Parallel charger thermal regulation systems and methods

Abstract

Circuits and methods are provided that more effectively and efficiently implement a parallel charging circuit. First and second charging circuits are configured in parallel between a power supply and a load. A controller circuit monitors temperature signals received from the first and second charging circuits and controls the relative charging currents sourced by each of the first and second charging circuits to maintain temperature balance between them, and to ensure that the first and second charging circuits reach their respective maximum thermal temperatures at the same time.

Description

Docket No.61658.58WO01 Client Ref. No. PER-551-PCT PARALLEL CHARGER THERMAL REGULATION SYSTEMS AND METHODS Inventor: Antony Routledge CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 559,136 filed February 28, 2024 and entitled “PARALLEL CHARGER THERMAL REGULATION SYSTEMS AND METHODS,” which is incorporated herein by reference in its entirety. BACKGROUND

[0002] This disclosure relates to electronic circuits, and more particularly for example to parallel charging circuits.

[0003] Many electronic products, including mobile computing and / or communication products and components (e.g., smartphones, notebook computers, ultra-book computers, tablet devices, LCD, LED displays, and the like) use re-chargeable batteries as a power source. A charging circuit is usually incorporated onboard such electronic products to control periodic charging of the re-chargeable battery.

[0004] Users of such electronic products typically wish to re-charge such batteries as quickly as possible, which, in turn, requires increased charging current. In traditional battery charging systems, increased battery charging current is usually associated with using larger chargers, or coupling two or more chargers in parallel. It is now common to supply voltage and current to such onboard charging circuits from a so-called Programmable Power Supply, or “PPS”. The PPS adjusts its voltage and / or current based upon the needs of the charging circuit driven thereby.

[0005] It is also common for charging circuits to trigger a reduction in current being sourced to the load when the charging circuit temperature reaches a predetermined temperature. Such a reduction in current may be implemented directly by the charging circuit itself (when the charging circuit is regulated, for example, a buck converter) or by signaling the PPS to decrease the amount of power being provided by the PPS (which works even for unregulated charging circuits, for example, charge pumps). This process of reducing current sourced by the charging circuit upon reaching a high temperature, either by self-reduction or by reducingDocket No.61658.58WO01 Client Ref. No. PER-551-PCT power supplied by the PPS to the charging circuit, is known as “thermal throttling”, and is sometimes required to maintain a safe operating temperature for the charging circuit. Alternatively, thermal throttling of the charging circuit may be desirable merely to prevent the electronic product from exhibiting an excessive “skin temperature”, i.e., becoming so warm that it becomes uncomfortable to a user holding such electronic product against the user’s skin.

[0006] If two like charging circuits are coupled in parallel to provide increased charging current, and if each such charging circuit provides essentially the same current, then the two charging circuits will generate approximately the same amount of heat. For example, if a 10A charging current is required to charge a battery or other load, then two identical buck chargers could be arranged in parallel, each set to deliver 5A to the load. As the two buck chargers are virtually identical to each other, at least to a first order, then the thermal characteristics of each buck charger would be the same, and each such buck charger will heat up by the same amount, with perhaps small differences due to process variations and / or mounting location within a product.

[0007] However, if two different types of charging circuits are operated in parallel, for example, a more efficient charge pump charging circuit is used in parallel with a less efficient buck converter charging circuit, then the higher-efficiency charge pump would dissipate less power (and create less heat) for a given amount of charging current compared to the buck converter. A controller is used to interface the two charging circuits with the PPS. One could try to configure the controller to split the load charging current, as between the charge pump and the buck converter, in a manner that would source more charging current from the charge pump than from the buck converter, and thereby even out the dissipated heat. For example, the controller could be configured to direct the buck converter to provide 3.5A, with another 6.5A being provided by the charge pump, thereby totalling to the 10A of current being supplied to the load. However, the thermal characteristics and power losses of the two charging circuits may change as the battery charges. Likewise, thermal characteristics and power losses of the two charging circuits may change with current load, temperature, process corners, and other factors. Inevitably, the result is that one of the two parallel charging circuits will reach its maximum operating temperature before the other, whereby only one of such charging circuits reaches its thermal limit. If this happens, the controller will signal the PPS to reduce supplied current in order to reduce the temperature in the charging circuit that has reached its thermalDocket No.61658.58WO01 Client Ref. No. PER-551-PCT limit. This will in turn reduce current being supplied to the load, even though the other charging circuit may well be considerably cooler than its own thermal limit.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT SUMMARY

[0008] Embodiments of the present disclosure include systems, circuits, and methods for operating and implementing various electronics circuits, including parallel charging circuits.

[0009] One embodiment encompasses a circuit including a first charging circuit having a first terminal configured to receive a current and voltage from a power supply, a second ter- minal configured to source a first charging current to a load, a third terminal configured to provide a first temperature signal related to the temperature of the first charging circuit, and a fourth terminal configured to receive a first control signal, wherein the first charging circuit is configured to be responsive to the first control signal and further configured to control a mag- nitude of the first charging current. A second charging circuit has a first terminal configured to receive current and voltage from the power supply voltage, a second terminal configured to source a second charging current to the load, and a third terminal configured to provide a sec- ond temperature signal related to the temperature of the second charging circuit. A controller circuit is configured to receive the first temperature signal and the second temperature signal, and is configured to provide the first control signal to the fourth terminal of the first charging circuit. The controller circuit is configured to adjust the first control signal based, at least in part, on the first temperature signal and the second temperature signal.

[0010] Another embodiment encompasses a circuit including a first charging circuit hav- ing a first terminal configured to receive current and voltage from a power supply, a second terminal configured to source a first charging current to a load, and a third terminal config- ured to receive a control signal, wherein the first charging circuit is configured to be respon- sive to the control signal and configured to control a magnitude of the first charging current. A first temperature sensor is configured to provide a first temperature signal related to the temperature of the first charging circuit. A second charging circuit has a first terminal con- figured to receive current and voltage form the power supply, and a second terminal config- ured to source a second charging current to the load. A second temperature sensor is config- ured to provide a second temperature signal related to the temperature of the second charging circuit. A controller circuit is configured to receive the first temperature signal and the sec- ond temperature signal, and is configured to provide the control signal to the third terminal of the first charging circuit. The controller circuit is configured to adjust the control signal based, at least in part, on the first temperature signal and the second temperature signal.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT

[0011] Another embodiment encompasses a method which includes of operating a plural- ity of parallel charging circuits, including operating a first charging circuit coupled to a pro- grammable power supply and sourcing a first charging current to a load, the first charging current being adjustable. The method also includes operating a second charging circuit cou- pled to the programmable power supply and sourcing a second charging current to the load, the second charging circuit being operated in parallel with the first charging circuit. The method includes obtaining a first temperature signal related to the temperature of the first charging circuit, and obtaining a second temperature signal related to the temperature of the second charging circuit. The method further includes adjusting the first charging current based, at least in part, in response to the first and second temperature signals.

[0012] The scope of the present disclosure is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the present disclosure will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly. DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a simplified circuit block diagram illustrating first and second charging circuits arranged in parallel for supplying current to a load.

[0014] FIG.2 is a block diagram illustrating two or more parallel charging circuits used to charge a load under the control of a controller circuit in accordance with one or more embodiments of the present disclosure.

[0015] FIG.3 is a simplified flow chart illustrating a method of operating first and second parallel charging circuits in accordance with one or more embodiments of the present disclosure.

