Patent ID: 12199515

DESCRIPTION

The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

FIG.1illustrates a schematic diagram of a power management system100configured to provide two (or more) regulated output voltages. In some embodiments, power management system100is configured to simultaneously provide multiple regulated output voltages, for instance to support front-end circuitry for multiple operating frequency bands of a radio-frequency (RF) communication system. As shown inFIG.1, a power management unit (PMU)104may be coupled within a power management system100to a voltage source102(e.g., a battery), and one or more control signals106. In some embodiments, voltage source102provides a DC voltage. In some embodiments, voltage source102provides an AC voltage. In some embodiments, a voltage source102, such as a battery, does not provide a constant voltage level, and PMU104converts the input voltage to a desired output voltage level.

The PMU104may also be connected to one or more front-end circuit blocks108,110, as shown inFIG.1, where a respective front-end circuit block is assigned to support one or more frequency bands or one or more sets of frequency bands. For example, front-end circuit block108may be configured to support transmission and reception of high-band signals (e.g., signals with a frequency of 2300 MHz or higher), while front-end circuit block110may be configured to support transmission and reception of low-band and mid-band signals (e.g., signals from 700 MHz up to 2300 MHz). Although not shown inFIG.1, PMU104may be configured to provide regulated output voltages to any number of front-end circuit blocks, each supporting different signal frequency bands.

FIG.1illustrates an embodiment of a unique power management system100for an RF communications system, implementing a single PMU104configured to support a plurality of front-end circuit blocks in simultaneous operation. Power management system100allows for a reduction in components and circuitry, compared to traditional power management solutions that require a dedicated power management unit for a respective front-end circuit block. In some implementations, a front-end circuit block108,110includes components such as, but not limited to power amplifiers, filters, switches and diplexers. Alternatively, traditional power management solutions implementing a single PMU tied to a plurality of front-end circuit blocks108,110do not allow for simultaneous operation of the plurality of front-end circuit blocks.

Power amplifier systems are often powered using a supply voltage102(e.g., from a battery). In some implementations, the voltage from the battery is regulated (e.g., with a buck converter or a boost converter) to a fixed value to compensate for variations in the voltage output from the battery due to manufacturing variation, age, temperature, discharge or other effects. Failure to employ such a regulator can result in a change in the compression characteristics of the power amplifier and degrade its linearity. Failure to employ a buck converter can result in undesirable current leakage and faster discharge of the supply voltage102. However, use of a regulator increases the overall cost of the system. In some embodiments, PMU104includes one or more voltage regulators configured to provide a higher or lower voltage than an available supply voltage102.

Power management using regulators and/or power management units is widely used in wireless devices, such as smartphones and other mobile devices, to increase the power amplifier (PA) efficiency and linearity. Certain protocols and wireless standards use relatively high bandwidths and therefore, improvements to typical power management strategies would be advantageous. For example, LTE advanced uses higher modulation bandwidth (e.g., about 40 MHz) than previous standards (e.g., less than or equal to about 20 MHz). In another example, HPUE support requires an increase in current over existing requirements for low, mid and high-band communications. In addition, uplink carrier aggregation of two or more cellular bands results in the need for increased power to be delivered by the PA. A typical front end module designed to handle these protocols (e.g., LTE Advanced) generally includes filters and switches that may not have been previously used or necessary. This increase in components can result in additional losses in the transmission path. Accordingly, there is a need to increase the power delivered to the antenna port to accommodate these additional losses and increases in power requirements for updated communication standards. Another driving design principle is to reduce the overall area usage of modules and components in a device implementing such an RF communication system (e.g., a wireless device).

Disclosed herein are various examples of circuits, devices and methods that can be configured to, among other things, address the foregoing challenges associated with power management systems. In some implementations, a power management system includes a single power management unit104coupled to a set of one or more power amplifiers (e.g., within respective front-end circuit blocks such as blocks108,110). The PMU104is configured to efficiently boost or lower a received input voltage (e.g., battery voltage102) while supplying a DC-DC regulated output voltage to each of a set of one or more front-end circuit blocks (e.g., blocks108,110), each front-end circuit block comprising a set of one or more power amplifiers. Wireless communications configurations with such power management systems can provide uplink carrier aggregation and/or cellular signals based on standards and protocols that require increased bandwidth (e.g., at least about 40 MHz) and/or power (e.g., at least about 31 dBm), such as LTE-Advanced.

