The present disclosure generally relates to the field of electronics. More particularly, an embodiment relates to a unified control scheme for non-inverting high-efficiency buck-boost power converters.
Direct Current (DC) to DC power converters are generally used in power delivery applications in which an input voltage needs to be transformed to an output voltage in a ratio that can be both smaller and larger than unity. Such converters may be particularly relevant in battery powered portable electronics, where battery voltage can be either greater than or less than the required operating voltage for the electronics. Hence, efficient utilization of such power converters is paramount to proper operation of battery-powered devices.
The detailed description is provided with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
FIGS. 1 and 10-12 illustrate block diagrams of embodiments of computing systems, which may be utilized to implement various embodiments discussed herein.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of various embodiments. However, various embodiments may be practiced without the specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the particular embodiments. Further, various aspects of embodiments may be performed using various means, such as integrated semiconductor circuits (“hardware”), computer-readable instructions organized into one or more programs (“software”), or some combination of hardware and software. For the purposes of this disclosure reference to “logic” shall mean either hardware, software, or some combination thereof.
As discussed above, DC-to-DC power converters may be used in power delivery applications that rely on battery power. One such converter is called a “buck-boost” power converter that is generally used in power delivery applications in which an input voltage needs to be transformed to an output voltage in a ratio that can be both smaller and larger than unity. Buck-boost converters are particularly relevant in battery powered portable electronics, where battery voltage can be either greater than or less than the required operating voltage for the electronics, e.g., depending on the state of charge of the battery.
Some embodiments provide a unified control scheme for non-inverting high-efficiency buck-boost power converters. For example, a unified control scheme for both buck and boost modes of a buck-boost power converter may be provided (e.g., via logic 140 of
Moreover, some embodiments may be applied in computing systems that include one or more processors (e.g., with one or more processor cores), such as those discussed with reference to
In an embodiment, the processor 102-1 may include one or more processor cores 106-1 through 106-M (referred to herein as “cores 106,” or “core 106”), a cache 108, and/or a router 110. The processor cores 106 may be implemented on a single integrated circuit (IC) chip. Moreover, the chip may include one or more shared and/or private caches (such as cache 108), buses or interconnections (such as a bus or interconnection 112), graphics and/or memory controllers (such as those discussed with reference to
In one embodiment, the router 110 may be used to communicate between various components of the processor 102-1 and/or system 100. Moreover, the processor 102-1 may include more than one router 110. Furthermore, the multitude of routers 110 may be in communication to enable data routing between various components inside or outside of the processor 102-1.
The cache 108 may store data (e.g., including instructions) that are utilized by one or more components of the processor 102-1, such as the cores 106. For example, the cache 108 may locally cache data stored in a memory 114 for faster access by the components of the processor 102 (e.g., faster access by cores 106). As shown in
The system 100 may also include a platform power source 120 (e.g., a direct current (DC) power source or an alternating current (AC) power source) to provide power to one or more components of the system 100. The power source 120 could include a PV (Photo Voltaic) panel, wind generator, thermal generator water/hydro turbine, etc. In some embodiments, the power source 120 may include one or more battery packs (e.g., charged by one or more of a PV panel, wind generator, thermal generator water/hydro turbine, plug-in power supply (e.g., coupled to an AC power grid), etc.) and/or plug-in power supplies. The power source 120 may be coupled to components of system 100 through a voltage regulator (VR) 130. Moreover, even though
Additionally, while
As shown in
Additionally, the logic 140 may be coupled to receive information (e.g., in the form of one or more bits or signals) to indicate status of one or more sensors 150. The sensor(s) 150 may be provided proximate to components of system 100 (or other computing systems discussed herein such as those discussed with reference to other figures including 10-12, for example), such as the cores 106, interconnections 104 or 112, components outside of the processor 102, etc., to sense variations in various factors affecting power/thermal behavior of the system/platform, such as temperature, operating frequency, operating voltage, power consumption, and/or inter-core communication activity, etc.
