KR20240047422A - Pseudo-bypass mode for power converters - Google Patents

Abstract

The system includes a boost converter configured to receive an input voltage and step the input voltage to an output voltage, and to enforce a maximum current limit to limit the current drawn by the boost converter and to respond to the output voltage decreasing below the input voltage so that the output voltage decreases. It may include a control circuit configured to dynamically increase the current above the maximum current limit so that it is approximately equal to the input voltage.

Description

Pseudo-bypass mode for power converters

Related applications

This disclosure claims priority to U.S. Provisional Patent Application Serial No. 63/236,739, filed August 25, 2021, which is incorporated herein by reference in its entirety.

Technology field

This disclosure relates generally to circuits for electronic devices, including but not limited to personal audio devices such as cordless phones and media players, and more specifically to circuits for converting the output voltage generated by a power converter to a power converter. It relates to the implementation of an operating mode of a power converter regulated by input voltage.

Personal audio devices, including wireless phones such as mobile/cellular phones, cordless phones, mp3 players, and other consumer audio devices, are widely used. These personal audio devices may include circuits for driving a pair of headphones or one or more speakers. These circuits often include a speaker driver that includes a power amplifier to send the audio output signal to headphones or speakers. Often a power converter can be used to provide a supply voltage to a power amplifier to amplify the signal driving speakers, headphones, or other transducers. A switching power converter is a type of electronic circuit that converts power from one direct current (DC) voltage level to another DC voltage level. Examples of such switching DC-DC converters include, but are not limited to, boost converters, buck converters, buck-boost converters, inverting buck-boost converters, and other types of switching DC-DC converters. Therefore, using a power converter, a DC voltage, such as that provided by the battery, can be converted to another DC voltage that is used to power the power amplifier. A power converter may be used to provide supply voltage rails to one or more components of the device. Power converters can also be used in other applications, such as driving haptic actuators or other electrical or electronic loads in addition to driving audio transducers.

The output voltage produced by the boost converter may fall below its set point depending on the current limiting constraints that may apply to the boost converter. Systems (e.g., mobile devices) that include such boost converters require that the output voltage produced by the boost converter not fall below the input voltage to the boost converter, referred to herein as a “collapse condition.” You can. Typically, this requirement can be achieved by closing the switch between the input and output voltages during collapse conditions, resulting in a state transition between regulation and bypass modes in which the boost converter regulates the output voltage. . However, these state transitions add design complexity and can have other drawbacks.

In accordance with the teachings of this disclosure, one or more drawbacks and problems associated with existing approaches for regulating the output voltage of a power converter can be reduced or eliminated.

According to an embodiment of the present disclosure, a system includes a boost converter configured to receive an input voltage and step the input voltage to an output voltage, and a maximum current limit to limit the current drawn by the boost converter and reduce the current below the input voltage. A control circuit configured to dynamically increase the current above the maximum current limit in response to the output voltage such that the output voltage is approximately equal to the input voltage.

According to this and other embodiments of the present disclosure, a method includes receiving an input voltage and enforcing a maximum current limit to limit the current drawn by a boost converter configured to step the input voltage to an output voltage. In response to the output voltage decreasing below the voltage, dynamically increasing the current above the maximum current limit such that the output voltage is approximately equal to the input voltage.

The technical advantages of the present disclosure can be easily understood by those skilled in the art from the drawings, description, and claims included herein. The objects and advantages of the above embodiments will be realized and achieved by at least the elements, features, and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and do not limit the scope of the claims presented in this disclosure.

