WO2017217994A1

WO2017217994A1 - Method and apparatus for decreasing power consumption in a low power device

Info

Publication number: WO2017217994A1
Application number: PCT/US2016/037853
Authority: WO
Inventors: John Fitzpatrick
Original assignee: Thomson Licensing
Priority date: 2016-06-16
Filing date: 2016-06-16
Publication date: 2017-12-21

Abstract

Efficient techniques are provided for decreasing energy consumption in a low power device. An apparatus includes a voltage source (610) including a first voltage output (612) at a first voltage level and a second voltage output (614) at a second voltage level lower than the first voltage level, a regulator (620) coupled to the first voltage output (612) that outputs a third voltage level not higher than the second voltage level responsive to a first control signal (632) and a coupling circuit that selectively couples a coupling output (654) to at least one of the second voltage output (614) and the regulator (620) responsive to a second control signal (634) to provide an output voltage. A method includes providing (1010) a first and second voltages, regulating (1020) the first voltage and selectively coupling (1030) to at least one of the second voltage and the regulator to provide an output voltage.

Description

METHOD AND APPARATUS FOR DECREASING POWER CONSUMPTION IN A LOW

POWER DEVICE TECHNICAL FIELD

[0001] The present disclosure relates to low power electronic devices and more specifically to decreasing power consumption in a low power device.

BACKGROUND

[0002] Any background information described herein is intended to introduce the reader to various aspects of art, which may be related to the present embodiments that are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light.

[0003] Unlike analog home and office networks of the past, today's digital home and office networks can distribute audio, video and data from one device to another, and can also support interactive dialogues between devices or between a device and the Internet. In particular, the advancement of low cost short range wireless communications has allowed many services to evolve and new services to be created within the home and office environment. Nearly every aspect of the home has become connected— from the living room to the kitchen to the garage. The traditional PC, mobile and CE domains are coming together and creating a melting pot of new interactive applications and interactive appliances blurring the boundaries of these traditional domains. For the consumer, service operators and device vendors, this evolution offers a continuous flow of new compelling applications, use cases and business opportunities which would be unthinkable in the past. Connected homes have smart appliances, connected lights, streaming media players and much more. The home space for connected accessories is rapidly growing. Thermostats, cameras, door locks, security or alert sensors, scales, kitchen appliances, TV's, stereo's, lighting, and even toothbrushes are all connected, meaning the 'home of the future' is becoming a reality.

[0004] Connectivity from the service operators or providers to the home and office environment may be accomplished via at least one medium, including cable/fiber, circuit switched or landline telephone also known as Public Switched Telephone Network (PSTN), cellular or mobile telephone, satellite, over the air terrestrial broadcast, wireless cable over microwave (e.g., Multichannel Multipoint Distribution Services), other wireless networks, etc. Some networks like cable, circuit switched telephone (e.g., using Digital Subscriber Line, DSL or xDSL, technology) and cellular or mobile telephone networks permit full connectivity through duplex communication channels, including downstream and upstream channels. Downstream channels are used to transmit signals from the server, or service provider to the user or subscriber. Upstream channels are used to transmit signals from the user to the server. Satellite, over the air terrestrial broadcast and wireless cable service providers cannot provide duplex communication through their respective mediums and generally combine their downstream systems with upstream channels or services of other service providers (e.g., circuit switched telephone, cellular telephone) to accomplish full connectivity to the home and office environment.

[0005] The connectivity to the home or office environments may include video, voice, audio and/or data. The data connectivity may include internet access. Nowadays, modems, such as cable modems, offer Internet and general data connectivity to subscribers' homes. These modems are typically connected to an information distribution network, such as a coaxial cable network, an optical fiber network, a hybrid fiber/coaxial cable network, or a wireless network, and communicate with a network device outside the home (e.g., a termination system, such as a cable modem termination server (CMTS)). Within the home, the modem may be connected to an in- home network, such as an Ethernet network, an in-home coaxial cable network (e.g., per the Multimedia over Coax Alliance (MoCA) specification), wireless network, etc., and various devices within the home may use that network to ultimately communicate with network devices outside the home. Additionally, the modem may provide telephone services to the home (e.g., Voice over IP (VoIP) services) and various other services, e.g., home security, home temperature control or thermostat, home fire alarm, home appliance control, home energy control (e.g., lighting), etc. Such multi -function modems are commonly referred to as a gateway or gateway device.

[0006] The connectivity within the home and office networks may also be performed through a number of low power short range wireless devices generally operated by batteries. These devices generally communicate via wireless sensor networks supporting e.g., the Institute of Electrical and Electronics Engineers (IEEE) standard 802.15.4 and Zigbee Alliance standard. [0007] FIG. 1 illustrates a block diagram of a prior art low power device 100 which is used as low power device 540 of a prior art home security system similar to home security/alert system 500. Low power device 100 includes battery pack 110 coupled to buck regulator 120. Battery pack 110 includes four batteries (510A-D) connected in series. The batteries are each 1.5 Volt (V) batteries, producing a 6V voltage source for the battery pack. Buck regulator 120 is a Direct Current (DC)-to-DC power converter which steps down voltage (while stepping up current) from its input (supply) to its output (load). Buck regulator 120 is coupled to controller or processor 130 and down-converts the 6V voltage input to 2.7V, as required by controller 130 and other loads. A 6V battery pack is used (instead of 3 V or 4.5 V) for a long operation of the device before batteries need to be replaced. Controller 130 provides one or more control signals 132 that control the operation of buck regulator 120. Controller 130 also provides control signals and communicates with functional components of the low power device 100 associated with its main functionality, for example, display 140, keypad 142, wireless interface 144 and audio output device 146.

[0008] In low power device 100, controller 130 operates in two modes; normal mode and sleep mode. The device remains in sleep mode for a large percentage of time, generally greater than 90 percent. In sleep mode, the current draw required at the output of buck regulator 120 is very low (e.g., 1-2 micro amps, μΑ). However, buck regulator 120 may consume 10 μΑ itself, which is undesirable when in sleep mode, unnecessarily decreasing battery life.