The logic 140 may in turn instruct the VR 130, power source 120, and/or individual components of system 100 (such as the cores 106) to modify their operations. For example, logic 140 may indicate to the VR 130 and/or power source 120 (or PSU) to adjust their output. In some embodiments, logic 140 may request the cores 106 to modify their operating frequency, power consumption, etc. Also, even though components 140 and 150 are shown to be included in processor 102-1, these components may be provided elsewhere in the system 100. For example, power control logic 140 may be provided in the VR 130, in the power source 120, directly coupled to the interconnection 104, within one or more (or alternatively all) of the processors 102, outside of computing device/system (e.g., as a standalone device), coupled to (or integrated with) the power source 120, etc. Furthermore, as shown in
For over-unit ratios, the output side of the inductor is duty-cycled exclusively with the input always connected. This type of converter is referred to herein as a “single-switched” buck-boost converter. If all four FETs (Field-Effect Transistors) are switched instead, the converter is referred to as a “dual-switched” buck-boost converter. Control techniques for such a buck-boost topology (where only one end of the inductor is duty-cycled in a given switching cycle) are required to control both buck and boost modes with stability. Since buck and boost modes have different transfer functions, the control mechanism tends to be implemented as two separate compensators with a transition between buck and boost modes that may be managed by mode-switching mechanisms that may be heuristic. Alternatively, a small dual-switched buck-boost transition region may be introduced between exclusive buck and boost modes, e.g., by switching both sides of the inductor in a less power efficient buck-boost topology.
To this end, some embodiments provide a unified control scheme for non-inverting high-efficiency buck-boost power converters. For example, a unified control scheme for both buck and boost modes may be provided (e.g., via logic 140 of
Moreover, such embodiments for control of the single-switched buck-boost converter proposes to ensure stability of the controller across operating points in both buck and boost modes, by designing compensation for the worst-case transfer function. To find the worst case, bode plots of transfer functions describing the buck and boost modes may be used such as illustrated in
In a practical buck-boost converter, both the buck-side switches and boost-side switches of
Referring to
Furthermore, with a unified control scheme, the controller simply needs to add 1 bit to its control word as shown on the right hand side of the equation and in
Also, although the MSB can switch the controller between buck and boost modes, the actual PWM presented to the buck and boost switches may take the pass-through region into account. To ensure smooth pass-through, the buck-boost PWM region may be divided into three regions, with transition points between them. This is illustrated in
Accordingly, some embodiments with a unified single-switched buck-boost have significant advantages over both a double-switched converter and a single-switched converter with a dual compensator design, including: (1) The area and power overhead of the digital controller can be reduced by almost half compared to a traditional dual-compensator design. In a digital controller, only one additional bit over the inherent PWM resolution is used in the controller output to enable buck-boost operation; (2) A single controller logic block can be designed using such techniques that handles buck, boost and buck-boost power stages by changing parameters of the compensator, which yields time-to-market improvements in product families with different types of converters; (3) By designing the controller with the worst-case transfer function, a stable and robust operation can be achieved; (4) mode-hopping heuristics can be avoided; and/or (5) Such techniques can improve both, analog and digital controllers by simplifying their design and providing a robust design paradigm.
A chipset 1006 may also communicate with the interconnection network 1004. The chipset 1006 may include a graphics and memory control hub (GMCH) 1008. The GMCH 1008 may include a memory controller 1010 that communicates with a memory 1012. The memory 1012 may store data, including sequences of instructions that are executed by the processor 1002, or any other device included in the computing system 1000. In one embodiment, the memory 1012 may include one or more volatile storage (or memory) devices such as random access memory (RAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), static RAM (SRAM), or other types of storage devices. Nonvolatile memory may also be utilized such as a hard disk. Additional devices may communicate via the interconnection network 1004, such as multiple CPUs and/or multiple system memories.
The GMCH 1008 may also include a graphics interface 1014 that communicates with a display device 1050, e.g., a graphics accelerator. In one embodiment, the graphics interface 1014 may communicate with the display device 1050 via an accelerated graphics port (AGP) or Peripheral Component Interconnect (PCI) (or PCI express (PCIe) interface). In an embodiment, the display device 1050 (such as a flat panel display (such as an LCD (Liquid Crystal Display), a cathode ray tube (CRT), a projection screen, etc.) may communicate with the graphics interface 1014 through, for example, a signal converter that translates a digital representation of an image stored in a storage device such as video memory or system memory into display signals that are interpreted and displayed by the display. The display signals produced may pass through various control devices before being interpreted by and subsequently displayed on the display device 1050.
