Multi-output supply generator for radio frequency power amplifiers with differential capacitive energy transfer

Abstract

The invention relates to a multiple output supply generator for a radio frequency power amplifier with differential capacitive energy transfer. There is provided a system for generating a plurality of supply voltages from an input voltage, the system comprising: a multi-regulation stage configured to receive an input voltage and to provide at least two independently regulated supply voltages at two or more outputs of the multi-regulation stage; and a differential capacitive energy transfer stage for synthesizing, at one or more outputs of the differential capacitive energy transfer stage, one or more additional supply voltages in a prescribed relationship with the at least two independently regulated supply voltages.

Description

[0001] This application is a divisional application of an invention patent application with an application date of July 8, 2020, application number 202080056421.X (international stage application number PCT / US2020 / 041162), and invention name “Multi-output supply generator for RF power amplifier with differential capacitive energy transfer”. Background Art

[0002] As is known in the art, the efficiency of a radio frequency (RF) power amplifier (PA) can be improved by a technique known as "supply modulation" (sometimes also referred to as "drain modulation" or "collector modulation"). In such a technique, the supply voltage provided to the PA is dynamically adjusted ("modulated") over time, depending on the RF signal being synthesized. For the greatest efficiency improvement, the supply voltage may be adjusted discretely (between discrete levels) or continuously on a short time scale to track or dynamically adapt to rapid changes in the RF signal amplitude (or envelope), such as may occur due to data being encoded in the RF signal or due to changes in the desired RF signal amplitude with a high envelope bandwidth (e.g., as in envelope tracking, advanced envelope tracking, polar modulation, "class G" power amplification, multi-stage backoff, multi-stage LINC, asymmetric multi-stage phase shifting, etc.). The supply voltage (or voltage level) provided to the PA may also be adapted to adapt to long-term changes in the desired RF envelope (e.g., "adaptive biasing"), such as associated with adapting transmitter output strength, for RF "flow" changes, etc., to minimize errors in data transfer.

[0003] "Continuous" supply modulation (e.g., "envelope tracking" or "adaptive biasing") can be advantageously implemented by dynamically selecting an intermediate voltage from a set of discrete supply voltages, and then further adjusting (reducing) the intermediate voltage to create a continuously variable supply voltage to be provided to the power amplifier. Some RF amplifier systems utilize "discrete" supply modulation (or discrete "drain modulation"), in which the supply voltage is switched between a set of discrete voltage levels, possibly including additional filtering or modulation to shape the voltage transitions between the voltage levels. This type of system is described and included in, for example, "Class G" amplifiers, multi-stage LINC (MLINC) power amplifiers, asymmetric multi-stage phase-shifted (AMO) power amplifiers, multi-stage back-off amplifiers (including "asymmetric multi-stage back-off" amplifiers), and digital polar transmitters, among other types. Hybrid systems utilizing a combination of continuous and discrete supply modulation can also be implemented. Summary of the invention

[0004] Concepts, systems, circuits, and techniques are described for improving the efficiency of radio frequency (RF) amplifiers, including RF power amplifiers (PAs), by "supply modulation" (also referred to as "drain modulation" or "collector modulation"), in which the supply voltage provided to the RF amplifier is dynamically adjusted ("modulated") over time based on characteristics (e.g., amplitude level) of the RF signal being synthesized. For maximum efficiency improvement, the supply voltage may be adjusted discretely (between discrete levels) or continuously over a short time scale so as to track or dynamically adapt to rapid changes in RF signal amplitude (or envelope), such as may occur due to data being encoded in the RF signal or due to desired RF signal amplitude variations with high envelope bandwidth (e.g., as in envelope tracking, advanced envelope tracking, polar modulation, "class G" power amplification, multi-stage backoff, multi-stage LINC, asymmetric multi-stage phase shifting, etc.). The supply voltage (or voltage level) provided to the PA may also be adapted to accommodate long-term changes such as the desired RF envelope associated with adapting transmitter output strength (e.g., “adaptive bias”) to minimize errors in data transfer, for example, in response to RF “traffic” changes.

[0005] According to one aspect of the concepts, systems, devices and techniques described herein, a method for generating a circuit having m power supply voltages (V1 to V m ) system, comprising: (a) independently controlling two (2) of m supply voltages (Vx and Vy, where x, y are both in the range of 1 to m); and (b) allocating the other m-2 supply voltages in a specified relationship to the two independently controlled supply voltages, so that the independent control of the two (2) of the m supply voltages is equivalent to independently specifying or controlling one or more of the following items: (1) the minimum supply voltage level (V min ) and the maximum supply voltage level (V max ), where the interval ΔV between the minimum voltage level and the maximum voltage level is based on the minimum supply voltage level (V min ) and the maximum supply voltage level (V max ) and the total number of levels m; (2) the minimum supply voltage level (V min ) and the voltage interval ΔV between levels, where the maximum supply voltage level (V max ) is determined by the voltage interval ΔV between levels and the total number of levels m; and (3) the maximum supply voltage level (V max ) and the voltage interval ΔV between levels, where the minimum supply voltage level (V min) is determined by the inter-horizontal voltage interval ΔV and the total number of levels m. In an embodiment, allocating the other m-2 power supply voltages in a prescribed relationship includes using a differential switched capacitor circuit to automatically allocate the other m-2 power supply voltages. In an embodiment, allocating the other m-2 power supply voltages in a prescribed relationship includes using a differential switched capacitor circuit to provide charge transfer to automatically allocate the other m-2 power supply voltages.

[0006] In an embodiment, allocating the other m-2 supply voltages in a prescribed relationship includes synthesizing the other m-2 supply voltages from two independently created supply voltages. In an embodiment, synthesizing the supply voltage from the two independently created supply voltages includes synthesizing the supply voltage from the two independently created supply voltages via a differential switched capacitor circuit to provide charge transfer. In an embodiment, allocating the other m-2 supply voltages in a prescribed relationship with the two independently controlled supply voltages includes allocating the other m-2 supply voltages so that the other m-2 supply voltages are spaced apart in a uniform manner between and / or around the two independently controlled supply voltages. In an embodiment, allocating the other m-2 supply voltages so that the other m-2 supply voltages are spaced apart in a uniform manner between or around the two independently controlled supply voltages includes allocating the other m-2 supply voltages so that adjacent voltage levels are separated by a voltage ΔV. In an embodiment, the method includes independently adjusting the two voltages V1 and V m And the other m-2 voltages are placed between two voltages V1 and V m are evenly spaced to provide m power supply voltages V k =V1+(k-1)·(V m -V1) / (m-1), wherein k=1...m. In an embodiment, m=3. In an embodiment, m=4.

[0007] According to another aspect of the concepts, systems, devices and techniques described herein, a system for generating a set of power supply voltages includes: a system for providing m power supply voltages (V1 to V m ) device, wherein two (2) of the m power supply voltages (e.g., V1 and V m ) can be independently controlled; for independently controlling two (2) power supply voltages (e.g., V1 and V m ) device; and a device for distributing other m minus two (m-2) power supply voltages in accordance with a prescribed relationship with two power supply voltages that can be independently controlled.

[0008] In an embodiment, at least two of the m power supply voltages (eg, V1 and V m) are independently controllable. In an embodiment, the means for independently controlling is configured to control at least two of the at least two of the m supply voltages. In an embodiment, the other m-2 supply voltages are allocated in relation to the two independently controlled supply voltages such that the other m-2 supply voltages are spaced uniformly between and / or around the two independently controlled supply voltages. In an embodiment, the other m-2 supply voltages are spaced uniformly between and / or around the two independently controlled supply voltages, wherein adjacent voltage levels are separated by a voltage ΔV. In an embodiment, the means for independently controlling two (2) of the m supply voltages (e.g., V1 and V m ) is provided for independently adjusting the first voltage V1 and the second voltage V m The device for distributing the other m-2 power supply voltages includes a device for making the other m-2 voltages between the first voltage V1 and the second voltage V m evenly spaced devices so that the system provides m supply voltages V k =V1+(k-1)·(V m -V1) / (m-1), where k=1...m. In an embodiment, two (2) power supply voltages (e.g., V1 and V m ) and means for distributing the other m-2 supply voltages in a specified relationship to the two independently controlled supply voltages operate such that the means for independently controlling and the means for distributing are equivalent to independently specifying or controlling one or more of the following: (1) a minimum supply voltage level (V min ) and the maximum supply voltage level (V max ), where the interval ΔV between the minimum voltage level and the maximum voltage level is based on the minimum supply voltage level (V min ) and the maximum supply voltage level (V max ) and the total number of levels m; (2) the minimum supply voltage level (V min ) and the voltage interval ΔV between levels, where the maximum supply voltage level (V max ) is determined by the voltage interval ΔV between levels and the total number of levels m; and (3) the maximum supply voltage level (V max ) and the voltage interval ΔV between levels, where the minimum supply voltage level (V min) is determined by the voltage interval ΔV between levels and the total number of levels m. In an embodiment, an apparatus for providing M power supply voltages includes a multi-output supply generator, comprising: (1) a multi-regulation stage configured to receive an input voltage and provide a plurality of independently regulated output voltages at two or more outputs thereof; (2) a differential capacitive energy transfer stage, which utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multi-regulation stage to synthesize one or more additional outputs, wherein the voltage and / or current of the additional output is a function of the voltage and / or current provided from the two independently regulated outputs. In an embodiment, the multi-regulation stage is provided as a single inductor multiple output (SIMO) power converter. In an embodiment, the differential capacitive energy transfer stage is provided as a single output or multi-output switched capacitor converter, whose input port is differentially connected between two outputs of the multi-regulation stage.

[0009] According to yet another aspect of the concepts, systems, devices and techniques described herein, a multi-output supply generator includes: (1) a multi-regulation stage configured to provide a plurality of independently regulated output voltages at two or more outputs thereof; and (2) a differential capacitive energy transfer stage that utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multi-regulation stage to synthesize one or more additional outputs, wherein the voltage and / or current of the one or more additional outputs is a function of the voltage and / or current provided from the two independently regulated outputs.

[0010] In an embodiment, the multi-output supply generator of claim 20, wherein the multi-regulation stage is provided as a single inductor multiple output (SIMO) power converter. In an embodiment, the differential capacitive energy transfer stage is provided as a single output or multi-output switched capacitor converter, whose input port is differentially connected between two outputs of the multi-regulation stage.

[0011] According to another aspect of the concepts, systems, devices and techniques described herein, a system includes: a radio frequency (RF) amplifier; a device coupled to the RF amplifier for providing m power supply voltages (V1 to V m ), where two (2) of the m supply voltages (e.g., V1 and V m ) can be independently controlled; for independently controlling two (2) power supply voltages (e.g., V1 and V m ) device; and a device for allocating other m-2 power supply voltages in accordance with a prescribed relationship with two power supply voltages that can be independently controlled.

[0012] In an embodiment, the RF amplifier is a first RF amplifier of a plurality of RF amplifiers, wherein at least some of the plurality of RF amplifiers are coupled to means for providing m supply voltages (V1 to Vm). In an embodiment, the RF amplifier is a RF power amplifier (PA).

[0013] According to yet another aspect of the concepts, systems, devices and techniques described herein, a method for operating a system includes: providing a radio frequency (RF) amplifier; and (b) providing one or more power supply voltages to the RF amplifier PA by independently controlling two (2) of the m power supply voltages; and (b) allocating the other m-2 power supply voltages in a prescribed relationship to the two independently controlled power supply voltages, such that the independent control of the two (2) of the m power supply voltages is equivalent to independently specifying or controlling one or more of the following items: (1) a minimum supply voltage level (V min ) and the maximum supply voltage level (V max ), where the interval ΔV between the minimum voltage level and the maximum voltage level is based on the minimum supply voltage level (V min ) and the maximum supply voltage level (V max ) and the total number of levels m; (2) the minimum supply voltage level (V min ) and the voltage interval ΔV between levels, where the maximum supply voltage level (V max ) is determined by the voltage interval ΔV between levels and the total number of levels m; and (3) the maximum supply voltage level (V max ) and the voltage interval ΔV between levels, where the minimum supply voltage level (V min ) is determined by the inter-horizontal voltage interval ΔV and the total number of levels m.