As an example of increased power requirements, LTE power delivered at an antenna as required by the 3GPP standard is 23 dBm. Assuming a 5 dB-loss due to filters, duplexers, switches, diplexers, board losses, and the like, the PA should be configured to deliver at least about 28 dBm at a bandwidth of about 20 MHz. For LTE Advanced, the modulation uplink bandwidth is increased from 20 MHz to 40 MHz. To achieve the same or similar signal to noise ratio (SNR) with the higher modulation bandwidth (assuming the same propagation environment), the output power of the PA should be increased to about 31 dBm for the output power delivered by the PA for an increase from 20 MHz to 40 MHz. Traditional solutions for an increased power requirement included incorporating larger passive devices such as larger inductors, and larger switch devices. Both of these design strategies result in undesirable compromises regarding an increase in die area and module area. These larger components may also degrade performance for lower current operation.

As described herein, a power management system100can be configured to provide carrier-aggregation (CA) functionality within an RF communications system, such that a plurality of input signals can be processed and combined into a common signal path. Various examples are described herein in the context of RF amplifiers; however, it will be understood that one or more features of the present disclosure can also be implemented in other types of amplifiers.

FIG.2illustrates an example of a power management unit200, in accordance with some implementations as described herein. In the example ofFIG.2, a power management chip (PMIC)202(e.g., integrated circuit, semiconductor die) includes at least some of the circuitry of PMU200. For example, as shown inFIG.2, in some implementations, a PMIC202includes a set of DC-DC converters, such as DC-DC converter208(e.g., boost converter) and DC-DC converter210(e.g., buck/boost converter). In some implementations, a PMIC202and/or PMU200includes a controller block206, configured to open and close one or more switches corresponding to each DC-DC converter. In some implementations, a PMIC202and/or PMU200includes a multi-mode radio-frequency front-end (RFFE) block204. In some implementations, RFFE block204includes registers corresponding to output voltage settings for one or more frequency bands. In some implementations, the RFFE block conforms to the MIPI RFFE standard.

PMU200includes a first set of switches corresponding to DC-DC converter208(e.g., a high performance boost converter), and a second set of switches corresponding to DC-DC converter210(e.g., a buck/boost converter). In the example ofFIG.2, the switches of the one or more DC-DC converters may be implemented as diodes, field-effect transistors (FETs), bipolar-junction transistors (BJTs) or any other comparable switching device.

DC-DC converter208includes a first set of switches to enable conversion of an input DC voltage to a desired output DC voltage. In the example of converter208, there are two switches, S1and S2in the first set of switches, to enable converter208to boost an input voltage. For example, during a charging phase, S2is closed (e.g., in response to receiving a signal from controller206), allowing the inductor Lboostto store power. During a discharging or boost phase, S2is opened (e.g., in response to receiving a signal from controller206) and S1is closed, effectively boosting the voltage seen at the Primary VCC output over the input voltage. Controller block206receives feedback about the voltage seen at the Primary VCC output, and uses this feedback to adjust the charging and discharging phases (e.g., duration of time S1or S2is closed), in order to achieve a desired output voltage.

In some embodiments, DC-DC converter210may be used to increase, or boost, the input voltage just as described above, with respect to DC-DC converter208. In the example shown inFIG.2, converter210is a buck/boost converter comprising a second set of switches, namely S3, S4, S5, S6and S7. In some implementations, S5is a single switch and in some implementations it is a pair of switches as shown inFIG.2. In some embodiments, DC-DC converter210may be used to provide a lower output voltage than the input voltage. For example, controller206sends signals to open or close one or more switches of the second set of switches to configure DC-DC converter210as a buck converter to provide a lower output voltage or as a boost converter to provide a higher output voltage.

In some embodiments, DC-DC converter210(or an additional converter within PMIC202) is coupled to more than one output voltage line. For example, as shown inFIG.2, DC-DC converter210is tied to the Primary VCCline when S7is closed, as well as the Secondary VCCline when S6is closed. That is to say that DC-DC converter210is configured to be switchably coupled to more than one output voltage port, pin or line.

