WO2017222568A1 - Multi-mode switching power converter - Google Patents

Multi-mode switching power converter Download PDF

Info

Publication number
WO2017222568A1
WO2017222568A1 PCT/US2016/040013 US2016040013W WO2017222568A1 WO 2017222568 A1 WO2017222568 A1 WO 2017222568A1 US 2016040013 W US2016040013 W US 2016040013W WO 2017222568 A1 WO2017222568 A1 WO 2017222568A1
Authority
WO
WIPO (PCT)
Prior art keywords
switch
terminal
power converter
coupled
switches
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2016/040013
Other languages
French (fr)
Inventor
Xiangcheng Wang
Eric J. King
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cirrus Logic International Semiconductor Ltd
Original Assignee
Cirrus Logic International Semiconductor Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cirrus Logic International Semiconductor Ltd filed Critical Cirrus Logic International Semiconductor Ltd
Publication of WO2017222568A1 publication Critical patent/WO2017222568A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/10—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • H02M3/1582—Buck-boost converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/10—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
    • H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
    • H03F1/0211—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers with control of the supply voltage or current
    • H03F1/0216—Continuous control
    • H03F1/0222—Continuous control by using a signal derived from the input signal
    • H03F1/0227—Continuous control by using a signal derived from the input signal using supply converters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/181—Low-frequency amplifiers, e.g. audio preamplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
    • H04R1/1041—Mechanical or electronic switches, or control elements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers
    • H04R3/04—Circuits for transducers for correcting frequency response
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0048—Circuits or arrangements for reducing losses
    • H02M1/0054—Transistor switching losses
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/03—Indexing scheme relating to amplifiers the amplifier being designed for audio applications
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/102—A non-specified detector of a signal envelope being used in an amplifying circuit
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
    • H04R1/1016—Earpieces of the intra-aural type
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the present disclosure relates in general to circuits for audio devices, including without limitation personal audio devices such as wireless telephones and media players, and more specifically, to a switch mode amplifier including a reconfigurable switched mode converter for driving an audio transducer of an audio device.
  • Personal audio devices including wireless telephones, such as mobile/cellular telephones, cordless telephones, mp3 players, and other consumer audio devices, are in widespread use.
  • Such personal audio devices may include circuitry for driving a pair of headphones or one or more speakers.
  • Such circuitry often includes a speaker driver including a power amplifier for driving an audio output signal to headphones or speakers.
  • Speaker driver 100 may include an envelope-tracking boost converter 102 (e.g., a Class H amplifier) followed by a full-bridge output stage 104 (e.g., a Class D amplifier) which effectively operates as another converter stage.
  • Boost converter 102 may include a power inductor 105, switches 106, 108, and a capacitor 110 arranged as shown.
  • Full-bridge output stage 104 may include switches 112, 114, 116, and 118, inductors 120 and 124, and capacitors 122 and 126 as shown.
  • Speaker drivers such as speaker driver 100 suffer from numerous disadvantages.
  • One disadvantage is that due to switching in output stage 104, such a speaker driver 100 may give rise to large amounts of radiated electromagnetic radiation, which may cause interference with other electromagnetic signals.
  • Such radiated electromagnetic interference may be mitigated by LC or resonant filters formed using inductor 120 and capacitor 122 and inductor 124 and capacitor 126.
  • LC filters are often quite large in size, and coupling capacitors 122 and 126 to the terminals of the output transducer may have a negative impact on the power efficiency of speaker driver 100.
  • boost converter 102 may operate at switching frequencies up to several megahertz, and full-bridge output stage may operate at switching frequencies up to several hundred kilohertz to generate an audio band frequency signal, which may result in high switching power loss.
  • reducing switching frequency may reduce switching loss but may require increases in physical dimension sizes of boost inductor 105 and output inductive-capacitive filters (not shown).
  • a typical edge slew rate control may be applied to full-bridge output stage 104, causing even higher switching loss.
  • an output voltage VEST generated by boost converter 102 may be varied in accordance with the output signal, such that output voltage VEST may operate at lower voltage levels for lower output signal magnitudes.
  • VEST may operate at lower voltage levels for lower output signal magnitudes.
  • one or more disadvantages and problems associated with existing approaches to driving an audio output signal to an audio transducer may be reduced or eliminated.
  • a multi-mode switching power converter may include a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal.
  • a method may include, in a multi-mode switching power converter comprising a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal, sequentially operating the first switch, the second switch, and the plurality of switches in a plurality of switch configurations in accordance with a selected operational mode of the power converter, the selected operational mode selected from a plurality of operational modes.
  • a switching power stage for producing an output voltage to a load may include a multi- mode switching power converter and a controller.
  • the multi-mode switching power converter may include a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal.
  • the controller may be configured to sequentially operate the first switch, the second switch, and the plurality of switches in a plurality of switch configurations in accordance with a selected operational mode of the power converter, the selected operational mode selected from a plurality of operational modes.
  • FIGURE 1 illustrates an example speaker driver, as is known in the relevant art
  • FIGURE 2 illustrates an example personal audio device, in accordance with embodiments of the present disclosure
  • FIGURE 3 illustrates a block diagram of selected components of an example audio integrated circuit of a personal audio device, in accordance with embodiments of the present disclosure
  • FIGURE 4 illustrates a block and circuit diagram of selected components of an example switched mode amplifier, in accordance with embodiments of the present disclosure
  • FIGURE 5 illustrates a circuit diagram of selected components of an example power converter, in accordance with embodiments of the present disclosure
  • FIGURE 6 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a buck mode, in accordance with embodiments of the present disclosure
  • FIGURES 7A-7D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 5 operating in various phases of a buck mode in accordance with the switch timing table of FIGURE 6, in accordance with embodiments of the present disclosure
  • FIGURE 8 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a boost mode, in accordance with embodiments of the present disclosure
  • FIGURES 9A-9D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 5 operating in various phases of a boost mode in accordance with the switch timing table of FIGURE 8, in accordance with embodiments of the present disclosure
  • FIGURE 10 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a differential buck-boost mode, in accordance with embodiments of the present disclosure
  • FIGURES 11 A- l lC illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 5 operating in various phases of a differential buck- boost in accordance with the switch timing table of FIGURE 10, in accordance with embodiments of the present disclosure;
  • FIGURE 12 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure
  • FIGURE 13 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure
  • FIGURE 14 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck mode, in accordance with embodiments of the present disclosure
  • FIGURES 15A-15D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 13 operating in various phases of a buck mode in accordance with the switch timing table of FIGURE 14, in accordance with embodiments of the present disclosure
  • FIGURE 16 illustrates a table setting forth switch configurations of the power converter of FIGURE 13 when operating in a boost mode, in accordance with embodiments of the present disclosure
  • FIGURES 17A-17D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 13 operating in various phases of a boost mode, in accordance with embodiments of the present disclosure
  • FIGURE 18 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck-boost mode, in accordance with embodiments of the present disclosure
  • FIGURES 19A-19D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 13 operating in various phases of a buck-boost mode in accordance with the switch timing table of FIGURE 18, in accordance with embodiments of the present disclosure;
  • FIGURE 20 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure
  • FIGURE 21 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure.
  • FIGURE 2 illustrates an example personal audio device 1, in accordance with embodiments of the present disclosure.
  • FIGURE 2 depicts personal audio device 1 coupled to a headset 3 in the form of a pair of earbud speakers 8 A and 8B.
  • Headset 3 depicted in FIGURE 2 is merely an example, and it is understood that personal audio device 1 may be used in connection with a variety of audio transducers, including without limitation, headphones, earbuds, in-ear earphones, and external speakers.
  • a plug 4 may provide for connection of headset 3 to an electrical terminal of personal audio device 1.
  • Personal audio device 1 may provide a display to a user and receive user input using a touch screen 2, or alternatively, a standard liquid crystal display (LCD) may be combined with various buttons, sliders, and/or dials disposed on the face and/or sides of personal audio device 1.
  • personal audio device 1 may include an audio integrated circuit (IC) 9 for generating an analog audio signal for transmission to headset 3 and/or another audio transducer.
  • IC audio integrated circuit
  • FIGURE 3 illustrates a block diagram of selected components of an example audio IC 9 of a personal audio device, in accordance with embodiments of the present disclosure.
  • a microcontroller core 18 may supply a digital audio input signal DIG_IN to a digital-to-analog converter (DAC) 14, which may convert the digital audio input signal to an analog signal V M .
  • DAC 14 may supply analog signal to an amplifier 16 which may amplify or attenuate audio input signal VI to provide an audio output signal VOUT, which may operate a speaker, a headphone transducer, a line level signal output, and/or other suitable output.
  • DAC 14 may be an integral component of amplifier 16.