[0014] In an embodiment, the RF amplifier may be an RF power amplifier (PA). In an embodiment, allocating the other m-2 power supply voltages in a specified relationship to the two independently controlled power supply voltages includes allocating the other m-2 power supply voltages so that the other m-2 power supply voltages are spaced apart in a uniform manner between and / or around the two independently controlled power supply voltages. In an embodiment, allocating the other m-2 power supply voltages so that the other m-2 power supply voltages are spaced apart in a uniform manner between or around the two independently controlled power supply voltages includes allocating the other m-2 power supply voltages so that adjacent voltage levels are separated by a voltage ΔV. In an embodiment, the method may further include: independently adjusting the two voltages V1 and V m And the other m-2 voltages are placed between two voltages V1 and V m are evenly spaced to provide m power supply voltages V k =V1+(k-1)·(V m-V1) / (m-1), wherein k=1...m. In an embodiment, m=3. In an embodiment, M=4.

[0015] According to yet another aspect of the concepts, systems, devices and techniques described herein, a radio frequency (RF) amplifier system comprises: (a) an RF amplifier having a power supply input; and (b) a multiple output supply generator coupled to provide a power supply signal to the RF amplifier, the multiple output supply generator comprising: (1) a multiple regulation stage configured to provide multiple independently regulated output voltages at two or more outputs thereof; and (2) a differential capacitive energy transfer stage utilizing capacitive energy transfer from at least two of the independently regulated outputs of the multiple regulation stage to synthesize one or more additional outputs, wherein the voltage and / or current of the one or more additional outputs is a function of the voltage and / or current provided from the two independently regulated outputs.

[0016] In an embodiment, the differential capacitive energy transfer stage utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multi-regulator stage to synthesize two or more additional outputs, the voltage and / or current of the two or more additional outputs being a function of the voltage and / or current provided from the two independently regulated outputs. In an embodiment, the multi-regulator stage may be provided as a single inductor multiple output (SIMO) power converter. In an embodiment, the differential capacitive energy transfer stage may be provided as a single output or multiple output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulator stage. In an embodiment, the RF amplifier system also includes a supply modulator having multiple inputs and at least one output, the supply modulator having an input coupled to the output of the multi-output supply generator and an output coupled to the power supply input of the RF amplifier. In an embodiment, the supply modulator includes a switching network configured to selectively couple an output of the supply generator output to the power supply input of the RF amplifier. In an embodiment, the RF amplifier system also includes a filter disposed between the output of the supply modulator and the power supply input to the RF amplifier. In an embodiment, the RF amplifier system further comprises: (a) a second RF amplifier having a power input; (b) a second supply modulator having a plurality of inputs coupled to the output of the multi-output supply generator and an output coupled to the power input of the second RF amplifier.

[0017] According to another aspect of the concepts, systems, devices and techniques described herein, a method for providing a power supply having m power supply voltages (V1 to V m) system, comprising: (a) independently controlling two (2) of m supply voltages (Vx and Vy, where x and y are both in the range of 1 to m); (b) allocating the other m minus two (m-2) supply voltages in a specified relationship to the two independently controlled supply voltages, such that the independent control of the two (2) of the m supply voltages is equivalent to independently specifying or controlling one or more of the following: (1) a minimum supply voltage level (V min ) and the maximum supply voltage level (V max ), where the interval ΔV between the minimum voltage level and the maximum voltage level is based on the minimum supply voltage level (V min ) and the maximum supply voltage level (V max ) and the total number of levels m; (2) the minimum supply voltage level (V min ) and the voltage interval ΔV between levels, where the maximum supply voltage level (V max ) is determined by the voltage interval ΔV between levels and the total number of levels m; and (3) the maximum supply voltage level (V max ) and the voltage interval ΔV between levels, where the minimum supply voltage level (V min ) is determined by the voltage interval ΔV between levels and the total number of levels m; (4) Minimum (V min ) supply voltage level; (5) maximum (V max ) supply voltage level; (6) voltage interval ΔV between levels; (7) minimum supply voltage level (V min ) and the voltage interval ΔV between levels; and (8) the maximum supply voltage level (V max ) and the horizontal voltage interval ΔV.

[0018] According to another aspect of the concepts, systems, devices and techniques described herein, a system includes: (a) a system configured to provide m power supply voltages (V1 to V m ) a multi-output supply generator; (b) a supply modulator system coupled to the multi-output supply generator, the supply modulator system being configured to generate a set of supply voltages that independently control two (2) of the m supply voltages (Vx and Vy, where x, y are both in the range of 1 to m); and (c) a differential capacitor energy stage configured to provide charge transfer to automatically distribute the other m minus two (m-2) supply voltages in a specified relationship to the two independently controlled supply voltages, such that independent control of two (2) of the m supply voltages is equivalent to independently specifying or controlling one or more of the following: (1) a minimum supply voltage level (V min ) and the maximum supply voltage level (V max ), where the interval ΔV between the minimum voltage level and the maximum voltage level is based on the minimum supply voltage level (Vmin ) and the maximum supply voltage level (V max ) and the total number of levels m; (2) the minimum supply voltage level (V min ) and the voltage interval ΔV between levels, where the maximum supply voltage level (V max ) is determined by the voltage interval ΔV between levels and the total number of levels m; and (3) the maximum supply voltage level (V max ) and the voltage interval ΔV between levels, where the minimum supply voltage level (V min ) is determined by the inter-horizontal voltage interval ΔV and the total number of levels m.

[0019] In an embodiment, distributing the other m-2 supply voltages in the prescribed relationship includes using a differential switched capacitor circuit to automatically distribute the other m-2 supply voltages. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The foregoing features may be more fully understood from the following description of the accompanying drawings, in which:

[0021] Figure 1A is a block diagram of an RF power amplifier system utilizing multiple supply levels and illustrating a system architecture including supplying multiple power amplifiers.

[0022] Figure 1B is a block diagram of an example system implementation including a single inductor multiple output boost converter as a supply generator, a "shunt" supply modulator, and an LC filter.

[0023] Figure 2 is a block diagram of the system architecture of the proposed multi-output supply generator, which is used as a part of the radio frequency amplifier system of FIG. 1 .

[0024] Figure 3 is a schematic diagram of an example implementation of the proposed multi-output supply generator for use as part of the radio frequency amplifier system of FIG. 1 .

[0025] Figure 4 It is a schematic diagram of multiple adjustment stages.

[0026] Figure 5A is used to generate a voltage between v A With v B The output voltage between C Schematic diagram of the differential capacitive energy transfer stage.

[0027] Figure 5B is a schematic diagram of a circuit model showing the operating characteristics of this design.

[0028] Figure 6is used to generate a voltage between v A With v B The output voltage between C Schematic diagram of the differential capacitive energy transfer stage.

[0029] Fig. 7A is a schematic diagram of a differential capacitive energy transfer stage having a differential switched capacitor ladder circuit structure that generates a voltage v A With v B The output voltage v is evenly spaced between C1 and v C2 .

[0030] Figure 7B is a schematic diagram of a differential switched capacitor ladder structure, which shows Fig. 7A The structure can be expanded to provide additional outputs by using additional stacked energy transfer capacitors and half-bridge switching circuits.

[0031] Figure 8 is a schematic diagram of a differential capacitive energy transfer stage having four (4) nodes W, X, Y and Z that can be used as inputs or outputs.

[0032] Fig. 9A is a schematic diagram of a differential capacitive energy transfer stage having three (3) nodes W, X, and Y, where X and Y serve as inputs (v A , v B ) and W is used as output v C .

[0033] Fig. 9B is a schematic diagram of a circuit model representing the operating characteristics of this design, which includes an ideal 1:1 transformer and resistors to simulate voltage drops and losses.

[0034] Fig.10 It can provide output voltage v C Schematic diagram of the differential capacitive energy transfer stage with additional voltage regulation.

[0035] Fig.11 is a schematic diagram of multiple regulation stages based on a dual output buck converter.

[0036] Fig.12 It is used for Fig.11 Schematic diagram of a multi-regulation-stage controller with multiple regulation stages.

[0037] Fig.13 By using the auxiliary switch S C and S Z Provides load LA and i LBSchematic diagram of a multi-regulated power stage with improved control at both ends.

[0038] Fig.14 is to provide load i LA and i LB Improved control of both ends and utilizing a one-way blocking switch S C1 , S C2 , S Z1 and S Z2 Schematic diagram of a multi-regulator power stage.

[0039] Fig.15 By using the auxiliary switch S C , S Z and S O Provides load LA and i LB Schematic diagram of a multi-regulated power stage with improved control at both ends. DETAILED DESCRIPTION

[0040] Now refer to Figure 1A , a radio frequency (RF) amplifier system 10 utilizes supply modulation, wherein a supply modulator subsystem 14 switches between a plurality of voltages generated by a supply generator 12. (Not shown are aspects of signal processing and control for such a system). Figure 1A is an example implementation of an architecture that is particularly suitable for discrete supply modulation.

[0041] The RF power amplifier system 10 includes a multiple output supply generator subsystem (or more simply "supply generator") 12 that can synthesize multiple supply voltages V1 to Vm from a single input source 11. In an embodiment, the supply generator 12 can regulate one or more of the supply voltages V1 to Vm. The supply generator 12 provides one or more of the voltages V1 to Vm to the inputs of one or more supply modulator subsystems (or more simply "supply modulators") 14a to 14N of the supply modulator system 14. The supply modulators 14a to 14N can switch (and ideally, switch rapidly) between different supply voltages provided to them by the supply generator 12, thereby providing a modulated supply voltage V at their outputs. 供应#1 To V 供应#N. The switches can be modulated fast enough to provide a supply voltage to the power amplifier according to techniques known in the art such as discrete drain modulation, advanced envelope tracking (ETA), discrete envelope tracking, and digital envelope tracking (digital ET) so that the RF amplifier can provide a desired RF output envelope while maintaining high efficiency. For example, such techniques are described in one or more of U.S. Patents 8,829,993; 9,160,287; 9,166,536; 9,172,336; 9,209,758; 9,755,672. The supply voltage input can be coupled to a supply terminal of a corresponding RF amplifier in one or more RF amplifiers 18a to 18N. In some embodiments, the RF amplifier can be provided as an RF power amplifier (PA). In an embodiment, the supply generator 12 can supply the same or different voltages to the supply modulator 14. In an embodiment, the supply generator 12 can couple different numbers of voltages between the supply generator 12 and the supply modulator 14.

[0042] In an embodiment, some or all of the supply voltage may be coupled to the supply terminal of the RF amplifier via a respective one of the optional filtering or voltage regulation stages 16a to 16N. The filtering / regulating stages 16a to 16N may include a filtering network including a regulator from the modulation voltage V mod The voltage V to the RF amplifier 供应 passive filters and / or active filters and / or additional devices (eg, including low dropout regulators, LDOs).

[0043] The manner in which the subsystems 12, 14 are best implemented may depend on a variety of factors, including, but not limited to: power level (i.e., the level of RF power provided at the output of the RF amplifier), voltage level (e.g., the voltage level of the energy source 11 and the range of voltage levels provided at the output of the supply generator 12), and the application space of the RF amplifier system 10 (i.e., the specific application in which the RF amplifier system 10 will be used). However, it should be understood that for many mobile applications (e.g., wireless systems such as cellular phones, cellular phone base stations, wireless personal computing devices such as laptop computers or tablet computers, to name just a few examples), it may be desirable to monolithically integrate the electronic components of both the supply generator and the supply modulator on a single semiconductor die (e.g., in a complementary metal oxide semiconductor (CMOS) process). Furthermore, in some cases, it may be desirable to integrate the electronics for the supply generator, supply modulator, and power amplifier on a single die. In other cases, it may be desirable to implement the semiconductor components supply generator and (one or more) supply modulators on separate semiconductor dies to better enable placement of these components within a system module. In other cases (particularly at high power), it may be desirable to implement the subsystem using discrete components connected to one or more printed circuit boards.