[0016] FIG. 4 is a flow chart illustrating a method of operating first and second parallel charging circuits and maintaining the temperatures of the first and second charging circuits equal to each other in accordance with one or more embodiments of the present disclosure.

[0017] FIG. 5 is a flow chart illustrating a method of operating first and second parallel charging circuits and maintaining the temperatures of both the first and second charging circuitsDocket No.61658.58WO01 Client Ref. No. PER-551-PCT below specified maximum temperatures in accordance with one or more embodiments of the present disclosure.

[0018] Embodiments of the present disclosure and their advantages are best understood by referring to the detailed description that follows. It is noted that sizes of various compo- nents and distances between these components are not drawn to scale in the figures. It should be appreciated that like reference numerals are used to identify like elements illustrated in one or more of the figures. DETAILED DESCRIPTION

[0019] The present disclosure encompasses novel circuits, architectures, systems, and methods that more effectively and efficiently address the operation and control of parallel charging circuits.

[0020] Figs. 1-5 illustrate various embodiments of parallel charging circuits for battery charging applications, such as single cell Li-ion and Li-polymer battery applications. It will be appreciated that various improvements disclosed herein encompass innovative circuits, hardware components, architectures, and related logic that are applicable to applications beyond the charging of batteries, and that extend to driving other types of loads as well. Such improvements can also be used to discharge batteries, as when the voltage on a storage battery is “boosted” back to a higher voltage.

[0021] In Fig.1, power supply 102 includes a voltage source 104 and a current source 106. Power supply 102 includes a regulator, or “brain”, adapted to selectively adjust the voltage and current supplied by power supply 102. The power supply 102 shown in Fig. 1 is a so-called programmable power supply, or “PPS”, of the type compatible with the USB PD 3.0 standard adopted by the USB Implementers Forum (USB-IF), also known as the “PPS fast charging” standard. Power supplies meeting this standard are able to adjusts their voltage and current in real-time, depending on the status of the device being charged, with the objective of supplying maximum power in a safe manner. While a PPS power supply is suitable for use in the disclosed embodiments, other power supply systems (e.g., AVS systems) capable of adjusting supplied voltage and current in accordance with the needs of the device being driven may also be used.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT

[0022] Still referring to Fig. 1, a first charging circuit 112 and a second charging circuit 114 are arranged in parallel with each other. Both first charging circuit 112 and second charging circuit 114 are coupled to power supply 102 via line 108 receiving voltage Vin and current Iin. The current sourcing output terminals of first charging circuit 112 and second charging circuit 114 are coupled to node 126 for supplying output charging current Iout to battery 118. As shown in Fig.1, first charging circuit 112 supplies charging current Iout1, and second charging circuit 114 supplies charging current Iout2.

[0023] As mentioned above, it is possible to make the first and second charging circuits identical to each other. For example, both first charging circuit 112 and second charging circuit 114 could be buck converters, each supplying one-half of the total charging current Iout. However, buck converters exhibit greater power losses as compared with other types of switched power converters. For example, charge pumps typically have lower power losses as compared to buck converters. Thus, for a given amount of output current, a charge pump will generate less heat than a buck converter sourcing the same amount of output current. On the other hand, if the first charging circuit is provided as a buck converter, and the second charging circuit is a charge pump, then the first and second charging circuits are likely to be at different temperatures, and one of them is likely to reach its maximum temperature before the other one does. In such a case, the power supply 102 is signaled to throttle back the input current Iin, and the charging current Iout will decrease, even though only one of the two charging circuits has reached its maximum temperature. In some cases, the overall skin temperature of the product (smartphone, laptop, etc.) is a function (e.g., average) of the temperatures of the first and second charging circuits, and thus, the maximum skin temperature can be reached even though only one of the two charging circuits is at an elevated temperature.

[0024] Now referring to Fig. 2, power supply 102 is the same as in Fig. 1. First charging circuit 212 and second charging circuit 214 are again arranged in parallel with each other. First charging circuit 212 has a first terminal coupled to power supply node 108 for receiving current and voltage from power supply 102. First charging circuit 212 includes a second terminal for sourcing first charging current Iout1 to output node 226 and to battery 118 which serves as the load. First charging circuit 212 also includes a third terminal, shown coupled to line 220, for providing a first temperature signal that is related to the temperature of first charging circuit 212. This first temperature signal may be generated onboard first charging circuit 212; for example, if first charging circuit 212 is formed as an integrated circuit, then a temperatureDocket No.61658.58WO01 Client Ref. No. PER-551-PCT sensor circuit can be included on the same integrated circuit die. If desired, the analog temperature signal provided by such temperature sensor can be converted into a digital format through use of an onboard analog-to-digital converter. Alternatively, it should be appreciated that the first temperature signal may be generated by a discrete temperature sensor that is located proximate to first charging circuit 212 but not fabricated on the same integrated circuit die. For example, the first temperature signal may be provided via a thermocouple secured to the package of first charging circuit 212. It should also be noted that the first temperature signal need not be an absolute temperature measurement (proportional to degrees Fahrenheit or degrees Centigrade), but may instead be a representation of the relative magnitude of the temperature and / or a representation of one of several temperature ranges.

[0025] First charging circuit 212 also includes a fourth terminal, shown in Fig. 2 as being coupled to line 224, configured to receive a first control signal. First charging circuit 212 is responsive to the first control signal received via line 224 for controlling the magnitude of the first charging current Iout1 sourced by first charging circuit 212 based at least partially on the first control signal. For example, if first charging circuit 212 is a buck converter, then this first control signal might correspond to a pulse width modulation signal that determines how much current the buck converter will source. By adjusting the control signal received via line 224, the magnitude of charging current Iout1 sourced by first charging circuit 212 can be regulated, i.e., increased, decreased, or maintained constant at any given time.

[0026] Also shown in Fig. 2 is second charging circuit 214. Second charging circuit 214 has a first terminal coupled to node 108 for receiving current and voltage from power supply 102. Second charging circuit 214 also includes a second terminal coupled to output node 226 for sourcing a second charging current Iout2 to battery 118. In addition, like first charging circuit 212, second charging circuit 214 includes a third terminal shown coupled to line 222 for providing a second temperature signal related to the temperature of second charging circuit 214. The second temperature signal may be generated onboard second charging circuit 214; if second charging circuit 214 is formed as an integrated circuit, then a temperature sensor circuit can be included on the same integrated circuit die. As in the case of the first charging circuit 212, the analog temperature signal provided by such temperature sensor can be converted into a digital format through use of an analog-to-digital converter fabricated on the second charging circuit integrated circuit die. Alternatively, it should be appreciated that the second temperature signal may be generated by a discrete temperature sensor that is located proximate to secondDocket No.61658.58WO01 Client Ref. No. PER-551-PCT charging circuit 214 but not fabricated on the same integrated circuit die. For example, the second temperature signal may be provided via a thermocouple secured to the package of second charging circuit 214. Once again, it will be appreciated that the second temperature signal need not be an absolute temperature measurement (proportional to degrees Fahrenheit or degrees Centigrade), but may instead be a representation of the relative magnitude of the temperature and / or a representation of one of several temperature ranges.