  • a power supply 10 may provide the power supply rail inputs of amplifier 16.
  • power supply 10 may comprise a battery.
  • FIGURES 2 and 3 contemplate that audio IC 9 resides in a personal audio device, systems and methods described herein may also be applied to electrical and electronic systems and devices other than a personal audio device, including audio systems for use in a computing device larger than a personal audio device, an automobile, a building, or other structure.
  • FIGURE 4 illustrates a block and circuit diagram of selected components of an example switched mode amplifier 20, in accordance with embodiments of the present disclosure.
  • switched mode amplifier 20 may implement all or a portion of amplifier 16 described with respect to FIGURE 3.
  • switched mode amplifier 20 may comprise a loop filter 22, a converter controller 24, and a power converter 26.
  • Loop filter 22 may comprise any system, device, or apparatus configured to receive an input signal (e.g., audio input signal VIN or a derivative thereof) and a feedback signal (e.g., audio output signal VOUT, a derivative thereof, or other signal indicative of audio output signal VOUT) and based on such input signal and feedback signal, generate a controller input signal to be communicated to converter controller 24.
  • a controller input signal may comprise a signal indicative of an integrated error between the input signal and the feedback signal.
  • such controller input signal may comprise a signal indicative of a target current signal to be driven as an output current ⁇ or a target voltage signal to be driven as an output voltage VOUT to a load coupled to the output terminals of power converter 26.
  • Converter controller 24 may comprise any system, device, or apparatus configured to, based on the controller input signal, sequentially select among a plurality of switch configurations of power converter 26 and based on an input signal (e.g., input signal INPUT), output signal V 0 UT, and/or other characteristics of switched mode amplifier 20, communicate a plurality of control signals to power converter 26 to apply a switch configuration from a plurality of switch configurations of switches of power converter 26 to selectively activate or deactivate each of the plurality of switches in order to transfer electrical energy from a power supply VSUPPLY to the load of switched mode amplifier 20 in accordance with the input signal. Examples of switch configurations associated with each are described in greater detail elsewhere in this disclosure. In addition, in some embodiments, converter controller 24 may control switches of a power converter 26 in order to regulate a common mode voltage of the output terminals of power converter 26, as described in greater detail below.
  • an input signal e.g., input signal INPUT
  • V 0 UT output signal
  • converter controller 24 may control switches of a
  • Power converter 26 may receive a voltage VSUPPLY (e.g., provided by power supply 10) at its input, and may generate at its output audio output signal VOUT- Although not explicitly shown in FIGURE 3, in some embodiments, voltage VSUPPLY may be received via input terminals including a positive input terminal and a negative input terminal which may be coupled to a ground voltage. As described in greater detail in this disclosure, power converter 26 may comprise a power inductor and a plurality of switches that are controlled by control signals received from converter controller 24 in order to convert voltage VSUPPLY to audio output signal V 0 UT > such that audio output signal V 0 UT is a function of the input signal to loop filter 22. Examples of power converter 26 are described in greater detail elsewhere in this disclosure.
  • FIGURE 5 illustrates a circuit diagram of selected components of an example power converter 26A, in accordance with embodiments of the present disclosure.
  • power converter 26A depicted in FIGURE 5 may implement all or a portion of power converter 26 described with respect to FIGURE 4.
  • power converter 26 A may receive a voltage VSUPPLY (e.g., provided by power supply 10) at input terminals, including a positive input terminal and a negative input terminal (which may in some embodiments be coupled to a ground voltage), and may generate at its output an output voltage VOUT- Power converter 26A may comprise a power inductor 62 and plurality of switches 51-60.
  • VSUPPLY e.g., provided by power supply 10
  • Power inductor 62 may comprise any passive two-terminal electrical component which resists changes in electrical current passing through it and such that when electrical current flowing through it changes, a time-varying magnetic field induces a voltage in power inductor 62, in accordance with Faraday's law of electromagnetic induction, which opposes the change in current that created the magnetic field.
  • Each switch 51-60 may comprise any suitable device, system, or apparatus for making a connection in an electric circuit when the switch is enabled (e.g., activated, closed, or on) and breaking the connection when the switch is disabled (e.g., deactivated, open, or off) in response to a control signal received by the switch.
  • control signals for switches 51-60 e.g., control signals communicated from converter controller 24
  • a switch 51-60 may comprise an n-type metal-oxide-semiconductor field- effect transistor.
  • Switch 51 may be coupled between a positive input terminal of the supply voltage VSUPPLY and a first terminal of power inductor 62 such that an anode of a body diode of switch 51 is coupled to the first terminal of power inductor 62 and a cathode of the body diode of switch 51 is coupled to the positive input terminal of the supply voltage VSUPPLY-
  • Switch 52 may be coupled between a negative input terminal of the supply voltage VSUPPLY and the first terminal of power inductor 62 such that a cathode of a body diode of switch 52 is coupled to the first terminal of power inductor 62 and an anode of the body diode of switch 52 is coupled to the negative input terminal of the supply voltage VSUPPLY- Together, switch 51 and switch 52 may form a half bridge.
  • Switch 53 may be coupled between a second terminal of power inductor 62 and a terminal of switch 54.
  • Switch 54 may be coupled between a first output terminal of power converter 26A and a terminal of switch 53.
  • Switches 53 and 54 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes. In some embodiments, switches 53 and 54 may be combined into a single switch.
  • Switch 55 may be coupled between the first output terminal of power converter 26A and a terminal of switch 56.
  • Switch 56 may be coupled between the negative input terminal of the supply voltage VSUPPLY and a terminal of switch 55.
  • Switches 55 and 56 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes.
  • switches 55 and 56 may be combined into a single switch.
  • Switch 57 may be coupled between the second terminal of power inductor 62 and a terminal of switch 58.
  • Switch 58 may be coupled between a second output terminal of power converter 26A and a terminal of switch 57.
  • Switches 57 and 58 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes.
  • switches 57 and 58 may be combined into a single switch.
  • Switch 59 may be coupled between the second output terminal of power converter 26A and a terminal of switch 60.
  • Switch 60 may be coupled between the negative input terminal of the supply voltage VSUPPLY and a terminal of switch 59.
  • Switches 59 and 60 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes. In some embodiments, switches 59 and 60 may be combined into a single switch.
  • switches 53-60 may comprise a full bridge having a first terminal coupled to the second terminal of power inductor 62 and a second terminal coupled to the second terminal of the supply voltage VSUPPLY-
  • power converter 26 A may include an output capacitor 64 coupled between the first output terminal of power converter 26A and the second output terminal of power converter 26A.
  • switches 51 and 52 may switch at a switching frequency up to several megahertz while the full-bridge output stage comprising switches 53-60 may switch at an audio-band frequency (e.g., 20 Hz to 20 KHz) in order to rectify output voltage VOUT, resulting in a substantial reduction in switching loss as compared with full-bridge output stage 104 depicted in FIGURE 1.
  • an audio-band frequency e.g., 20 Hz to 20 KHz
  • FIGURE 6 illustrates a table setting forth switch configurations of the power converter of FIGURE 5 when operating in a buck mode, in accordance with embodiments of the present disclosure.
  • Power converter 26A may operate in a buck mode when output voltage VOUT has a magnitude lower than that for which the duration of a charging phase Tl becomes too small to operate power converter 26A in a boost mode (e.g., IVQUTI ⁇ VSUPPLY)- AS shown in FIGURE 6, during a charging phase Tl of power converter 26A, when output voltage VOUT is positive, converter controller 24 may enable switches 51, 53, 54, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7A (closed switches shown, open switches removed).
  • a boost mode e.g., IVQUTI ⁇ VSUPPLY
  • converter controller 24 may enable switches 52, 53, 54, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7B (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 51, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7C (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 52, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7D (closed switches shown, open switches removed).
  • FIGURE 8 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a boost mode, in accordance with embodiments of the present disclosure.
  • switches 51 and 52 may switch at a switching frequency of several megahertz, while switches 53-60 may switch at an audio band frequency of approximately 20 Hz to 20 KHz.
  • Power converter 26A may operate in a boost mode when output voltage VOUT has a magnitude higher than that for which the duration of a charging phase Tl becomes too large to operate power converter 26A in a buck mode (e.g., IVOUTI > VSUPPLY)- AS shown in FIGURE 8, during a charging phase Tl of power converter 26A, when output voltage VOUT is positive, converter controller 24 may enable switches 51, 53, 54, 55, and 56 of power converter 26 A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9A (closed switches shown, open switches removed).
  • a boost mode when output voltage VOUT has a magnitude higher than that for which the duration of a charging phase Tl becomes too large to operate power converter 26A in a buck mode (e.g., IVOUTI > VSUPPLY)- AS shown in FIGURE 8
  • converter controller 24 may enable switches 51, 53, 54, 55, and 56 of power converter 26 A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9A (closed switches
  • converter controller 24 may enable switches 51, 53, 54, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9B (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 51, 57, 58, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9C (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 51, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9D (closed switches shown, open switches removed).
  • FIGURE 10 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a differential buck-boost mode, in accordance with embodiments of the present disclosure.
  • switches 51 and 52 may switch at a switching frequency of several megahertz, while switches 53-60 may switch at an audio band frequency of approximately 20 Hz to 20 KHz.
  • Power converter 26A may operate in the differential buck-boost mode for very low magnitudes (e.g., IVOUTI 3 ⁇ 4 0).
