Patent ID: 12191766

DETAILED DESCRIPTION

FIG.2illustrates a circuit diagram of selected components of an example hybrid 3-level buck-boost converter200A, in accordance with embodiments of the present disclosure. As shown inFIG.2, hybrid 3-level buck-boost converter200A may include an input configured to receive an input voltage VINand an output configured to generate an output voltage VOUT. Further, hybrid 3-level buck-boost converter200A may include a switching node having a voltage Lx. Hybrid 3-level buck-boost converter200A may also include a power inductor202coupled between the switching node and the output. Moreover, hybrid 3-level buck-boost converter200A may include a flying capacitor204having a first flying capacitor terminal and a second flying capacitor terminal and a pump capacitor208having a first pump capacitor terminal and a second pump capacitor terminal, wherein the second pump capacitor terminal may be coupled to ground. In addition, hybrid 3-level buck-boost converter200A may include a plurality of switches206a,206b,206c,206d,206e, and206f, wherein switch206ais coupled between the input and the first flying capacitor terminal, switch206bis coupled between the first flying capacitor terminal and the switching node, switch206cis coupled between the second flying capacitor terminal and the switching node, switch206dis coupled between the second flying capacitor terminal and a ground voltage, switch206eis coupled between the second flying capacitor terminal and the first pump capacitor terminal, and switch206fis coupled between the output and the first pump capacitor terminal.

In operation, a control circuit (not shown for purposes of clarity and exposition) may control switching of switches206a,206b,206c,206d,206e, and206fto regulate output voltage VOUTto a desired target voltage. To that end, the control circuit may cause hybrid 3-level buck-boost converter200A to operate, at any given time, in one of a plurality of modes, as depicted inFIGS.3-8, and described in greater detail below.

Perhaps most advantageously over the existing topology shown inFIG.1, hybrid 3-level buck-boost converter200A may be operated in a forward hybrid boost mode, depicted inFIG.3, which enables regulation of output voltage VOUTto a desired target voltage greater than 2VIN. As shown inFIG.3, operation in the forward hybrid boost mode may include commutation of switches between a first phase (φ1) and a second phase (φ2). Switch206bmay remain activated and switch206cmay remain deactivated during both the first phase and the second phase, and switches206a,206d,206e, and206fmay be commutated to regulate output voltage VOUT, with switches206aand206dactivated (and switch206edeactivated) during the first phase, and switch206eactivated (and switches206a,206d, and206fdeactivated) during the second phase. During the first phase, a voltage VPUMPacross pump capacitor208may be charged to output voltage VOUT, allowing the switching node voltage Lxto switch between VINand VOUT+VIN. Accordingly, output voltage VOUTis not limited to 2VIN, and may be set to a desired target voltage greater than 2VIN. Notably, by swapping the input and output of hybrid 3-level buck-boost converter200A, hybrid 3-level buck-boost converter200A may operate the same two phases depicted inFIG.3in order to operate in a reverse hybrid buck mode.

In addition, hybrid 3-level buck-boost converter200A may be operated in a bypass mode, depicted inFIG.4, which bypasses input voltage VINto output voltage VOUT. Accordingly, through the entirety of operation in bypass mode, switches206aand206bmay remain activated, such that input voltage VINpasses to output voltage VOUTvia switches206aand206band power inductor202. In some embodiments, switches206c,206e, and206fmay also be activated in addition to or in lieu of switches206aand206b, in order to reduce losses that may occur due to the resistance of power inductor202.

Further, hybrid 3-level buck-boost converter200A may be operated in a forward 2:1 switched capacitor mode, depicted inFIG.5, which may enable regulation of output voltage VOUTto 2VIN. As shown inFIG.5, operation in the forward 2:1 switched capacitor mode may include commutation of switches between a first phase (φ1) and a second phase (φ2). Switch206fmay remain activated during both the first phase and the second phase, and switches206a,206b,206c,206d, and206emay be commutated to regulate output voltage VOUT, with switches206a,206c, and206eactivated (and switches206band206ddeactivated) during the first phase, and switches206band206dactivated (and switches206a,206c, and206edeactivated) during the second phase.