[0009] Short battery life is not only inconvenient but also fatal to the commercial success of these multi-year low power electronics devices due to the complexity and cost of replacing batteries.

[0010] Therefore, there is a need to provide efficient techniques for improving the operational life of low power sources, e.g., battery sources. In general, it is of interest to decrease energy or power consumption in low power devices. The present disclosure is directed towards such a technique.

SUMMARY

[0011] According to an aspect of the present disclosure, an apparatus is provided, the apparatus including a voltage source including a first voltage output at a first voltage level and a second voltage output at a second voltage level lower than the first voltage level, a regulator coupled to the first voltage output that outputs a third voltage level not higher than the second voltage level responsive to a first control signal, and a coupling circuit that selectively couples a coupling circuit output to at least one of said second voltage output and said regulator responsive to a second control signal to provide an output voltage.

[0012] According to another aspect of the present disclosure, a method is provided, the method including providing a first voltage and a second voltage lower than the first voltage, regulating in a regulator the first voltage responsive to a first control signal to output a third voltage not higher than the second voltage and selectively coupling an output to at least one of the second voltage and the regulator responsive to a second control signal to provide an output voltage.

[0013] Additional features and advantages of the present disclosure will be made apparent from the following detailed description of illustrative embodiments which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood in accordance with the following exemplary figures briefly described below:

FIG. 1 Illustrates a block diagram of a prior art low power device;

FIG. 2 illustrates a block diagram of an exemplary arrangement for a networking communication system in accordance with an embodiment of the present disclosure;

FIG. 3 illustrates a block diagram of an exemplary gateway system in accordance with an embodiment of the present disclosure;

FIG. 4 illustrates a block diagram of an exemplary gateway device in accordance with an embodiment of the present disclosure;

FIG. 5 illustrates a simplified block diagram of a home security/alert system in accordance with an embodiment of the present disclosure;

FIG. 6 illustrates a block diagram of a low power device used in a home security/alert system in accordance with an embodiment of the present disclosure;

FIG. 7A illustrates a simplified schematic for a regulator in accordance with an embodiment of the present disclosure;

FIG. 7B illustrates the behavior of control signals for a regulator as a function of time in accordance with an embodiment of the present disclosure; FIG. 7C illustrates the behavior of control signals for a regulator as a function of time in accordance with an embodiment of the present disclosure;

FIG. 8A illustrates a voltage source in accordance with one embodiment of the present disclosure;

FIG. 8B illustrates a coupling circuit in accordance with one embodiment of the present disclosure;

FIG. 8C illustrates the behavior of control signals for a coupling circuit as a function of time in accordance with one embodiment of the present disclosure;

FIG. 8D illustrates a coupling circuit in accordance with one embodiment of the present disclosure;

FIG. 9 illustrates a regulator coupled to a coupling circuit in accordance with one embodiment of the present disclosure; and

FIG. 10 illustrates a flowchart of an exemplary method in accordance to one embodiment of to the present disclosure.

DETAILED DISCUSSION OF THE EMBODIMENTS

[0014] It should be understood that the elements shown in the figures may be implemented in various forms of hardware, software or combinations thereof. Preferably, these elements are implemented in a combination of hardware and software on one or more appropriately programmed general-purpose devices, which may include a processor, memory and input/output interfaces. Herein, the phrase "coupled" is defined to mean directly connected to or indirectly connected with through one or more intermediate components. Such intermediate components may include both hardware and software based components.

[0015] The present description illustrates the principles of the present disclosure. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its spirit and scope.

[0016] All examples and conditional language recited herein are intended for educational purposes to aid the reader in understanding the principles of the disclosure and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. [0017] Moreover, all statements herein reciting principles, aspects, and embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.

[0018] Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of illustrative circuitry embodying the principles of the disclosure. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudocode, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

[0019] The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, read only memory (ROM) for storing software, random access memory (RAM), and nonvolatile storage.

[0020] Other hardware, conventional and/or custom, may also be included. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the implementer as more specifically understood from the context.

[0021] In the claims hereof, any element expressed as a means for performing a specified function is intended to encompass any way of performing that function including, for example, a) a combination of circuit elements that performs that function or b) software in any form, including, therefore, firmware, microcode or the like, combined with appropriate circuitry for executing that software to perform the function. The disclosure as defined by such claims resides in the fact that the functionalities provided by the various recited means are combined and brought together in the manner which the claims call for. It is thus regarded that any means that can provide those functionalities are equivalent to those shown herein.

[0022] The present disclosure is directed to efficient techniques for decreasing energy or power consumption in a low power device. It includes improving the operational life of low power sources, e.g., battery sources, used in a number of low power short range wireless devices within the home or office environment. These devices generally communicate via wireless sensor networks supporting e.g., the Institute of Electrical and Electronics Engineers (IEEE) standard 802.15.4 and Zigbee Alliance standard. Short battery life is fatal to the commercial success of these multi-year low power electronics devices due to the complexity and cost of replacing batteries.

[0023] Battery operated devices include remote controls, key fobs or general keyless entry, starter or opener devices (e.g., garage door opener, car starter, etc.), and other similar devices. A set of these devices are used for home control or home security devices, and often include keypads, audible indicators or alarms, sensors, cameras, and other functions. Customer requirements may include a requirement for minimum operational life before the batteries have to be changed or replaced. In addition, some of these devices may include the requirement to automatically and periodically communicate (wirelessly) with other devices. For example, a security/alert tablet that is the main control center for a home security/alert system may have to wirelessly communicate every 2 to 6 seconds with a remote keypad, window sensor or door sensor, for some type of handshake, a requirement not typically found on previous devices (e.g., wired remote keypads which are powered through the connecting wires). Achieving long operational life from a battery or set of batteries can be a challenge when faced with this new requirement.

[0024] Remote control devices have been shown to operate with battery life of greater than five years. However, they do not usually include a requirement for periodic wireless communication. The present disclosure addresses these issues by providing a dual mode operational configuration for the battery connection.