This architecture for PMIC202allows for a highly versatile set of operating modes, where DC-DC converter210can be used to provide a lower output voltage than the supply voltage (VBATT) on either output voltage line. DC-DC converter208can be used to provide a higher output voltage than the supply voltage (VBATT) on the Primary VCCoutput voltage line and DC-DC converter210can be used to provide a higher output voltage than the supply voltage (VBATT) on the Secondary VCCoutput voltage line.

Additionally, both DC-DC converters (e.g., a plurality of converters)208and210can be used to provide higher output power on the Primary VCCoutput line than can be provided for by either DC-DC converter alone. For example, both DC-DC converters208and210can be configured to operate as boost converters by having corresponding switches opened or closed. In this example, as S2is closed in the charging state of Lboostof DC-DC converter208and S1is opened, S7of DC-DC converter210can be closed in order to discharge Lbuck/boostand provide an additional source of current to boost the Primary VCCoutput power level.

FIG.3illustrates another configuration for a PMU200without switch S7ofFIG.2, and a third (or otherwise distinct from first and second) set of switches implemented within PMIC202and outside of either DC-DC converter208or210. In this example, the third set of switches includes S8, a switch tying both output voltage lines together. The configuration shown inFIG.3allows for the same voltage to be provided at each output voltage line when S8is closed.

Applications of the power management units and systems described herein are particularly useful for RF communications activities, such as carrier aggregation. It should be noted that various cellular bands, including those disclosed herein, can be carrier-aggregated, assuming that within a given group the corresponding bands do not overlap. WhileFIG.2andFIG.3refer to a PMIC and PMU implementing two DC-DC converters, it should be understood that additional DC-DC converters can be implemented within a single PMU and/or PMIC, each additional DC-DC converter providing an additional output voltage line.

FIG.4is a graphical representation of a packaged module comprising a power management device, according to some embodiments of the present disclosure.FIG.4illustrates an example physical layout of a PMU300, implemented on substrate302. For example, as shown inFIG.4, PMU300includes a PMIC306implemented as a semiconductor die with a flip-chip packaging interface mounted on a printed circuit board (PCB). Passive components such as inductors404and406, as well as capacitors408a,408b,410a,410b,412aand412bare implemented on substrate302of PMU300. In some embodiments, capacitor408ais an input capacitor for a primary DC-DC converter of PMU300, and is tied to VINand a first common ground. In some embodiments, capacitor408bis an input capacitor for a secondary DC-DC converter of PMU300, and is tied to VINand a second common ground.

In some embodiments, inductor404is an inductor for the primary DC-DC converter of PMU300, such as Lboostdescribed with respect toFIG.2andFIG.3. In some embodiments, inductor406is an inductor for the secondary DC-DC converter of PMU300, such as Lbuck/boostdescribed with respect toFIG.2andFIG.3. In some embodiments, capacitors410aand410bare output capacitors for the primary DC-DC converter of PMU300, and capacitors412aand412bare output capacitors for the secondary DC-DC converter of PMU300.

FIG.4illustrates the significant area savings achieved by implementing multiple DC-DC converters in a single PMU300. As can be seen from footprint414, a single PMU would require the majority of passive components and size of the PMIC in order to support a single DC-DC converter. Furthermore, traditional PMUs only implement a boost converter, resulting in a wastage of power to provide a lower output voltage than the one provided as a supply voltage (e.g., VBATT). As a result, PMU300offers a more versatile power management design, as well as a reduction in area required to implement it on package substrate402of package400.

In some implementations, an architecture, device and/or circuit having one or more features described herein can be included in an RF device such as a wireless device. Such an architecture, device and/or circuit can be implemented directly in the wireless device, in one or more modular forms as described herein, or in some combination thereof. In some embodiments, such a wireless device can include, for example, a cellular phone, a smart-phone, a hand-held wireless device with or without phone functionality, a wireless tablet, a wireless router, a wireless access point, a wireless base station, etc. Although described in the context of wireless devices, it will be understood that one or more features of the present disclosure can also be implemented in other RF systems such as base stations.