Moreover, hybrid 3-level buck-boost converter200A may be operated in a forward 2-level buck mode, depicted inFIG.6. As shown inFIG.6, operation in the forward 2-level buck mode may include commutation of switches between a first phase (φ1) and a second phase (φ2). Switches206eand206fmay remain deactivated during both the first phase and the second phase, and switches206a,206b,206c, and206dmay be commutated to regulate output voltage VOUT, with switches206aand206bactivated (and one or both of switches206cand206ddeactivated) during the first phase, and switches206cand206dactivated (and one or both switches206aand206bdeactivated) during the second phase. Notably, by swapping the input and output of hybrid 3-level buck-boost converter200A, hybrid 3-level buck-boost converter200A may operate the same two phases depicted inFIG.6in order to operate in a reverse 2-level boost mode.

Hybrid 3-level buck-boost converter200A may also be operated in a forward 3-level buck mode, depicted inFIGS.7and8. As shown inFIG.7, for duty cycles of less than 0.5, operation in the forward 3-level buck mode may include commutation of switches among a first phase (φ1), a second phase (φ2), a third phase (φ3), and a fourth phase (φ4). Switches206eand206fmay remain deactivated during all four phases, and switches206a,206b,206c, and206dmay be commutated to regulate output voltage VOUT, with switches206aand206cactivated (and switches206band206ddeactivated) during the first phase, switches206cand206dactivated (and switches206aand206bdeactivated) during the second phase, switches206band206dactivated (and switches206aand206cdeactivated) during the third phase, and switches206cand206dactivated (and switches206aand206bdeactivated) during the fourth phase. Further, as shown inFIG.8, for duty cycles of greater than 0.5, operation in the forward 3-level buck mode may include commutation of switches among a first phase (φ1), a second phase (φ2), a third phase (φ3), and a fourth phase (φ4). Switches206eand206fmay remain deactivated during all four phases, and switches206a,206b,206c, and206dmay be commutated to regulate output voltage VOUT, with switches206aand206cactivated (and switches206band206ddeactivated) during the first phase, switches206aand206bactivated (and switches206cand206ddeactivated) during the second phase, switches206band206dactivated (and switches206aand206cdeactivated) during the third phase, and switches206aand206bactivated (and switches206cand206ddeactivated) during the fourth phase. Notably, by swapping the input and output of hybrid 3-level buck-boost converter200A, hybrid 3-level buck-boost converter200A may operate the same four phases depicted inFIGS.7and8in order to operate in a reverse 3-level boost mode.

FIG.9illustrates a circuit diagram of selected components of another example hybrid 3-level buck-boost converter200B, in accordance with embodiments of the present disclosure. Hybrid 3-level buck-boost converter200B may be similar in many respects to hybrid 3-level buck-boost converter200A depicted inFIG.2, except that in addition to those components depicted inFIG.2, hybrid 3-level buck-boost converter200B may include a switch206gcoupled between the first flying capacitor terminal and the first pump capacitor terminal. In operation, a control circuit (not shown for purposes of clarity and exposition) may control switching of switches206a,206b,206c,206d,206e,206f, and206gto regulate output voltage VOUTto a desired target voltage. To that end, the control circuit may cause hybrid 3-level buck-boost converter200B to operate, at any given time, in one of a plurality of modes, similar to those modes depicted inFIGS.3-8, and described in greater detail below with reference toFIGS.10-15.

Similar to that depicted inFIG.3, hybrid 3-level buck-boost converter200B may operate in a forward hybrid boost mode, depicted inFIG.10, which enables regulation of output voltage VOUTto a desired target voltage greater than 2VIN. As shown inFIG.10, operation of hybrid 3-level buck-boost converter200B in the forward hybrid boost mode may be similar to operation of hybrid 3-level buck-boost converter200A in the forward hybrid boost mode, except that in the case of hybrid 3-level buck-boost converter200B, switch206gmay remain deactivated during both the first phase and the second phase. Notably, by swapping the input and output of hybrid 3-level buck-boost converter200B, hybrid 3-level buck-boost converter200B may operate the same two phases depicted inFIG.10in order to operate in a reverse hybrid buck mode.

