DC-DC converter 320 can only operate in one energy transfer mode at a time. For example, DC-DC converter 320 cannot operate in output energy transfer mode 502(1) and simultaneously operate in input energy transfer mode 402. As another example, DC-DC converter 320 cannot operate in output energy transfer mode 502(N) and simultaneously operate in output energy transfer mode 502(1) (unless the corresponding voltage V L (N) and V LSometimes, two or more ports of the power management device 302 require energy at a common time, and one port must wait for the other port to be serviced, i.e., wait for energy to be transferred to the other port before receiving energy via the DC-DC converter 320, thereby causing crosstalk between the ports.

[0080] For example, Fig.19 The three graphs 1900, 1902 and 1904 show that the controller 322 is configured according to Fig.18 The state diagram 1800 is an example of the operation of the electrical system 300 in an embodiment of the present invention. The graph 1900 is a graph of the voltage V L (1) Relationship with time, curve 1902 is voltage V T vs. time, and graph 1904 is the inductor current I ind Relationship with time. Fig.19 As shown, although the voltage V L The average value of (1) is approximately equal to V ref1 , but the crosstalk associated with servicing the second input port 314, i.e., operating the DC-DC converter 320 in the input energy transfer mode 402 to charge the capacitor 306, may be at a voltage V L (1) produces significant ripples.

[0081] Crosstalk can be mitigated by delaying transitions between energy transfer modes until a predetermined timeout period has expired. Fig. 20 is state diagram 2000, which is an alternative embodiment of state diagram 1800, including additional conditions for transitioning from output energy transfer mode 502(1) to input energy transfer mode 402. Specifically, not only V L (1) Must be no less than V ref1 And V T Must be less than V ref2 , and a predetermined timeout period must have expired before the DC-DC converter 320 switches from the output energy transfer mode 502(1) to the input energy transfer mode 402. As specified by Equation 3, such a timeout period may reduce the voltage V L (1) The crosstalk noise V noise , where V ripple is the voltage V L (1) Ripple, W pulse is the switching period of the DC-DC converter 320 in the input energy transfer mode 402, and T timeout is the predetermined timeout period.

[0082]

[0083] Fig.21 The three graphs 2100, 2102 and 2104 show that the controller 322 is configured according to Fig. 20 The state diagram 2000 is an example of the operation of the electrical system 300 in an embodiment of the present invention. The graph 2100 is a graph of the voltage V L (1) vs. time, curve 2102 is voltage V T vs. time, and graph 2104 is the inductor current I ind When the curve 2100 is compared with the curve 1900 ( Fig.19 ) is compared, it is apparent that the implementation of the timeout period in state diagram 2000 significantly reduces the voltage V L (1) The ripple is at the expense of voltage V T The greater change is when curve 2102 is compared with curve 1902 ( Fig.19 ).

[0084] Feature combination

[0085] The above features can be combined in various ways without departing from the scope of this document. The following examples illustrate some possible combinations.

[0086] (A1) A power management device comprising multiple input ports, the power management device comprising: (1) a first input port configured to be electrically coupled to an energy source, (2) a second input port configured to be electrically coupled to a first capacitor, (3) a first output port configured to be electrically coupled to a first load; and (4) a direct current-to-direct current (DC-DC) converter configured to: (i) charge the first capacitor using energy from the energy source; and (ii) provide energy to the first output port at least partially using energy stored in the first capacitor.

[0087] (A2) In the power management device denoted as (A1), the DC-DC converter may be further configured to transfer energy stored in the second capacitor to the first capacitor, wherein the second capacitor is electrically coupled to the first output port.

[0088] (A3) In the power management device represented as (A2), the DC-DC converter can be further configured to: (1) charge the first capacitor using energy from the energy source; (2) provide energy to the first output port at least partially using the energy stored in the first capacitor; and (3) transfer energy from the second capacitor to the first capacitor using a common inductor of the DC-DC converter.

[0089] (A4) In either of the power management devices represented as (A1) or (A2), the DC-DC converter can be further configured to: (1) charge the first capacitor using energy from the energy source; and (2) use a common inductor of the DC-DC converter to provide energy to the first output port at least partially using the energy stored in the first capacitor.

[0090] (A5) Any one of the power management devices represented as (A1) to (A4) may further include a second output port, and the DC-DC converter may be further configured to provide energy to the second output port at least partially using energy stored in the first capacitor.

[0091] (A6) In any one of the power management devices represented as (A1) to (A5), the DC-DC converter may include: (1) a first switching device electrically coupled between the first input port and a first switching node, (2) a second switching device electrically coupled between the first switching node and a reference node, (3) an inductor electrically coupled between the first switching node and the second switching node, (4) a third switching device electrically coupled between the second switching node and the reference node, (5) a fourth switching device electrically coupled between the second switching node and the second input port, and (6) a fifth switching device electrically coupled between the first switching node and the first output port.