[0044] In an embodiment, one, some, or all of the supply modulator subsystems 14a to 14N may include one or more switches to couple one or more voltages provided by the supply generator 12 to the RF amplifier power supply terminals 19a to 19N. A variety of different switching circuits (i.e., switches having various switch configurations or switch topologies) may be used to implement the supply modulator subsystem 14. For example, in an embodiment, the supply modulator subsystem may include a plurality of serially coupled switches configured to provide a "series" modulator. Alternatively, in an embodiment, the supply modulator subsystem may include a plurality of parallelly coupled switches configured to provide a "parallel" modulator. Still alternatively, in an embodiment, the supply modulator subsystem may include one or more serially coupled switches and one or more parallel coupled switches.

[0045] Important to the concepts described herein is how the voltage synthesized by the supply generator affects the required rating of the switches in one or more of the supply modulators 14a to 14N. This is an important consideration because the required voltage rating of the modulator switches can affect (and in some cases, highly affect) the switching speed (and achievable modulation rate) and modulator efficiency, both of which are important system factors. Regardless of the modulator switch topology used, if there is a voltage rating that is increased by increasing the voltage v1, ..., v m Sorting (i.e. v1<v2<...<v m ) of m supply levels, then coupled to the jth supply voltage vj With output v mod The multiple switches (or switch chains) between them should ideally be rated to have a blocking size of at least (v m -v j ) and (v j -v1) or v j In some embodiments of the latter type of design, where the power supply to the power amplifier needs to be "cut off" (discharged to a zero volt supply), a separate low frequency "off" switch can be advantageously placed in parallel with the modulator output voltage v1, ..., v m The supply modulator output is connected in series. Such a cutoff switch can reduce the modulator switch chain voltage blocking requirement from V j Reduce to (v j -v1); this can be particularly advantageous in modulator design. As will be seen below, the described concept provides control voltages v1, ..., v m A natural means by which the modulator switching network can be implemented in the desired manner.

[0046] In some embodiments, an RF power amplifier system such as RF power amplifier system 10 may include a "series" modulator that is suitable for integrated circuit manufacturing and is suitable for ratiometric supply voltages (e.g., V2=2V1, V3=3V1, V4=4V1). Such a design illustrates the effect of supply levels on the rated voltages required for individual modulator devices; through the proper selection of horizontal voltages, the use of both core devices and extended voltage devices can fully utilize the integrated CMOS process to achieve the voltage blocking characteristics required for the modulator switch chain. In addition, such a circuit illustrates the use of the levels generated for the gate drive of the device. This type of drive method promotes high efficiency and switching speed. However, in order to fully utilize the voltage between adjacent horizontal voltages (e.g., between V j With V j-1 The horizontal voltages used in this design should maintain sufficient spacing; otherwise, a more complex gate drive design may be required, which will limit the achievable switching performance. As described below, the concepts described herein facilitate maintaining voltage levels suitable for implementing integrated circuit-based modulators and high-performance gate drives through the ability to maintain a desired voltage relationship between levels.

[0047] Prior art supply generators have been implemented by various approaches. Supply generators have been implemented using multiple independent converters, multi-output magnetic converters, multi-output switched capacitor converters, and hybrid magnetic / switched capacitor converters, providing a ratiometric set of output voltages. Each of these prior art approaches has significant limitations, limiting the achievable size, cost, efficiency, and performance (e.g., modulation bandwidth) of supply modulated RF amplifier systems.

[0048] The use of multiple independent power converters to generate multiple supply voltages produces a very flexible solution, allowing each output voltage to be independently adjusted to a desired value to vary independently of the input voltage, and providing the ability to continuously adjust the output voltage over time (e.g., the ability to provide an adaptive bias of a power amplifier). Unfortunately, due to the need for a large number of physically large power supply components (especially magnetic components), this solution is inherently large and expensive. Single inductor multiple output converters, sometimes referred to as "SIMO" converters, allow multiple output voltages to be independently adjusted when only a single magnetic component is required, alleviating the size challenges of multiple power converters to a certain extent. However, since the SIMO design inherently utilizes time-sharing of the inductor to supply multiple outputs, performance and efficiency rapidly decrease and control complexity rapidly increases as the number of outputs increases. This characteristic limits the efficacy of this approach in multi-level supply modulator systems, which typically utilize three and seven supply levels to achieve high performance (where even more levels may be desired in some cases).

[0049] Certain types of converters, such as conventional multi-output magnetic converters (e.g., multi-output flyback converters), multi-output switched capacitor converters, and hybrid magnetic / switched capacitor converters, generate multiple ratiometrically related output voltages while reducing the number of magnetic components required compared to using multiple independent power converters. Conventional multi-output magnetic converters typically utilize transformers with scaled turns ratios to generate multiple (ideally) ratiometrically scaled output voltages. These designs are typically only able to regulate a single output, with the ratiometric relationship of the other outputs being approximately maintained by the transformer turns ratio (unless additional "post regulation" is provided for the other outputs, such as by using added linear regulators.) The use of transformers tends to compromise the efficiency achievable in these designs (often to unacceptable levels), and such designs often suffer from significant cross regulation between outputs in practice (i.e., one output voltage varies depending on the load on a different output), which produces poor performance in RF amplifier systems unless additional "post" regulation is used (which further compromises performance).

[0050] A multiple output switched capacitor converter circuit can generate multiple ratiometrically related output voltages while achieving very high efficiency and small size, where the reasonable (ideal) ratio between the output voltages is determined by the circuit topology and / or switching pattern. However, for this type of circuit, the output voltages are all scaled versions of the input voltage, which does not provide a method for continuously adjusting the output voltage independent of changes in the input voltage; this can be a significant disadvantage in many systems.

[0051] Some of the limitations of these previous multi-output supply generation methods can be addressed via hybrid magnetic / switched capacitor circuits with ratiometrically scaled outputs. In these designs, the magnetic regulation stage independently regulates a single output voltage (independent of the system input voltage) with an additional ratiometrically related output voltage synthesized and enforced through the action of a switched capacitor voltage balancer stage. For example, in an m-output supply generator, the magnetic stage may accept an input voltage V X And the voltage k1·V is synthesized (ideally) by switching capacitor voltage action Y , k2·V Y ……k m-1 ·V Y To regulate a single output voltage V Y , where the constants k1…k m-1 is a rational number determined by the circuit topology and / or switching pattern. Advantages of this approach include relatively high efficiency and small size requirements for synthesizing multiple related output voltages and relatively simple control.

[0052] Despite the advantages of the above design approaches, all designs that produce ratiometric supply generator voltage outputs have limitations (and in some cases, significant limitations) for power amplifier systems that utilize multi-level supply modulation. The first limitation of the ratiometric output is related to the available supply voltage range for available power amplifiers. Some power amplifiers may operate properly over a wide supply voltage range of up to 4:1 or even greater (e.g., from a maximum voltage V max Reduce to equal to or less than V min =V max / 4 of the minimum voltage allowed for PA supply modulation. ) Many other power amplifiers—including those commonly used in applications such as Wi-Fi, mobile handsets, and MIMO transmitters for LTE and 5G applications—can only operate over a much narrower supply voltage range (e.g., 3:1 or even less). With ratiometric supply voltages, if the maximum voltage produced is reduced (e.g., for a situation where the average PA output power is reduced), then the synthesized ratiometric voltages are all reduced proportionally. This typically means that in this case, one or more of the lowest synthesized voltages will not be available for supply modulation because it is reduced below the minimum allowed PA supply voltage. This in turn reduces the achievable PA efficiency enhancement that can be provided by supply modulation under these conditions. It would be even more desirable if the supply voltages were not maintained at a fixed set of ratios so that all (or nearly all) of the synthesized supply voltage levels would remain above the minimum voltage allowed for the PA under reduced power operation.

[0053] The second limitation of the ratiometric output has to do with how the spacing between the voltages changes as the combined maximum supply voltage decreases. In a ratiometric output supply generator, two adjacent voltages may be k j ·V Y and k j-1 ·V Y , where V Y The value can be adjusted along with the average transmit power of the PA via the proportional factor k j Therefore, the difference between the voltage levels is (k j -k j-1 )·V Y , which is related to V Y As discussed above, this can be problematic for driving the integrated modulator switches, especially where the gate drive voltage is derived from the inter-level voltage (the voltage difference between the levels). This can drive increased gate drive complexity in the integrated modulator and can also limit the achievable switching performance of the modulator. It would be further desirable if the supply voltages were not maintained at a fixed set of ratios so that the spacing between adjacent levels could be controlled independently of the resultant maximum supply voltage.

[0054] For example Figure 1AThe power amplifier architecture shown in , it is desirable to provide a system that can provide both very rapid changes (e.g., on the time scale of the RF envelope or within an order of magnitude close to the time scale of the RF envelope, or sufficiently fast for discrete tracking of the envelope) of the supply voltage (e.g., in multiple discrete levels), while also providing the ability to slowly adapt (e.g., on a time scale associated with changes in RF data traffic, changes in position between a transmitter and a receiver, or for adaptive biasing of a power amplifier as is commonly used in the art) the voltage to discrete levels within a desired range. (e.g., rapidly modulate the supply voltage on a time scale shorter than microseconds or, alternatively, shorter than 100ns, and adapt the supply voltage on a time scale longer than microseconds or, alternatively, longer than 10 microseconds.) One of ordinary skill in the art will appreciate that the switching time scale may be application specific, at least to some extent. In embodiments, switching on the order of 10ns or even lower may be described. Of course, the same is true with respect to the ability to adapt the voltage to discrete levels within a desired range. In particular, it would be useful to be able to efficiently and compactly generate a set of supply voltages, where two of the m supply voltages (e.g., a first supply voltage V1 and a second supply voltage V m ), where the other m-2 supply voltages are allocated in some prescribed relationship to the two independently controlled supply voltages, such as being spaced uniformly between and / or around them (e.g., where adjacent voltage levels are separated by a voltage ΔV). For example, if voltages V1 and V m And the other m-2 voltages are placed between voltages V1 and V m If the voltages V k =V1+(k-1)·(V m -V1) / (m-1), where k=1…m, where m is the maximum number of voltage levels. This arrangement is equivalent to allowing independent specification or control of:

[0055] (a) Minimum voltage level (V min ) and the maximum voltage level (V max )(where the interval ΔV between voltage levels is based on V min and V max and the total number of levels m is determined).

[0056] (b) Minimum supply voltage level (V min ) and the horizontal voltage interval ΔV (where the maximum voltage level V max Determined by ΔV and the total number of levels m. )

[0057] (c) Maximum supply voltage level (V max) and the horizontal voltage interval ΔV (where the minimum voltage level V min Determined by ΔV and the total number of levels m. )

[0058] Although not as good as true independent control of all voltages (e.g., as with Figure 1B The present invention provides a method for providing a power amplifier that is as flexible as a conventional design (e.g., in terms of power amplifier efficiency) but will obtain most of the practical benefits that can be obtained from supply modulation (e.g., in terms of power amplifier efficiency) while avoiding the above-mentioned limitations associated with providing truly independent voltage level control or ratiometric levels. Therefore, a design according to the above-mentioned method will provide significant advantages in terms of the combination of size, cost, efficiency and performance compared to existing methods.

[0059] Now refer to Figure 1B , the RF amplifier system 30 includes: a multi-output supply generator 34, a supply modulator 36 and an optional filter 38, and an RF amplifier 40 having an RF input 40a, an RF output 40b and a supply terminal 40c. In this example embodiment, the supply generator 34 is provided as a single inductor 3-output boost converter, which includes an inductor L having a first terminal coupled to the voltage supply 32 and a second terminal coupled to a node 34a. One or more switches (here three switches S1, S2, S3) have a first terminal coupled to the node 34a and a second terminal coupled to at least one voltage node, and the voltage node is established by a capacitor stack portion C1, C2, C3, C4 (for example, a plurality of capacitors C1, C2, C3, C4 coupled in series between the first voltage node and ground to establish a plurality of voltage nodes V1 to V3). The fourth switch S0 has a first terminal coupled to the node 34a and a second terminal coupled to the ground. In Figure 1A In the example implementation, second terminals of the switches S1, S2, S3 are coupled to respective ones of the voltage nodes V1, V2, V3.