A more complete understanding of embodiments of the present invention and its advantages can be obtained by reference to the following description taken in conjunction with the accompanying drawings, where like reference numerals designate like features.
1 illustrates an example mobile device according to embodiments of the present disclosure.
2 shows a block diagram of selected components within a mobile device according to embodiments of the present disclosure.
3A shows a block diagram of selected components of an example boost converter with multiple operating modes illustrating operation in a bypass mode in accordance with embodiments of the present disclosure.
FIG. 3B shows a block diagram of selected components of an example boost converter with multiple operating modes illustrating operation in a boost active mode in accordance with embodiments of the present disclosure.
FIG. 3C shows a block diagram of selected components of an example boost converter with multiple operating modes illustrating operation in a boost inactive mode according to embodiments of the present disclosure.
4 shows a block diagram of selected components of an example control circuit for a boost converter in accordance with embodiments of the present disclosure.
5 shows an example state machine that may be implemented by part of a control circuit for a boost converter in accordance with embodiments of the present disclosure.
Figure 6 shows a graph showing the increase in maximum current over time in an attack state according to an embodiment of the present disclosure.

1 shows an example mobile device 1 according to embodiments of the present disclosure. Figure 1 shows a mobile device 1 coupled to a headset 3 in the form of a pair of earbud speakers 8A and 8B. The headset 3 shown in FIG. 1 is merely an example, and the mobile device 1 may include a variety of audio transducers including, but not limited to, headphones, earbuds, in-ear earphones, and external speakers. It must be understood that it can be used in relation to . The plug 4 can connect the headset 3 to an electrical terminal of the mobile device 1. The mobile device 1 may present a display to the user and receive user input using a touch screen 2, or alternatively, a standard liquid crystal display (LCD) may be displayed on the face of the mobile device 1. and/or various buttons, sliders and/or dials disposed on the sides.

2 shows a block diagram of selected components integrated into mobile device 1 in accordance with embodiments of the present disclosure. As shown in FIG. 2 , the mobile device 1 boosts the battery voltage V _BAT to generate a supply voltage V _SUPPLY for a plurality of downstream components 18 of the mobile device 1. It may include a boost converter 20 configured to do so. Downstream components 18 of mobile device 1 may include any suitable functional circuits or devices of mobile device 1, including without limitation processors, audio coders/decoders, amplifiers, display devices, etc. may include. As shown in FIG. 2 , mobile device 1 may also include a battery charger 16 to recharge battery 22 .

In some embodiments of mobile device 1, boost converter 20 and battery charger 16 may include only components of mobile device 1 that are electrically coupled to battery 22, and the boost converter 20 may electrically interface between the battery 22 and all downstream components of the mobile device 1 . However, in other embodiments of mobile device 1, some downstream components 18 may be electrically coupled directly to battery 22.

3A shows a block diagram of selected components of an example boost converter 20 with multiple operating modes illustrating operation in a bypass mode in accordance with embodiments of the present disclosure. As shown in FIG. 3A, boost converter 20 includes a battery 22, a plurality of inductive boost phases 24, a sense capacitor 26, a sense resistor 28, a bypass switch 30, and It may include a control circuit 40. As shown in FIG. 3A, each inductive boost phase 24 may include a power inductor 32, a charging switch 34, a rectifying switch 36, and an output capacitor 38.

3A-3C show boost converter 20 with three inductive boost phases 24, embodiments of boost converter 20 may have any suitable number of inductive boost phases 24. You can. In some embodiments, boost converter 20 may include three or more inductive boost phases 24. In other embodiments, boost converter 20 may include less than three phases (eg, single or two phases).

Boost converter 20 is configured such that the supply voltage (V _SUPPLY ) generated by boost converter 20 is greater than the threshold minimum voltage (V _MIN ) and the voltage (VDD_SENSE) across sense capacitor 26 is greater than the supply voltage (V _SUPPLY ). If larger, it can operate in bypass mode. In some embodiments, this threshold minimum voltage (V _MIN ) may be a function of the monitored current (e.g., current through sense resistor 28). In some embodiments, this threshold minimum voltage (V _MIN ) may vary in response to changes in the monitored current to provide desired headroom from the components supplied from the supply voltage (V _SUPPLY ). Therefore, the control circuit 40 not only senses the supply voltage (V _SUPPLY ) and compares the supply voltage (V _SUPPLY ) to the threshold minimum voltage (V _MIN ), but also senses the voltage (VDD_SENSE) and compares the supply voltage (V _SUPPLY ) to the voltage It can be configured to compare with (VDD_SENSE). When the supply voltage (V _SUPPLY ) is greater than the threshold minimum voltage (V _MIN ) and the voltage (VDD_SENSE) across sense capacitor 26 is greater than the supply voltage (V _SUPPLY ), the control circuit 40 switches the bypass switch 30 and activating (e.g., enabling, closing, turning on) one or more commutation switches 36 and deactivating (e.g., disabling, opening, turning off) the charging switches 34. In such bypass mode, the resistances of rectifier switches 36, power inductors 32, and bypass switch 30 combine to total the effective resistance of the path between battery 22 and supply voltage V _SUPPLY . can be minimized. In some embodiments, bypass switch 30 may not be present and bypass mode may be achieved by activating one or more commutation switches 36 and deactivating charging switches 34.