[0027] Second charge circuit 214 may be a charge pump. A charge pump is generally unlimited in the amount of output current that it can provide when operated in a fixed voltage division mode. In this case, the charge pump of second charge circuit 214 will supply whatever portion of the total input current Iin is not already being claimed by the first charging circuit 212. On the other hand, if second charging circuit 214 were a second buck converter, then it could include its own control terminal, shown in Fig. 2 as being coupled to dashed line 228, for receiving its own control signal for regulating the amount of charging current Iout2 sourced thereby.

[0028] Still referring to Fig.2, a controller circuit 216 is provided, for among other rea- sons, to control the division of total output charging current Iout as between first charging cir- cuit 212 (Iout1) and second charging circuit 214 (Iout2). While controller circuit 216 is shown as a separate block in Fig.2, it should be appreciated that controller circuit 216 may be incorporated onto the same integrated circuit as either first charging circuit 212 or second charging circuit 214. Controller circuit 216 has a first terminal coupled, via line 220, to the third terminal of first charging circuit 212 to receive the first temperature signal therefrom. Controller circuit 216 has a second terminal coupled, via line 222, to the third terminal of sec- ond charging circuit 214 for receiving the second temperature signal therefrom. Controller circuit 216 also includes a third terminal, shown in Fig.2 coupled to line 224, for providing the first control signal to the fourth terminal of first charging circuit 212. Controller circuit 216 is configured to adjust the first control signal, carried by line 224, based, at least in part, on the first temperature signal and the second temperature signal. Controller circuit 216 is also coupled to power supply 102 via line 210. Under the PPS protocol, power supply 102 and the device being supplied (in this case, first and second charging circuits 212 and 214) need to communicate with each other regarding the level of voltage and / or current to be sup- plied. This communication may include a request to increase provided current or to decreaseDocket No.61658.58WO01 Client Ref. No. PER-551-PCT provided current (as in the case where thermal maximums are being reached in the device be- ing supplied. Controller circuit 216 is continuously aware of the total charging current Iout (either by directly monitoring the current Iout to battery 118 or by monitoring the Iout1 and Iout2 charging currents and summing them together. Controller 216 is able to signal power supply 102 to request a decrease in current if at least one of the charging circuits has reached or exceeded its thermal maximum operating temperature, thereby causing thermal throttling.

[0029] If first charging circuit 212 is a buck converter, and if second charging circuit 214 is a charge pump, then controller circuit 216 can thereby monitor the first temperature signal and the second temperature signal and make adjustments to the first charging current Iout1 that will produce corresponding, but opposite, changes to the second charging current Iout2; this is simply because the total incoming current Iin is fixed by power supply 102, the total output charging current Iout is also fixed, and the charge pump will source that portion of the total charging current Iout that is not already being sourced by the buck converter. In this manner, controller circuit 216 can manipulate the first charging current Iout1, via the control signal transmitted by control line 224, to balance the first and second temperatures. The total charging current Iout sourced to battery 118 will remain essentially the same (in reality, there may be small current differences in total charging current Iout as current share is shifted be- tween the buck converter and charge pump due to differences in the relative power conver- sion efficiencies of buck converters versus charge pumps), but the respective charging cur- rents sourced by the buck converter (first charging circuit 212) and the charge pump (second charging circuit 214) can be varied to keep the first and second temperatures (i.e., the temper- atures of the first and second charging circuits 212 and 214) in balance and approximately equal to each other. The result is that the first and second charging circuits 212 and 214 will reach their respective maximum operating temperatures at the same time, thereby maximizing the charging current supplied to battery 118. In this way, maximum charging current Iout is supplied irrespective of process corner difference, changes in Vin, changes in Vout, changes in output charging current Iout; the power supply 102 will not be signaled to impose thermal throttling until both the first charging circuit 212 and the second charging circuit 214 both reach their thermal maximum limits.

[0030] As noted earlier, Fig.2 may also be used to illustrate a scenario in which both first charging circuit 212 and second charging circuit 214 are buck converters. In this case, the first control signal provided on line 224 controls the first charging current Iout1, and the secondDocket No.61658.58WO01 Client Ref. No. PER-551-PCT control signal provided on dashed line 228 controls the second charging current Iout2. Even though the two charging circuits are virtually identical to each other, the placement of such charging circuits within a product package could result in different operating temperatures even when the charging circuits are sourcing the same amount of charging current (i.e., Iout1 is equal to Iout2). This difference in temperatures might result, for example, because the first charging circuit 212 is physically located closer to battery 118, which itself heats up during charging. Alternatively, the second charging circuit 214 might be running cooler because it is physically located closer to a heat sink that is drawing away generated heat. In this case, controller circuit 216 can be used to regulate the relative currents sourced by each of first and second charging circuits 212 and 214 to ensure that both devices reach the maximum thermal limit temperature at the same time to ensure maximum charging current to battery 118. It should also be appreciated that the disclosed embodiments may be advantageous even in those cases wherein the first and second charging circuits 212 and 214 are fabricated upon the same integrated circuit die, since thermal variations may nonetheless result due to process variations and heat concentrations within a single integrated circuit die.

[0031] Still referring to Fig.2, a third charging circuit 230 could be added in parallel with first and second charging circuits 212 and 214 if desired. In this case, third charging circuit 230 has a first terminal coupled to node 108 to receive current and voltage from power supply 102, and a second terminal configured to source a third charging current to the load via line 234. Third charging circuit 230 includes a third terminal, shown in Fig.2 coupled to dashed line 236, configured to provide a third temperature signal related to the temperature of third charging circuit 230. If third charging circuit 230 is a buck converter or similar power con- verter that sources output current that can be controlled, then third charging circuit 230 may also include a control terminal, shown in Fig.2 coupled to dashed line 238, for receiving a control signal used to regulate the magnitude of the charging current being supplied by third charging circuit 230 based at least partially on the control signal transmitted via dashed line 238. In this case, controller circuit 216 is coupled to third charging circuit 230 via dashed line 236 for receive the third temperature signal. Controller 216 may then monitor the tem- peratures of all three charging circuits and adjust the relative charging currents being supplied by the first, second and third charging circuits based, at least in part, on the first temperature signal, the second temperature signal, and the third temperature signal. Controller 216 can adjust the charging currents being supplied by charging circuits 212, 214 and 230 by making adjustments to one or more of the control signals transmitted along lines 224, 228 and 238, allDocket No.61658.58WO01 Client Ref. No. PER-551-PCT in accordance with the first temperature signal (line 220), the second temperature signal (line 222), and the third temperature signal (line 236). The same considerations could be applied to monitor and control any number of parallel charging circuits added to the system beyond third charging circuit 230.

[0032] Fig.3 illustrates a method of operating parallel first and second charging circuits, e.g., charging circuits 212 and 214 of Fig.2. Block 300 represents a starting point, and con- trol then flows to block 302 where the first charging circuit 212 is set to provide an initial value of a first charging current Iout1. At block 304, the controller circuit exchanges a “handshake” communication with the programmable power supply 102 to set the initial volt- age and current to be supplied by the power supply. Control then flows to block 306 wherein the value of the second charging current Iout2 is determined. In the case where the first charging circuit 212 is a buck converter, and the second charging circuit 214 is a charge pump, the charge pump attempts to source as much current as is available from power supply 102, less the amount of current already being sourced by the buck converter. In other words, Iout2 will be the load current Iout less Iout1. On the other hand, if the second charging cir- cuit 214 is a second buck converter, the controller can set an initial value for Iout2. Control then passes to block 308, in which the controller circuit 216 obtains a first temperature signal T1 from the first charging circuit 212, and obtains a second temperature signal T2 from the second charging circuit 214. At block 310, controller 216 determines whether the buck con- verter of first charging circuit 212 needs to be adjusted to increase, decrease, or hold constant, the first charging current Iout1 in order to maintain a desired balance of temperatures (T1 and T2) between the first and second charging circuits. Control then flows back to block 304 for an updated “handshake” with the programmable power supply, and the described steps 306, 308, and 310 are repeated.