[0025] Turning to FIG. 2, a block diagram of a typical arrangement for a networking communication system 200 according to aspects of the present disclosure is shown. According to an exemplary embodiment, gateway 201 is an advanced cable gateway, cable modem, DSL (Digital Subscriber Line) modem or the like, and is coupled to a wide area network (WAN) link 225 through a WAN interface to service provider 210. The WAN link 225 may be any one or more of the possible communication links including, but not limited to, coaxial cable, fiber optic cable, telephone line, or over the air links. The gateway 201 is also coupled via a local area network (LAN) interface to home network 250 which couples one or more customer premises equipment (CPE) devices 280A-N. The home network 250 preferably includes a wireless link but may also include wired links such as co-axial cable or Ethernet. CPE devices 280A-N may include, for example, personal computers, network printers, digital set-top boxes, and/or audio/visual media servers and players, among others.

[0026] Service provider 210 provides one or more services, such as voice, data, video and/or various advanced services, over WAN link 225 to CPE devices 280 A-N through gateway 201 and home network 250. Service provider 210 may include Internet related services and server structures such as a Dynamic Host Configuration Protocol (DHCP) server 211 and Domain Name System (DNS) server 212, and may include other servers and services as well (e.g., video on demand, news, weather). It is important to note that these servers and services can be co- located or widely distributed, physically and/or virtually, in both hardware and software. It is contemplated that service provider 210 operates in a conventional manner in accordance with well-known protocols (e.g., Data Over Cable Service Interface Specification, DOCSIS). In an illustrative cable application, service provider 210 may be, for example, a cable multiple service operator (MSO).

[0027] Gateway 201 acts as the interface between the WAN link 225 external to the customer's home and the home network 250 located in the customer's home. Gateway 201 converts transport data packets, such as packets in an IP protocol, from a format used in the WAN to a format used in the home network or LAN. Gateway 201 also routes data packets, including the converted data packets between the WAN and one or more devices on the home network. Gateway 201 may include interfaces for both wired networking (e.g., Ethernet MoCA) and wireless networking. Gateway 201 allows data, voice, video and audio communication between the WAN and CPE devices 280A-N used in the customer's home, such as analog telephones, televisions, computers, and the like.

[0028] It is important to note that in some configurations, the gateway 201 may be partitioned into two separate devices coupled together in some communicative manner. The first device, connected to the WAN portion of the system, may be referred to as a cable modem or network termination device (NTD). The second device, connected to the home LAN portion of the system, may be referred to as a home router, a home server, or a home gateway. Functionally, and as will be described below, the two devices operate in a manner consistent with gateway 201.

[0029] FIG. 3, shows a gateway system 300 according to aspects of the present disclosure. Gateway system 300 operates in a manner similar to networking communication system 200 described in FIG. 2. In gateway system 300, network 301 is coupled to gateway 302, which is similar to gateway 201. Gateway 302 connects to a wired phone 303. Gateway 302 also connects to computer 305 by wired means, e.g., Ethernet cable. In addition, gateway 302 interfaces with devices 304A-304C through a wireless interface using one or more antennas 306. Gateway 302 may also connect to devices 304A-304C by wired means, e.g., Ethernet cable. Gateway 302 may also interface with computer 305 using the one or more antennas 306. Devices 304A-304C may be consumer electronics devices, e.g., a television, a set-top box, a clock radio, a Compact Disk (CD) player, DVD player, a Videocassette Recorder (VCR), a Digital Video Recorder (DVR), refrigerator, washing machine, dishwasher, etc. Devices 304A- 304C may also be control devices for various services, e.g., home security, home temperature control or thermostat, home fire alarm, home appliance control, home energy control (e.g., lighting), etc. Devices 304A-C may also connect (wirelessly or not) to yet other devices, 304A1, 304A2, 304B1, that are necessary for the particular service that they provide, e.g., keypads, sensors, cameras, remote controls.

[0030] In particular, gateway system 300 operates as part of a cable network interface and acts to interface a packet data cable system to one or more home networks. Gateway system 300 includes gateway 302 that provides the interface between the network 301, operating as a WAN, and the home network(s). Gateway system 300 also includes wired analog telephone device 303 capable of operating as a home telephone when connected through gateway 302. In addition, gateway 302 also acts to provide a radio frequency (RF) interface to multiple wireless devices 304A, 304B, and 304C. Wireless devices 304A, 304B and 304C may be handheld devices that operate using wireless packet transmissions via one or more antennas 306 on gateway 302. Wireless devices 304A, 304B and 304C may also be devices that are not handheld and that are mounted on walls or placed in different rooms of the home (not shown). For example, it is commonplace to mount a control device for a home security system on a wall. In other embodiments, other devices with wireless interfaces including, but not limited to routers, tablets, set-top boxes, televisions, media players and home appliances may be used.

[0031] The wireless interface included in gateway 302 may also accommodate one or more wireless formats including Wi-Fi, Institute of Electrical and Electronics Engineers standard IEEE 802.11 or other similar wireless communication protocols. Further, it is important to note that each antenna in the system may be attached to a separate transceiver circuit. As shown in FIG. 3, gateway 302 includes two transceiver circuits and two antennas. Device 304 A and computer 305 also include two transceiver circuits and two antennas while device 304B and device 304C include only one transmit / receive circuit and one antenna. In some alternate designs it may be possible that more than one antenna may be included with, and used by, a single transceiver circuit.

[0032] In operation, gateway 302 may provide Internet protocol (IP) services (e.g., data, voice, video, and/or audio) between devices 304A-C and Internet destinations identified and connected via network 301. Gateway 302 may also provide IP voice services between wired phone 303 and call destinations routed through network 301. Gateway 302 may also provide other services between service provider (e.g., 200) and control devices 304A-304C for the services, e.g., home security, home temperature control or thermostat, home fire alarm, home appliance control, home energy control, etc. Gateway 302 may further provide connectivity to a local computer 305 either via a wired connection such as is shown in FIG. 3 or via a wireless connection through one or more antennas and transceiver circuits. Thus, example interfaces for computer 305 include Ethernet and IEEE 802.11. As noted above, gateway 302 may physically be configured as two components, a cable modem or NTD that connects to network 301 and a home gateway that connects to all other devices in the home.