FIG. 3B shows a block diagram of selected components of an example boost converter 20 illustrating operation in a boost active mode in accordance with embodiments of the present disclosure. In the boost active mode, control circuit 40 maintains the supply voltage (V _SUPPLY ) above the threshold minimum voltage (V _MIN ) while maintaining the programmed (or servoed) desired current (e.g., average current). _Deactivate the _bypass switch _{30 (} disable, open, turn off) and appropriate control signals (e.g. ) (e.g., during the charging state of the inductive boost phase 24) and the rectifier switches of the inductive boost phase 24 (as described in more detail below) by generating (36) may periodically commit (during the transfer state of the inductive boost phase (24)). For example, control circuit 40 may be used to control peak It may operate in a boost active mode to maintain the inductor current I _L (e.g., I _L1 , I _L2 , I _L3 ) between the current and the valley current. In the boost active mode, control circuit 40 may operate boost converter 20 by operating inductive boost phase 24 in peak and valley detection operation, as described in greater detail below. The resulting switching frequency of the charging switches 34 and rectifying switches 36 of the inductive boost phase 24 is a function of the sense voltage (VDD_SENSE), the supply voltage (V _SUPPLY ), the inductance of the power inductor 32A, and the programming It can be determined by the ripple parameter (e.g., the configuration of the target current ripple for the inductor current ( _IL )).

FIG. 3C shows a block diagram of selected components of boost converter 20 illustrating operation in a boost inactive mode in accordance with embodiments of the present disclosure. The boost converter 20 operates when the supply voltage (V _SUPPLY ) generated by the boost converter 20 rises above the hysteresis voltage (V _HYST ) and the sensing voltage (VDD_SENSE) remains below the supply voltage (V _SUPPLY ). , can operate in boost inactive mode. In the boost inactive mode, control circuit 40 may deactivate (e.g., disable, open, turn off) bypass switch 30, charge switches 34, and rectifier switches 36. . Accordingly, when the sense voltage (VDD_SENSE) remains below _the supply voltage (V _SUPPLY ), the control circuit 40 switches the boost converter ( 20) prevents it from entering bypass mode. Additionally, when the supply voltage (V _SUPPLY ) falls below the threshold minimum voltage (V _MIN ), the control circuit 40 maintains the supply voltage (V _SUPPLY ) between the threshold minimum voltage (V _MIN ) and the hysteresis voltage (V _HYST ). To do this, the boost converter 20 can be allowed to enter the boost active mode again.

Accordingly, through operation in the above-described modes, boost converter 20 may operate to provide hysteresis regulation of the supply voltage (V _SUPPLY ) between the threshold minimum voltage (V _MIN ) and the hysteresis voltage (V _HYST ). .

It should be understood that in some embodiments of the present disclosure, bypass switch 30 may not be present in boost converter 20. Accordingly, as will be explained in more detail below, in addition to or instead of the bypass function provided by bypass switch 30, boost converter 20 may switch to supply voltage ( It may be configured to regulate the supply voltage (V _SUPPLY ) to approximately the battery voltage (V _BAT ) during a voltage collapse condition that may exist at V _SUPPLY ).