[0092] (A7) In any of the power management devices denoted as (A1) to (A6), the DC-DC converter may include a buck-boost converter.

[0093] (B1) A method for supplying power to one or more loads using a power management device, comprising: (1) using an inductor of a first direct current-to-direct current (DC-DC) converter to charge a first capacitor using energy from an energy source, (2) using the inductor of the first DC-DC converter to provide energy to a first load from energy stored in the first capacitor, and (3) using the inductor of the first DC-DC converter to transfer energy stored in a second capacitor to the first capacitor, wherein the second capacitor is electrically coupled to the first load.

[0094] (B2) The method denoted as (B1) may further include limiting the magnitude of current flowing from the energy source to the first capacitor when charging the first capacitor using energy from the energy source.

[0095] (B3) In either of the methods denoted as (B1) or (B2), the magnitude of the voltage across the first capacitor may be greater than the magnitude of the voltage across the energy source.

[0096] (B4) Any of the methods denoted as (B1) to (B3) may further include supplying energy to the first load from energy stored in the first capacitor in response to a voltage at the first load crossing a first threshold.

[0097] (B5) Any of the methods denoted as (B1) to (B4) may further include charging the first capacitor using energy from an energy source in response to both (1) a voltage of the first capacitor crossing a second threshold and (2) expiration of a timeout period.

[0098] (B6) Any of the methods denoted as (B1) to (B5) may further include supplying energy to a second load from energy stored in the first capacitor using an inductor of the first DC-DC converter.

[0099] (B7) The method represented as (B6) may further include transferring energy stored in a third capacitor to the first capacitor using an inductor of the first DC-DC converter, wherein the third capacitor is electrically coupled to the second load.

[0100] (B8) In any of the methods represented by (B1) to (B7), the energy source may include a battery.

[0101] (B9) In any of the methods denoted as (B1) to (B8), the energy source may include a buck-boost converter.

[0102] (C1) An electrical system comprising (1) an energy source, (2) a first capacitor, (3) a first load, and (4) a power management device. The power management device comprises (i) a first input port electrically coupled to the energy source, (ii) a second input port electrically coupled to the first capacitor, (iii) a first output port electrically coupled to the first load, and (iv) a direct current-to-direct current (DC-DC) converter configured to (a) charge the first capacitor from energy of the energy source, and (b) provide energy to the first load at least partially using energy stored in the first capacitor.

[0103] (C2) In the electrical system denoted as (C1), the DC-DC converter may be further configured to transfer energy stored in a second capacitor to the first capacitor, wherein the second capacitor is electrically coupled to the first load.

[0104] (C3) In the electrical system represented as (C2), the DC-DC converter can be further configured to: (a) charge the first capacitor from energy from an energy source, (b) provide energy to the first load at least partially using energy stored in the first capacitor, and (c) transfer energy from the second capacitor to the first capacitor using a common inductor of the DC-DC converter.

[0105] (C4) In either of the electrical systems represented as (C1) or (C2), the DC-DC converter can be further configured to: (a) charge the first capacitor from energy from an energy source and (b) use a common inductor of the DC-DC converter to provide energy to the first load at least partially using the energy stored in the first capacitor.

[0106] (C5) In any one of the electrical systems represented as (C1) to (C4), (1) the electrical system may further include a second load, and (2) the DC-DC converter may be further configured to provide energy to the second load at least partially using the energy stored in the first capacitor.

[0107] (C6) In any one of the electrical systems represented as (C1) to (C5), the DC-DC converter may include: (1) a first switching device electrically coupled between an energy source and a first switching node, (2) a second switching device electrically coupled between the first switching node and a reference node, (3) an inductor electrically coupled between the first switching node and the second switching node, (4) a third switching device electrically coupled between the second switching node and the reference node, (5) a fourth switching device electrically coupled between the second switching node and the first capacitor, and (6) a fifth switching device electrically coupled between the first switching node and a first load.

[0108] (C7) Any of the electrical systems represented as (C1) to (C6) may further include a controller configured to control operation of the DC-DC converter based at least in part on (a) a voltage across the first capacitor and (b) a voltage at the first load.

[0109] (C8) In any of the electrical systems represented as (C1) to (C7), the energy source may include a battery.

[0110] (C9) In any one of the electrical systems denoted as (C1) to (C8), the DC-DC converter may include a buck-boost converter.