[0060] Also in this example embodiment, the power modulator includes a plurality of switches S m1 To S m3 , where each switch S m1 To S m3 The first terminal of the switch S is coupled to a corresponding one of the voltage terminals V1 to V3, and each switch S m1 To S m3 A second terminal of is coupled to the node 36a.

[0061] In this example embodiment, the node 36a is coupled to the supply terminal 40c of the RF amplifier 40 through the filter 38. In this example, the filter 38 is provided as an LC filter, which includes an inductor Lf, a resistor Rf and capacitors C4, C5. In other embodiments, the node 36a can be coupled to the supply terminal 40c of the RF amplifier 40 through other circuit systems (i.e., circuit systems other than the filter circuit system). In other embodiments, the node 36a can be directly coupled to the supply terminal 40c of the RF amplifier 40.

[0062] Now refer to Figure 2 , supply generator 44 includes a power conversion stage 48 configured to receive an input voltage from a voltage source 46. Voltage source 46 is shown here as a phantom because it is not properly part of supply generator 44. Supply generator 44 includes a power conversion stage having multiple independently regulated outputs and may therefore be referred to as a multi-regulation stage.

[0063] The power conversion stage 48 has an output coupled to an input of a differential capacitive energy transfer stage 50. In this example embodiment, the differential capacitive energy transfer stage 50 receives a voltage V from the power conversion stage 48. A 、V B And provides a voltage V at its output C,M-2 、V C1 .therefore, Figure 2 An architecture for a supply generator according to the described concept is shown. The multi-output supply generator is suitable for use as part of a radio frequency amplifier system (e.g., as Figure 1A , 1B ).

[0064] Now refer to Figure 3 , an example implementation of a supply generator 52 including a power conversion stage 56 having multiple independently regulated outputs (which may sometimes be referred to herein as a "multi-regulation stage") and a power converter stage 58, (which may sometimes be referred to herein as a "differential capacitive energy transfer stage" or more simply a "DCT stage"), the power converter stage 58 utilizing capacitive energy transfer from at least two of the independently regulated outputs of the multi-regulation stage 56 to synthesize one or more additional outputs whose voltage and / or current is a function of the voltage and / or current provided by the two independently regulated outputs. The multi-regulation stage may preferably be implemented as a single inductor multiple output (SIMO) power converter, and the differential capacitive energy transfer stage may preferably be implemented as a single output switched capacitor converter or a multiple output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

[0065] therefore, Figure 3An example implementation of a multi-output supply generator is shown. In this implementation, the multiple regulation stages are implemented as a single inductor dual output buck converter, where the switch S X and S Y Allows the input voltage V IN The controlled step-down regulation and switch S A With S B The modulation between the inductor current i L The time division provides a voltage v relative to the reference potential. A and v B The differential capacitive energy transfer stage is implemented as a switched capacitor (SC) circuit with its input connected to v A With v B between and provide a single output v C1 The SC circuit switches in two phases, alternately switching the energy transfer capacitor C T Connect to V A With V C1 between (open φ1 and close φ2) and connected at V B With V C1 The operation of the differentially connected switched capacitor converter is enforced by: In the switched capacitor circuit v C1 The current provided at the output of is drawn equally from both inputs to the switched capacitor circuit (i.e., equally from v A and v B The steady-state open-circuit output voltage condition of the switched capacitor circuit is v C1 =(v A +v B ) / 2, and when operating at high efficiency the voltage v C1 The open circuit output voltage condition is maintained near this condition (limited by the output voltage drop of the SC circuit known for switched capacitor systems.) Thus, the multiple output supply generator system can synthesize three voltages: an independently regulated voltage v A and v B and the third voltage v C1 =(v A +v B ) / 2 (which provides to the output v C1 The current is averaged from v A and v B . ).

[0066] As described herein, switches Sx, Sy are pulse width modulated (ie, controlled or switched) at a certain frequency with a duty cycle to produce an average voltage at the left terminal of inductor L to regulate the output voltage. A and S BPulse width modulation with a duty cycle to provide a pulse to node V A and V B Provide appropriate current distribution to regulate them (thus S X / S Y and S A / S B The duty cycle allows proper regulation of the voltage V A 、V B . Switch the switches marked φ1 and φ2 in a complementary manner (when marked φ i2 The switch labeled φ1 is opened when the switch labeled φ1 is closed, and the switch labeled φ2 is opened when the switch labeled φ1 is closed), typically at a defined switching frequency, to provide SC charge transfer to keep the voltage Vc1 close to the target voltage, where the switching frequency rather than the duty cycle between φ1 and φ2 is most important.

[0067] It should be understood that a wide variety of topological approaches can be implemented for multiple regulation stages.

[0068] For example, and now referring to Figure 4 , shows a multi-regulation stage based on a non-inverting buck-boost converter 60. By modulating the switch S X , S Y , S Z , S A and S B , this topology can independently convert the voltage V A and V B regulated above and / or below the voltage V IN The value of the value of . This topology may be useful, for example, when the input voltage (e.g., as may be provided by a battery) and / or the output voltage varies over a wide range, such that the relative amplitudes of the input voltage and the output voltage cross each other. As shown, by adding switches and further time-sharing the inductor current, optional additional outputs may be supplied and independently regulated. This is valuable when one or more additional outputs may need to be supplied or a pair of additional outputs may need to be supplied to support a second differential capacitor energy transfer stage and supply a modulator. However, the introduction of such additional outputs comes at the expense of reduced efficiency and transient performance and increased complexity in controlling multiple regulation stages. Additional outputs may be similarly provided with other multi-regulation stage topologies.

[0069] For example, a multi-regulation stage topology can be derived from a boost converter. Such a topology may be useful when at least one of the output voltages is continuously maintained above the input voltage. For such applications, such a topology has the advantage of providing direct energy conversion by requiring the inductor current to pass through only one switch at any given time, which reduces conduction losses.

[0070] Multiple regulation stages can also be derived from an inverting buck-boost converter. Such a topology can be valuable when the input source voltage is negative, where the positive terminal of the input source is connected to the output reference node, as is common in many telecommunications applications (e.g., with a -48V nominal input). Such a topology can also provide the benefit that the regulated output voltage can have a magnitude less than, greater than, or the same as the input voltage magnitude, as described above in conjunction with Figure 4 The same as the non-inverting design described in Figure 4 It will be appreciated that many other approaches to multiple regulation stages may be used, including those derived from single inductor dual output (SIDO) DC-DC converters (or more generally, single inductor multiple output, or SIMO DC-DC converters) with independent output voltage control and from using multiple independent converters to regulate a pair of voltages V A and V B Those methods of other dual output converters.

[0071] exist Figure 5A Again, it is shown Figure 3 The differential capacitive energy transfer stage used in the embodiment of the present invention may also be referred to as a "differential switched capacitor" stage or DSC stage. As described above, in this topology, the differentially connected switched capacitor circuit 70 topology averages from v A and v B The output voltage is supplied to the C current and maintain the output voltage v C Approximately equal to v A and v B The design can be modeled using known techniques for analyzing switched capacitor circuits.

[0072] Figure 5B The DSC level 70 ( Figure 5A ) circuit model 70 ', where the ideal transformer captures the current transfer and the ideal open circuit voltage of the stage, and the resistor R out Indicates that the energy transfer from the capacitor C T The losses and drops in the output voltage of the charging and discharging of the capacitor are shown in the embodiment. In the embodiment, the transformer 76 represents an ideal 1:1 transformer. It can be shown that in the slow switching limit (i.e., as is known in the art, when the switching period of the differential switched capacitor converter is long compared to the time constant associated with charging / discharging the capacitor, so that the capacitor substantially completes its charging / discharging within the switched capacitor switching period.) the effective output resistance R for this example design is out is 1 / (4·f·C T), where f is the switching frequency at which the DSC circuit is operated and C T is the value of the energy transfer capacitor. In the fast switching limit (i.e., when the switching period of the differential switched capacitor circuit is short compared to the time constant associated with charging / discharging the energy transfer capacitor, such that the capacitor has not completed its charge / discharge within the switching period), R out becomes R CT +2·R sw , where R CT is the energy transfer capacitor C T The equivalent series resistance of 2·R sw represents the total resistance of the two switches, and the current flows through the two switches to the capacitor C T Charge or discharge.

[0073] The differential capacitive energy transfer stage can be implemented in a variety of different ways, each with its own benefits and limitations. For example, Figure 6 shows a staggered DSC design that provides Figure 3 The function is similar to that in , but with an interleaved differential switched capacitor circuit structure. For the same switching frequency and total capacitance, Figure 5A Compared with the non-interleaved design, the interleaved differential switched capacitor circuit structure reduces the A and V B The interleaved design requires a higher Figure 5A The non-interleaved version has more switches, capacitors, and interconnects, but reduces the amount of power required by the switched capacitor circuits from V A and v B The switching ripple current drawn can reduce electromagnetic interference and help improve efficiency. Other differential capacitive energy transfer stage designs can also benefit from interleaving. In addition, although the design shown uses a two-phase switching method, it should be understood that more switching phases can be used, and in such cases, appropriate multi-phase interleaving can also be advantageously adopted.

[0074] It should be understood that although Figure 5A , Figure 5B , Figure 6 The differential capacitive energy transfer stage provides a single output v C , but proper design can produce the desired distribution over v A With v B Between and / or about v A and v B Any number of outputs.

[0075] For example, Fig. 7A An example DSC 84 is shown (ie, having a topology) that provides two output voltages v C1 and vC2 (Total 4 supply generator outputs), where v C1 Keep at v A +(v B -v A ) / 3 and v C2 Keep at v A +(v B -v A )·2 / 3. The differentially connected ladder structure can be extended to use m-2 stacked transfer capacitors C T,1 ……C T,m-2 and m-1 half-bridges provide m-2 DSC outputs, such as Figure 7B as shown in .

[0076] It should be understood that the voltage v C，j It does not need to be distributed only in v A With v B For example, Figure 8 A differential capacitor energy transfer stage 90 is shown having four (4) input / output nodes W, X, Y, and Z (i.e., nodes W, X, Y, and Z can be used as inputs or outputs). For example, any two of nodes W, X, Y, and Z can be used as inputs according to a multiple output magnetic stage (v A , v B ), while the remaining two nodes can be provided as outputs of the energy transfer stage according to the differential capacitor. For example, if the voltage v A With v B are provided to nodes W and Z respectively, and nodes X and Y are used as outputs, the circuit provides Fig. 7A The illustrative circuit in the same basic function.

[0077] in this case, Figure 8 The circuit in Fig. 7A One difference between the circuits is the filter / holding capacitor C H2 To C H4 The differential supply between the supply generator levels, rather than ground, may be advantageous in terms of their size and filtering capabilities, since they are then rated only for the voltage difference between adjacent supply voltage levels. (In many of the circuit designs described herein, a choice may be made between differentially connected capacitors and commonly referenced capacitors for filtering / decoupling / holding, with the preferred choice depending on the circuit details.) However, it should be understood that any two of the nodes W, X, Y, and Z may be selected as input voltages to the differential capacitor energy transfer stage, while the remaining two are selected as outputs of the differential capacitor energy transfer stage. By selecting an appropriate one of the nodes W, X, Y, and Z as input and output, the differential capacitor energy transfer stage may then be made to develop (establish) a voltage above and / or below and / or between v AWith v B voltage between the two, while providing the supply generator output (including v A 、v B and the differential capacitors (energy transfer stage output). Although Figure 8 The design provides four (4) nodes W, X, Y, Z for input and output, but the basic design can provide any number of nodes from 3 up to, for example, Figure 7B The extended DSC structure is shown in FIG.

[0078] As an example, Fig. 9A The following table shows the supply voltage below v A and v B The single output voltage v C The circuit is similar in some respects to the differential capacitor energy transfer stage. Figure 5A circuit, but with different nodes selected as input and output. The operation of the DSC circuit will output voltage v C Maintain at 2 V A -v B nearby. Fig. 9B The circuit model for this DSC stage is shown, where an ideal transformer captures the current transfer and ideal open circuit voltage of the stage, and R droop Captured in the energy transfer capacitor C T The 1:1 transformer in the model will use the power loss and drop in the output voltage due to the charging and discharging of the transformer. A The current drawn is divided equally to supply v B and v C Come and v C Keep below v A Approximately equal to v B -v A The difference between Figure 5A The effective drop resistance R droop is 1 / (4·f·C T ), where f is the switching frequency at which the DSC circuit is operated and C T is the value of the energy transfer capacitor. In the fast switching limit, R droop becomes R CT +2·R sw , where R CT is the energy transfer capacitor C T The equivalent series resistance of 2·R sw represents the total resistance of the two switches, and the current flows through the two switches to the capacitor C T Charge or discharge.