As described in U.S. Patent Application Serial No. 17/237,373, filed April 22, 2021, which is incorporated herein by reference, one or more constraints may apply to the operation of the power converter, which determines the amount of energy drawn from the battery by the power converter. One or more limits can be placed on the current that can come. In some examples, these current limits applied to boost converter 20 may result in a collapse condition, where the supply voltage (V _SUPPLY ) drops to the battery voltage (V _BAT ), and thus power converter 20 reduces the supply voltage (V SUPPLY) to the battery voltage (V BAT). V _SUPPLY ) cannot be adjusted. As explained in the background section of this specification, in traditional approaches, control circuit 40 bypasses the battery voltage (V _BAT ) to the supply voltage (V _SUPPLY ) as a result of current limiting of boost converter 20. The bypass switch 30 (and/or one or more commutation switches 36) may be activated to do this. However, according to the present disclosure, the boost converter 20 may be configured to adjust the supply voltage (V _SUPPLY ) to be substantially equal to the battery voltage (V _BAT ) in the case of a collapse condition.

4 shows a block diagram of selected components of an example control circuit 40 in accordance with embodiments of the present disclosure. As shown in Figure 4, control circuit 40 includes a comparator 52, a collapse controller 54, a maximum block 56, a current controller 58, a minimum block 60, and a switch controller. (62) may be included.

Comparator 52 may be configured to compare the supply voltage (V _SUPPLY ) to the battery voltage (V _BAT ) to control the operation of collapse controller 54. For example, when the supply voltage (V _SUPPLY ) is greater than the battery voltage (V _BAT ), comparator 52 causes collapse controller 54 to operate in a release mode to reduce collapse state current (I _COL ). can do. On the other hand, if the supply voltage (V _SUPPLY ) is less than the battery voltage (V _BAT ), comparator 52 causes collapse controller 54 to operate in attack mode to increase collapse state current (I _COL ). can do.

The maximum block 56 may select the maximum value of the protection current (I _PROT ) and the collapse state current (I _COL ) to generate the maximum current (I _MAX ) delivered to the minimum block 60. Protection current I _PROT may represent the maximum current that can be drawn by boost converter 20 to satisfy any battery protection constraints and/or other protection constraints, for example as described in the '373 application. there is. Accordingly, if a collapse condition exists, collapse controller 54 in conjunction with maximum block 56 may temporarily override such protection current (I _PROT ) in order to regulate supply voltage (V _SUPPLY ).

Current controller 58 adjusts the supply voltage (V _SUPPLY ) to a desired voltage level based on the supply voltage (V _SUPPLY ), threshold minimum voltage (V _MIN ), hysteresis voltage (V _HYST ), and/or any other suitable parameters. In order to adjust , the target current (I _TARGET ) to be drawn by the boost converter 20 can be determined. Determination of this target current based on the supply voltage (V _SUPPLY ) is beyond the scope of this disclosure, but may be determined in any suitable manner, including without limitation the approach of determining the target average current as described in the '517 application. there is.

The minimum block 60 may select the minimum value of the target current (I _TARGET ) and the maximum current (I _MAX ) and transmit the result to the switch controller 62. Based on the received current value, switch controller 62 sends _appropriate control signals ( ) can be created.

In operation, the functionality of decay controller 54 may be integrated with maximum block 56 to implement a state machine to generate maximum current I _MAX . As described above, the maximum current (I _MAX ) may be based on the output of comparator 52 and the protection current (I _PROT ) to satisfy battery protection constraints. When not in a collapse state, the maximum current (I _MAX ) may be equal to the protection current (I _PROT ). On the other hand, in a collapsed state, the maximum current (I _MAX ) may exceed the protection current (I _PROT ).

5 shows an example state machine 70 that may be implemented by collapse controller 54 and max block 56 in accordance with embodiments of the present disclosure. As shown in Figure 5, state machine 70 has four states: idle state 72, attack state 74, release state 76, and slow release state 78. Slow release state 78 is shown as a dashed line because in some embodiments of state machine 70 such state may not exist.