  • converter controller 24 may enable switches 52, 53, 54, 59, and 60 of power converter 26 A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 11 A (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 51, 57, 58, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 11B (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 52, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 11C (closed switches shown, open switches removed). Accordingly, output voltage VOUT may be regulated by adjusting an on-time difference between phases Tl and T3, including regulating at a voltage of zero when the on-times of phases Tl and T3 are the same.
  • FIGURE 12 illustrates a circuit diagram of selected components of another example power converter 26B, in accordance with embodiments of the present disclosure.
  • power converter 26B depicted in FIGURE 12 may implement all or a portion of power converter 26 described with respect to FIGURE 4.
  • Power converter 26B depicted in FIGURE 12 may in many respects be identical to power converter 26A of FIGURE 5, and thus only the differences between power converter 26B and power converter 26A are discussed.
  • power converter 26B includes another switch 61 coupled between the second terminal of power inductor 62 and the second terminal of supply voltage VSUPPLY-
  • switch 61 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a diode of its body diode is coupled to the second terminal of power inductor 62.
  • Switch 61 may be enabled at certain times (e.g., when switches 53, 54, 55, and 56 are enabled or when switches 57, 58, 59, and 60 are enabled, so as to reduce a conduction resistance to minimize power loss in either of the boost mode or buck mode.
  • FIGURE 13 illustrates a circuit diagram of selected components of another example power converter 26C, in accordance with embodiments of the present disclosure.
  • power converter 26C depicted in FIGURE 13 may implement all or a portion of power converter 26 described with respect to FIGURE 4.
  • power converter 26C may receive a voltage VSUPPLY (e.g., provided by power supply 10) at input terminals, including a positive input terminal and a negative input terminal (which may in some embodiments be coupled to a ground voltage), and may generate at its output an output voltage VOUT- Power converter 26C may comprise a power inductor 82 and plurality of switches 71-78.
  • VSUPPLY e.g., provided by power supply 10
  • Power inductor 82 may comprise any passive two-terminal electrical component which resists changes in electrical current passing through it and such that when electrical current flowing through it changes, a time-varying magnetic field induces a voltage in power inductor 82, in accordance with Faraday's law of electromagnetic induction, which opposes the change in current that created the magnetic field.
  • Each switch 71-78 may comprise any suitable device, system, or apparatus for making a connection in an electric circuit when the switch is enabled (e.g., activated, closed, or on) and breaking the connection when the switch is disabled (e.g., deactivated, open, or off) in response to a control signal received by the switch.
  • control signals for switches 71-78 e.g., control signals communicated from converter controller 24
  • a switch 71-78 may comprise an n-type metal-oxide-semiconductor field- effect transistor.
  • Switch 71 may be coupled between a positive input terminal of the supply voltage VSUPPLY and a first terminal of power inductor 82 such that an anode of a body diode of switch 71 is coupled to the first terminal of power inductor 82 and a cathode of the body diode of switch 71 is coupled to the positive input terminal of the supply voltage VSUPPLY-
  • Switch 72 may be coupled between a negative input terminal of the supply voltage VSUPPLY and the first terminal of power inductor 72 such that a cathode of a body diode of switch 72 is coupled to the first terminal of power inductor 72 and an anode of the body diode of switch 72 is coupled to the negative input terminal of the supply voltage VSUPPLY- Together, switch 71 and switch 72 may form a half bridge.
  • Switch 73 may be coupled between the second terminal of power inductor 82 and the second terminal of supply voltage VSUPPLY- In addition, switch 73 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a diode of its body diode is coupled to the second terminal of power inductor 82.
  • Switch 74 may be coupled between the second terminal of power inductor 82 and terminals of switches 75 and 77.
  • switch 74 may be arranged such that an anode of its body diode is coupled to the second terminal of power inductor 82 and a cathode of its body diode is coupled to terminals of switches 75 and 77.
  • Switch 75 may be coupled between a terminal of switch 74 and a first output terminal of power converter 26C.
  • switch 75 may be arranged such that an anode of its body diode is coupled to the first output terminal of power converter 26C and a cathode of its body diode is coupled to terminals of switches 74 and 77.
  • Switch 76 may be coupled between the second terminal of supply voltage VSUPPLY and the first output terminal of power converter 26C. In addition, switch 76 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a cathode of its body diode is coupled to the first output terminal of power converter 26C.
  • Switch 77 may be coupled between a terminal of switch 74 and a second output terminal of power converter 26C. In addition, switch 77 may be arranged such that an anode of its body diode is coupled to the second output terminal of power converter 26C and a cathode of its body diode is coupled to terminals of switches 74 and 75.
  • Switch 78 may be coupled between the second terminal of supply voltage VSUPPLY and the second output terminal of power converter 26C.
  • switch 78 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a cathode of its body diode is coupled to the second output terminal of power converter 26C.
  • switches 75-78 may comprise a full bridge having a first terminal coupled to the second terminal of power inductor 82 via switch 74 and a second terminal coupled to the second terminal of the supply voltage VSUPPLY-
  • power converter 26C may include an output capacitor 84 coupled between the first output terminal of power converter 26C and the second output terminal of power converter 26C.
  • switches 71-74 may switch at a switching frequency up to several megahertz while the full-bridge output stage comprising switches 53-60 may switch at an audio-band frequency (e.g., 20 Hz to 20 KHz) in order to rectify output voltage VOUT, resulting in a substantial reduction in switching loss as compared with full-bridge output stage 104 depicted in FIGURE 1.
  • FIGURE 14 illustrates a switch table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck mode, in accordance with embodiments of the present disclosure.
  • Power converter 26C may operate in a buck mode when output voltage VOUT has a magnitude lower than that for which the duration of a charging phase Tl becomes too small to operate power converter 26C in a boost mode (e.g., IVOUTI ⁇ VSUPPLY)- AS shown in FIGURE 14, during a charging phase Tl of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 71 , 74, 75, and 78 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15 A (closed switches shown, open switches removed).
  • a boost mode e.g., IVOUTI ⁇ VSUPPLY
  • converter controller 24 may enable switches 72, 74, 75, and 78, of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15B (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 71, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15C (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 72, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15D (closed switches shown, open switches removed).
  • FIGURE 16 illustrates a switching timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a boost mode, in accordance with embodiments of the present disclosure.
  • Power converter 26C may operate in a buck mode when output voltage V 0 UT has a magnitude lower than that for which the duration of a charging phase Tl becomes too large to operate power converter 26C in a buck mode (e.g., IVOUTI > VSUPPLY)- AS shown in FIGURE 16, during a charging phase Tl of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17A (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 71, 74, 75, and 78, of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17B (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17C (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 71, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17D (closed switches shown, open switches removed).
  • FIGURE 18 illustrates a switching timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck-boost mode, in accordance with embodiments of the present disclosure.
  • converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 19A (closed switches shown, open switches removed).
  • FIGURE 19A closed switches shown, open switches removed.
  • FIGURE 19B closed switches shown, open switches removed.
  • converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 19C (closed switches shown, open switches removed).
  • converter controller 24 may enable switches 72, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 19D (closed switches shown, open switches removed).
  • FIGURE 20 illustrates a circuit diagram of selected components of another example power converter 26D, in accordance with embodiments of the present disclosure.
  • power converter 26D depicted in FIGURE 20 may implement all or a portion of power converter 26 described with respect to FIGURE 4.
  • Power converter 26D depicted in FIGURE 20 may in many respects be identical to power converter 26C of FIGURE 13, and thus only the differences between power converter 26D and power converter 26C are discussed.
  • the main differences between power converter 26D and power converter 26C are that:
  • switch 74A is added in series with switch 75;
  • switch 74B is added in series with switch 77.
  • Power converter 26D may have the same operating modes as described above with respect to power converter 26C.
  • switch 74A When output voltage VOUT is positive, switch 74A may have the same function as and operate like switch 74 of power converter 26C and switch 74B may be disabled.
  • switch 74B When output voltage VOUT is negative, switch 74B may have the same function as and operate like switch 74 of power converter 26C and switch 74A may be disabled.
  • FIGURE 21 illustrates a circuit diagram of selected components of another example power converter 26E, in accordance with embodiments of the present disclosure.
  • power converter 26E depicted in FIGURE 21 may implement all or a portion of power converter 26 described with respect to FIGURE 4.
  • Power converter 26E depicted in FIGURE 21 may in many respects be identical to power converter 26C of FIGURE 13, and thus only the differences between power converter 26E and power converter 26C are discussed.
  • the main differences between power converter 26E and power converter 26C are that:
  • switch 73 present in power converter 26C is not present in power converter 26D and is replaced with an open;
  • switch 74 present in power converter 26C is not present in power converter 26D and is replaced with a short;
  • switch 74A is added in series with switch 76;
  • switch 74B is added in series with switch 78.
  • Power converter 26E may have the same operating modes as power converter 26D, but with fewer components.
  • references 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.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Dc-Dc Converters (AREA)