[0033] Thus, if the first charging circuit 212 is configured as an integrated circuit and has a first maximum operating temperature associated therewith, and if the second charging cir- cuit 214 is configured as a second integrated circuit and has a second maximum operating temperature associated therewith, then operating controller circuit 216 in accordance with the method of Fig.3 will adjust the first control signal supplied to the first charging circuit 212 to maintain the temperature of first charging circuit 212 below its first maximum operating tem- perature, and will also maintain the temperature of the second charging circuit 214 below its second maximum operating temperature. It will be appreciated that the relevant maximumDocket No.61658.58WO01 Client Ref. No. PER-551-PCT operating temperatures may, if desired, correspond to a selected maximum skin temperature or system temperature for the product in which such charging circuits are included.

[0034] Fig.4 is a more detailed flowchart illustrating how the circuity shown in Fig.2 may be operated to maintain the first temperature of the first charging circuit 212 essentially equal to the second temperature of the second charging circuit 214. Starting at block 400, control passes to block 402 wherein the charging current Iout1 of first charging circuit 212 is set to an initial value. Control then passes to block 404, wherein controller circuit 216 com- municates with programmable power supply 102 to select a suitable voltage Vin and supply current Iin. Control then passes to block 406 wherein the charging current Iout2 to be sourced by second charging circuit 214 is determined. As mentioned above, if second charg- ing circuit 214 is a charge pump, then charging current Iout2 will simply be the total load cur- rent being supplied to battery 118 less the charging current being contributed by Iout1. Con- trol then passes to block 408, and controller circuit 216 obtains current values for the first temperature signal T1 and the second temperature signal T2.

[0035] Still referring to Fig.4, control then passes from block 408 to decision block 410, wherein controller circuit 216 checks whether temperature signals T1 and T2 are both below their respective thermal maximum values. If the answer is No, then at least one of the charg- ing circuits is overheated, and control passes to block 414; controller circuit 216 then signals to the programmable power supply 102 that it needs to reduce the power (current) being sup- plied because the temperatures of at least one of the first and second charging circuits is too high. Control then passes from block 414 along return line 416 to Controller Handshake block 404.

[0036] On the other hand, if decision block 410 confirms that both charging circuits are below their respective maximum operating temperatures, then control passes to decision block 418 for determination whether the second temperature T2 (i.e., the temperature of sec- ond charging circuit 214) is greater than the first temperature T1 (i.e., the temperature of first charging circuit 212). If the answer is “Yes”, then control passes along line 420 to block 422. At block 422, controller circuit 216 adjusts the control signal sent to first charging circuit 212 (via line 224 in Fig.2) for increasing the first charging current Iout1; this will cause first charging circuit 212 to work harder and raise its temperature T1. Assuming that the second charging circuit 214 is a charge pump, this will also reduce the second charging current Iout2Docket No.61658.58WO01 Client Ref. No. PER-551-PCT sourced by second charging circuit 214 and reduce its temperature T2. Control then passes from block 422 along return line 416 back to Controller Handshake block 404.

[0037] Referring again to decision block 418 in Fig.4, if the answer is “No”, i.e., that T2 is not greater than T1, then control passes along line 424 to block 426. At block 426, control- ler circuit 216 adjusts the control signal sent to first charging circuit 212 to decrease the charging current Iout1 being sourced by first charging circuit 212. This will tend to reduce the first temperature T1 of first charging circuit 212. Again, if second charging circuit 214 is a charge pump, then the reduction of first charging current Iout1 will result in an equal and opposite increase in the second charging current Iout2, which will tend to increase the second temperature T2 of second charging circuit 214. Control then passes back along return line 416 back to Controller Handshake block 404.

[0038] In the manner illustrated in Fig.4, controller circuit 216 continuously monitors the first and second temperature signals T1 and T2, and continuously adjusts the control signal applied to first charging circuit 212, for maintaining T1 and T2 substantially equal to each other. Accordingly, when demands for relatively high charging current Iout are imposed, the first and second charging circuits 212 and 214 will both reach their maximum thermal tem- peratures at substantially the same time before controller circuit 216 is compelled to signal programmable power supply 102 to throttle back the power being supplied. Once again, the referenced maximum thermal temperatures may, if desired, relate to the maximum skin tem- perature or overall maximum system temperature of the product in which such charging cir- cuits are included.

[0039] There may be good reasons not to operate the first and second charging circuits at exactly the same temperature when lighter loads are demanded, or when a more efficient charge pump is able to source needed charging current without overheating. For example, if first charging circuit 212 is a buck converter, and second charging circuit 214 is a charge pump, the charge pump is much more efficient, and has a lower power loss conversion factor, than the buck converter. Assume that both the buck converter of first charging circuit 212 and the charge pump of second charging circuit 214 should not be operated above 70°C, and hence, that thermal throttling of power supply 102 should be triggered if either of charging circuits 212 or 214 reaches 70°C. If the temperature of the charge pump (T2) is less than, say, 50°C, corresponding to a lower temperature range, then the buck converter contribution to charging current (Iout1) can be tapered down to a minimum value (but still “on”), since theDocket No.61658.58WO01 Client Ref. No. PER-551-PCT charge pump is much more efficient, and it should do the work at lighter loads. Should the charge pump temperature (T2) increase above 50°C, corresponding to a higher temperature range, the controller circuit 216 can control the buck converter to start to increase its contri- bution (Iout1) to the load until both the first and second charging circuits 212 and 214 are at or near 50°C. As charging current demand is further increased, controller circuit 216 can be programmed to maintain the first and second temperatures T1 and T2 equal to each other un- til the thermal throttling temperature of 70°C is reached, after which overall system power will be limited by programmable power supply 102.

[0040] The flowchart illustrated in Fig.5 illustrates an operation scheme similar to the example just described. Starting at block 500, control passes to block 502 wherein the charg- ing current Iout1 of first charging circuit 212 is set to an initial value. Control then passes to block 504, wherein controller circuit 216 communicates with programmable power supply 102 to select a suitable voltage Vin and supply current Iin. Control then passes to block 506 wherein the charging current Iout2 to be sourced by second charging circuit 214 is deter- mined. As mentioned above, if second charging circuit 214 is a charge pump, then charging current Iout2 will simply be the total load current being supplied to battery 118 less the charging current being contributed by Iout1. Control then passes to block 508, and controller circuit 216 obtains current values for the first temperature signal T1 and the second tempera- ture signal T2.

[0041] Still referring to Fig.5, control then passes from block 508 to decision block 510, wherein controller circuit 216 checks whether temperature signals T1 and T2 are both below their respective thermal maximum values. If the answer is No, then at least one of the charg- ing circuits is overheated, and control passes to block 514; controller circuit 216 then signals to the programmable power supply 102 that it needs to reduce the power (current) being sup- plied because the temperature of at least one of the first and second charging circuits is too high. It should be noted, however, that assuming that the system is working properly at this point, the first and second temperatures T1 and T2 should be the same as each other. Control then passes from block 514 along return line 516 to Controller Handshake block 504.