[0033] Gateway 302 further includes a communication front end circuit for interfacing with the headend or CMTS through the network 301. In some embodiments, the gateway 302 further includes circuitry for communicating in the home network or LAN using MoCA protocols over a co-axial cable. The communication front end circuit may include a diplexer filter or a triplexer filter if MoCA is included, for separating the upstream communication and downstream communication signals (as well as MoCA signals if present).

[0034] Turning to FIG. 4, a block diagram of an exemplary gateway device 400 according to aspects of the present disclosure is shown. Gateway device 400 may be similar to gateway 302 described in FIG. 3 or to gateway 201 described in FIG. 2. In gateway device 400, an input signal is provided to RF input 401. RF input 401 connects to tuner 402. Tuner 402 connects to central processor unit 404. Central processor unit (CPU) 404 connects to phone D/A (digital to analog) interface 406, transceiver 408, transceiver 409, Ethernet interface 410, system memory 412, and user control 414. Transceiver 408 further connects to antenna 420. Transceiver 409 further connects to antenna 421. It is important to note that several components and interconnections necessary for complete operation of gateway device 400 are not shown in the interest of conciseness, as the components not shown are well known to those skilled in the art. Gateway device 400 may be capable of operating as an interface to a cable communication network, to a DSL network and to over the air networks, e.g., cellular telephone, satellite, etc., and further may be capable of providing an interface to one or more devices connected through either a wired and wireless home network.

[0035] A signal, such as a cable signal on the WAN, is interfaced to tuner 402 through RF input 401. Tuner 402 performs RF modulation functions on a signal provided to the WAN and demodulation functions on a signal received from the WAN. The RF modulation and demodulation functions are the same as those commonly used in communication systems, such as cable systems. Central processor unit 404 accepts the demodulated cable signals and digitally processes the signal from tuner 402 to provide voice signals and data for the interfaces in gateway 400. Similarly, central processor unit 404 also processes and directs any voice signals and data received from any of the interfaces in gateway 400 for delivery to tuner 402 and transmission to the WAN.

[0036] System memory 412 supports the processing and IP functions in central processor unit 404 and also serves as storage for program and data information. A portion of system memory 412 is a non-transitory computer readable medium having stored thereon instructions of program code for executing methods when the program code is executed on a computer. Processed and/or stored digital data from central processor unit 404 is available for transfer to and from Ethernet interface 410. Ethernet interface may support a typical Registered Jack type RJ-45 physical interface connector or other standard interface connector and allow connection to an external local computer. Processed and/or stored digital data from central processor unit 404 is also available for digital to analog conversion in interface 406. Interface 406 allows connection to an analog telephone handset. Typically, this physical connection is provided via an RJ-11 standard interface, but other interface standards may be used. Processed and/or stored digital data from central processor unit 404 is additionally available for exchange with transceiver 408 and transceiver 409. Transceiver 408 and transceiver 409 can both support multiple operations and networked devices simultaneously. Central processor unit 404 is also operative or configured to receive and process user input signals provided via a user control interface 414, which may include a display and/or a user input device such as a hand-held remote control and/or other type of user input device.

[0037] As noted above, the gateway device 400 may be configured to operate as an NTD. In this case, central processing unit 404 may only connect to tuner 402, Ethernet interface 410, and system memory 412. Phone D/A interface 406, transceiver 408 and/or transceiver 409 may not be present or used. Further, an NTD may not include a direct user interface and as such may not include user control 414. Additionally, the NTD may include and support more than one Ethernet interface 410 and may be capable operating each Ethernet interface as a separate virtual circuit between the content service provider(s) and the home gateway attached to the Ethernet interface, thus allowing the creation of separate LANs for each content consumer.

[0038] FIG. 5 illustrates a simplified block diagram 500 of a home security/alert system according to aspects of the present disclosure. The service is provided by service provider 510 similar to service provider 200 and coupled to gateway 520 similar to gateway 201 and 302. The security/alert system includes security/alert control device 530 coupled to gateway 520 and implemented in a home or office, similarly to any of CPE devices 280A-N or devices 304A-C. Security control device 530 may be implemented using a computing system including a processor, at least one input/output interface, at least one memory (e.g., Random Access Memory, RAM) and/or storage devices (e.g., Hard Disk Drive, HDD). Security control device 530 may be implemented on, but is not limited to, desktop computers, cellular phones, smart phones, phone watches, tablet computers, personal digital assistant (PDA), netbooks, laptop computers, set-top boxes or general multimedia content receiver and/or transmitter devices. In addition, security control device 530 is coupled and communicates wirelessly to low power device 540, e.g., keypad, lock, window sensors, door sensors, motion sensors, shock sensors, video camera, etc. The wireless connection between security control device 530 and low power device 540 may be performed via wireless sensor networks supporting e.g., the Institute of Electrical and Electronics Engineers (IEEE) standard 802.15.4 and the Zigbee Alliance standard. Security control device 530 may regularly communicate with low power device 540 for a handshake, e.g., every 2 to 6 seconds. In addition, low power device 540 may sporadically send information to security control device 530.

[0039] A home security or alarm system generally includes three main components. The first component is a detection element that detects status changes or emergencies (e.g., the door is opened by an unauthorized party or the front window is broken). Detection components (e.g., low power device 540) include door and window contacts or sensors, Passive Infrared (PIR) motion detectors, glass break sensors (to detect sounds of glass breakage), shock sensors (to detect forces applied to walls, doors, roofs, etc.), environmental sensors (to detect presence of water and sudden temperature changes), smoke detectors, carbon monoxide detectors, etc.