[0079] Utilize in supply generator Fig. 9AThe benefit of the capacitive energy transfer stage design 90 shown in FIG. 1 is that only the power delivered to the low voltage output v C (and to output v B The current of the matched amount) is processed by the DSC circuit 90, while the rest is directly provided by the multiple output magnetic stage. Because in many power amplifier systems, the lower voltage output v C The duty to lower peak power is greater than the higher voltage output, which reduces the required rating of the DSC circuit and also infers the amount of system losses caused by the DSC circuit. The disadvantage of this design is that it is not flexible in terms of loading or design of the supply generator system. In particular, with this design, the power delivered to v by the DSC circuit is C Any current delivered to v B If the current from v B The load current drawn is always lower than the current drawn from v C The current drawn, then ideally the multi-output magnetic stage should be able to handle the output v B bidirectional power flow to be able to regulate v A and v B both. Fig.13 , Fig.14 and Fig.15 An example power stage topology with multiple output magnetic stages that can effectively achieve this is shown in .

[0080] It should be noted that the differential capacitive energy transfer stage may be implemented based on various types of differentially connected switched capacitor circuits, resulting in different achievable voltage distributions.

[0081] In an embodiment, a differential capacitive energy transfer stage based on a DSC circuit derived from a series-parallel switched capacitor converter can be used. In such a design, a voltage close to the corresponding voltage (v B -v A ) / 3 to maintain a pair of energy transfer capacitors so that the output voltage v C Keep at v A With v B 1 / 3 of the distance between C =v A +(v B -v A ) / 3. A differential capacitive energy transfer stage can be implemented based on a DSC circuit derived from any type of switched capacitor converter, including Fibonacci, Dickson, Cockroft-Walton, Hybrid Dickson / Cockroft-Walton or other hybrids, etc. Likewise, such a stage can be implemented using partial or complete cascading of different types of switched capacitor structures.

[0082] In some designs, due to the operation of the differential capacitive energy transfer stage based on the change of the operating mode, the reconfigurability of the voltage distribution can be achieved, similar to the reconfiguration technique utilized in the switched capacitor DC-DC converter. For example, in some designs, the differential capacitive energy transfer stage can have a first operating mode in which the switches are operated so that the voltage close to (v B -v A ) / 3 to maintain a pair of energy transfer capacitors, so that the output v C Keep at v A With v B 1 / 3 of the distance between C =v A +(v B -v A ) / 3. In the second operation mode, the switch can be operated so that the utilization voltage is close to (v B -v A ) / 2 to maintain the energy transfer capacitors CT1 and CT2, so that the output v C Keep at v A With v B 1 / 2 of the distance between C =v A +(v B -v A ) / 2=(v B +v A ) / 2. The benefit of such a reconfigurable design is that it provides the flexibility to achieve higher performance across different operating conditions at the expense of higher complexity and more switches and / or capacitors and / or interconnects than a non-reconfigurable design.

[0083] It is also possible to implement a differential capacitive energy transfer stage that incorporates a small amount of magnetic material that enhances the capacitive energy transfer. Doing so can improve efficiency and / or provide an additional degree of control over the voltage profile, as is sometimes implemented in resonant switched capacitor converters and hybrid magnetic / switched capacitor converters.

[0084] For example, in an embodiment, the differential capacitive energy transfer stage may utilize an additional small inductor L. This inductor may be implemented as a physical inductor and / or by utilizing circuit parasitics such as capacitor parasitic inductance and printed circuit board traces. Operating such a circuit with a 50% duty cycle switching the first and second switch groups in a complementary manner at an appropriate (low) frequency (e.g., associated with resonant switched capacitor energy conversion) allows for a low output resistance while incurring only low switching losses. In principle, a low output resistance associated with fast switching limits may be achieved while operating at a low switching frequency.

[0085] For example, consider Fig.10 The differential capacitive energy transfer stage design 100 utilizes a circuit structure according to the above configuration, in which the energy transfer can be managed by modulating (e.g., by modulating with a controlled duty cycle) one of the following four possible switch states: S1, S3 is on; S2, S4 is on; S1, S2 is on; and S3, S4 is on. This gives the energy transfer capacitor C T voltage / charge on the output voltage v C Controlled at v A With v B Any value between provides flexibility while retaining the small size of the inductor L and the required energy storage. To this end, it is possible to cycle between two, three or four of these switching states with a controlled duty cycle, preferably with two switching states S1, S3 on and S2, S4 on.

[0086] As mentioned above, at least combined Figure 3 and Figure 4 , various multi-output power level designs (multi-regulation levels) can be realized to match Figure 2 Described next are multiple regulation stage designs and associated controls that have unique advantages in: multiple output supply generators for RF amplifiers, including but not limited to RF power amplifiers), including designs with differential capacitive energy transfer. These can also be employed in other single-input, multiple-output power converter designs.

[0087] One challenge that may arise in certain multi-regulator stages in RF amplifier system applications is the ability to obtain Figure 2 V A 、V B ) may become zero while the other may be positive. For some differential switched capacitor converter topologies, such as those combined with Fig. 9A , Fig. 9B As described above, the load current on one of the outputs can even become negative, potentially overcharging the voltage on that output. This can be a significant challenge in some designs.

[0088] For example, consider that the load current on the first output is large enough that the inductor current i LContinuously positive multiple regulation stages. If the load current on the first output goes to zero and the voltage at the first output becomes transiently higher than its desired value (due to load reduction), there is no way the power stage can do both of these: supply a large load current at the second output (to keep the output voltage at the second output near the second output reference voltage), and reduce the voltage at the first output to its desired voltage. The same problem arises if it is desired to regulate the command voltages at the first and second outputs so that the second output becomes larger and the first output becomes smaller. An inductor current having only one polarity can be used to source (or sink) current from both outputs to limit the average current fed to both outputs to the same polarity. (Otherwise, either a large inductor ripple current is required or the inductor current direction must be changed between supplying the two outputs, which results in substantial losses and adverse transient consequences.)

[0089] It would be desirable to have a single output that can regulate a pair of outputs (V A 、V B ). It would also be desirable to have a power stage that can simultaneously increase the voltage of a first output while decreasing the voltage on a second output without requiring a large load on either output. Described next is a power stage design and associated controls suitable for meeting such a requirement.

[0090] Now refer to Fig.11 , the multiple regulation stages 110 include a load current I LA ,I LB A two-output buck converter. One method for controlling this converter is to switch S B With S A (where for the duty cycle d o Connect S B ) to control (or establish or set) the fraction of the inductor current delivered to output B, and modulate (i.e., turn on and off for a specific period of time) the switch S X and S Y (For duty cycle d i Connect S X ) to control (or establish or set) the voltage v m The local average of the output voltage v A and v B The weighted average of .

[0091] In a variation of this method, the duty cycle d i As a control handle for reference voltage v B，ref With vA，ref The common mode regulation v B With v A The common mode (or average) and the duty cycle d o With respect to the reference voltage v B，ref With v A，ref The difference adjustment v B With v A difference. Fig.13 An illustrative schematic diagram of such a controller is shown in FIG.

[0092] Now refer to Fig.12 The power stage 108 includes a first differential circuit 110 and a second differential circuit 111, wherein the differential circuit 110 is configured to receive a reference voltage V at a corresponding input of a first input 110a and a second input 110b. ref，A and voltage V A The differential circuit 110 generates or otherwise forms a voltage corresponding to the voltage V ref，A With V A The difference in voltage between V e，A , and provides a differential (or error) voltage V at output 110c e，A Similarly, the differential circuit 111 is configured to receive a reference voltage V at a corresponding input of the first input 111a and the second input 111b. ref，B and voltage V B The differential circuit 111 generates or otherwise forms a voltage corresponding to V ref，B With V B The difference between the differential (or error) voltage V e，B , and provides a differential voltage V at output 111c e，B .

[0093] Differential voltage V e，A 、V e，B The output of scaling circuit 112 is provided to a first input 116a of differential circuit 116, and the output of scaling circuit 114 is provided to a second input 116b of differential circuit 116. Differential circuit 116 generates or otherwise forms a voltage V corresponding to the difference between the voltages provided thereto. Diff , and provides a differential voltage V at output 116c Diff Thus, the differential circuit 116 provides the differential of the scaled error (or V e，A 、V e，B Some other function, such as based on which has a larger magnitude in -V e,A 、V e,B to choose between ).

[0094] The scaling considered is selected to keep the signal within the desired range. They can also control the overall loop gain differently for A and B output changes. Therefore, the scaling value can be selected to provide the desired signal scaling and desirable closed-loop dynamics. In terms of using some other functions (instead of the differential function 116 or in addition to the differential function 116), a nonlinear function can be inserted, for example, to drive the controller to compensate for different errors (for example, it can be considered to have a significant impact in an embodiment, that is, it can be considered to be a more "important" error, such as the error between 116a and 116b). Regarding the selection based on the amplitude of the amplified error signal, doing so can make the controller work to compensate for larger errors (or larger scaling errors), thereby reducing (and ideally minimizing) the worst (i.e., maximum) deviation between multiple output voltages.

[0095] The differential circuit output 116c is coupled to a first input 118a of a compensator circuit 118 (a so-called "output-side" or "o-side" compensator). The compensator circuit 118 may be provided as a finite linear or nonlinear compensator and receives a provided signal at an input 118a and provides a compensated output signal V at its output 118b. Compl The compensation signal adjusts the duty cycle to compensate for (minimize) the error between the difference between the output voltages Vb and Va and the desired difference (or reference difference) between the output voltages Vb and Va.

[0096] The compensator output 118b is coupled to the input of an optional offset circuit 120. The offset circuit converts the offset voltage V Offset Added to the compensation voltage V Comp1 and provides a duty cycle control value d at its output o The optional insertion offset can reduce the compensator variation range and speed up the transition to steady state at startup, at the expense of a slight increase in circuit complexity. In an embodiment, the duty cycle control value d is set at the compensator or elsewhere in or after the circuit 108. o The value of can be constrained to be between 0 and 1.

[0097] Differential voltage V e，A 、V e，B is also provided to the corresponding circuits in the scaling circuits 122, 124. The output of the scaling circuit 122 is provided to the first input 126a of the adding circuit 126 and the output of the scaling circuit 124 is provided to the second input 126b of the adding circuit 126. It should be noted that the scaling circuits 122, 124 can scale the error voltage aging V e，A 、V e，B Or some other function can be applied to the voltage V e，A 、V e，BFor example, the scaling circuits 122, 124 and the summing circuit 126 may apply some other function (ie, other than simple scaling and summing), such as e，A 、V e，B For example, select max[V e，A , V e，B ]、max[K iA V e，A , K iA V e，B ] etc. Such an approach can indicate the worst-case output deviation to be adjusted.

[0098] Summing circuit 126 generates or otherwise forms a voltage V corresponding to the difference between the voltages supplied thereto. Sum and provides a summed voltage V at output 126c Sum Therefore, the summing circuit 126 provides the sum of the scaled errors V at the output 126c. Sum (or some other function mentioned above).

[0099] The output 126c of the summing circuit 126 is coupled to a first input 128a of a compensator circuit 128 (a so-called “input-side” or “i-side” compensator). The compensator circuit 128 may be provided as a finite linear or nonlinear compensator and receives a provided signal at an input 128a and provides a compensated output signal V at its output 128b. Comp2 The compensation signal adjusts the o-side duty cycle to compensate (minimize) the error between the sum of the output voltages Vb and Va and the desired sum (or reference sum) of the output voltages Vb and Va.

[0100] As described above, the scaling value may be selected to keep the signal within a desired range and / or to control the overall loop gain differently for A and B output variations. The scaling value may thus be selected to provide the desired signal scaling and desirable closed loop dynamics. In using some other function (instead of or in addition to the addition function 126), a non-linear function may be inserted, for example, to drive the controller to compensate for different errors.