[0042] On the other hand, if decision block 510 confirms that both charging circuits are below their respective maximum operating temperatures, then control passes to decision block 518 for determination whether the second temperature T2 (i.e., the temperature of sec- ond charging circuit 214) is approaching its maximum temperature T2max (e.g., within 10-Docket No.61658.58WO01 Client Ref. No. PER-551-PCT 20°C thereof). If the answer is “Yes”, then control passes along line 520 to block 522. At block 522, controller circuit 216 adjusts the control signal sent to first charging circuit 212 (via line 224 in Fig.2) for increasing the first charging current Iout1; this will cause first charging circuit 212 to work harder and raise its temperature T1. Assuming that the second charging circuit 214 is a charge pump, this will also reduce the second charging current Iout2 sourced by second charging circuit 214 and reduce its temperature T2. Control then passes from block 522 along return line 516 back to Controller Handshake block 404.

[0043] Referring again to decision block 518 in Fig.5, if the answer is “No”, i.e., that T2 is not approaching T2max, then control passes along line 524 to block 526. At block 526, controller circuit 216 adjusts the control signal sent to first charging circuit 212 to decrease the charging current Iout1 being sourced by first charging circuit 212; of course, if Iout1 is already being maintained at a nominal stand-by level, it is not further reduced. This will al- low the charge pump within second charging circuit 214 to continue sourcing the major por- tion of the total charging current Iout, which the charge pump can accomplish in a more effi- cient manner. Control then passes back along return line 516 back to Controller Handshake block 504.

[0044] When operated in the manner illustrated in Fig.5, first charging circuit 212 is ad- justed to increase the first charging current Iout1 when temperature T2 of second charging circuit 214 is proximate to and / or approaches the second maximum operating temperature T2max, while first charging circuit 212 is adjusted to decrease first charging current Iout1 when temperature T2 of second charging circuit 214 is not proximate to second maximum operating temperature T2max. Thus, when temperature T2 of second charging circuit 214 is in a lower temperature range, first charging current Iout1 is adjusted to be a relatively low magnitude; however, when temperature T2 of second charging circuit 214 is in a higher tem- perature range (closer to T2max), first charging current Iout1 is increased to maintain first and second temperatures T1 and T2 approximately equal to each other. When both T1 and T2 reach their respective maximum operating temperatures (T1max and T2max, respec- tively), controller circuit 216 signals the programmable power supply 102 to supply less cur- rent,

[0045] While the description above has included buck converters and charge pumps, those skilled in the art will appreciate that the embodiments disclosed herein can be applied to a variety of different switched power converter circuits, including buck converters, multi-Docket No.61658.58WO01 Client Ref. No. PER-551-PCT level buck converters, multi-phase buck converters, hybrid buck converters, charge pumps, multi-level power converters, and buck-boost converter circuits.

[0046] Further aspects of the present disclosure include the following:

[0047] Aspect 1 includes a circuit including a first charging circuit having a first terminal configured to receive current and voltage from a power supply, a second terminal configured to source a first charging current to a load, a third terminal configured to provide a first tem- perature signal related to the temperature of the first charging circuit, and a fourth terminal configured to receive a first control signal, the first charging circuit configured to be respon- sive to the first control signal and further configured to control a magnitude of the first charg- ing current based at least partially on the first control signal; a second charging circuit having a first terminal configured to receive current and voltage from the power supply, a second ter- minal configured to source a second charging current to the load, and a third terminal config- ured to provide a second temperature signal related to the temperature of the second charging circuit; a controller circuit configured to receive the first temperature signal and the second temperature signal, and configured to provide the first control signal to the fourth terminal of the first charging circuit; and wherein the controller circuit is configured to adjust the first control signal based, at least in part, on the first temperature signal and the second tempera- ture signal.

[0048] Aspect 2 includes the circuit of aspect 1,wherein the load is a battery.

[0049] Aspect 3 includes the circuit of any of aspects 1-2, further comprising a program- mable power supply configured to provide current and voltage to the first charging circuit and to the second charging circuit.

[0050] Aspect 4 includes the circuit of any of aspects 1-3, wherein the first charging cir- cuit is buck converter.

[0051] Aspect 5 includes the circuit of any of aspects 1-4, wherein the second charging circuit is a charge pump.

[0052] Aspect 6 includes the circuit of any of aspects 1-5, wherein the first charging cir- cuit is configured as an integrated circuit and has a first maximum operating temperature as- sociated therewith; the second charging circuit is configured as an integrated circuit and has aDocket No.61658.58WO01 Client Ref. No. PER-551-PCT second maximum operating temperature associated therewith; and the controller circuit is configured to adjust the first control signal to maintain the temperature of the first charging circuit below the first maximum operating temperature and to maintain the temperature of the second charging circuit below the second maximum operating temperature.

[0053] Aspect 7 includes the circuit of any of aspects 1-6, further comprising: a third charging circuit having a first terminal configured to receive current and voltage from the power supply, a second terminal configured to source a third charging current to the load, and a third terminal configured to provide a third temperature signal related to the temperature of the third charging circuit; the controller circuit is configured to receive the third temperature signal; and wherein the controller circuit is configured to adjust the control signal based, at least in part, on the first temperature signal, the second temperature signal, and the third tem- perature signal.

[0054] Aspect 8 includes the circuit of any of aspects 1-7 further comprising: a third charging circuit having a first terminal configured to receive current and voltage from the power supply, a second terminal configured to source a third charging current to the load, a third terminal configured to provide a third temperature signal related to the temperature of the third charging circuit, and a fourth terminal configured to receive a second control signal, the third charging circuit configured to be responsive to the second control signal and config- ured to control a magnitude of the third charging current based at least partially on the second control signal; wherein the controller circuit is configured to receive the third temperature signal, and the controller circuit is configured to provide the second control signal; and the controller circuit is configured to adjust the second control signal based, at least in part, on the first temperature signal, the second temperature signal, and the third temperature signal.

[0055] Aspect 9 includes circuit comprising: a first charging circuit having a first termi- nal configured to receive current and voltage from a power supply, a second terminal config- ured to source a first charging current to a load, a third terminal configured to receive a con- trol signal, the first charging circuit configured to be responsive to the control signal and con- figured to control a magnitude of the first charging current based at least partially on the first control signal; a first temperature sensor configured to provide a first temperature signal re- lated to the temperature of the first charging circuit; a second charging circuit having a first terminal configured to receive current and voltage from the power supply, and a second ter- minal configured to source a second charging current to the load; a second temperature sensorDocket No.61658.58WO01 Client Ref. No. PER-551-PCT configured to provide a second temperature signal related to the temperature of the second charging circuit; and a controller circuit configured to receive the first temperature signal and the second temperature signal, and configured to provide the control signal to the third termi- nal of the first charging circuit; and wherein the controller circuit is configured to adjust the control signal based, at least in part, on the first temperature signal and the second tempera- ture signal.

[0056] Aspect 10 includes the circuit of aspect 9, wherein the load is a battery.

[0057] Aspect 11 includes the circuit of any of aspects 9-10, further comprising: a pro- grammable power supply configured to provide current and voltage to the first charging cir- cuit and to the second charging circuit.