FIG.5is a schematic diagram of a power management unit700with three output voltage lines, according to some embodiments of the present disclosure.FIG.5is similar to the power management unit200ofFIG.2andFIG.3, however, power management unit700supports a third output voltage line. To the extent that elements of power management unit700occur in the examples ofFIG.2andFIG.3, further description of those elements can be found above. In the example shown inFIG.5, the first output voltage line is associated with DC-DC converter708(e.g., a boost converter), the second output voltage line is associated with DC-DC converter710(e.g., a buck/boost converter), and the third output voltage line is associated with both DC-DC converters708and710.

In some embodiments, a first set of switches for power management unit700, is associated with DC-DC converter708, and/or with the first output voltage line. For example, the first set of switches may include S1aand S2, or the first set of switches may include S1a, S1band S2. Operation of the switches to perform a boost voltage function can be referred to with respect toFIGS.2and3above. Additionally, the second set of switches for PMU700may include S3, S4, S5(e.g., a single-pole-double-throw switch), S6aand S6b. In some embodiments, the second set of switches is only associated with the second output voltage line, and therefore includes S5, S3, S4and S6b. In some embodiments, a third set of switches is associated with the third output voltage line, such as switches S8, S9, S1b, S10, S6a, S3, S4and S5. A fourth set of switches may be associated with the first output voltage line and the second output voltage line. A fifth set of switches may be associated with the first output voltage line and the third output voltage line (e.g., S8). A sixth set of switches may be associated with the second output voltage line and the third output voltage line.

FIG.6is a graphical representation of a packaged module comprising a power management device with three output voltage lines, according to some embodiments of the present disclosure.FIG.6is similar to the packaged module described with respect toFIG.4, however, as can be seen inFIG.6, an additional set of capacitors416aand416bare supported for an additional output voltage line.

FIG.7is a schematic diagram of a carrier aggregation system supported by a power management device, according to some embodiments of the present disclosure. As can be seen inFIG.7, a PMU700can support multiple output voltages (e.g., VCC1, VCC2, VCC3), and have a corresponding controller and RFFE to support various front-end circuit blocks for HB (high-band), MLB (mid-low-band), UHB (ultra-high-band), MB (mid-band), LB (low-band), MB/HB ULCA and also 2G carrier circuitry in a system powered by a DC voltage source as shown. Various combinations of output voltages can therefore be supported by this single PMU700(or300).

FIG.8shows that in some embodiments, some or all of a power management integrated circuit (PMIC)306having one or more features as described herein can be implemented on a semiconductor die302. Additionally, a PMU300, as described herein, may implement a die304with a PMIC306. Such a PMU300can include a substrate302configured to implement some or all of one or more components such as inductors, capacitors, resistors, filters, pins, ports, and/or other interfacing parts.

In some embodiments, some or all of the capacitances and inductances utilized by PMIC306within PMU300can be implemented on the foregoing substrate 302. For example, a capacitance can be implemented as a MIM (metal-insulator-metal) capacitor, a MIS (metal-insulator-semiconductor) capacitor, a modified form of transistor, etc. An inductance can be implemented as a metal trace, a portion of a conductor, or some combination thereof.

Additionally, die304may also have a semiconductor substrate. In the context of the example switches described herein in reference toFIG.2,FIGS.3and5, the semiconductor substrate302can be, for example, a silicon substrate, a silicon-germanium substrate, or a silicon-on-insulator (SOI) substrate, if the switches are implemented as field-effect transistors (FETs). In another example, where bipolar-junction transistors (BJTs) are utilized in the PMIC306, the semiconductor substrate can be, for example, a silicon substrate or a gallium arsenide substrate.

FIG.9shows that in some embodiments, some or all of a PMU300having one or more features as described herein can be implemented on a packaged module400. Such a module can include a packaging substrate402configured to receive a plurality of components such as one or more die, one or more modules and one or more passive components.

FIG.10depicts an example wireless device500having one or more advantageous features described herein. In some embodiments, a power management unit having one or more features as described herein can be implemented in each of one or more places in such a wireless device. For example, in some embodiments, such advantageous features can be implemented in a module such as a power management module506having one or more power management units (PMUs).