In the idle state 72, the maximum current (I _MAX ) may be equal to the protection current (I _PROT ). From idle state 72, state machine 70 determines the battery voltage (V _BAT ) in excess of the supply voltage (V _SUPPLY ) and the minimum allowable regulated voltage (which may be below the threshold minimum voltage (V _MIN ) described above). It may transition to the attack state 74 in response to the supply voltage (V _SUPPLY ) falling below V _UV ).

The decay controller 54 may cause the maximum current I _MAX to continuously increase while in the attack state 74 . From attack state 74, state machine 70 responds to maximum current (I _MAX ) falling below protection current (I _PROT ) and battery voltage (V _BAT ) falling below supply voltage (V _SUPPLY ) into idle state ( 72) can be converted back to . Additionally, from attack state 74, state machine 70 determines that the supply voltage (V _SUPPLY ) is above the battery voltage (V _BAT ) and the supply voltage (V _SUPPLY ) remains below the minimum allowable regulation voltage (V _UV ). It may transition to the release state 76 in response. Additionally, from attack state 74, state machine 70 may transition to slow release state 78 in response to supply voltage (V _SUPPLY ) exceeding the minimum allowable regulation voltage (V _UV ).

The decay controller 54 may cause the maximum current I _MAX to continuously decrease while in the release state 76 . From release state 76, state machine 70 may transition back to idle state 72 in response to maximum current I _MAX falling below protection current I _PROT . Additionally, from release state 76, state machine 70 determines that the battery voltage (V _BAT ) exceeds the supply voltage (V _SUPPLY ) and the supply voltage (V _SUPPLY ) remains below the minimum allowable regulation voltage (V _UV ). In response, it may be switched back to the attack state 74. Additionally, from release state 76, state machine 70 determines whether the battery voltage (V _BAT ) exceeds the supply voltage (V _SUPPLY ) and the supply voltage (V _SUPPLY ) rises above the minimum allowable regulated voltage (V _UV ). It may transition to the slow release state 78 in response.

The slow release state 78 is such that the boost converter 20 is activated when the supply voltage (V _SUPPLY ) is equal to the battery voltage (V _BAT ) and the supply voltage (V _SUPPLY ) is above the minimum acceptable regulation voltage (V _UV ). It may only be present in embodiments with a dedicated bypass switch 30 that can be used. Implemented by the collapse controller 54 when the collapse controller 54 is engaged (e.g., I _MAX > I _PROT ) and the supply voltage (V _SUPPLY ) is higher than the minimum allowable regulation voltage (V _UV ). A controlled control loop may be necessary to properly avoid negative interactions with the bypass switch 30. This negative interaction causes the maximum current (I _MAX ) to decrease continuously while in the slow release state 78 , but at a rate that may be slower than the decrease in the maximum current (I _MAX ) that occurs in the release state 76 can be achieved.

In the slow release state 78, the decay controller 54 may reduce the maximum current (I _MAX ) at a programmable rate of decrease that is slower than the rate of decrease in the release state 76, which corresponds to the minimum allowable regulation voltage (V _UV ). Chattering of the supply voltage (V _SUPPLY ) can be reduced near the boundary of .

From slow release state 78, state machine 70 may transition back to idle state 72 in response to maximum current I _MAX falling below protection current I _PROT . Additionally, from the slow release state 78, the state machine 70 determines whether the battery voltage (V _BAT ) exceeds the supply voltage (V _SUPPLY ) and the supply voltage (V _SUPPLY ) falls below the minimum acceptable regulation voltage (V _UV ). In response, it may be switched back to the attack state 74. Additionally, from the slow release state 78, the state machine 70 determines whether the supply voltage (V _SUPPLY ) exceeds the battery voltage (V _BAT ) and the supply voltage (V _SUPPLY ) falls below the minimum acceptable regulation voltage (V _UV ). It may transition to the release state 76 in response.

In particular, the minimum allowable regulation voltage (V _UV ) may only be relevant in the state machine 70 in embodiments where a dedicated bypass switch 30 is present. Accordingly, in embodiments where there is no dedicated bypass switch 30 and the state machine 70 does not include a slow release state 78, the comparison to the minimum allowable regulation voltage (V _UV ) shown in FIG. 5 is It can be ignored.