[0058] Aspect 12 includes the circuit of any of aspects 9-11, wherein the first charging circuit is a buck converter.

[0059] Aspect 13 includes the circuit of any of aspects 9-12, wherein the second charging circuit is a charge pump.

[0060] Aspect 14 includes the circuit of any of aspects 9-13, wherein the first charging circuit is configured as an integrated circuit and has a first maximum operating temperature associated therewith; the second charging circuit is configured as an integrated circuit and has a second maximum operating temperature associated therewith; and the controller circuit is configured to adjust the first control signal to maintain the temperature of the first charging circuit below the first maximum operating temperature and to maintain the temperature of the second charging circuit below the second maximum operating temperature.

[0061] Aspect 15 includes a method of operating a plurality of parallel charging circuits, the method comprising: operating a first charging circuit coupled to a programmable power supply and sourcing a first charging current to a load, the first charging current being adjusta- ble; operating a second charging circuit coupled to the programmable power supply and sourcing a second charging current to the load, the second charging circuit being operated in parallel with the first charging circuit; obtaining a first temperature signal related to the tem- perature of the first charging circuit; obtaining a second temperature signal related to the tem- perature of the second charging circuit; and adjusting the first charging current based, at least in part, in response to the first and second temperature signals.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT

[0062] Aspect 16 includes the method of aspect 15, wherein the load is a battery.

[0063] Aspect 17 includes the method of any of aspects 15-16, wherein the first charging current is adjusted to maintain the first and second temperatures approximately equal to each other.

[0064] Aspect 18 includes the method of any of aspects 15-17, wherein the first charging circuit is configured as an integrated circuit and has a first maximum operating temperature associated therewith; the second charging circuit is configured as an integrated circuit and has a second maximum operating temperature associated therewith; and the first charging current is adjusted to maintain the temperature of the first charging circuit below the first maximum operating temperature and to maintain the temperature of the second charging circuit below the second maximum operating temperature.

[0065] Aspect 19 includes the method of any of aspects 15-18, wherein the second charg- ing circuit has a lower power loss conversion factor than the first charging circuit; and the first charging circuit is adjusted to increase the first charging current when the temperature of the second charging circuit is proximate to the second maximum operating temperature; and the first charging circuit is adjusted to decrease the first charging current when the tempera- ture of the second charging circuit is not proximate to the second maximum operating tem- perature.

[0066] Aspect 20 includes the method of any of aspects 15-19, wherein when the temper- ature of the second charging circuit is in a lower temperature range, the first charging current is adjusted to be a relatively low magnitude; and when the temperature of the second charg- ing circuit is in a higher temperature range, the first charging current is increased to maintain the first and second temperatures approximately equal to each other.

[0067] Aspect 21 includes the method of any of aspects 15-20, further comprising signal- ing the programmable power supply to decrease supplied current when both the temperature of the first charging circuit is proximate to the first maximum operating temperature; and the temperature of the second charging circuit is proximate to the second maximum operating temperature.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT

[0068] Aspect 22 includes the method of any of aspects 15-21, wherein the second charg- ing current is adjustable, and wherein the method includes adjusting the second charging cur- rent in response to the first and second temperature signals.

[0069] Aspect 23 includes the method of any of aspects 15-22, further comprising provid- ing a third charging circuit configured to be coupled to the programmable power supply and sourcing a third charging current to the load; obtaining a third temperature signal related to the temperature of the third charging circuit; and adjusting the first charging current in re- sponse to the first, second and third temperature signals.

[0070] Aspect 24 includes the method of any of aspects 15-23, wherein the first charging circuit is a buck converter. Aspect 25 includes the method of any of aspects 15-24, wherein the second charging circuit is a charge pump.

[0071] The embodiments described herein may be implemented in a number of IC tech- nologies (e.g., MOSFETs, GaN, GaAs, and bulk silicon) and packaging technologies (e.g., flip chips, ball-grid arrays, wafer level scale chip packages, wide-fan out packaging, and em- bedded packaging).

[0072] The advantages and benefits of the embodiments described herein enable usage in a wide array of applications. For example, applications include portable and mobile compu- ting and / or communication products and components (e.g., notebook computers, ultra-book computers, tablet devices, and cell phones), displays (e.g., LCDs, LEDs), radio-based devices and systems (e.g., cellular systems, WiFi, Bluetooth, Zigbee, Z-Wave, and GPS-based de- vices), wired network devices and systems, data centers (e.g., for battery-backup systems and / or power conversion for processing systems and / or electronic / optical networking sys- tems), internet-of-things (IOT) devices (e.g., smart switches and lights, safety sensors, and security cameras), household appliances and electronics (e.g., set-top boxes, battery-operated vacuum cleaners, appliances with built-in radio transceivers such as washers, dryers, and re- frigerators), AC / DC power converters, electric vehicles of all types (e.g., for drive trains, control systems, and / or infotainment systems), and other devices and systems that utilize portable electricity generating sources and / or require power conversion.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT

[0073] Radio system usage includes wireless RF systems (including base stations, relay stations, and hand-held transceivers) that use various technologies and protocols, including various types of orthogonal frequency-division multiplexing (“OFDM”), quadrature ampli- tude modulation (“QAM”), Code-Division Multiple Access (“CDMA”), Time-Division Mul- tiple Access (“TDMA”), Wide Band Code Division Multiple Access (“W-CDMA”), Global System for Mobile Communications (“GSM”), Long Term Evolution (“LTE”), 5G, and WiFi (e.g., 802.11a, b, g, ac, ax), as well as other radio communication standards and protocols.

[0074] Programmable Embodiments

[0075] Some or all aspects of the invention, particularly firmware coding embedded in controller circuit 2016, may be implemented in hardware or software, or a combination of both (e.g., programmable logic arrays). Unless otherwise specified, the algorithms included as part of the invention are not inherently related to any particular computer or other appa- ratus. In particular, various general purpose computing machines may be used with programs written in accordance with the teachings herein, or it may be more convenient to use a special purpose computer or special-purpose hardware (such as integrated circuits) to perform partic- ular functions. Thus, embodiments of the invention may be implemented in one or more com- puter programs (i.e., a set of instructions or codes) executing on one or more programmed or programmable computer systems (which may be of various architectures, such as distributed, client / server, or grid) each comprising at least one processor, at least one data storage system (which may include volatile and non-volatile memory and / or storage elements), at least one input device or port, and at least one output device or port. Program instructions or code may be applied to input data to perform the functions described in this disclosure and generate output information. The output information may be applied to one or more output devices in known fashion.

[0076] Each such computer program may be implemented in any desired computer lan- guage (including machine, assembly, or high-level procedural, logical, or object-oriented pro- gramming languages) to communicate with a computer system, and may be implemented in a distributed manner in which different parts of the computation specified by the software are performed by different computers or processors. In any case, the computer language may be a compiled or interpreted language. Computer programs implementing some or all of the in- vention may form one or more modules of a larger program or system of programs. Some or all of the elements of the computer program can be implemented as data structures stored in aDocket No.61658.58WO01 Client Ref. No. PER-551-PCT computer readable medium or other organized data conforming to a data model stored in a data repository.