Abstract

In accordance with embodiments of the present disclosure, a multi-mode switching power converter may include a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal.

Description

MULTI-MODE SWITCHING POWER CONVERTER
FIELD OF DISCLOSURE
The present disclosure relates in general to circuits for audio devices, including without limitation personal audio devices such as wireless telephones and media players, and more specifically, to a switch mode amplifier including a reconfigurable switched mode converter for driving an audio transducer of an audio device.
BACKGROUND
Personal audio devices, including wireless telephones, such as mobile/cellular telephones, cordless telephones, mp3 players, and other consumer audio devices, are in widespread use. Such personal audio devices may include circuitry for driving a pair of headphones or one or more speakers. Such circuitry often includes a speaker driver including a power amplifier for driving an audio output signal to headphones or speakers.
One existing approach to driving an audio output signal is to employ a speaker driver, such as speaker driver 100 depicted in FIGURE 1. Speaker driver 100 may include an envelope-tracking boost converter 102 (e.g., a Class H amplifier) followed by a full-bridge output stage 104 (e.g., a Class D amplifier) which effectively operates as another converter stage. Boost converter 102 may include a power inductor 105, switches 106, 108, and a capacitor 110 arranged as shown. Full-bridge output stage 104 may include switches 112, 114, 116, and 118, inductors 120 and 124, and capacitors 122 and 126 as shown.
Speaker drivers such as speaker driver 100 suffer from numerous disadvantages. One disadvantage is that due to switching in output stage 104, such a speaker driver 100 may give rise to large amounts of radiated electromagnetic radiation, which may cause interference with other electromagnetic signals. Such radiated electromagnetic interference may be mitigated by LC or resonant filters formed using inductor 120 and capacitor 122 and inductor 124 and capacitor 126. However, such LC filters are often quite large in size, and coupling capacitors 122 and 126 to the terminals of the output transducer may have a negative impact on the power efficiency of speaker driver 100. Another disadvantage is that boost converter 102 may operate at switching frequencies up to several megahertz, and full-bridge output stage may operate at switching frequencies up to several hundred kilohertz to generate an audio band frequency signal, which may result in high switching power loss. However, reducing switching frequency may reduce switching loss but may require increases in physical dimension sizes of boost inductor 105 and output inductive-capacitive filters (not shown). To further reduce common-mode electromagnetic interference of full-bridge output stage 104, a typical edge slew rate control may be applied to full-bridge output stage 104, causing even higher switching loss.
In addition, such architectures often do not handle large impulsive signals. To reduce power consumption, an output voltage VEST generated by boost converter 102 may be varied in accordance with the output signal, such that output voltage VEST may operate at lower voltage levels for lower output signal magnitudes. Thus, if a signal quickly increases, adequate time may not be present to increase voltage VEST, thus leading to signal clipping unless a delay is placed in the signal path. However, adding a delay to a signal path may cause incompatibility with other types of audio circuits, such as adaptive noise cancellation circuits.
SUMMARY
In accordance with the teachings of the present disclosure, one or more disadvantages and problems associated with existing approaches to driving an audio output signal to an audio transducer may be reduced or eliminated.
In accordance with embodiments of the present disclosure, a multi-mode switching power converter may include a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal. In accordance with these and other embodiments of the present disclosure, a method may include, in a multi-mode switching power converter comprising a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal, sequentially operating the first switch, the second switch, and the plurality of switches in a plurality of switch configurations in accordance with a selected operational mode of the power converter, the selected operational mode selected from a plurality of operational modes.
In accordance with these and other embodiments of the present disclosure, a switching power stage for producing an output voltage to a load may include a multi- mode switching power converter and a controller. The multi-mode switching power converter may include a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing the output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal. The controller may be configured to sequentially operate the first switch, the second switch, and the plurality of switches in a plurality of switch configurations in accordance with a selected operational mode of the power converter, the selected operational mode selected from a plurality of operational modes. Technical advantages of the present disclosure may be readily apparent to one skilled in the art from the figures, description and claims included herein. The objects and advantages of the embodiments will be realized and achieved at least by 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 examples and explanatory and are not restrictive of the claims set forth in this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
FIGURE 1 illustrates an example speaker driver, as is known in the relevant art; FIGURE 2 illustrates an example personal audio device, in accordance with embodiments of the present disclosure;
FIGURE 3 illustrates a block diagram of selected components of an example audio integrated circuit of a personal audio device, in accordance with embodiments of the present disclosure;
FIGURE 4 illustrates a block and circuit diagram of selected components of an example switched mode amplifier, in accordance with embodiments of the present disclosure;
FIGURE 5 illustrates a circuit diagram of selected components of an example power converter, in accordance with embodiments of the present disclosure;
FIGURE 6 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a buck mode, in accordance with embodiments of the present disclosure;
FIGURES 7A-7D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 5 operating in various phases of a buck mode in accordance with the switch timing table of FIGURE 6, in accordance with embodiments of the present disclosure; FIGURE 8 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a boost mode, in accordance with embodiments of the present disclosure;
FIGURES 9A-9D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 5 operating in various phases of a boost mode in accordance with the switch timing table of FIGURE 8, in accordance with embodiments of the present disclosure;
FIGURE 10 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a differential buck-boost mode, in accordance with embodiments of the present disclosure;
FIGURES 11 A- l lC illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 5 operating in various phases of a differential buck- boost in accordance with the switch timing table of FIGURE 10, in accordance with embodiments of the present disclosure;
FIGURE 12 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure;
FIGURE 13 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure;
FIGURE 14 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck mode, in accordance with embodiments of the present disclosure;
FIGURES 15A-15D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 13 operating in various phases of a buck mode in accordance with the switch timing table of FIGURE 14, in accordance with embodiments of the present disclosure;
FIGURE 16 illustrates a table setting forth switch configurations of the power converter of FIGURE 13 when operating in a boost mode, in accordance with embodiments of the present disclosure;
FIGURES 17A-17D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 13 operating in various phases of a boost mode, in accordance with embodiments of the present disclosure; FIGURE 18 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck-boost mode, in accordance with embodiments of the present disclosure;
FIGURES 19A-19D illustrate equivalent circuit diagrams of selected components of the power converter of FIGURE 13 operating in various phases of a buck-boost mode in accordance with the switch timing table of FIGURE 18, in accordance with embodiments of the present disclosure;
FIGURE 20 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure; and FIGURE 21 illustrates a circuit diagram of selected components of another example power converter, in accordance with embodiments of the present disclosure.
DETAILED DESCRIPTION