Upon entering the attack state 74, the collapse controller 54 may continue to increase the maximum current I _MAX for the duration of time the state machine 70 remains in the attack state 74. In some embodiments, as shown in FIG. 6 , this increase in maximum current (I _MAX ) is achieved in a programmable linear term (e.g., increases linearly with time), programmable 2 of the attack state 74, where a quadratic term is added to the linear term to create a programmable quadratic term (e.g., increasing exponentially with time), and a composite curve for the maximum current (I _MAX ). Can include a programmable time delay after startup. These compound ramps can enable steady-state stability through a linear term and fast tracking of the supply voltage (V _SUPPLY ) relative to the battery voltage (V _BAT ) through a quadratic term. The decay controller 54 may generate a similar composite curve that reduces the maximum current (I _MAX ) during the release state 76 and the slow release state 78.

In addition to the example waveforms described above, other waveforms that vary in time, current, and/or voltage may be used.

As used herein, when two or more elements are referred to as being "coupled" with one another, such term is applicable to electronic or mechanical communication whether such two or more elements are connected indirectly or directly, or with or without intervening elements. Indicates that it is in a state.

This disclosure covers all changes, substitutions, variations, modifications, and modifications to the exemplary embodiments herein that may be understood by those skilled in the art. Similarly, the appended claims, where appropriate, cover all changes, substitutions, variations, modifications, and modifications to the exemplary embodiments herein that may occur to those skilled in the art. Additionally, in the appended claims for a device or system, or component of a device or system, adapted, arranged, capable, configured, enabled, operable, or operative to perform a particular function. A reference to a device, system, or component, insofar as the device, system, or component is adapted, arranged, capable, configured, enabled, operable, or operable. Covers any device, system, or component regardless of whether a particular function is activated, turned on, or unlocked. Accordingly, modifications, additions, or omissions may be made to the systems, devices, and methods described herein without departing from the scope of the present disclosure. For example, components of systems and devices may be integrated or separate. Additionally, the operations of the systems and devices disclosed herein may be performed by more, fewer, or different components and the methods described may include more, fewer, or different steps. Additionally, the steps may be performed in any suitable order. As used herein, “each” refers to each member of a set or each member of a subset of a set.

Although representative embodiments are illustrated and described in the drawings, the principles of the present disclosure may be implemented using any technology, whether or not currently known. The present disclosure should in no way be limited to the representative implementations and techniques illustrated in the drawings and described above.

Unless specifically noted otherwise, parts depicted in the drawings are not necessarily drawn to scale.

All examples and conditional expressions listed herein are intended for instructional purposes to assist the reader in understanding the disclosure and the concepts contributed by the inventor to advance the technology, and examples specifically cited as such are It should be interpreted that there are no restrictions on the terms and conditions. Although embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions, and alterations may be made without departing from the spirit and scope of the present disclosure.

Although specific advantages are listed above, various embodiments may or may not include some, all, or all of the listed advantages. Additionally, other technical advantages will become readily apparent to those skilled in the art after review of the foregoing drawings and description.

To assist the Patent and Trademark Office and any reader of any patent issued on this application in interpreting the claims appended hereto, Applicants have used the words ("means for" or "steps for") We wish to note that none of the appended claims or claim elements are intended to make 35 U.S.C. §112(f) apply unless explicitly used in a particular claim.