A hub interface 1018 may allow the GMCH 1008 and an input/output control hub (ICH) 1020 to communicate. The ICH 1020 may provide an interface to I/O devices that communicate with the computing system 1000. The ICH 1020 may communicate with a bus 1022 through a peripheral bridge (or controller) 1024, such as a peripheral component interconnect (PCI) bridge, a universal serial bus (USB) controller, or other types of peripheral bridges or controllers. The bridge 1024 may provide a data path between the processor 1002 and peripheral devices. Other types of topologies may be utilized. Also, multiple buses may communicate with the ICH 1020, e.g., through multiple bridges or controllers. Moreover, other peripherals in communication with the ICH 1020 may include, in various embodiments, integrated drive electronics (IDE) or small computer system interface (SCSI) hard drive(s), USB port(s), a keyboard, a mouse, parallel port(s), serial port(s), floppy disk drive(s), digital output support (e.g., digital video interface (DVI)), or other devices.
The bus 1022 may communicate with an audio device 1026, one or more disk drive(s) 1028, and one or more network interface device(s) 1030 (which is in communication with the computer network 1003). Other devices may communicate via the bus 1022. Also, various components (such as the network interface device 1030) may communicate with the GMCH 1008 in some embodiments. In addition, the processor 1002 and the GMCH 1008 may be combined to form a single chip. Furthermore, the graphics accelerator may be included within the GMCH 1008 in other embodiments.
Furthermore, the computing system 1000 may include volatile and/or nonvolatile memory (or storage). For example, nonvolatile memory may include one or more of the following: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM), a disk drive (e.g., 1028), a floppy disk, a compact disk ROM (CD-ROM), a digital versatile disk (DVD), flash memory, a magneto-optical disk, or other types of nonvolatile machine-readable media that are capable of storing electronic data (e.g., including instructions). In an embodiment, components of the system 1000 may be arranged in a point-to-point (PtP) configuration. For example, processors, memory, and/or input/output devices may be interconnected by a number of point-to-point interfaces.
As illustrated in
In an embodiment, the processors 1102 and 1104 may be one of the processors 1002 discussed with reference to
In at least one embodiment, one or more operations discussed with reference to
Chipset 1120 may communicate with the bus 1140 using a PtP interface circuit 1141. The bus 1140 may have one or more devices that communicate with it, such as a bus bridge 1142 and I/O devices 1143. Via a bus 1144, the bus bridge 1142 may communicate with other devices such as a keyboard/mouse 1145, communication devices 1146 (such as modems, network interface devices, or other communication devices that may communicate with the computer network 1003), audio I/O device, and/or a data storage device 1148. The data storage device 1148 may store code 1149 that may be executed by the processors 1102 and/or 1104.
In some embodiments, one or more of the components discussed herein can be embodied as a System On Chip (SOC) device.
As illustrated in
The I/O interface 1240 may be coupled to one or more I/O devices 1270, e.g., via an interconnect and/or bus such as discussed herein with reference to other figures. I/O device(s) 1270 may include one or more of a keyboard, a mouse, a touchpad, a display, an image/video capture device (such as a camera or camcorder/video recorder), a touch screen, a speaker, or the like. Furthermore, SOC package 1202 may include/integrate the logic 140 in an embodiment. Alternatively, the logic 140 may be provided outside of the SOC package 1202 (i.e., as a discrete logic).
The following examples pertain to further embodiments. Example 1 includes an apparatus comprising: compensator logic, at least a portion of which is in hardware, to cause a buck-boost power converter to provide an output voltage with a higher voltage level than an input voltage in a boost operational mode of the buck-boost power converter and to provide the output voltage with a lower voltage level than the input voltage in a buck operational mode of the buck-boost power converter, wherein the compensator logic is to provide N+1 bits to Pulse Width Modulation (PWM) generator logic to cause the buck-boost power converter to provide the output voltage, wherein one of the N+1 bits is to indicate whether the buck-boost power converter is to provide the buck operation or the boost operation. Example 2 includes the apparatus of example 1, wherein each of the buck operational mode or the boost operational mode include N operational voltage levels. Example 3 includes the apparatus of example 1, wherein the buck-boost power converter is to comprise a single-switched buck-boost power converter. Example 4 includes the apparatus of example 1, wherein the compensator logic is to operate in accordance with a worst case transfer function. Example 5 includes the apparatus of example 4, wherein the worst case transfer function is to be determined based on one or more bode plots. Example 6 includes the apparatus of example 5, wherein the worst case transfer function is to be determined based on one or more of: a minimum gain margin and a phase margin of the one or more bode plots. Example 7 includes the apparatus of example 4, wherein the worst case transfer function is to be determined based on one or more of state space averaging and a Lyapunov criteria. Example 8 includes the apparatus of example 1, further comprising one or more sensors, coupled to the logic, wherein the one or more sensors are to detect variations in one or more of: temperature, operating frequency, operating voltage, and power consumption. Example 9 includes the apparatus of example 1, wherein one or more of: the logic, a processor, and memory are on a single integrated circuit.