[0077] Each such computer program may be stored on or downloaded to (for example, by being encoded in a propagated signal and delivered over a communication medium such as a network) a tangible, non-transitory storage media or device (e.g., solid state memory media or devices, or magnetic or optical media) for a period of time (e.g., the time between refresh periods of a dynamic memory device, such as a dynamic RAM, or semi-permanently or per- manently), the storage media or device being readable by a general or special purpose pro- grammable computer or processor for configuring and operating the computer or processor when the storage media or device is read by the computer or processor to perform the proce- dures described above. The inventive system may also be considered to be implemented as a non-transitory computer-readable storage medium, configured with a computer program, where the storage medium so configured causes a computer or processor to operate in a spe- cific or predefined manner to perform the functions described in this disclosure.

[0078] Fabrication Technologies & Options

[0079] In various embodiments of buck converters and charge pumps, it may be benefi- cial to use specific types of capacitors. For example, it is generally useful for such capacitors to have low equivalent series resistance (ESR), low DC bias degradation, high capacitance, and small volume. Low ESR may be especially important. Selection of a particular capacitor should be made after consideration of specifications for power level, efficiency, size, etc. Various types of capacitor technologies may be used, including ceramic (including multi- layer ceramic capacitors), electrolytic capacitors, film capacitors (including power film ca- pacitors), and IC-based capacitors. Capacitor dielectrics may vary as needed for particular ap- plications, and may include dielectrics that are paraelectric, such as silicon dioxide (SiO2), hafnium dioxide (HFO2), or aluminum oxide Al2O3. In addition, buck converter and charge pump designs may beneficially utilize intrinsic parasitic capacitances (e.g., intrinsic to the power FETs) in conjunction with or in lieu of designed capacitors to reduce circuit size and / or increase circuit performance. Selection of capacitors for such power converters may also take into account such factors as capacitor component variations, reduced effective ca- pacitance with DC bias, and ceramic capacitor temperature coefficients (minimum and maxi- mum temperature operating limits, and capacitance variation with temperature).Docket No.61658.58WO01 Client Ref. No. PER-551-PCT

[0080] Similarly, in various embodiments of buck converters, it may be beneficial to use specific types of inductors. For example, it is generally useful for the inductors to have low DC equivalent resistance, high inductance, and small volume.

[0081] The controller(s) used to control the charging circuits may be implemented as a microprocessor, a microcontroller, a digital signal processor (DSP), register-transfer level (RTL) circuitry, and / or combinatorial logic.

[0082] The term “MOSFET”, as used in this disclosure, includes any field effect transis- tor (FET) having an insulated gate whose voltage determines the conductivity of the transis- tor, and encompasses insulated gates having a metal or metal-like, insulator, and / or semicon- ductor structure. The terms “metal” or “metal-like” include at least one electrically conduc- tive material (such as aluminum, copper, or other metal, or highly doped polysilicon, gra- phene, or other electrical conductor), “insulator” includes at least one insulating material (such as silicon oxide or other dielectric material), and “semiconductor” includes at least one semiconductor material.

[0083] As used in this disclosure, the term “radio frequency” (RF) refers to a rate of os- cillation in the range of about 3 kHz to about 300 GHz. This term also includes the frequen- cies used in wireless communication systems. An RF frequency may be the frequency of an electromagnetic wave or of an alternating voltage or current in a circuit.

[0084] With respect to the figures referenced in this disclosure, the dimensions for the various elements are not to scale; some dimensions have been greatly exaggerated vertically and / or horizontally for clarity or emphasis. In addition, references to orientations and direc- tions (e.g., “top”, “bottom”, “above”, “below”, “lateral”, “vertical”, “horizontal”, etc.) are rel- ative to the example drawings, and not necessarily absolute orientations or directions.

[0085] Various embodiments of the invention can be implemented to meet a wide variety of specifications. Unless otherwise noted above, selection of suitable component values is a matter of design choice. Various embodiments of the invention may be implemented in any suitable integrated circuit (IC) technology (including but not limited to MOSFET structures), or in hybrid or discrete circuit forms. Integrated circuit embodiments may be fabricated using any suitable substrates and processes, including but not limited to standard bulk silicon, high- resistivity bulk CMOS, silicon-on-insulator (SOI), and silicon-on-sapphire (SOS). Unless otherwise noted above, embodiments of the invention may be implemented in other transistorDocket No.61658.58WO01 Client Ref. No. PER-551-PCT technologies such as bipolar, BiCMOS, LDMOS, BCD, GaAs HBT, GaN HEMT, GaAs pHEMT, and MESFET technologies. However, embodiments of the invention are particu- larly useful when fabricated using an SOI or SOS based process, or when fabricated with pro- cesses having similar characteristics. Fabrication in CMOS using SOI or SOS processes ena- bles circuits with low power consumption, the ability to withstand high power signals during operation due to FET stacking, good linearity, and high frequency operation (i.e., radio fre- quencies up to and exceeding 300 GHz). Monolithic IC implementation is particularly useful since parasitic capacitances generally can be kept low (or at a minimum, kept uniform across all units, permitting them to be compensated) by careful design.

[0086] Voltage levels may be adjusted, and / or voltage and / or logic signal polarities re- versed, depending on a particular specification and / or implementing technology (e.g., NMOS, PMOS, or CMOS, and enhancement mode or depletion mode transistor devices). Component voltage, current, and power handling capabilities may be adapted as needed, for example, by adjusting device sizes, serially “stacking” components (particularly FETs) to withstand greater voltages, and / or using multiple components in parallel to handle greater currents. Additional circuit components may be added to enhance the capabilities of the dis- closed circuits and / or to provide additional functionality without significantly altering the functionality of the disclosed circuits.

[0087] Circuits and devices in accordance with the present invention may be used alone or in combination with other components, circuits, and devices. Embodiments of the present invention may be fabricated as integrated circuits (ICs), which may be encased in IC pack- ages and / or in modules for ease of handling, manufacture, and / or improved performance. In particular, IC embodiments of this invention are often used in modules in which one or more of such ICs are combined with other circuit blocks (e.g., filters, amplifiers, passive compo- nents, and possibly additional ICs) into one package. The ICs and / or modules are then typi- cally combined with other components, often on a printed circuit board, to form part of an end product such as a cellular telephone, laptop computer, or electronic tablet, or to form a higher-level module which may be used in a wide variety of products, such as vehicles, test equipment, medical devices, etc. Through various configurations of modules and assemblies, such ICs typically enable a mode of communication, often wireless communication.

[0088] A number of embodiments of the disclosure have been described. It is to be understood that various modifications may be made without departing from the spirit and scopeDocket No.61658.58WO01 Client Ref. No. PER-551-PCT of the disclosure. For example, some of the steps described above may be order independent, and thus can be performed in an order different from that described. Further, some of the steps described above may be optional. Various activities described with respect to the methods identified above can be executed in repetitive, serial, and / or parallel fashion.

[0089] It is to be understood that the foregoing description is intended to illustrate and not to limit the scope of the disclosure, which is defined by the scope of the following claims, and that other embodiments are within the scope of the claims. In particular, the scope of the disclosure includes any and all feasible combinations of one or more of the processes, machines, manufactures, or compositions of matter set forth in the claims below. (Note that the parenthetical labels for claim elements are for ease of referring to such elements, and do not in themselves indicate a particular required ordering or enumeration of elements; further, such labels may be reused in dependent claims as references to additional elements without being regarded as starting a conflicting labeling sequence).