In addition, similar to that depicted inFIG.4, hybrid 3-level buck-boost converter200B may be operated in a bypass mode, depicted inFIG.11, which bypasses input voltage VINto output voltage VOUTAccordingly, through the entirety of operation in bypass mode, switches206a,206g, and206fmay remain activated, such that input voltage VINpasses to output voltage VOUTvia switches206a,206g, and206f. In some cases, operation of hybrid 3-level buck-boost converter200B in the bypass mode may be preferable to operation of hybrid 3-level buck-boost converter200A in the bypass mode, in that bypassing through power inductor202as shown inFIG.3may lead to losses (e.g., due to DC resistance of power inductor202) that may not occur when power inductor202is bypassed as shown inFIG.11. In some embodiments, switches206b,206c, and206emay also be activated in addition to switches206a,206g, and206f, in order to further minimize losses that may occur due to resistances of switches206a,206g, and206f.

Further, similar to that depicted inFIG.5, hybrid 3-level buck-boost converter200B may be operated in a forward 2:1 switched capacitor mode, depicted inFIG.12, which may enable regulation of output voltage VOUTto 2VIN. As shown inFIG.12, operation in the forward 2:1 switched capacitor mode may include commutation of switches between a first phase (φ1) and a second phase (φ2). Switch206fmay remain activated and switches206band206cmay remain deactivated during both the first phase and the second phase, and switches206a,206d,206e, and206gmay be commutated to regulate output voltage VOUT, with switches206aand206eactivated (and switches206dand206gdeactivated) during the first phase, and switches206dand206gactivated (and switches206aand206edeactivated) during the second phase. In some cases, operation of hybrid 3-level buck-boost converter200B in the forward 2:1 switched capacitor mode may be preferable to operation of hybrid 3-level buck-boost converter200A in the forward 2:1 switched capacitor mode, as no current flows through power inductor202in the forward 2:1 switched capacitor mode of hybrid 3-level buck-boost converter200B, whereas current flowing through power inductor202in the forward 2:1 switched capacitor mode of hybrid 3-level buck-boost converter200A as shown inFIG.5may lead to losses (e.g., due to DC resistance of power inductor202).

Similar to that depicted inFIG.6, hybrid 3-level buck-boost converter200B may operate in a forward 2-level buck mode, depicted inFIG.13, which enables regulation of output voltage VOUTto a desired target voltage greater than 2VIN. As shown inFIG.13, operation of hybrid 3-level buck-boost converter200B in the forward 2-level buck mode may be similar to operation of hybrid 3-level buck-boost converter200A in the forward 2-level buck mode, except that in the case of hybrid 3-level buck-boost converter200B, switch206gmay remain deactivated during both the first phase and the second phase. Notably, by swapping the input and output of hybrid 3-level buck-boost converter200B, hybrid 3-level buck-boost converter200B may operate the same two phases depicted inFIG.13in order to operate in a reverse 2-level boost mode.

Similar to that depicted inFIGS.7and8, hybrid 3-level buck-boost converter200B may operate in a forward 3-level buck mode, depicted inFIGS.14and15. As shown inFIGS.14and15, operation of hybrid 3-level buck-boost converter200B in the forward 3-level buck mode may be similar to operation of hybrid 3-level buck-boost converter200A in the forward 3-level buck mode, except that in the case of hybrid 3-level buck-boost converter200B, switch206gmay remain deactivated during all four phases. Notably, by swapping the input and output of hybrid 3-level buck-boost converter200B, hybrid 3-level buck-boost converter200B may operate the same four phases depicted inFIGS.14and15in order to operate in a reverse 3-level boost mode.

FIG.16illustrates operation of the hybrid 3-level buck-boost converter200B in a forward 3-level buck mode with flying capacitor balancing for duty cycles less than 0.5, in accordance with embodiments of the present disclosure. Similarly,FIG.17illustrates operation of the hybrid 3-level buck-boost converter200B in a forward 3-level buck mode with flying capacitor balancing for duty cycles greater than 0.5, in accordance with embodiments of the present disclosure.