Claims (18)

As a system:
A boost converter configured to receive an input voltage and step up the input voltage to an output voltage; and
Includes a control circuit,
The control circuit is:
Implement maximum current limiting to limit the current drawn by the boost converter;
A system configured to dynamically increase current above a maximum current limit in response to the output voltage decreasing below the input voltage such that the output voltage is approximately equal to the input voltage. The system of claim 1, wherein the maximum current limit is based on determination of the maximum current level that ensures protection of components of the boost converter or components electrically coupled to the boost converter. 3. The system of claim 1 or 2, wherein the control circuit implements a feedback loop that controls the output voltage and a current to adjust the output voltage based on the input voltage. 4. The method of any one of claims 1 to 3, wherein the control circuit further:
Continuously increase the current when the output voltage is less than the input voltage and the current is greater than the maximum current limit;
A system configured to continuously reduce current when the output voltage is greater than the input voltage and the current is greater than the maximum current limit. According to clause 4,
When the output voltage is less than the input voltage and the current is greater than the maximum current limit, the rate of increase of the current is non-linear;
When the output voltage is greater than the input voltage and the current is greater than the maximum current limit, the rate of reduction of the current is non-linear, system. According to clause 5,
The rate of increase is a function of the time after which the control circuit enters an attack state where the output voltage is less than the input voltage and the current is greater than the maximum current limit;
wherein the rate of decay is a function of the time after the control circuit enters a release state where the output voltage is greater than the input voltage and the current is greater than the maximum current limit. 7. The system of any one of claims 4 to 6, wherein the control circuit is further configured to continuously increase the current when the output voltage is greater than the input voltage and the output voltage is less than the threshold voltage. 8. The method of any one of claims 4 to 7, wherein the control circuit is further configured to continuously reduce the current when the output voltage is greater than the threshold voltage and the current is greater than the maximum current limit, and the control circuit is further configured to continuously reduce the current when the output voltage is greater than the threshold voltage. The second rate of reduction that occurs when the output voltage is greater than the input voltage and the current is less than the maximum current limit is different from the rate of decrease that occurs when the output voltage is greater than the input voltage and the current is less than the maximum current limit. 9. The system of claim 8, wherein the second rate of decay that occurs when the output voltage is greater than the threshold voltage and the current is greater than the maximum current limit is less than the rate of decrease when the output voltage is greater than the input voltage and the current is less than the maximum current limit. As a method:
enforcing a maximum current limit to limit the current drawn by a boost converter configured to receive an input voltage and step up the input voltage to an output voltage; and
In response to the output voltage decreasing below the input voltage, dynamically increasing the current above the maximum current limit such that the output voltage is approximately equal to the input voltage. 11. The method of claim 10, wherein the maximum current limit is based on determination of a maximum current level that ensures protection of components of the boost converter or components electrically coupled to the boost converter. 12. The method of claim 10 or 11, further comprising implementing a feedback loop that controls the output voltage and the current to adjust the output voltage based on the input voltage. According to any one of claims 10 to 12,
Continuously increasing the current when the output voltage is less than the input voltage and the current is greater than the maximum current limit; and
The method further comprising continuously reducing the current when the output voltage is greater than the input voltage and the current is greater than the maximum current limit. According to clause 13,
When the output voltage is less than the input voltage and the current is greater than the maximum current limit, the rate of increase of the current is non-linear;
When the output voltage is greater than the input voltage and the current is greater than the maximum current limit, the rate of reduction of the current is nonlinear. According to clause 14,
The rate of increase is a function of the time after which the control circuit enters an attack state where the output voltage is less than the input voltage and the current is greater than the maximum current limit;
wherein the rate of decay is a function of the time after the control circuit enters a release state where the output voltage is greater than the input voltage and the current is greater than the maximum current limit. 16. The method of any one of claims 13-15, further comprising continuously increasing the current when the output voltage is greater than the input voltage and the output voltage is less than the threshold voltage. 17. The method of any one of claims 13 to 16, further comprising continuously reducing the current when the output voltage is greater than the threshold voltage and the current is greater than the maximum current limit,
The second rate of reduction that occurs when the output voltage is greater than the threshold voltage and the current is greater than the maximum current limit is different from the rate of decrease when the output voltage is greater than the input voltage and the current is less than the maximum current limit. 18. The method of claim 17, wherein the second rate of decrease that occurs when the output voltage is greater than the threshold voltage and the current is greater than the maximum current limit is less than the rate of decrease when the output voltage is greater than the input voltage and the current is less than the maximum current limit.

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