Claims

Docket No.61658.58WO01 Client Ref. No. PER-551-PCT CLAIMS WHAT IS CLAIMED IS:

1. A circuit comprising: a first charging circuit having a first terminal configured to receive current and volt- age from a power supply, a second terminal configured to source a first charging cur- rent to a load, a third terminal configured to provide a first temperature signal related to the temperature of the first charging circuit, and a fourth terminal configured to re- ceive a first control signal, the first charging circuit configured to be responsive to the first control signal and further configured to control a magnitude of the first charging current based at least partially on the first control signal; a second charging circuit having a first terminal configured to receive current and voltage from the power supply, a second terminal configured to source a second charging current to the load, and a third terminal configured to provide a second tem- perature signal related to the temperature of the second charging circuit; a controller circuit configured to receive the first temperature signal and the second temperature signal, and configured to provide the first control signal to the fourth ter- minal of the first charging circuit; and wherein the controller circuit is configured to adjust the first control signal based, at least in part, on the first temperature signal and the second temperature signal.

2. The circuit recited by claim 1, wherein the load is a battery.

3. The circuit recited by claim 1, further comprising a programmable power supply con- figured to provide current and voltage to the first charging circuit and to the second charging circuit.

4. The circuit recited by claim 1, wherein the first charging circuit is a buck converter.

5. The circuit recited by claim 1, wherein the second charging circuit is a charge pump.

6. The circuit recited by claim 1, wherein:Docket No.61658.58WO01 Client Ref. No. PER-551-PCT a) the first charging circuit is configured as an integrated circuit and has a first maxi- mum operating temperature associated therewith; b) the second charging circuit is configured as an integrated circuit and has a second maximum operating temperature associated therewith; and c) the controller circuit is configured to adjust the first control signal to maintain the temperature of the first charging circuit below the first maximum operating tem- perature and to maintain the temperature of the second charging circuit below the second maximum operating temperature.

7. The circuit recited by claim 1, further comprising: a third charging circuit having a first terminal configured to receive current and voltage from the power supply, a second terminal configured to source a third charging current to the load, and a third terminal configured to provide a third temperature signal related to the temperature of the third charging circuit; the controller circuit configured to receive the third temperature signal; and wherein the controller circuit is configured to adjust the control signal based, at least in part, on the first temperature signal, the second temperature signal, and the third temperature signal.

8. The circuit recited by claim 1, further comprising: a third charging circuit having a first terminal configured to receive current and voltage from the power supply, a second terminal configured to source a third charging current to the load, a third terminal configured to provide a third temper- ature signal related to the temperature of the third charging circuit, and a fourth terminal configured to receive a second control signal, the third charging circuit configured to be responsive to the second control signal and configured to control a magnitude of the third charging current based at least partially on the second control signal; wherein the controller circuit is configured to receive the third temperature signal, and the controller circuit is configured to provide the second control signal; andDocket No.61658.58WO01 Client Ref. No. PER-551-PCT the controller circuit is configured to adjust the second control signal based, at least in part, on the first temperature signal, the second temperature signal, and the third temperature signal.

9. A circuit comprising: a first charging circuit having a first terminal configured to receive current and volt- age from a power supply, a second terminal configured to source a first charging cur- rent to a load, a third terminal configured to receive a control signal, the first charging circuit configured to be responsive to the control signal and configured to control a magnitude of the first charging current based at least partially on the first control sig- nal; a first temperature sensor configured to provide a first temperature signal related to the temperature of the first charging circuit; a second charging circuit having a first terminal configured to receive current and voltage from the power supply, and a second terminal configured to source a second charging current to the load; a second temperature sensor configured to provide a second temperature signal related to the temperature of the second charging circuit; a controller circuit configured to receive the first temperature signal and the second temperature signal, and configured to provide the control signal to the third terminal of the first charging circuit; and wherein the controller circuit is configured to adjust the control signal based, at least in part, on the first temperature signal and the second temperature signal.

10. The circuit recited by claim 9, wherein the load is a battery.

11. The circuit recited by claim 9, further comprising a programmable power supply con- figured to provide current and voltage to the first charging circuit and to the second charging circuit.

12. The circuit recited by claim 9, wherein the first charging circuit is a buck converter.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT 13. The circuit recited by claim 9, wherein the second charging circuit is a charge pump.

14. The circuit recited by claim 9 wherein: a) the first charging circuit is configured as an integrated circuit and has a first maxi- mum operating temperature associated therewith; b) the second charging circuit is configured as an integrated circuit and has a second maximum operating temperature associated therewith; and c) the controller circuit is configured to adjust the first control signal to maintain the temperature of the first charging circuit below the first maximum operating tem- perature and to maintain the temperature of the second charging circuit below the second maximum operating temperature.

15. A method of operating a plurality of parallel charging circuits, the method compris- ing: a. operating a first charging circuit coupled to a programmable power supply and sourcing a first charging current to a load, the first charging current being adjusta- ble; b. operating a second charging circuit coupled to the programmable power supply and sourcing a second charging current to the load, the second charging circuit be- ing operated in parallel with the first charging circuit; c. obtaining a first temperature signal related to the temperature of the first charging circuit; d. obtaining a second temperature signal related to the temperature of the second charging circuit; and e. adjusting the first charging current based, at least in part, in response to the first and second temperature signals.

16. The method recited by claim 15, wherein the load is a battery.

17. The method recited by claim 15, wherein the first charging current is adjusted to maintain the first and second temperatures approximately equal to each other.Docket No.61658.58WO01 Client Ref. No. PER-551-PCT 18. The method recited by claim 15, wherein; a) the first charging circuit is configured as an integrated circuit and has a first maxi- mum operating temperature associated therewith; b) the second charging circuit is configured as an integrated circuit and has a second maximum operating temperature associated therewith; and c) the first charging current is adjusted to maintain the temperature of the first charg- ing circuit below the first maximum operating temperature and to maintain the temperature of the second charging circuit below the second maximum operating temperature.

19. The method recited by claim 15, wherein: a) the second charging circuit has a lower power loss conversion factor than the first charging circuit; and b) the first charging circuit is adjusted to increase the first charging current when the temperature of the second charging circuit is proximate to the second maximum operating temperature; and c) the first charging circuit is adjusted to decrease the first charging current when the temperature of the second charging circuit is not proximate to the second maxi- mum operating temperature.

20. The method recited by claim 19, wherein: a) when the temperature of the second charging circuit is in a lower temperature range, the first charging current is adjusted to be a relatively low magnitude; and b) when the temperature of the second charging circuit is in a higher temperature range, the first charging current is increased to maintain the first and second tem- peratures approximately equal to each other.

21. The method recited by claim 15, including signaling the programmable power supply to decrease supplied current when both:Docket No.61658.58WO01 Client Ref. No. PER-551-PCT the temperature of the first charging circuit is proximate to the first maximum operat- ing temperature; and the temperature of the second charging circuit is proximate to the second maximum operating temperature.

22. The method recited by claim 15, wherein the second charging current is adjustable, and wherein the method includes adjusting the second charging current in response to the first and second temperature signals.

23. The method recited by claim 15, including: providing a third charging circuit configured to be coupled to the programmable power supply and sourcing a third charging current to the load; obtaining a third temperature signal related to the temperature of the third charging circuit; and adjusting the first charging current in response to the first, second and third tempera- ture signals.

24. The method recited by claim 15, wherein the first charging circuit is a buck converter.

25. The method recited by claim 15, wherein the second charging circuit is a charge pump.

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