[0101] In an embodiment, the compensator output 128b is coupled to a first input of an optional summing circuit 130. A second input of the summing circuit 130 may be configured to receive an input from an optional offset or feed-forward circuit 131. This is similar to the differential circuit Voffset, but may be based on the input voltage V INFeed forward is added to help quickly compensate for input voltage variations. While some forms of input voltage feed forward are known in the art, the use of input voltage feed forward is not known or used in the context of sum and difference control. The optional insertion of offset and / or feed forward circuits 130, 131 can reduce the variation range of the compensator and speed up the transition to a steady state at startup and input voltage variations, at the expense of a slight increase in circuit complexity. A duty cycle control value d is provided at the output of the optional summing circuit 130 (or at the output of the compensator 128 in embodiments that do not include the optional summing circuit 130). i In an embodiment, the duty cycle control value d is set at the compensator or elsewhere in or after the circuit 108. i The value of can be constrained to be between 0 and 1.

[0102] In this example implementation, circuit 131 includes an offset circuit 132 and a limit circuit 134. Offset circuit 131 provides a feed-forward value based on the input voltage and the output switch duty cycle to suppress the effect of changes in the input voltage on the average value of the output voltage.

[0103] In many instances, Fig.11 The power level and Fig.12 The compensator combination will exhibit the above-mentioned inability to quickly reduce the voltage at the first output when the second output is heavily loaded because there is only one available polarity of current (i L ) for output v A and v B Charge / discharge.

[0104] like Fig.11 , Fig.12 The power stage and associated control circuitry and scheme shown in FIG. 4 may alternatively or additionally adjust v B，ref and V A，ref and v B and v A For example, we can have a function consisting of a nonlinear function such as max(k i，A (v A，ref -v A ), k i，B (v B，ref -v B )) where max(x, y) takes the maximum value of x and y, and k i，A and k i，B are constants chosen to help adjust the loop dynamics for the A and B outputs respectively—the drivers that produce d i Similarly, one can have an “input side” compensator based on a function such as max(-k o，A (v A，ref -vA ,),k o，B (v B，ref -v B )), where k o，A and k o，B are constants chosen to help tune the loop dynamics for the A and B outputs respectively—yielding d o The o-side compensator is the “output-side” compensator of the output. Such compensators may themselves be linear or nonlinear and include proportional, integral, derivative terms, and / or utilize techniques such as anti-windup. Likewise, d i With d o Cross coupling between compensators, feed forward from input, offset, etc.

[0105] Now refer to Fig.13 ,in Fig.11 The same elements are provided with the same reference numerals, the alternative power stage 136 includes two additional switches S C and S Z Rather than Fig.11 The circuit topology shown in FIG. includes a switch S C and S Z One or two of the switches and the operation of the switches in certain modes, as described below, can improve the ability of the multiple output power stage to adjust the output voltage as needed, independent of the load conditions (i.e., the switches S can be operated in a manner that improves the ability of the multiple output power stage to adjust the output voltage C and S Z ). It should be noted that S can be used depending on the needs. C or S Z One or use S C and S Z Both complete the power stage. One might often choose to have both Sc and Sz, but one might only need Sc when bidirectional current (or power) transfer is required to output B, and only need Sz when bidirectional current (or power) transfer is required to output A. Therefore, the inclusion of one or both switches depends on the load current range required for outputs A and B, with the inclusion of both providing flexibility for any associated loads between the outputs.

[0106] Additional switch S C and S Z The momentary switch S C and S ZIncorporated into converter operation to provide additional control given output overvoltage and underload, unloading or overloading (i.e., absorbing energy from the load rather than delivering energy to the load). One possible approach is to enter one or more special operating modes under predetermined conditions of the converter output and / or compensator and / or internal power stage states. The decision to make a special mode active can be made on a cycle-by-cycle basis, for example, determining whether a special mode is active at the beginning of each switching cycle.

[0107] An example of such a special operating mode (referred to as "Special Mode 1") is as follows: During Special Mode 1, X With S Z Between rather than in S X With S Y modulate between the two (as is done in normal operation).

[0108] For example, when v A >v A，ref And v B <v B，ref , Special Mode 1 can be activated during the cycle. In this case, when output A exceeds its desired voltage and output B is below its desired voltage, Special Mode 1 uses the (positive) inductor current i L Charging from output A to output B accelerates each of these voltages toward their desired values. This can increase the voltage v even when there is no load on output A or when there is a negative load at output A. A Reduce to the reference voltage v A，ref Once the output A drops to the desired value (v A <=v A，ref ), the special mode will automatically end and normal operation will continue. Special Mode 1 can optionally utilize the normal mode input side compensator to make modulation decisions during Special Mode 1 (e.g., synthesize Fig.12 The duty cycle command d i The “i-side compensator” may be used, or a separate compensator may be utilized for this special mode.

[0109] It should be understood that additional or alternative constraints may be used to determine the special mode 1 (using switch S Z ) is active. For example, any of the following alternative sets of constraints may be used to determine when special mode 1 is active (e.g., making a special mode decision at the beginning of each cycle):

[0110] When v A >v A，ref And d O When the compensator output is ≥ 1, special mode 1 is activated (i.e., output A is overvoltage and switch SB The output side compensator is kept on continuously. This ensures that there will be no inductor current i L Duration of cycling between on and off only. )

[0111] When v A >v A，ref And v B <v B，ref And d O When the compensator output is ≥ 1, special mode 1 is activated (i.e., special mode 1 is constrained for both undervoltage on output A, overvoltage on output B, and the output side compensator keeps switch B continuously turned on.)

[0112] When v A >v A，ref And v B <v B，ref And i L > 0 to activate special mode 1 (i.e., constrain special mode 1 for both overvoltage on output A, undervoltage on output B, and inductor current i L > 0. Inductor current i L The evaluation of can be for a specific time point, such as at the beginning of the current cycle or at a time point in the previous cycle. L Some equivalent current is used for decision making purposes or to use some local average current as a constraint. This helps ensure that v A 、v B The charge between them is in the correct direction.)

[0113] When v A In case of overvoltage, the above special mode 1 uses an additional switch S Z to aid in transient situations. When v B In case of overvoltage, we can use the additional switch S in special mode C to aid in transient situations. One way to do this is to use special mode 2 as follows:

[0114] Special Mode 2: During Special Mode 2, in S C With S Y between S as in normal operation X With S Y Modulation between.

[0115] For example, when v B >v B，ref And v A <v A，ref , Special Mode 2 can be activated during the cycle. In this case, when output B exceeds its desired voltage and output A is below its desired voltage, Special Mode 2 uses the (positive) inductor current iL Output A is charged from output B. This can increase the voltage v even when there is no load on output B or when there is a negative load at output B. B Reduce to the reference voltage v B，ref Once output B drops to the desired value (v B <=v B，ref ), the special mode will automatically end and normal operation will continue. Special Mode 2 can optionally utilize the normal mode input side compensator to make modulation decisions during Special Mode 2 (e.g., synthesizing Fig.12 The duty cycle command d i The “i-side compensator” may be used, or a separate compensator may be utilized for this special mode.

[0116] It should be understood that additional or alternative constraints may be used to determine the special mode 2 (using switch S C ) is active. For example, any of the following alternative sets of constraints may be used to determine when special mode 2 is active (e.g., making a special mode decision at the beginning of each cycle):

[0117] When v B >v B，ref And d O When the compensator output is ≤ 0, special mode 2 is activated (i.e., output B is overvoltage and switch S A The output side compensator is kept on continuously. This ensures that there will be no inductor current i L Duration of cycling between on and off only. )

[0118] When v B >v B，ref And v A <v A，ref And d O When the compensator output is ≤ 0, special mode 2 is activated (i.e.,

[0119] Constrained special mode 2 is used for both undervoltage on output A, overvoltage on output B, and the output side compensator keeps switch A continuously turned on. )

[0120] When v B >v B，ref And v A <v A，ref And i L > 0, special mode 2 is activated (i.e., special mode 2 is constrained for both overvoltage on output B, undervoltage on output A, and inductor current i L > 0. Inductor current i L The evaluation of can be for a specific time point, such as at the beginning of the current cycle or at a time point in the previous cycle.L Equivalently some current is used for decision making purposes or using some local average current as a constraint. This helps ensure that the charge is in the correct direction. )

[0121] When there is a load change on outputs A, B and / or when the reference voltage v B，ref and v A，ref Existence Fig.11 When the power level is difficult to handle quickly, the above special mode uses the auxiliary switch S C and S Z To provide improved control and transient performance. Since the auxiliary switch S C and S Z Only transient operation is required, so it will be appreciated that it can be dimensioned to be significantly smaller (ie, have a higher on-state resistance and / or a smaller semiconductor device area) than the main power stage switches. Z The size can be relative to S Y Small and S C Size and S X The auxiliary switches may be smaller than the power stage without significantly reducing system efficiency. For example, the auxiliary switches may be rated to have between 4 and 20 times the on-state resistance of their corresponding main power stage switches. Such appropriate sizing of the auxiliary switches helps to reduce (and ideally, minimize) the impact on the overall converter size and / or semiconductor die area of ​​the power management integrated circuit used to implement the power stage. Fig.13 Switch S in C and S Z Essentially they must be implemented as bidirectional blocking switches. They can therefore be implemented as back-to-back connections of MOSFET devices or using integrated lateral MOSFET devices (e.g. in a silicon CMOS process), where the potential of their back-gates is adjusted at a given point in time according to the desired blocking direction (i.e. "back-gate" or "body" switching).

[0122] It should be understood that although Fig.13 The power stage 136 is shown with capacitors from each of the outputs A, B to common ground, but a practical design may include a capacitor between the outputs A, B in addition to or in place of one of these capacitors. Likewise, there may be a differentially connected load between the outputs A, B. Furthermore, the loads on the outputs A, B may include a differential switched capacitor stage to provide additional outputs between or around the voltage space at the outputs A, B.

[0123] It should be understood that the proposed special mode can also be implemented using other topological configurations, some of which do not need to be used, such as in Fig.14 The circuit topology shown in the figure shows a bidirectional blocking switch with auxiliary switch.

[0124] Now refer to Fig.14 , the input voltage from source 142 is coupled to the first switch S C1 The first terminal of the switch S C1 The second terminal of the second switch S C2 The first terminal of the switch S C2 The second terminal is coupled to a load current I LA The output 147. A pair of switches Sx, Sy are coupled to the first switch S C1 between the second terminal and the reference potential. Z1 has a first terminal coupled to a reference potential (here, shown as ground) and a second terminal coupled to a terminal of a switch Sy. Z2 having a first terminal coupled to a second terminal of a switch Sy and coupled to a load current I associated therewith LB A second terminal of the output 148. A pair of switches S A , S B Coupled to switch S C2 The second terminal of the switch S Z2 The inductor L is coupled to the switch S X The second terminal of the switch S B between the second terminals.

[0125] exist Fig.14 In the implementation mode, the switch S C1 , S C2 , S Z1 and S Z2 Can be made into one-way blocking. Fig.11 The input side modulation can be achieved by using the duty cycle d i Use switch S X and S Y Implementation (e.g., according to Fig.12 ), and the output side modulation can be achieved by the duty cycle d o Using device S B and S A Implementation (e.g., according to Fig.12 . ) In normal mode operation, switch S C1 and S Z1 In special mode 1 operation, switch S is kept “on” (ie, the switch is biased into a conductive state such that a low resistance signal path exists between the first switch terminal and the second switch terminal). C1 and S Z2 remains on, while in Special Mode 2 operation, switch S C2 and S Z1 For this topology, it may be desirable to switch SC1 and S Z1 The size is set to S X , S Y Compared to similar size or larger (i.e. having similar or much lower resistance, such as S C1 and S Z1 The resistance and S X , S Y Compared with the zoom 0.1 to 1 times), while the switch S C2 and S Z2 Can be done better than switch S X , S Y Smaller (ie having a much larger resistance, e.g. scaled by a factor of 4 to 20).