[0111] Changes may be made to the above methods, devices, and systems without departing from the scope of this document. It should therefore be noted that the matter contained in the above description and shown in the accompanying drawings should be interpreted as illustrative and not restrictive. The following claims are intended to cover all statements of the general and specific features described herein, as well as the scope of the present methods and systems, which, as a matter of language, may be considered to fall between them.

Claims

1. A power management device comprising a plurality of input ports, the power management device comprising: a first input port configured to be electrically coupled to an energy source; a second input port configured to be electrically coupled to the first capacitor; A first output port configured to be electrically coupled to a first load; and A DC-DC converter configured to: charging the first capacitor using energy from the energy source, and Energy is provided to the first output port at least in part using energy stored in the first capacitor. 2 . The power management device of claim 1 , wherein the DC-DC converter is further configured to transfer energy stored in a second capacitor to the first capacitor, the second capacitor being electrically coupled to the first output port.

3. A power management device according to claim 2, wherein the DC-DC converter is further configured to: (a) charge the first capacitor using energy from the energy source; (b) provide energy to the first output port at least partially using the energy stored in the first capacitor; and (c) transfer energy from the second capacitor to the first capacitor using a common inductor of the DC-DC converter.

4. A power management device according to claim 1, wherein the DC-DC converter is further configured to (a) charge the first capacitor using energy from the energy source; and (b) use a common inductor of the DC-DC converter to provide energy to the first output port at least partially using energy stored in the first capacitor. 5 . The power management device of claim 1 , further comprising a second output port, wherein the DC-DC converter is further configured to provide energy to the second output port at least partially using energy stored in the first capacitor.

6. The power management device according to claim 1, wherein the DC-DC converter comprises: a first switching device electrically coupled between the first input port and a first switching node; a second switching device electrically coupled between the first switching node and a reference node; an inductor electrically coupled between the first switch node and the second switch node; a third switching device electrically coupled between the second switching node and the reference node; a fourth switching device electrically coupled between the second switching node and the second input port; and A fifth switching device is electrically coupled between the first switching node and the first output port.

7. The power management device of claim 1, wherein the DC-DC converter comprises a buck-boost converter.

8. A method for supplying power to one or more loads using a power management device, the method comprising: charging a first capacitor using energy from an energy source using an inductor of a first direct current to direct current (DC-DC) converter; providing energy to a first load from energy stored in the first capacitor using an inductor of the first DC-DC converter; and Energy stored in a second capacitor is transferred to the first capacitor using an inductor of the first DC-DC converter, the second capacitor being electrically coupled to the first load.

9. The method of claim 8, further comprising limiting the magnitude of current flowing from the energy source to the first capacitor when charging the first capacitor using energy from the energy source.

10. The method of claim 8, wherein the magnitude of the voltage across the first capacitor is greater than the magnitude of the voltage across the energy source.

11. The method of claim 8, further comprising providing energy to the first load from energy stored in the first capacitor in response to a voltage at the first load crossing a first threshold.

12. The method of claim 8, further comprising charging the first capacitor using energy from the energy source in response to both (a) a voltage of the first capacitor crossing a second threshold and (b) expiration of a timeout period.

13. The method of claim 8, further comprising providing energy to a second load from energy stored in the first capacitor using an inductor of the first DC-DC converter.

14. The method of claim 13, further comprising transferring energy stored in a third capacitor to the first capacitor using an inductor of a first DC-DC converter, the third capacitor being electrically coupled to the second load.

15. The method of claim 8, wherein the energy source comprises a battery.

16. The method of claim 8, wherein the first DC-DC converter comprises a buck-boost converter.

17. An electrical system comprising: Energy source; a first capacitor; First load; and A power management device, the power management device comprising: electrically coupled to a first input port of the energy source, electrically coupled to a second input port of the first capacitor, a first output port electrically coupled to the first load, and A direct current-to-direct current (DC-DC) converter is configured to: (a) charge the first capacitor from energy from an energy source; and (b) provide energy to the first load using at least in part the energy stored in the first capacitor.

18. The electrical system of claim 17, wherein the DC-DC converter is further configured to transfer energy stored in a second capacitor to the first capacitor, the second capacitor being electrically coupled to the first load.

19. An electrical system according to claim 18, wherein the DC-DC converter is further configured to: (a) charge the first capacitor from energy from an energy source; (b) provide energy to the first load using at least in part the energy stored in the first capacitor; and (c) transfer energy from the second capacitor to the first capacitor using a common inductor of the DC-DC converter.

20. The electrical system of claim 17, wherein the DC-DC converter is further configured to: (a) charge the first capacitor from energy from an energy source; and (b) provide energy to the first load using, at least in part, energy stored in the first capacitor using a common inductor of the DC-DC converter.

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