In the example ofFIG.10, power amplifiers (PAs) in a PA module512can receive their respective RF signals from a transceiver510that can be configured and operated to generate RF signals to be amplified and transmitted, and to process received signals. The transceiver510is shown to interact with a baseband sub-system508that is configured to provide conversion between data and/or voice signals suitable for a user and RF signals suitable for the transceiver510. The transceiver510is also shown to be connected to a power management module506that is configured to manage power for the operation of the wireless device500. Such power management can also control operations of the baseband sub-system508and/or other components of the wireless device500. In some embodiments, a PMU300is implemented within power management module506, while in some implementations, a PMU300is implemented as a distinct module within wireless device500. In some implementations, power management module506and/or PMU300are directly connected to the PA module512.

The baseband sub-system508is shown to be connected to a user interface502to facilitate various input and output of voice and/or data provided to and received from the user. The baseband sub-system508can also be connected to a memory504that is configured to store data and/or instructions to facilitate the operation of the wireless device, and/or to provide storage of information for the user.

In the example ofFIG.10, the DRx module600can be implemented between one or more diversity antennas (e.g., diversity antenna530) and the antenna switch module (ASM)514. Such a configuration can allow an RF signal received through the diversity antenna530to be processed (in some embodiments, including amplification by an LNA) with little or no loss of and/or little or no addition of noise to the RF signal from the diversity antenna530. Such processed signal from the DRx module600can then be routed to the ASM through one or more signal paths.

In the example ofFIG.10, a main antenna520can be configured to, for example, facilitate transmission of RF signals from the PA module512. In some embodiments, receive operations can also be achieved through the main antenna.

A number of other wireless device configurations can utilize one or more features described herein. For example, a wireless device does not need to be a multi-band device. In another example, a wireless device can include additional antennas such as diversity antenna, and additional connectivity features such as Wi-Fi, Bluetooth, and GPS.

One or more features of the present disclosure can be implemented with various cellular frequency bands as described herein. Examples of such bands are listed in Table 3. It will be understood that at least some of the bands can be divided into sub-bands. It will also be understood that one or more features of the present disclosure can be implemented with frequency ranges that do not have designations such as the examples of Table 3.

TABLE 3BandModeTx Freq Range (MHz)Rx Frequency Range (MHz)B1FDD1,920-1,9802,110-2,170B2FDD1,850-1,9101,930-1,990B3FDD1,710-1,7851,805-1,880B4FDD1,710-1,7552,110-2,155B5FDD824-849869-894B6FDD830-840875-885B7FDD2,500-2,5702,620-2,690B8FDD880-915925-960B9FDD1,749.9-1,784.91,844.9-1,879.9B10FDD1,710-1,7702,110-2,170B11FDD1,427.9-1,447.91,475.9-1,495.9B12FDD699-716729-746B13FDD777-787746-756B14FDD788-798758-768B15FDD1,900-1,9202,600-2,620B16FDD2,010-2,0252,585-2,600B17FDD704-716734-746B18FDD815-830860-875B19FDD830-845875-890B20FDD832-862791-821B21FDD1,447.9-1,462.91,495.9-1,510.9B22FDD3,410-3,4903,510-3,590B23FDD2,000-2,0202,180-2,200B24FDD1,626.5-1,660.51,525-1,559B25FDD1,850-1,9151,930-1,995B26FDD814-849859-894B27FDD807-824852-869B28FDD703-748758-803B29FDDN/A716-728B30FDD2,305-2,3152,350-2,360B31FDD452.5-457.5462.5-467.5B33TDD1,900-1,9201,900-1,920B34TDD2,010-2,0252,010-2,025B35TDD1,850-1,9101,850-1,910B36TDD1,930-1,9901,930-1,990B37TDD1,910-1,9301,910-1,930B38TDD2,570-2,6202,570-2,620B39TDD1,880-1,9201,880-1,920B40TDD2,300-2,4002,300-2,400B41TDD2,496-2,6902,496-2,690B42TDD3,400-3,6003,400-3,600B43TDD3,600-3,8003,600-3,800B44TDD703-803703-803

It is noted that while some examples are described herein in the context of carrier aggregation of two bands, one or more features of the present disclosure can also be implemented in configurations involving carrier aggregation of different numbers of bands.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” The word “coupled”, as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

The above detailed description of embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise form disclosed above. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. For example, while processes or blocks are presented in a given order, alternative embodiments may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and/or modified. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.

While some embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.