Operation of hybrid 3-level buck-boost converter200B in the flying capacitor balancing forward 3-level buck mode may be similar to operation of the forward 3-level buck mode depicted inFIG.14. As shown inFIG.16, for duty cycles of less than 0.5, operation in the flying capacitor balancing forward 3-level buck mode may include commutation of switches among a first phase (φ1), a second phase (φ2), a third phase (φ3), and a fourth phase (φ4). Switch206fmay remain deactivated during all four phases, and switches206a,206b,206c,206d,206e, and206gmay be commutated to regulate output voltage VOUT, with switches206a,206c, and206eactivated (and switches206b,206dand206gdeactivated) during the first phase, switches206cand206dactivated (and switches206a,206b,206e, and206gdeactivated) during the second phase, switches206b,206d, and206gactivated (and switches206a,206cand206edeactivated) during the third phase, and switches206cand206dactivated (and switches206a,206b,206e, and206gdeactivated) during the fourth phase. Further, as shown inFIG.17, for duty cycles of greater than 0.5, operation in the flying capacitor balancing forward 3-level buck mode may include commutation of switches among a first phase (φ1), a second phase (φ2), a third phase (φ3), and a fourth phase (φ4). Switch206fmay remain deactivated during all four phases, and switches206a,206b,206c,206d,206e, and206gmay be commutated to regulate output voltage \Tour, with switches206a,206c, and206eactivated (and switches206b,206d, and206gdeactivated) during the first phase, switches206aand206bactivated (and switches206c,206d,206e, and206gdeactivated) during the second phase, switches206b,206d, and206gactivated (and switches206a,206c, and206edeactivated) during the third phase, and switches206aand206bactivated (and switches206c,206d,206e, and206gdeactivated) during the fourth phase. Notably, by swapping the input and output of hybrid 3-level buck-boost converter200A, hybrid 3-level buck-boost converter200A may operate the same four phases depicted inFIGS.16and17in order to operate in a reverse 3-level boost mode.

A main difference between operation in the flying capacitor balancing forward 3-level buck mode ofFIGS.16and17and operating in the forward 3-level buck mode ofFIGS.14and15, is that in the flying capacitor balancing forward 3-level buck mode, flying capacitor204may be coupled in series with pump capacitor208during the first phase (e.g., via switch206e) and flying capacitor204may be coupled in parallel with pump capacitor208during the third phase (e.g., via switch206g), which in turn may cause a voltage across flying capacitor204to remain balanced at a voltage VIN/2.

In some embodiments, certain components of either of hybrid 3-level buck-boost converter200A and hybrid 3-level buck-boost converter200B may be formed within a single integrated circuit while other components may reside external to such integrated circuit. For example, in some embodiments, switches206a,206b,206c,206d,206e,206f, and206g, as well as control circuitry for controlling switches206a,206b,206c,206d,206e,206f, and206g, may reside on an integrated circuit, while power inductor202, flying capacitor204, and pump capacitor208are external to such integrated circuit. As another example, flying capacitor204, pump capacitor208, and switches206a,206b,206c,206d,206e,206f, and206g, as well as control circuitry for controlling switches206a,206b,206c,206d,206e,206f, and206g, may reside on an integrated circuit, while power inductor202resides external to such integrated circuit.

As used herein, when two or more elements are referred to as “coupled” to one another, such term indicates that such two or more elements are in electronic communication or mechanical communication, as applicable, whether connected indirectly or directly, with or without intervening elements.

This disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. Accordingly, modifications, additions, or omissions may be made to the systems, apparatuses, and methods described herein without departing from the scope of the disclosure. For example, the components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses disclosed herein may be performed by more, fewer, or other components and the methods described may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order. As used in this document, “each” refers to each member of a set or each member of a subset of a set.

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

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

All examples and conditional language recited herein are intended for pedagogical objects to aid the reader in understanding the disclosure and the concepts contributed by the inventor to furthering the art, and are construed as being without limitation to such specifically recited examples and conditions. Although embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the disclosure.

Although specific advantages have been enumerated above, various embodiments may include some, none, or all of the enumerated advantages. Additionally, other technical advantages may become readily apparent to one of ordinary skill in the art after review of the foregoing figures and description.

To aid the Patent Office and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims or claim elements to invoke 35 U.S.C. § 112(f) unless the words “means for” or “step for” are explicitly used in the particular claim.