[0040] The second component of the security or alert system is the security/alarm control device (e.g., security control device 530) that is the brain of the system. The security/alarm control device performs monitoring and carries out the decision function by processing the information it receives from various sensors (e.g., low power device 540) and responding accordingly. The security/alarm control device communicates emergencies and system maintenance information to a central station monitoring center run by the service provider. The security/alarm control device may also broadcast alerts to anyone who is directly associated with the premises. In the event of a triggered alarm, a trained dispatcher may contact the home owner or user to verify the emergency situation and if necessary, contact the police, fire station or emergency services like 911 on the home owner' s or user' s behalf.

[0041] The third component of the security or alert system is the annunciation or deterrent that announces that a system has been breached or needs attention at the source, e.g., sirens, bells or flashing lights (e.g., low power device 540). Alerting people who are currently away from the home perimeter is part of the monitoring or communication component.

[0042] A home security/alert system may also include keypads to arm and disarm the system, or to enter passwords for access to the premises (e.g., low power device 540). And a home security/alert system may also include panic buttons that send an immediate, discreet call for help upon the press of a button (e.g., low power device 540).

[0043] Customer requirements may dictate that low power device 100 or 540, get regular status updates or perform a regular handshake with the main "brain" control device 530 (usually a tablet or similar device) of the security/alert system (wirelessly using ZigBee or similar communication standard), e.g., every 2 to 6 seconds. The constant switching from sleep mode to normal mode implies that the buck regulator/converter 120 is constantly using battery energy. The problem is worsened due to some losses and inefficiencies will occur as a result of the difference between battery voltage 110 and the desired voltage at control IC 130 and other elements 140-148. In addition, the buck regulator 120 may consume 10 μΑ itself, which is not desirable when in sleep mode, unnecessarily decreasing battery life. It is therefore of interest to conserve battery power in order to increase the operational life of the low power device before a user is required to exchange batteries. In general, it is of interest to keep energy consumption in a low power device as low as possible, be it a battery source or a rectified power source.

[0044] The present disclosure provides a circuit or apparatus that decreases the power demands or energy consumption of a low power device (e.g., device 540) by providing a dual mode operational configuration for the power (e.g., battery) connection. FIG. 6 illustrates a block diagram of low power device 600 similar to low power device 540 of home security/alert system 500 in accordance to aspects the present disclosure. Low power device 600 includes voltage (or power) source 610, which includes a first voltage output and a second voltage output. First voltage output terminal 612 is at a first voltage level VI and is coupled to regulator 620. Second voltage output terminal 614 is at a second voltage level V2 and is coupled to coupling circuit 650. The first and second voltage output terminals may also be provided by two independent voltage sources. Regulator 620 may be a DC-to-DC power converter which steps down voltage (while stepping up current) from its input (supply) to its output (load). Regulator 620 may be similar to buck regulator 120 and is coupled to coupling circuit 650. Regulator 620 may be any of the regulator circuits well-known by one of ordinary skill in the pertinent art. Coupling circuit 650 is coupled to controller or processor 630. Controller or processor 630 may be any of well-known integrated circuits (IC's) known by one of ordinary skill in the pertinent art. Controller 630 provides one or more control signals 632 that control the operation of regulator 620. Controller 630 also provides one or more control signals 634 to coupling circuit 650 as will be described below. Controller 630 further provides control signals and communicates with functional components of the low power device associated with its main functionality, for example, display 640, keypad 642, wireless interface 644, audio output device 646 and sensor 648, as are well-known by one of ordinary skill in the pertinent art. Some or all the functional components 640 to 648 may be present in the low power device 600, depending on its functionality.

[0045] FIG. 7A illustrates a simplified schematic for a buck regulator 700 according to aspects of the present disclosure. Buck regulator 700 includes input terminal 710 to be coupled to an external voltage source (not shown), e.g., voltage source 610 that provides a voltage level Vin to buck regulator 620, for example, 6V. Input terminal 710 is coupled to switch A 720. Switch A 720 is coupled to switch B 730 and to inductor 740. Switch A 720 is controlled by control signal Sa 722. Switch B 730 is controlled by control signal Sb 732. Inductor 740 is coupled to capacitor 750. Capacitor 750 is coupled to output terminal 760. Output terminal 750 is to be coupled to one or more output loads and provide a voltage level Vout that is a down-conversion of the voltage level Vin, for example, 2.7V required by the output loads (e.g., controller 630). In addition, Switch B 730 and capacitor 750 are also coupled to a reference level or ground.

[0046] Switches A 720 and B 730 may be implemented with Field Effect Transistors (FET) or other types of switches known by one of ordinary skill in the pertinent art. Switches A 720 and B 730 may be controlled by a controller similar to controller 630, via control signals Sa 722 and Sb 732, respectively, similar to control signals 632. The control signals Sa 722 and Sb 732 sent by the controller are Pulse Width Modulated (PWM) waveforms delivered to buck regulator 700 to open and close switches A 720 and B 730. PWM based controller holds the frequency constant and varies the pulse width of signals Sa and Sb to adjust the output voltage. The controller (e.g., controller 630) uses either voltage or current feedback in a control loop to regulate the output voltage Vout in response to load changes.

[0047] FIG. 7B illustrates exemplary plots 725 and 735 of switch drive control signals Sa 722 and Sb 732, respectively, according to one embodiment of the present disclosure, during normal mode of operation as a function of time. Non-overlapping switch drives A and B ensure that only one switch is on at a time to avoid unwanted current "shoot through". In Phase 1, Switch B 730 is open (Sb = 0), and Switch A 720 is closed (Sa = 1). The inductor 740 is coupled to Vin through input terminal 710, so current flows from Vin to the load. The current increases due to the positive voltage across the inductor 740. In Phase 2, Switch A 720 is open (Sa = 0) and Switch B 730 is closed (Sb = 1). The inductor 740 is coupled to ground, so current flows from ground to the load. The current decreases due to the negative voltage across the inductor 740, and energy stored in the inductor is discharged into the load. A simple relationship for buck regulator 700 or 620 and the controller (e.g., controller 630) is that the output voltage of the regulator is a function of the duty cycle for switches A and B, more specifically: Vin * duty cycle (A/B) = Vout.