FIGURE 2 illustrates an example personal audio device 1, in accordance with embodiments of the present disclosure. FIGURE 2 depicts personal audio device 1 coupled to a headset 3 in the form of a pair of earbud speakers 8 A and 8B. Headset 3 depicted in FIGURE 2 is merely an example, and it is understood that personal audio device 1 may be used in connection with a variety of audio transducers, including without limitation, headphones, earbuds, in-ear earphones, and external speakers. A plug 4 may provide for connection of headset 3 to an electrical terminal of personal audio device 1. Personal audio device 1 may provide a display to a user and receive user input using a touch screen 2, or alternatively, a standard liquid crystal display (LCD) may be combined with various buttons, sliders, and/or dials disposed on the face and/or sides of personal audio device 1. As also shown in FIGURE 2, personal audio device 1 may include an audio integrated circuit (IC) 9 for generating an analog audio signal for transmission to headset 3 and/or another audio transducer.
FIGURE 3 illustrates a block diagram of selected components of an example audio IC 9 of a personal audio device, in accordance with embodiments of the present disclosure. As shown in FIGURE 3, a microcontroller core 18 may supply a digital audio input signal DIG_IN to a digital-to-analog converter (DAC) 14, which may convert the digital audio input signal to an analog signal VM. DAC 14 may supply analog signal to an amplifier 16 which may amplify or attenuate audio input signal VI to provide an audio output signal VOUT, which may operate a speaker, a headphone transducer, a line level signal output, and/or other suitable output. In some embodiments, DAC 14 may be an integral component of amplifier 16. A power supply 10 may provide the power supply rail inputs of amplifier 16. In some embodiments, power supply 10 may comprise a battery. Although FIGURES 2 and 3 contemplate that audio IC 9 resides in a personal audio device, systems and methods described herein may also be applied to electrical and electronic systems and devices other than a personal audio device, including audio systems for use in a computing device larger than a personal audio device, an automobile, a building, or other structure.
FIGURE 4 illustrates a block and circuit diagram of selected components of an example switched mode amplifier 20, in accordance with embodiments of the present disclosure. In some embodiments, switched mode amplifier 20 may implement all or a portion of amplifier 16 described with respect to FIGURE 3. As shown in FIGURE 4, switched mode amplifier 20 may comprise a loop filter 22, a converter controller 24, and a power converter 26.
Loop filter 22 may comprise any system, device, or apparatus configured to receive an input signal (e.g., audio input signal VIN or a derivative thereof) and a feedback signal (e.g., audio output signal VOUT, a derivative thereof, or other signal indicative of audio output signal VOUT) and based on such input signal and feedback signal, generate a controller input signal to be communicated to converter controller 24. In some embodiments, such controller input signal may comprise a signal indicative of an integrated error between the input signal and the feedback signal. In other embodiments, such controller input signal may comprise a signal indicative of a target current signal to be driven as an output current Ιουτ or a target voltage signal to be driven as an output voltage VOUT to a load coupled to the output terminals of power converter 26.
Converter controller 24 may comprise any system, device, or apparatus configured to, based on the controller input signal, sequentially select among a plurality of switch configurations of power converter 26 and based on an input signal (e.g., input signal INPUT), output signal V0UT, and/or other characteristics of switched mode amplifier 20, communicate a plurality of control signals to power converter 26 to apply a switch configuration from a plurality of switch configurations of switches of power converter 26 to selectively activate or deactivate each of the plurality of switches in order to transfer electrical energy from a power supply VSUPPLY to the load of switched mode amplifier 20 in accordance with the input signal. Examples of switch configurations associated with each are described in greater detail elsewhere in this disclosure. In addition, in some embodiments, converter controller 24 may control switches of a power converter 26 in order to regulate a common mode voltage of the output terminals of power converter 26, as described in greater detail below.
Power converter 26 may receive a voltage VSUPPLY (e.g., provided by power supply 10) at its input, and may generate at its output audio output signal VOUT- Although not explicitly shown in FIGURE 3, in some embodiments, voltage VSUPPLY may be received via input terminals including a positive input terminal and a negative input terminal which may be coupled to a ground voltage. As described in greater detail in this disclosure, power converter 26 may comprise a power inductor and a plurality of switches that are controlled by control signals received from converter controller 24 in order to convert voltage VSUPPLY to audio output signal V0UT> such that audio output signal V0UT is a function of the input signal to loop filter 22. Examples of power converter 26 are described in greater detail elsewhere in this disclosure.
FIGURE 5 illustrates a circuit diagram of selected components of an example power converter 26A, in accordance with embodiments of the present disclosure. In some embodiments, power converter 26A depicted in FIGURE 5 may implement all or a portion of power converter 26 described with respect to FIGURE 4. As shown in FIGURE 5, power converter 26 A may receive a voltage VSUPPLY (e.g., provided by power supply 10) at input terminals, including a positive input terminal and a negative input terminal (which may in some embodiments be coupled to a ground voltage), and may generate at its output an output voltage VOUT- Power converter 26A may comprise a power inductor 62 and plurality of switches 51-60. Power inductor 62 may comprise any passive two-terminal electrical component which resists changes in electrical current passing through it and such that when electrical current flowing through it changes, a time-varying magnetic field induces a voltage in power inductor 62, in accordance with Faraday's law of electromagnetic induction, which opposes the change in current that created the magnetic field.
Each switch 51-60 may comprise any suitable device, system, or apparatus for making a connection in an electric circuit when the switch is enabled (e.g., activated, closed, or on) and breaking the connection when the switch is disabled (e.g., deactivated, open, or off) in response to a control signal received by the switch. For purposes of clarity and exposition, control signals for switches 51-60 (e.g., control signals communicated from converter controller 24) are not depicted although such control signals would be present to selectively enable and disable switches 51-60. In some embodiments, a switch 51-60 may comprise an n-type metal-oxide-semiconductor field- effect transistor. Switch 51 may be coupled between a positive input terminal of the supply voltage VSUPPLY and a first terminal of power inductor 62 such that an anode of a body diode of switch 51 is coupled to the first terminal of power inductor 62 and a cathode of the body diode of switch 51 is coupled to the positive input terminal of the supply voltage VSUPPLY- Switch 52 may be coupled between a negative input terminal of the supply voltage VSUPPLY and the first terminal of power inductor 62 such that a cathode of a body diode of switch 52 is coupled to the first terminal of power inductor 62 and an anode of the body diode of switch 52 is coupled to the negative input terminal of the supply voltage VSUPPLY- Together, switch 51 and switch 52 may form a half bridge.
Switch 53 may be coupled between a second terminal of power inductor 62 and a terminal of switch 54. Switch 54 may be coupled between a first output terminal of power converter 26A and a terminal of switch 53. Switches 53 and 54 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes. In some embodiments, switches 53 and 54 may be combined into a single switch.
Switch 55 may be coupled between the first output terminal of power converter 26A and a terminal of switch 56. Switch 56 may be coupled between the negative input terminal of the supply voltage VSUPPLY and a terminal of switch 55. Switches 55 and 56 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes. In some embodiments, switches 55 and 56 may be combined into a single switch. Switch 57 may be coupled between the second terminal of power inductor 62 and a terminal of switch 58. Switch 58 may be coupled between a second output terminal of power converter 26A and a terminal of switch 57. Switches 57 and 58 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes. In some embodiments, switches 57 and 58 may be combined into a single switch.
Switch 59 may be coupled between the second output terminal of power converter 26A and a terminal of switch 60. Switch 60 may be coupled between the negative input terminal of the supply voltage VSUPPLY and a terminal of switch 59. Switches 59 and 60 may be arranged such that their respective body diodes are coupled together via the respective cathodes of such respective body diodes. In some embodiments, switches 59 and 60 may be combined into a single switch.