[0126] As mentioned above, special operating modes can selectively utilize the input side d i The compensator is used to control the switch modulation during the special mode operation. In doing so, it may be desirable to adjust the compensator output (d i This can be done, for example, so that Fig.13 The local mean v in m The compensator output is not disturbed by the change of operating mode during the transient period (i.e., the compensator output is m The relationship between the local average voltage commanded at V and V remains unchanged.) For each special mode, the compensator offset can be selected as a predetermined function of one or more of the following: in 、v A 、v B d i 、v A，ref 、v B，ref .

[0127] Alternatively, one can simply use an input-side compensator based on the output voltage v A and v B The average error (or v A 、v B 、v A，ref and v B，ref Some other function of i , regardless of whether it is in normal mode (with a duty cycle d i Using S X Connect to S X With S Y Modulation between), special mode 1 (with duty cycle d i Using S X Connect to S X With S Z Modulation) or special mode 2 (with duty cycle d i Using S C Connect to SC With S Y between modulation).

[0128] The above design introduces a special operating mode based on input side switch modulation. It is also possible to have the following design: alternatively or additionally adjust the output side switch for special mode operation. The above design introduces auxiliary switches and operating modes in which energy can be transferred between outputs A and B instantaneously to more quickly adapt to load changes and / or reference voltage changes. It is also possible to introduce a special operating mode in which energy is transferred from both outputs A and B to the input to more quickly adapt to changes in operating conditions.

[0129] For example Fig.15 The auxiliary switch S is shown O Another power stage circuit 150 can have a special operation mode 3, when v B >v B，ref And v A >v A，ref It can be activated when (i.e. when the two output voltages are overvoltage). In this special mode 3, S X , S Y , S A , S B Shut down, keep S O is turned on, and in S Z With S C The time depends on the discharge v A and v B The relative duty cycle required is modulated. This causes the (positive) inductor current i L can be quickly (i.e. only affected by the current i) by transferring energy to the input L Available amplitude limit) discharge v A and v B , without first reversing the inductor current direction. Since Special Mode 3 can be used as a transient operating mode, switch S can again be optionally O The dimensions are set relative to the switch S X and S Y is small (e.g., 4 to 20 times smaller). The following special operating mode can also be conceived: the auxiliary switches SC, SZ and SO are influenced to realize the three ports V in 、v A 、v B Fast energy transfer between any ports in the L direction.

[0130] Illustrative examples of supply generators including power conversion stages and power converter stages with multiple independently regulated outputs are described herein and shown in the accompanying drawings. Those of ordinary skill in the art will appreciate that the circuit implementations described herein are provided as examples only, and that no particular circuit implementation is implied to be necessary or desirable unless otherwise specified.

[0131] Thus, having described several aspects of at least one embodiment of the concept described, it will be appreciated that various changes, modifications, and improvements will be readily apparent to those skilled in the art. Such changes, modifications, and improvements are intended to be a part of the present disclosure and are intended to fall within the spirit and scope of the concept described herein. In addition, although the advantages of the concept described herein are noted, it will be appreciated that not every embodiment of the technology described herein will include each described advantage. Some embodiments may not implement any of the features described herein as being advantageous, and in some cases, one or more of the described features may be implemented to implement other embodiments. Therefore, the above description and accompanying drawings are by way of example only.

[0132] The various aspects of the concepts described herein may be used alone, in combination, or in a variety of arrangements not specifically discussed in the foregoing embodiments, and therefore their application is not limited to the details and arrangements of the components set forth in the foregoing description or shown in the accompanying drawings. For example, aspects described in one embodiment may be combined with aspects described in other embodiments in any manner.

[0133] In addition, the concepts described herein can be implemented as methods. The actions performed as part of the method can be ordered in any suitable manner. Therefore, embodiments can be constructed that perform actions in an order different from the order shown, and even if the actions are shown as sequential in the illustrative embodiments, the embodiments can also include performing some actions simultaneously.

[0134] The use of ordinal terms such as "first", "second", "third", etc. in the claims to modify claim elements does not itself imply any priority, precedence or order of one claim element relative to another claim element or the temporal order of the actions of performing the method, but is merely used as a mark to distinguish one claim element with a certain name from another element with the same name (except for the use of ordinal terms) to distinguish the claim elements.

[0135] The terms "near," "close," "approximately," and "approximately" may be used to mean within ±20% of a target value in some embodiments, within ±10% of a target value in some embodiments, within ±5% of a target value in some embodiments, and within ±2% of a target value in some embodiments. The terms "near," "close," "approximately," and "approximately" may include a target value. The term "substantially equal" may be used to refer to values ​​that are within ±20% of each other in some embodiments, within ±10% of each other in some embodiments, within ±5% of each other in some embodiments, and within ±2% of each other in some embodiments.

[0136] The term "substantially" may be used to refer to values ​​within ±20% of a comparison measure in some embodiments, within ±10% of a comparison measure in some embodiments, within ±5% of a comparison measure in some embodiments, and within ±2% of a comparison measure in some embodiments. For example, a first direction that is "substantially" perpendicular to a second direction may refer to a first direction that is within ±20% of a 90° angle with the second direction in some embodiments, a first direction that is within ±10% of a 90° angle with the second direction in some embodiments, a first direction that is within ±5% of a 90° angle with the second direction in some embodiments, and within ±2% of a 90° angle with the second direction in some embodiments.

[0137] The phrase "slow switching limit" (e.g., as known in the analysis of SC converters and as described above in conjunction with Figure 5A The ) used refers to the value of Rout within this limit as a function of the switching frequency and capacitor size.

[0138] In addition, the words and terms used in this article are for descriptive purposes and should not be regarded as limiting. The use of "including", "comprising" or "having", "containing", "involving" and variations thereof in this article is intended to include the items listed thereafter and their equivalents as well as additional items.

[0139] For the purposes of the above description, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom" and their derivatives shall refer to the described structures and methods, as shown in the accompanying drawings. The terms "covering", "on top", "on top", "located at" or "located on top" refer to a first element (e.g., a first structure) being present on a second element (e.g., a second structure), wherein there may be an intermediate element such as an interface structure between the first element and the second element. The term "direct contact" refers to a first element (e.g., a first structure) and a second element (e.g., a second structure) being connected without any intermediate layer or structure at the interface of the two elements.

[0140] In the foregoing detailed description, various features of the embodiments are grouped together in one or more separate embodiments for the purpose of simplifying the present disclosure. The method of the present disclosure should not be interpreted as reflecting the intention that the claims require more features than those explicitly listed herein. Rather, inventive aspects may lie in less than all features of each disclosed embodiment.

[0141] Having described implementations for illustrating the various concepts, structures, and techniques that are the subject of this disclosure, it will now be apparent to one of ordinary skill in the art that other implementations incorporating these concepts, structures, and techniques may be used. Therefore, it should be noted that the scope of this patent should not be limited to the described implementations, but should only be limited by the spirit and scope of the appended claims.

[0142] All publications and references cited herein are incorporated by reference in their entirety.

[0143] In addition, the present disclosure also provides the following configuration.

[0144] 1. A method for generating a voltage source having m power supply voltages (V1 to V m ) system, comprising:

[0145] (a) independently controlling two (2) power supply voltages Vx and Vy of the m power supply voltages, wherein x and y are both in the range of 1 to m; and

[0146] (b) allocating the other m minus two (m-2) supply voltages in a specified relationship to the two independently controlled supply voltages such that independent control of the two (2) of the m supply voltages is equivalent to independently specifying or controlling one or more of:

[0147] (1) Minimum supply voltage level (V min ) and the maximum supply voltage level (V max ), wherein the interval ΔV between the minimum voltage level and the maximum voltage level is based on the minimum supply voltage level (V min ) and the maximum supply voltage level (V max ) and the total number of levels m is determined;

[0148] (2) Minimum supply voltage level (V min ) and the voltage interval ΔV between levels, where the maximum supply voltage level (V max ) is determined by the inter-horizontal voltage interval ΔV and the total number of levels m; and

[0149] (3) Maximum supply voltage level (V max) and the voltage interval ΔV between levels, where the minimum supply voltage level (V min ) is determined by the inter-horizontal voltage interval ΔV and the total number of levels m.

[0150] 2. The method of configuration 1, wherein allocating the other m-2 power supply voltages according to a prescribed relationship comprises automatically allocating the other m-2 power supply voltages using a differential switched capacitor circuit.

[0151] 3. The method of configuration 1, wherein allocating the other m-2 supply voltages in accordance with a prescribed relationship comprises using a differential switched capacitor circuit to provide charge transfer to automatically allocate the other m-2 supply voltages.

[0152] 4. The method according to configuration 1, wherein allocating the other m-2 power supply voltages according to the prescribed relationship includes synthesizing the other m-2 power supply voltages from two independently created power supply voltages.

[0153] 5. A method according to configuration 1, wherein allocating the other m-2 power supply voltages in accordance with a prescribed relationship to the two independently controlled power supply voltages includes allocating the other m-2 power supply voltages so that the other m-2 power supply voltages are spaced apart in a uniform manner between and / or around the two independently controlled power supply voltages.

[0154] 6. The method of configuration 5, wherein allocating the other m-2 supply voltages to be spaced apart in a uniform manner between or around the two independently controlled supply voltages comprises allocating the other m-2 supply voltages such that adjacent voltage levels are separated by a voltage ΔV.

[0155] 7. The method according to configuration 6 further includes independently adjusting the two voltages V1 and V m And the other m-2 voltages are placed between the two voltages V1 and V m are evenly spaced to provide m power supply voltages V k =V1+(k-1)·(V m -V1) / (m-1), where k=1 to m.

[0156] 8. The method according to configuration 7, wherein m is equal to one of the following: m=3; or m=4.

[0157] 9. A system for generating a set of power supply voltages, comprising:

[0158] Used to provide M power supply voltages (V1 to V M ) device, wherein two (2) of the M power supply voltages (e.g., V m1 and Vm2 ) can be controlled independently;

[0159] For independently controlling two (2) power supply voltages (e.g., V m1 and V m2 ) devices; and

[0160] Means for distributing said other M-2 supply voltages in a specified relationship to said two independently controllable supply voltages.

[0161] 10. The system of configuration 9, wherein at least two of the M power supply voltages (V m1 and V m2 ) can be controlled independently.

[0162] 11. The system of configuration 10, wherein the means for independently controlling is configured to control at least two of the at least two of the M power supply voltages.

[0163] 12. A system according to configuration 9, wherein the other M-2 power supply voltages are allocated in relationship to the two independently controlled power supply voltages such that the other M-2 power supply voltages are spaced in a uniform manner between and / or around the two independently controlled power supply voltages.

[0164] 13. The system of configuration 12, wherein the other M-2 supply voltages are evenly spaced between and / or around the two independently controlled supply voltages, with adjacent voltage levels separated by a voltage ΔV.

[0165] 14. The system according to configuration 9, wherein:

[0166] For independently controlling the two (2) power supply voltages (V m1 and V m2 ) is provided for independently regulating the two voltages V m1 and V m2 devices; and

[0167] The device for distributing the other M-2 power supply voltages comprises the following device: the device is used to distribute the other M-2 voltages at the first voltage V m1 and the second voltage V m2 are evenly spaced apart so that the system provides M power supply voltages V k =V1+(k-1)·(V m -V1) / (m-1), where k=1...M.

[0168] 15. The system of configuration 9, wherein the two (2) power supply voltages (V m1 and V m2 ) and the means for distributing the other M-2 supply voltages in a specified relationship to the two independently controlled supply voltages operate such that the means for independently controlling and the means for distributing are equivalent to independently specifying or controlling one or more of the following:

[0169] (1) Minimum supply voltage level (V min ) and the maximum supply voltage level (V max ), wherein the interval ΔV between the minimum voltage level and the maximum voltage level is based on the minimum supply voltage level (V min ) and the maximum supply voltage level (V max ) and the total number of levels M is determined;

[0170] (2) Minimum supply voltage level (V min ) and the voltage interval ΔV between levels, where the maximum supply voltage level (V max ) is determined by the inter-horizontal voltage interval ΔV and the total number of levels M; and

[0171] (3) Maximum supply voltage level (V max ) and the voltage interval ΔV between levels, where the minimum supply voltage level (V min ) is determined by the inter-horizontal voltage interval ΔV and the total number of levels M.