[0048] In low power device 600, controller 630 operates in two modes; normal mode and sleep mode. During normal mode, operation of the control signals Sa 722 and Sb 732 that drive buck regulator 620 is as shown in FIG. 7B and previously explained. The same control signals and their behavior described in FIG. 7B may also apply to regulator 120 in low power device 100. However, the device remains in sleep mode for a large percentage of time, generally greater than 90 percent. In sleep mode, the current draw at the output of coupling circuit 650 is very low (e.g., 1-2 micro amps, μΑ). FIG. 7C illustrates plots 726 and 736 of the behavior of control signals Sa 722 and Sb 732 throughout a cycle of normal and sleep mode as a function of time, according to one embodiment of the present disclosure. During sleep mode, control signal Sa 722 remains at "1", meaning that switch A 720 of buck regulator 700 or 620 remains closed. Also, during sleep mode, control signal Sb 732 remains at "0", meaning that switch B 730 of buck regulator 700 or 620 remains open. The same control signals and their behavior described in FIG. 7C may also apply to regulator 120 in low power device 100. According to the present disclosure, the number and values of control signals Sa 722 and Sb 732 are exemplary and other numbers and values may be chosen without departing from the scope of the present disclosure. For example, in one embodiment, one control signal Sab may include two bits, bO and bl, where b0=Sa and bl=Sb.

[0049] In one embodiment, regulator 620 may down-convert the input voltage down to 2.7V, for example, as required by controller 630 and other loads (e.g., 640-648). It is to be understood that the present disclosure is not limited to the precise embodiment of a regulator described in Figs. 7A-C, and various changes and modifications can be effected therein by one of ordinary skill in the pertinent art without departing from the scope of the present disclosure. In one embodiment, voltage source 610 may be a battery pack including a plurality of batteries coupled in series and/or parallel. In another embodiment, voltage source 610 may be a rectified power source utilizing rectification circuits known by one of ordinary skill in the pertinent art. Rectification is the conversion of alternating current (AC) to direct current (DC). In one embodiment, regulator 620 may be an AC-to-DC regulator, including a rectification circuit.

[0050] FIG. 8 A illustrates an exemplary voltage (or power) source 860 similar to voltage source 610 in accordance with one embodiment of the present disclosure, Voltage source 860 consists of a battery pack including a plurality of batteries connected in series, e.g., four batteries, 860A- D. The batteries may each be, for example, 1.5 Volt (V) batteries, producing a 6V voltage source for the battery pack. Voltage source 860 includes first voltage output terminal 862 similar to 612 and second voltage output terminal 864 similar to 614. The voltage level at second voltage output terminal 864 is lower than the voltage level at first voltage output terminal 862 (e.g., 3V versus 6V, respectively). The second voltage level is derived from a connection 864 between batteries in the plurality of batteries. In one embodiment, the second voltage level, the closest voltage level to the desired voltage level by the controller 630 and other loads. The closet voltage level is the ideal voltage level as will be explained below. For example, for 4 batteries of 1.5V, there are only 4 possibilities of voltage level: 1.5, 3.0, 4.5 and 6V. In this case, 3V is the closest voltage level to, e.g., 2.7V required by controller 630.

[0051] FIG. 8B illustrates a coupling circuit 870 similar to coupling circuit 650 in accordance with one embodiment of the present disclosure. Coupling circuit 870 includes input terminal 873 (similar to input terminal 658) coupled to resistor 876. Resistor 876 is coupled to switch S 877. Coupling circuit 870 also includes input terminal 872 (similar to input terminal 652) coupled to switch N 878. Switches S 877 and N 878 are coupled together and to output terminal 874 (similar to output terminal 654). Switches S 877 and N 878 are controlled by control signals 8772 and 8782, respectively

[0052] In operation, when applied to low power device 600, coupling circuit 870 couples its output 654 (or 874) to regulator 620 and controller 630, and receives one or more control signals 634 to control the behavior of switches S 877 and N 878 (e.g., control signals 8772 and 8782, respectively). According to the present disclosure, when controller 630 enters normal mode of operation (e.g., as in Figs. 7B-C), control signal 8782 closes switch N 878 and control signal 8772 simultaneously opens switch S 877. In normal mode of operation, the highest voltage level VI at terminal 612 from voltage source 610 is utilized, or similarly, terminal 862 of voltage source 860. For the example of a battery pack with 4 batteries in series of 1.5 V each, regulator 620 may down-convert the input voltage of 6V down to 2.7V, for example, as required by controller 630 and other loads (e.g., 640-648). In normal mode of operation, the required current draw at the output of coupling circuit 650 may be, for example, in the order of 0.1 A.

[0053] On the other hand, when controller 630 enters sleep mode of operation (e.g., as in FIG. 7C), control signal 8782 opens switch N 878 and control signal 8772 simultaneously closes switch S 877. In sleep mode of operation, the lowest voltage level V2 at terminal 614 from voltage source 610 is utilized. For the example of a battery pack with 4 batteries in series of 1.5V each, 3V are provided through a resistor R 876 to controller 630 and other loads (e.g., 640-648). In sleep mode of operation, the required current draw at the output of coupling circuit 650 may be, for example, in the order of 1 to 2 μΑ and resistor R 876 may be between 150 and 300 ΚΩ. Since regulator 620 may itself draw current in the order of 10 μΑ, by bypassing regulator 620 in sleep mode, the operational life of voltage source 610, or similarly 860, will improve. More generally, the energy consumption of low power device 600 will decrease.

[0054] In one embodiment of coupling circuit 870, resistor R 876 may be removed. In one embodiment of coupling circuit 870, resistor R 876 may be replaced by a low-dropout (LDO) regulator. An LDO regulator is a DC linear voltage regulator that can regulate the output voltage even when the supply voltage is very close to the output voltage.