Together, switches 53-60 may comprise a full bridge having a first terminal coupled to the second terminal of power inductor 62 and a second terminal coupled to the second terminal of the supply voltage VSUPPLY-
In addition to switches 51-60 and power inductor 62, power converter 26 A may include an output capacitor 64 coupled between the first output terminal of power converter 26A and the second output terminal of power converter 26A. In order to generate a rectified audio signal at the terminal labeled with voltage Voswi in FIGURE 5, switches 51 and 52 may switch at a switching frequency up to several megahertz while the full-bridge output stage comprising switches 53-60 may switch at an audio-band frequency (e.g., 20 Hz to 20 KHz) in order to rectify output voltage VOUT, resulting in a substantial reduction in switching loss as compared with full-bridge output stage 104 depicted in FIGURE 1.
As described above, a power converter 26A may operate in a plurality of different switch configurations. FIGURE 6 illustrates a table setting forth switch configurations of the power converter of FIGURE 5 when operating in a buck mode, in accordance with embodiments of the present disclosure. Power converter 26A may operate in a buck mode when output voltage VOUT has a magnitude lower than that for which the duration of a charging phase Tl becomes too small to operate power converter 26A in a boost mode (e.g., IVQUTI < VSUPPLY)- AS shown in FIGURE 6, during a charging phase Tl of power converter 26A, when output voltage VOUT is positive, converter controller 24 may enable switches 51, 53, 54, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7A (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26A, when output voltage VOUT is positive, converter controller 24 may enable switches 52, 53, 54, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7B (closed switches shown, open switches removed). Similarly, during a charging phase Tl of power converter 26 A, when output voltage VOUT is negative, converter controller 24 may enable switches 51, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7C (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26A, when output voltage VOUT is negative, converter controller 24 may enable switches 52, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 7D (closed switches shown, open switches removed).
FIGURE 8 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a boost mode, in accordance with embodiments of the present disclosure. In accordance with the switch timing table of FIGURE 8, switches 51 and 52 may switch at a switching frequency of several megahertz, while switches 53-60 may switch at an audio band frequency of approximately 20 Hz to 20 KHz. Power converter 26A may operate in a boost mode when output voltage VOUT has a magnitude higher than that for which the duration of a charging phase Tl becomes too large to operate power converter 26A in a buck mode (e.g., IVOUTI > VSUPPLY)- AS shown in FIGURE 8, during a charging phase Tl of power converter 26A, when output voltage VOUT is positive, converter controller 24 may enable switches 51, 53, 54, 55, and 56 of power converter 26 A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9A (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26A, when output voltage VOUT is positive, converter controller 24 may enable switches 51, 53, 54, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9B (closed switches shown, open switches removed). Similarly, during a charging phase Tl of power converter 26A, when output voltage VOUT is negative, converter controller 24 may enable switches 51, 57, 58, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9C (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26A, when output voltage VOUT is negative, converter controller 24 may enable switches 51, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 9D (closed switches shown, open switches removed).
FIGURE 10 illustrates a switch timing table setting forth switch configurations of the power converter of FIGURE 5 when operating in a differential buck-boost mode, in accordance with embodiments of the present disclosure. In accordance with the switch timing table of FIGURE 10, switches 51 and 52 may switch at a switching frequency of several megahertz, while switches 53-60 may switch at an audio band frequency of approximately 20 Hz to 20 KHz. Power converter 26A may operate in the differential buck-boost mode for very low magnitudes (e.g., IVOUTI ¾ 0). As shown in FIGURE 10, during a first phase Tl of power converter 26A, converter controller 24 may enable switches 52, 53, 54, 59, and 60 of power converter 26 A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 11 A (closed switches shown, open switches removed). During a second phase T2 of power converter 26A, converter controller 24 may enable switches 51, 57, 58, 59, and 60 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 11B (closed switches shown, open switches removed). During a third phase T3 of power converter 26A, converter controller 24 may enable switches 52, 55, 56, 57, and 58 of power converter 26A, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 11C (closed switches shown, open switches removed). Accordingly, output voltage VOUT may be regulated by adjusting an on-time difference between phases Tl and T3, including regulating at a voltage of zero when the on-times of phases Tl and T3 are the same.
FIGURE 12 illustrates a circuit diagram of selected components of another example power converter 26B, in accordance with embodiments of the present disclosure. In some embodiments, power converter 26B depicted in FIGURE 12 may implement all or a portion of power converter 26 described with respect to FIGURE 4. Power converter 26B depicted in FIGURE 12 may in many respects be identical to power converter 26A of FIGURE 5, and thus only the differences between power converter 26B and power converter 26A are discussed. The main difference between power converter 26B and power converter 26 A is that power converter 26B includes another switch 61 coupled between the second terminal of power inductor 62 and the second terminal of supply voltage VSUPPLY- In addition, switch 61 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a diode of its body diode is coupled to the second terminal of power inductor 62. Switch 61 may be enabled at certain times (e.g., when switches 53, 54, 55, and 56 are enabled or when switches 57, 58, 59, and 60 are enabled, so as to reduce a conduction resistance to minimize power loss in either of the boost mode or buck mode.
FIGURE 13 illustrates a circuit diagram of selected components of another example power converter 26C, in accordance with embodiments of the present disclosure. In some embodiments, power converter 26C depicted in FIGURE 13 may implement all or a portion of power converter 26 described with respect to FIGURE 4. As shown in FIGURE 13, power converter 26C may receive a voltage VSUPPLY (e.g., provided by power supply 10) at input terminals, including a positive input terminal and a negative input terminal (which may in some embodiments be coupled to a ground voltage), and may generate at its output an output voltage VOUT- Power converter 26C may comprise a power inductor 82 and plurality of switches 71-78. Power inductor 82 may comprise any passive two-terminal electrical component which resists changes in electrical current passing through it and such that when electrical current flowing through it changes, a time-varying magnetic field induces a voltage in power inductor 82, in accordance with Faraday's law of electromagnetic induction, which opposes the change in current that created the magnetic field.
Each switch 71-78 may comprise any suitable device, system, or apparatus for making a connection in an electric circuit when the switch is enabled (e.g., activated, closed, or on) and breaking the connection when the switch is disabled (e.g., deactivated, open, or off) in response to a control signal received by the switch. For purposes of clarity and exposition, control signals for switches 71-78 (e.g., control signals communicated from converter controller 24) are not depicted although such control signals would be present to selectively enable and disable switches 71-78. In some embodiments, a switch 71-78 may comprise an n-type metal-oxide-semiconductor field- effect transistor. Switch 71 may be coupled between a positive input terminal of the supply voltage VSUPPLY and a first terminal of power inductor 82 such that an anode of a body diode of switch 71 is coupled to the first terminal of power inductor 82 and a cathode of the body diode of switch 71 is coupled to the positive input terminal of the supply voltage VSUPPLY- Switch 72 may be coupled between a negative input terminal of the supply voltage VSUPPLY and the first terminal of power inductor 72 such that a cathode of a body diode of switch 72 is coupled to the first terminal of power inductor 72 and an anode of the body diode of switch 72 is coupled to the negative input terminal of the supply voltage VSUPPLY- Together, switch 71 and switch 72 may form a half bridge.