[0172] 16. The system of configuration 9, wherein the means for providing the M supply voltages comprises a multi-output supply generator, the multi-output supply generator comprising:

[0173] (1) a multiple regulation stage configured to receive an input voltage and provide a plurality of independently regulated output voltages at two or more outputs of the multiple regulation stage; and

[0174] (2) a differential capacitive energy transfer stage that utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multiple regulation stage to synthesize one or more additional outputs, wherein the voltage and / or current of the one or more additional outputs is a function of the voltage and / or current provided from the two independently regulated outputs.

[0175] 17. The system of configuration 16, wherein the multiple regulation stages are provided as a single inductor multiple output (SIMO) power converter.

[0176] 18. The system of configuration 16, wherein the differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between two outputs of the multi-regulation stage.

[0177] 19. A multiple output supply generator comprising:

[0178] (1) a multiple regulation stage configured to receive an input voltage and provide a plurality of independently regulated output voltages at two or more outputs of the multiple regulation stage; and

[0179] (2) a differential capacitive energy transfer stage that utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multiple regulation stage to synthesize one or more additional outputs, wherein the voltage and / or current of the one or more additional outputs is a function of the voltage and / or current provided from the two independently regulated outputs.

[0180] 20. The multi-output supply generator of configuration 19, wherein:

[0181] The multiple regulation stages are provided as single inductor multiple output (SIMO) power converters; and the differential capacitive energy transfer stage is provided as a single output or multiple output switched capacitor converter, whose input port is differentially connected between two outputs of the multiple regulation stages.

Claims

1. A system for generating a plurality of supply voltages from an input voltage, the system comprising: a multi-regulation stage configured to receive an input voltage and provide at least two independently regulated supply voltages at two or more outputs of the multi-regulation stage; as well as A differential capacitive energy transfer stage is provided for synthesizing, at one or more outputs of the differential capacitive energy transfer stage, one or more additional supply voltages in a specified relationship to the at least two independently regulated supply voltages.

2. The system according to claim 1, wherein: The differential capacitive energy transfer stage provides charge transfer from the two or more outputs of the multiple regulation stages to distribute the one or more additional supply voltages.

3. The system according to claim 2, wherein: The one or more additional supply voltages are evenly distributed between two of the at least two independently regulated supply voltages.

4. The system according to claim 2, wherein: The one or more additional supply voltages are evenly distributed around two of the at least two independently regulated supply voltages.

5. The system according to claim 1, wherein: The one or more additional supply voltages include at least two additional supply voltages.

6. The system according to claim 1, wherein: The multiple regulation stages include a single inductor multiple output (SIMO) power converter.

7. The system according to claim 1, wherein: The differential capacitive energy transfer stage includes a switched capacitor converter having an input port differentially connected between two of the two or more outputs of the multiple regulation stage.

8. The system according to claim 7, wherein: The differential capacitive energy transfer stage includes a single output switched capacitor converter.

9. The system according to claim 7, wherein: The differential capacitive energy transfer stage includes a multiple output switched capacitor converter.

10. The system according to claim 1, wherein: The differential capacitive energy transfer stage includes a circuit having a plurality of switches connected in series between two of the two or more outputs of the multi-regulation stage, and also includes a capacitor connected in parallel with one or more of the plurality of switches.

11. The system according to claim 10, wherein: The plurality of switches are operated to provide charge transfer from the two or more outputs of the multiple regulation stages to distribute the one or more additional supply voltages.

12. The system according to claim 10, wherein: The differential capacitive energy transfer stage has an interleaved structure including two of the circuits connected in parallel.

13. The system according to claim 10, wherein: The differential capacitive energy transfer stage has a ladder structure including two of the circuits connected in series.

14. The system of claim 1, wherein: The differential capacitive energy transfer stage comprises at least three outputs, wherein two of the at least three outputs are directly connected to the two or more outputs of the multi-regulation stage.

15. The system of claim 1, wherein: The differential capacitive energy transfer stage comprises at least four outputs, wherein two of the at least four outputs are directly connected to the two or more outputs of the multi-regulation stage, and wherein other of the at least four outputs correspond to the one or more outputs of the differential capacitive energy transfer stage providing the additional supply voltage.

16. The system of claim 15, wherein: The differential capacitive energy transfer stage includes a plurality of filter / holding capacitors connected between different pairs of the at least four outputs.

17. The system of claim 16, wherein: Each of the plurality of filter / holding capacitors is rated for a difference between supply voltages provided at a corresponding pair of outputs.

18. The system of claim 1, wherein: The multiple regulation stages include a dual output buck converter.

19. The system of claim 1, wherein: The multiple regulation stages include a circuit having an inductor and a plurality of switches connected between the inductor and different ones of the two or more outputs.

20. The system of claim 19, further comprising a controller for operating the plurality of switches of the plurality of regulation stages.

21. The system of claim 1, wherein: The multiple regulation stages are configured to regulate the at least two independently regulated supply voltages if a load current on one of the two or more outputs becomes zero or negative while a load current on another of the two or more outputs is zero or positive.

22. A multiple output supply generator comprising: (1) a multiple regulation stage configured to receive an input voltage and provide a plurality of independently regulated output voltages at two or more outputs of the multiple regulation stage; as well as (2) a differential capacitive energy transfer stage that utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multiple regulation stage to synthesize one or more additional outputs, wherein the voltage and / or current of the one or more additional outputs is a function of the voltage and / or current provided from the two independently regulated outputs.

23. A multiple output supply generator according to claim 22, wherein: The multiple regulation stages are provided as a single inductor multiple output (SIMO) power converter; and The differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

24. A system for generating multiple supply voltages using parallel power converters, the system comprising: a multiple regulation stage having two or more dc-dc converters each configured to receive an input voltage and regulate at least one independently regulated supply voltage at one or more outputs thereof; as well as A differential capacitive energy transfer stage is configured to synthesize one or more additional supply voltages at one or more outputs of the differential capacitive energy transfer stage in a specified relationship to the independently regulated supply voltage.

25. The system of claim 24, wherein: Each dc-dc converter has an input and an output.

26. The system of claim 24, wherein: At least one of the two or more dc-dc converters is a buck converter.

27. A multiple output supply generator comprising: (1) a multi-regulation stage having two or more dc-dc converters, each configured to receive an input voltage and regulate at least one independently regulated supply voltage at one or more of its outputs; as well as (2) a differential capacitive energy transfer stage that utilizes capacitive energy transfer from the independently regulated outputs of the multiple regulation stages to synthesize one or more additional outputs, the voltage and / or current of the one or more additional outputs being a function of the voltage and / or current provided from the output of the multiple regulation stages.

28. A multiple output supply generator according to claim 27, wherein: At least one of the two or more dc-dc converters is provided as a single inductor multiple output (SIMO) power converter; and The differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

29. The multiple output supply generator of claim 27, wherein: at least one of the two or more dc-dc converters is provided as an independently regulated dc-dc converter having one input and one output; and The differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

30. The multiple output supply generator of claim 27, wherein: At least one of the two or more dc-dc converters is provided as a buck converter.

31. A radio frequency power amplifier system, comprising: a supply generator configured to provide a plurality of supply voltages, the plurality of supply voltages comprising at least two independently regulated supply voltages and one or more additional supply voltages in a specified relationship to the at least two independently regulated supply voltages; a supply modulator configured to switch between the plurality of supply voltages to provide a supply voltage to a power amplifier (PA); as well as A low frequency turn-off switch is connected between the supply modulator and the PA to selectively provide a zero output to the PA.

32. The system of claim 31, wherein: The supply generator comprises: a multi-regulation stage configured to regulate the at least two independently regulated supply voltages at two or more outputs of the multi-regulation stage; and A differential capacitive energy transfer stage is configured to synthesize, at one or more outputs of the differential capacitive energy transfer stage, the one or more additional supply voltages in a specified relationship to the at least two independently regulated supply voltages.

33. The system of claim 32, wherein: The multiple regulation stages include two or more independently regulated dc-dc converters, each configured to receive an input voltage and provide at least one independently regulated supply voltage at its output.

34. The system of claim 33, wherein: At least one of the two or more dc-dc converters is a buck converter.

35. The system of claim 31 further comprising a controller for operating the low frequency shutoff switch.

36. A radio frequency power amplifier system, comprising: Supply generator with: a multiple regulation stage configured to provide a plurality of independently regulated output voltages at two or more outputs of the multiple regulation stage; as well as a differential capacitive energy transfer stage that utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multiple regulation stage to synthesize one or more additional outputs, the voltage and / or current of the one or more additional outputs being a function of the voltage and / or current provided from the two independently regulated outputs; a supply modulator configured to switch between voltages provided at an output of the supply generator to provide a supply voltage to a power amplifier (PA); as well as A low frequency turn-off switch is connected between the supply modulator and the PA to selectively provide a zero output to the PA.

37. The system of claim 36, wherein: The multiple regulation stages are provided as a single inductor multiple output (SIMO) power converter; and The differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

38. The system of claim 36, wherein: The multiple regulation stages are provided as two or more independently regulated dc-dc converters; and The differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

39. The multi-regulation stage according to claim 38, wherein: One or more of the independently regulated dc-dc converters are provided as buck converters.

40. A radio frequency power amplifier system, comprising: a supply generator configured to provide a plurality of supply voltages, the plurality of supply voltages comprising at least two independently regulated supply voltages and one or more additional supply voltages in a specified relationship to the at least two independently regulated supply voltages; as well as A plurality of supply modulators are each configured to provide a supply voltage selected from the plurality of supply voltages to one or more power amplifiers (PAs).

41. The system of claim 40, wherein: The one or more PAs include a plurality of PAs, wherein each of the plurality of supply modulators is configured to provide a supply voltage to a corresponding one of the plurality of PAs.

42. The system of claim 40, wherein: The one or more PAs include a plurality of PAs, wherein one of the supply modulators is configured to provide a supply voltage to more than one of the plurality of PAs.

43. The system of claim 42, wherein: At least one of the PAs supplied by a single supply modulator is inactive, while at least one of the other PAs supplied similarly is active.

44. The system of claim 42, wherein: Multiple PAs of the one or more PAs supplied by a single supply modulator are activated simultaneously.

45. The system of claim 44, wherein: The system includes two supply modulators, each of the two supply modulators being configured to provide a supply voltage to more than one simultaneously activated PA.

46. ​​The system of claim 40, wherein: The supply generator comprises: a multi-regulation stage configured to regulate the at least two independently regulated supply voltages at two or more outputs of the multi-regulation stage; and A differential capacitive energy transfer stage is configured to synthesize, at one or more outputs of the differential capacitive energy transfer stage, the one or more additional supply voltages in a specified relationship to the at least two independently regulated supply voltages.

47. The system of claim 46, wherein: The multiple regulation stages include two or more dc-dc converters, each configured to receive an input voltage and provide at least one independently regulated supply voltage at its output.

48. The system of claim 47, wherein: At least one of the two or more dc-dc converters is a buck converter.

49. A radio frequency power amplifier system, comprising: Supply generator with: a multiple regulation stage configured to provide a plurality of independently regulated output voltages at two or more outputs of the multiple regulation stage; as well as a differential capacitive energy transfer stage that utilizes capacitive energy transfer from at least two of the independently regulated outputs of the multiple regulation stage to synthesize one or more additional outputs, the voltage and / or current of the one or more additional outputs being a function of the voltage and / or current provided from the two independently regulated outputs; as well as A plurality of supply modulators are configured to switch between voltages provided at outputs of the supply generator to provide supply voltages to corresponding power amplifiers of a plurality of power amplifiers (PAs).

50. The system of claim 49, wherein: The multiple regulation stages are provided as a single inductor multiple output (SIMO) power converter; and The differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

51. The system of claim 49, wherein: The multiple regulation stages are provided as two or more independently regulated dc-dc converters; and The differential capacitive energy transfer stage is provided as a single-output or multi-output switched capacitor converter, whose input port is differentially connected between the two outputs of the multi-regulation stage.

52. The multi-regulation stage of claim 51, wherein: One or more of the independently regulated dc-dc converters are provided as buck converters.

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