Example 10 includes a method comprising: causing, at a compensator logic, a buck-boost power converter to provide an output voltage with a higher voltage level than an input voltage in a boost operational mode of the buck-boost power converter and to provide the output voltage with a lower voltage level than the input voltage in a buck operational mode of the buck-boost power converter, wherein the compensator logic provides N+1 bits to Pulse Width Modulation (PWM) generator logic to cause the buck-boost power converter to provide the output voltage, wherein one of the N+1 bits indicates whether the buck-boost power converter is to provide the buck operation or the boost operation. Example 11 includes the method of example 10, wherein each of the buck operational mode or the boost operational mode include N operational voltage levels. Example 12 includes the method of example 10, wherein the buck-boost power converter is a single-switched buck-boost power converter. Example 13 includes the method of example 10, further comprising operating the compensator logic in accordance with a worst case transfer function. Example 14 includes the method of example 13, further comprising determining the worst case transfer function based on one or more bode plots. Example 15 includes the method of example 14, further comprising determining the worst case transfer function based on one or more of: a minimum gain margin and a phase margin of the one or more bode plots. Example 16 includes the method of example 13, further comprising determining the worst case transfer function based on one or more of state space averaging and a Lyapunov criteria. Example 17 includes the method of example 10, further comprising one or more sensors detecting variations in one or more of: temperature, operating frequency, operating voltage, and power consumption.
Example 18 includes a system comprising: a processor having one or more processor cores; compensator logic to cause a buck-boost power converter to provide an output voltage with a higher voltage level than an input voltage in a boost operational mode of the buck-boost power converter and to provide the output voltage with a lower voltage level than the input voltage in a buck operational mode of the buck-boost power converter, wherein the compensator logic is to provide N+1 bits to Pulse Width Modulation (PWM) generator logic to cause the buck-boost power converter to provide the output voltage, wherein one of the N+1 bits is to indicate whether the buck-boost power converter is to provide the buck operation or the boost operation. Example 19 includes the system of example 18, wherein each of the buck operational mode or the boost operational mode include N operational voltage levels. Example 20 includes the system of example 18, wherein the buck-boost power converter is to comprise a single-switched buck-boost power converter. Example 21 includes the system of example 18, wherein the compensator logic is to operate in accordance with a worst case transfer function. Example 22 includes the system of example 21, wherein the worst case transfer function is to be determined based on one or more bode plots. Example 23 includes the system of example 21, wherein the worst case transfer function is to be determined based on one or more of state space averaging and a Lyapunov criteria. Example 24 includes the system of example 18, further comprising one or more sensors, coupled to the logic, wherein the one or more sensors are to detect variations in one or more of: temperature, operating frequency, operating voltage, and power consumption. Example 25 includes the system of example 18, wherein one or more of: the logic, a processor, and memory are on a single integrated circuit. Example 26 includes the system of example 18, wherein one or more of: the logic, the processor, and memory are on a single integrated circuit.
Example 27 includes the system of example 18, further comprising one or more battery packs to supply power to the logic.
Example 28 includes a machine readable medium including code, when executed, to cause a machine to perform the method of any one of examples 10 to 17.
Example 29 includes an apparatus comprising means to perform a method as set forth in any one of examples 10 to 17.
Example 30 includes an apparatus comprising means to perform a method as set forth in any preceding example.
Example 31 a machine-readable storage including machine-readable instructions, when executed, to implement a method or realize an apparatus as set forth in any preceding claim.
In various embodiments, the operations discussed herein, e.g., with reference to
Additionally, such computer-readable media may be downloaded as a computer program product, wherein the program may be transferred from a remote computer (e.g., a server) to a requesting computer (e.g., a client) by way of data signals provided in a carrier wave or other propagation medium via a communication link (e.g., a bus, a modem, or a network connection).
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, and/or characteristic described in connection with the embodiment may be included in at least an implementation. The appearances of the phrase “in one embodiment” in various places in the specification may or may not be all referring to the same embodiment.
Also, in the description and claims, the terms “coupled” and “connected,” along with their derivatives, may be used. In some embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements may not be in direct contact with each other, but may still cooperate or interact with each other.
Thus, although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that claimed subject matter may not be limited to the specific features or acts described. Rather, the specific features and acts are disclosed as sample forms of implementing the claimed subject matter.