Switch 73 may be coupled between the second terminal of power inductor 82 and the second terminal of supply voltage VSUPPLY- In addition, switch 73 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a diode of its body diode is coupled to the second terminal of power inductor 82.
Switch 74 may be coupled between the second terminal of power inductor 82 and terminals of switches 75 and 77. In addition, switch 74 may be arranged such that an anode of its body diode is coupled to the second terminal of power inductor 82 and a cathode of its body diode is coupled to terminals of switches 75 and 77.
Switch 75 may be coupled between a terminal of switch 74 and a first output terminal of power converter 26C. In addition, switch 75 may be arranged such that an anode of its body diode is coupled to the first output terminal of power converter 26C and a cathode of its body diode is coupled to terminals of switches 74 and 77.
Switch 76 may be coupled between the second terminal of supply voltage VSUPPLY and the first output terminal of power converter 26C. In addition, switch 76 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a cathode of its body diode is coupled to the first output terminal of power converter 26C. Switch 77 may be coupled between a terminal of switch 74 and a second output terminal of power converter 26C. In addition, switch 77 may be arranged such that an anode of its body diode is coupled to the second output terminal of power converter 26C and a cathode of its body diode is coupled to terminals of switches 74 and 75.
Switch 78 may be coupled between the second terminal of supply voltage VSUPPLY and the second output terminal of power converter 26C. In addition, switch 78 may be arranged such that an anode of its body diode is coupled to the second terminal of supply voltage VSUPPLY and a cathode of its body diode is coupled to the second output terminal of power converter 26C.
Together, switches 75-78 may comprise a full bridge having a first terminal coupled to the second terminal of power inductor 82 via switch 74 and a second terminal coupled to the second terminal of the supply voltage VSUPPLY-
In addition to switches 71-78 and power inductor 82, power converter 26C may include an output capacitor 84 coupled between the first output terminal of power converter 26C and the second output terminal of power converter 26C. In order to generate a rectified audio signal at the terminal labeled with voltage V0sw2 in FIGURE 13, switches 71-74 may switch at a switching frequency up to several megahertz while the full-bridge output stage comprising switches 53-60 may switch at an audio-band frequency (e.g., 20 Hz to 20 KHz) in order to rectify output voltage VOUT, resulting in a substantial reduction in switching loss as compared with full-bridge output stage 104 depicted in FIGURE 1.
As described above, a power converter 26C may operate in a plurality of different switch configurations. FIGURE 14 illustrates a switch table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck mode, in accordance with embodiments of the present disclosure. Power converter 26C may operate in a buck mode when output voltage VOUT has a magnitude lower than that for which the duration of a charging phase Tl becomes too small to operate power converter 26C in a boost mode (e.g., IVOUTI < VSUPPLY)- AS shown in FIGURE 14, during a charging phase Tl of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 71 , 74, 75, and 78 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15 A (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 72, 74, 75, and 78, of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15B (closed switches shown, open switches removed). Similarly, during a charging phase Tl of power converter 26C, when output voltage VOUT is negative, converter controller 24 may enable switches 71, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15C (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26C, when output voltage VOUT is negative, converter controller 24 may enable switches 72, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 15D (closed switches shown, open switches removed).
FIGURE 16 illustrates a switching timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a boost mode, in accordance with embodiments of the present disclosure. Power converter 26C may operate in a buck mode when output voltage V0UT has a magnitude lower than that for which the duration of a charging phase Tl becomes too large to operate power converter 26C in a buck mode (e.g., IVOUTI > VSUPPLY)- AS shown in FIGURE 16, during a charging phase Tl of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17A (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 71, 74, 75, and 78, of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17B (closed switches shown, open switches removed). Similarly, during a charging phase Tl of power converter 26C, when output voltage VOUT is negative, converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17C (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26C, when output voltage VQUT is negative, converter controller 24 may enable switches 71, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 17D (closed switches shown, open switches removed).
FIGURE 18 illustrates a switching timing table setting forth switch configurations of the power converter of FIGURE 13 when operating in a buck-boost mode, in accordance with embodiments of the present disclosure. As shown in FIGURE 18, during a charging phase Tl of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 19A (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26C, when output voltage VOUT is positive, converter controller 24 may enable switches 72, 74, 75, and 78, of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 19B (closed switches shown, open switches removed). Similarly, during a charging phase Tl of power converter 26C, when output voltage VOUT is negative, converter controller 24 may enable switches 71 and 73 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 19C (closed switches shown, open switches removed). During a discharge phase T2 of power converter 26C, when output voltage VOUT is negative, converter controller 24 may enable switches 72, 74, 76, and 77 of power converter 26C, with such switch configuration resulting in the equivalent circuit depicted in FIGURE 19D (closed switches shown, open switches removed).
FIGURE 20 illustrates a circuit diagram of selected components of another example power converter 26D, in accordance with embodiments of the present disclosure. In some embodiments, power converter 26D depicted in FIGURE 20 may implement all or a portion of power converter 26 described with respect to FIGURE 4. Power converter 26D depicted in FIGURE 20 may in many respects be identical to power converter 26C of FIGURE 13, and thus only the differences between power converter 26D and power converter 26C are discussed. The main differences between power converter 26D and power converter 26C are that:
(a) switch 74 present in power converter 26C is not present in power converter
26D and is replaced with a short; (b) switch 74A is added in series with switch 75; and
(c) switch 74B is added in series with switch 77.
Power converter 26D may have the same operating modes as described above with respect to power converter 26C. When output voltage VOUT is positive, switch 74A may have the same function as and operate like switch 74 of power converter 26C and switch 74B may be disabled. When output voltage VOUT is negative, switch 74B may have the same function as and operate like switch 74 of power converter 26C and switch 74A may be disabled.
FIGURE 21 illustrates a circuit diagram of selected components of another example power converter 26E, in accordance with embodiments of the present disclosure. In some embodiments, power converter 26E depicted in FIGURE 21 may implement all or a portion of power converter 26 described with respect to FIGURE 4. Power converter 26E depicted in FIGURE 21 may in many respects be identical to power converter 26C of FIGURE 13, and thus only the differences between power converter 26E and power converter 26C are discussed. The main differences between power converter 26E and power converter 26C are that:
(a) switch 73 present in power converter 26C is not present in power converter 26D and is replaced with an open;
(b) switch 74 present in power converter 26C is not present in power converter 26D and is replaced with a short;
(c) switch 74A is added in series with switch 76; and
(d) switch 74B is added in series with switch 78.
Power converter 26E may have the same operating modes as power converter 26D, but with fewer components.
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 exemplary 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 exemplary 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.
All examples and conditional language recited herein are intended for pedagogical objects to aid the reader in understanding the invention 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 inventions 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.