[0055] Fig 8C illustrates the plots 8785 and 8775 of the behavior of control signals Sn 8782 and Ss 8772, respectively, throughout a cycle of normal and sleep mode as a function of time. During normal mode of operation, control signal Sn 8782 remains at "1", meaning that switch N 878 remains closed, and control signal Ss 8772 remains at "0", meaning that switch S 877 remains open. During sleep mode of operation, control signal Sn 8782 remains at "0", meaning that switch N 878 remains open, and control signal Ss 8772 remains at "1", meaning that switch S 877 remains closed. According to the present disclosure, the number and values of control signals Sn 8782 and Ss 8772 are exemplary and other numbers and values may be chosen without departing from the scope of the present disclosure. For example, in one embodiment, one control signal Sns similar to control signal 634 may include two bits, bO and bl, where b0=Sn and bl=Ss or vice-versa.

[0056] FIG. 8D illustrates a coupling circuit 880 similar to coupling circuit 650 in accordance with one embodiment of the present disclosure. Coupling circuit 880 includes input terminal 883 (similar to input terminal 658) coupled to resistor 886. Resistor 886 is coupled to switch S 887 (similar to switch S 877). Coupling circuit 880 also includes input terminal 882 (similar to input terminal 652). Switch S 887 and input terminal 882 are coupled together and to output terminal 884 (similar to output terminal 654).

[0057] In operation, when applied to low power device 600, coupling circuit 880 selectively couples its output 654 (or 884) to regulator 620 and controller 630, and receives one control signal 634 (or 8872) to control the behavior of switch S 887. According to the present disclosure, when controller 630 enters normal mode of operation (e.g., as in Figs. 7B-C), control signal 634 opens switch S 887. In normal mode of operation, the highest voltage level VI at terminal 612 from voltage source 610 is utilized, or similarly, terminal 862 of voltage source 860. For the example of a battery pack with 4 batteries in series of 1.5V each, regulator 620 may down- convert the input voltage of 6V down to 2.7V, for example, as required by controller 630 and other loads (e.g., 640-648). In normal mode of operation, the required current draw at the output of coupling circuit 650 may be, for example, in the order of 0.1 A.

[0058] On the other hand, when controller 630 enters sleep mode of operation (e.g., as in FIG. 7C), control signal 634 closes switch S 887. In sleep mode of operation, the lowest voltage level V2 at terminal 614 from voltage source 610 is utilized. For the example of a battery pack with 4 batteries in series of 1.5V each (as in FIG. 8A), 3V are provided through a resistor R 886 to controller 630 and other loads (e.g., 640-648). In sleep mode of operation, the required current draw at the output of coupling circuit 650 may be, for example, in the order of 1 to 2 μΑ and resistor R 886 may be between 150 and 300 ΚΩ. Since regulator 620 may itself draw current in the order of 10 μΑ, by bypassing regulator 620 in sleep mode, the operational life of voltage source 610, or similarly 860, will improve. More generally, the energy consumption of low power device 600 will decrease. In a second embodiment of coupling circuit 880, resistor R 886 may be removed. In a third embodiment of coupling circuit 880, resistor R 886 may be replaced by an LDO regulator.

[0059] Coupling circuit 880 differs from coupling circuit 870 in that switch N 878 of coupling circuit 870 is always closed in coupling circuit 880, or equivalently, does not exist in coupling circuit 880. This fundamental difference permits the output of regulator 620 of low power device 600 to always be coupled to controller 630, whether in normal or sleep mode of operation. In addition, during sleep mode, the control switches of regulator 620 are kept open. As a result, capacitor C at the output of regulator 620 does not discharge during sleep mode, maintaining its charge from one normal mode period to the next. Due to residual resistances within practical regulator designs, a loss of charge in capacitor C is possible if regulator 620 is simply disconnected during sleep mode, for example, by opening switch N 878 of coupling circuit 870. As a result, coupling circuit 880 represents further savings in power consumption, since there is not a need to recharge capacitor C at the output of regulator 620 when the regulator transitions from sleep to normal mode of operation.

[0060] Control switch S 887 of coupling circuit 880 may be controlled by control signal Ss 8872 similarly to control signal 8772, in curve 8775 of FIG. 8C. When in operation, during normal mode, control signal Ss 8872 remains at "0", meaning that switch S 887 remains open. During sleep mode of operation, control signal Ss 8872 remains at " 1", meaning that switch S 887 remains closed. According to the present disclosure, the values of control signal Ss 8872 are exemplary and other values may be chosen without departing from the scope of the present disclosure.

[0061] FIG. 9 illustrates regulator 900 similar to regulator 700 and 620 coupled to coupling circuit 980 similar to coupling circuit 880 and 650 in accordance with one embodiment of the present disclosure. Figure 9 shows that capacitor C 950 is coupled to output terminal 984. When in operation, during normal mode, switch S 987 is open (control signal 9872 is at "0"), switch A 920 is closed (control 922 is at "1") and switch B 930 is open (control 923 is at "0"). Input voltage VI at input terminal 910 drives the output terminal 984. During sleep mode of operation, switch S 987 is closed (control signal 9872 is at "1"), and switches A and B are open (controls 922 and 923 are at "0"). Input voltage V2 drives the output terminal 984, maintaining capacitor C 950 charged throughout sleep mode. This represents further savings in power consumption, since there is not a need to recharge capacitor C 950 at the output of regulator 970 when the regulator transitions from sleep to normal mode of operation, as previously explained.

[0062] According to one aspect of the present disclosure, an apparatus 600 is described for providing an output voltage that decreases power consumption in a low power device. The apparatus includes a voltage source 610, 860, the voltage source including a first voltage output 612, 862, 910 at a first voltage level VI and a second voltage output 614, 864, 983 at a second voltage level V2 lower than the first voltage level, a regulator 620, 970 coupled to the first voltage output 612, 862, 910 that outputs a third voltage level V3 652, 960 not higher than the second voltage level (V2) 614, 864, 983 responsive to a first control signal 632, and a coupling circuit 650, 870, 880 that selectively couples a coupling circuit output 654, 874, 884, 984 to at least one of the second voltage output 614, 864, 983 and the regulator 620, 700, 870 responsive to a second control signal 634 to provide an output voltage. [0063] According to one embodiment of the apparatus, the apparatus may further include a controller 630 coupled to the regulator 620 and to the coupling circuit 650 that receives the output voltage and provides the first 632 and second 634 control signals to the regulator 620 and the coupling circuit 650, respectively.