Claims

WHAT IS CLAIMED IS:
1. A multi-mode switching power converter comprising:
a power inductor;
a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage;
a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage;
a full bridge comprising a plurality of switches and having an output for producing an output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal; and
a capacitor coupled between the first output terminal and the second output terminal.
2. The multi-mode switching power converter of Claim 1, wherein the first switch, the second switch, and the plurality of switches are arranged to sequentially operate in a plurality of switch configurations in accordance with a selected operational mode of the power converter, the selected operational mode selected from a plurality of operational modes.
3. The multi-mode switching power converter of Claim 2, wherein the plurality of operational modes comprises a buck mode wherein the multi-mode switching power converter operates as a buck converter and a boost mode wherein the multi-mode switching power converter operates as a boost converter.
4. The multi-mode switching power converter of Claim 1, wherein the second terminal of the power inductor is directly coupled by a first direct connection to the first input of the full bridge and is directly coupled by a second direct connection to the second input of the full bridge.
5. The multi-mode switching power converter of Claim 1, wherein the second terminal of the power inductor is coupled via a third switch to the first input of the full bridge and is coupled via a fourth switch to the second input of the full bridge.
6. The multi-mode switching power converter of Claim 1, wherein the first switch and the second switch are each half-bridge switches.
7. A method comprising, in a multi-mode switching power converter comprising a power inductor, a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage, a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage, a full bridge comprising a plurality of switches and having an output for producing an output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal, and a capacitor coupled between the first output terminal and the second output terminal, sequentially operating the first switch, the second switch, and the plurality of switches in a plurality of switch configurations in accordance with a selected operational mode of the power converter, the selected operational mode selected from a plurality of operational modes.
8. The method of Claim 7, wherein the plurality of operational modes comprises a buck mode wherein the multi-mode switching power converter operates as a buck converter and a boost mode wherein the multi-mode switching power converter operates as a boost converter.
9. The method of Claim 7, wherein the second terminal of the power inductor is directly coupled by a first direct connection to the first input of the full bridge and is directly coupled by a second direct connection to the second input of the full bridge.
10. The method of Claim 7, wherein the second terminal of the power inductor is coupled via a third switch to the first input of the full bridge and is coupled via a fourth switch to the second input of the full bridge.
11. The method of Claim 7, wherein the first switch and the second switch are each half-bridge switches.
12. A switching power stage for producing an output voltage to a load, comprising:
a multi-mode switching power converter comprising:
a power inductor;
a first switch coupled between a first terminal of the power inductor and a first supply terminal having a first voltage;
a second switch coupled between the first terminal of the power inductor and a second supply terminal having a second voltage;
a full bridge comprising a plurality of switches and having an output for producing an output voltage comprising a first output terminal and a second output terminal, wherein a first input of the full bridge is coupled to a second terminal of the power inductor and a second input of the full bridge is coupled to one of the first supply terminal and the second supply terminal; and
a capacitor coupled between the first output terminal and the second output terminal; and
a controller configured to sequentially operate the first switch, the second switch, and the plurality of switches in a plurality of switch configurations in accordance with a selected operational mode of the power converter, the selected operational mode selected from a plurality of operational modes.
13. The switching power stage of Claim 12, wherein the plurality of operational modes comprises a buck mode wherein the multi-mode switching power converter operates as a buck converter and a boost mode wherein the multi-mode switching power converter operates as a boost converter.
14. The switching power stage of Claim 12, wherein the second terminal of the power inductor is directly coupled by a first direct connection to the first input of the full bridge and is directly coupled by a second direct connection to the second input of the full bridge.
15. The switching power stage of Claim 12, wherein the second terminal of the power inductor is coupled via a third switch to the first input of the full bridge and is coupled via a fourth switch to the second input of the full bridge.
16. The switching power stage of Claim 12, wherein the first switch and the second switch are each half-bridge switches.
PCT/US2016/040013 2016-06-23 2016-06-29 Multi-mode switching power converter Ceased WO2017222568A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US15/190,819 2016-06-23
US15/190,819 US20170373600A1 (en) 2016-06-23 2016-06-23 Multi-mode switching power converter

Publications (1)

Publication Number Publication Date
WO2017222568A1 true WO2017222568A1 (en) 2017-12-28

Family

ID=56609930

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2016/040013 Ceased WO2017222568A1 (en) 2016-06-23 2016-06-29 Multi-mode switching power converter

Country Status (2)

Country Link
US (1) US20170373600A1 (en)
WO (1) WO2017222568A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI833545B (en) * 2022-01-14 2024-02-21 聯發科技股份有限公司 Amplifier system and power converter

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10135340B1 (en) * 2017-09-11 2018-11-20 Linear Technology Holding Llc Pass through regulation of buck-boost regulator

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2118994A1 (en) * 2007-02-16 2009-11-18 Siemens AG Österreich Current inverter
WO2015119961A1 (en) * 2014-02-04 2015-08-13 Cirrus Logic, Inc. Differential output mode for a multi-mode power converter

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002104082A1 (en) * 2001-06-13 2002-12-27 Matsushita Electric Works, Ltd. Electronic ballast for a high intensity discharge lamp
US6556462B1 (en) * 2002-06-28 2003-04-29 General Electric Company High power factor converter with a boost circuit having continuous/discontinuous modes
US7525256B2 (en) * 2004-10-29 2009-04-28 International Rectifier Corporation HID buck and full-bridge ballast control IC
TWI307571B (en) * 2006-03-31 2009-03-11 Delta Electronics Inc Current source inverter with energy clamp circuit and controlling method thereof having relatively better effectiveness
JP4768498B2 (en) * 2006-04-14 2011-09-07 日立コンピュータ機器株式会社 Bidirectional DC-DC converter and power supply device using the same
US7812579B2 (en) * 2006-12-30 2010-10-12 Advanced Analogic Technologies, Inc. High-efficiency DC/DC voltage converter including capacitive switching pre-converter and up inductive switching post-regulator
TWI371909B (en) * 2007-12-28 2012-09-01 Ind Tech Res Inst Dc/ac reference modulation circuit with feedforward compensation scheme
US8350538B2 (en) * 2009-04-11 2013-01-08 Cuks, Llc Voltage step-down switching DC-to-DC converter
JP2011097787A (en) * 2009-10-30 2011-05-12 Sanyo Electric Co Ltd Grid-connected inverter device and grid-connection system
CN102136801B (en) * 2010-01-21 2014-02-19 台达电子工业股份有限公司 Resonant converter and intermittent mode control method thereof
EP2495858A1 (en) * 2011-03-01 2012-09-05 Rheinisch-Westfälisch-Technische Hochschule Aachen Bidirectional direct current converter
JP5273197B2 (en) * 2011-05-13 2013-08-28 ウシオ電機株式会社 Power supply device for high-pressure discharge lamp
EP2693847A1 (en) * 2012-01-31 2014-02-05 Panasonic Corporation High-voltage discharge lamp ignition device, projector using this high-voltage discharge lamp ignition device, and high-voltage discharge lamp ignition method
EP2634909B1 (en) * 2012-03-02 2017-02-15 ABB Research Ltd. Method for controlling a grid-connected boost-buck full-bridge current-source inverter cascade for photovoltaic applications and device
WO2015005155A1 (en) * 2013-07-08 2015-01-15 株式会社村田製作所 Power conversion circuit, power transmission system, and power conversion system
WO2015094374A1 (en) * 2013-12-20 2015-06-25 Intel Corporation Apparatus for charge recovery during low power mode
WO2015171931A1 (en) * 2014-05-08 2015-11-12 Cirrus Logic, Inc. System with multiple signal loops and switched mode converter
US10177661B2 (en) * 2015-06-15 2019-01-08 Futurewei Technologies, Inc. Control method for buck-boost power converters
US9853547B2 (en) * 2016-04-13 2017-12-26 Texas Instruments Incorporated Methods and apparatus for adaptive timing for zero voltage transition power converters

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2118994A1 (en) * 2007-02-16 2009-11-18 Siemens AG Österreich Current inverter
WO2015119961A1 (en) * 2014-02-04 2015-08-13 Cirrus Logic, Inc. Differential output mode for a multi-mode power converter

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI833545B (en) * 2022-01-14 2024-02-21 聯發科技股份有限公司 Amplifier system and power converter
US12519432B2 (en) 2022-01-14 2026-01-06 Mediatek Inc. Power converter and associated control method for high-efficiency audio amplifier

Also Published As

Publication number Publication date
US20170373600A1 (en) 2017-12-28

Similar Documents

Publication Publication Date Title
CN109983685B (en) High-efficiency boost converter
US10848061B2 (en) Switching power converter
EP3103192A1 (en) Differential output mode for a multi-mode power converter
WO2017127132A1 (en) Switched mode converter with variable common mode voltage buffer
US10659887B2 (en) High efficiency transducer driver
WO2018148344A1 (en) Charge pump with current mode output power throttling
US9929664B2 (en) Prevention of switching discontinuity in a hybrid switched mode amplifier
US10177657B2 (en) Reconfigurable switched mode converter
WO2017160520A2 (en) Removal of switching discontinuity in a hybrid switched mode amplifier
US20170373600A1 (en) Multi-mode switching power converter
US10651800B2 (en) Boosted amplifier with current limiting
CN114762247B (en) On-chip inductor with audio headphone amplifier
GB2550019A (en) Prevention of switching discontinuity in a hybrid switched mode amplifier

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16747926

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16747926

Country of ref document: EP

Kind code of ref document: A1