[0064] According to one embodiment of the apparatus, the voltage source 610 may be a battery pack.

[0065] According to one embodiment of the apparatus, the battery pack may be a plurality of batteries coupled in series 860.

[0066] According to one embodiment of the apparatus, the second voltage output 614, 864 may be the output voltage of a subset of the plurality of batteries 860C, 860D of the battery pack 860.

[0067] According to one embodiment of the apparatus, the second control signal 634 may be one of a first mode and a second mode.

[0068] According to one embodiment of the apparatus, the first mode may be a normal mode and the second mode may be a sleep mode, the sleep mode being a lower current mode than the normal mode.

[0069] According to one embodiment of the apparatus, the coupling circuit output 654, 874 may be coupled to the regulator 620 when the second control signal 634, 8772, 8782 is set to the first mode and may be coupled to the second voltage output 614 when the second control signal 634, 8772, 8782 is set to the second mode.

[0070] According to one embodiment of the apparatus, the regulator 620 may be a buck regulator 700 further including a first switch 720 and a second switch 730, the first and second switches responsive to the first control signal 632, 722, 732.

[0071] According to one embodiment of the apparatus, when the second control signal 634, 8772, 8782 is set to the second mode, the first control signal 632, 722, 732 may close the first switch 720 and open the second switch 730.

[0072] According to one embodiment of the apparatus, when the second control signal 634 is set to the first mode, the first control signal 632, 722, 732 may alternately open and close the first switch 720 while, at the same time, alternately closing and opening the second switch (730), respectively, keeping only one switch open or closed at a time. In summary, the first and second switches have opposite behavior, with one closing when the other opens, and vice-versa. [0073] According to one embodiment of the apparatus, the coupling circuit output 654, 884, 984 may be coupled to the regulator 620, 970 when the second control signal 634, 8872, 9872 is set to the first mode and may be coupled to the second voltage output 614, 983 and to the regulator 620, 970 when the second control signal 634, 8872, 9872 is set to the second mode.

[0074] According to one embodiment of the apparatus, the regulator 620 may be a buck regulator further including a first switch 720, 920 and a second switch 730, 930, the first and second switches responsive to the first control signal 632, 722, 922, 732, 932.

[0075] According to one embodiment of the apparatus, when the second control signal 634, 8872, 9872 is set to the second mode, the first control signal 632, 722, 922, 732, 932 may open the first switch 720, 920 and the second switch 730, 930.

[0076] According to one embodiment of the apparatus, when the second control signal 634, 8872, 9872 is set to the first mode, the first control signal 632, 722, 922, 732, 932 may alternately open and close the first switch 720, 920 while, at the same time, alternately closing and opening the second switch 730, 930, respectively, keeping only one switch open or closed at a time. In summary, the first and second switches have opposite behavior, with one closing when the other opens, and vice-versa.

[0077] According to one embodiment of the apparatus, the apparatus may further include at least one functional component 640-648 coupled to the controller 630.

[0078] According to one embodiment of the apparatus, the coupling circuit 650 may include FET transistors.

[0079] FIG. 10 illustrates a flowchart of an exemplary method of providing an output voltage that decreases power consumption in a low power device in accordance with one aspect of the present disclosure. The method includes, at step 1010, accessing or providing a first voltage at a first voltage level and a second voltage at a second voltage level lower than the first voltage. The step 1010 may be performed by, for example, voltage source 610 or 860.

[0080] Next, at step 1020, the method includes regulating in a regulator the first voltage responsive to a first control signal to output a third voltage not higher than the second voltage. The step of regulating 1020 may be performed by, for example, regulator 620, 720 or 970.

[0081] Finally, at step 1030, the method includes selectively coupling an output to at least one of the second voltage output and the regulator responsive to a second control signal to provide an output voltage. The step of selectively coupling 1030 may be performed by, for example, coupling circuit 650, 870, 880 or 980.

[0082] In one embodiment of the method, the method may further include receiving the output voltage at step 1040, and generating, at step 1050, the first control signal and the second control signal. The steps of receiving the voltage output and generating may be performed by, for example, controller 630 and are optional steps of the method. In at least one embodiment of the method, the steps of receiving and generating may be bypassed.

[0083] In one embodiment of the method, the first and second voltages may be provided by a battery pack. The battery pack may be, for example, battery pack 860. In another embodiment of the method, the voltage source may be, for example, a rectified AC source, as previously explained.

[0084] In one embodiment of the method, the battery pack may be a plurality of batteries coupled in series. The battery pack may be, for example, battery pack 860.

[0085] In one embodiment of the method, the second voltage may be an output voltage of a subset of the plurality of batteries of the battery pack. The battery pack may be, for example, battery pack 860.

[0086] In one embodiment of the method, the second control signal may be one of a first mode and a second mode. The second control signal may be, for example, control signal 630, control signals 8772 and 8782, control signal 8872 or control signal 9872.

[0087] In one embodiment of the method, the first mode may be a normal mode and the second mode may be a sleep mode, the sleep mode being a lower current mode than the normal mode. The normal mode and sleep mode are as previously described in relation to regulators 700 or 970.

[0088] In one embodiment of the method, the step of selectively coupling may further include coupling said output to the regulator when the second control signal is set to the first mode, and coupling said output to the second voltage output when the second control signal is set to the second mode. The step of coupling may be performed, for example, by coupling circuit 870.

[0089] In one embodiment of the method, the step of regulating may be performed by a buck regulator, the step of regulating further including switching a first switch and a second switch within the regulator responsive to the first control signal. The step of regulating may be performed, for example, by regulator 700. [0090] In one embodiment of the method, the step of switching may further include, when the second control signal is set to the second mode, setting the first control signal to close the first switch and open the second switch. The step of regulating may be performed, for example, by regulator 700 and the step of switching may be as explained in Figs. 7A-7C.

[0091] In one embodiment of the method, the step of switching may further include, when the second control signal is set to the first mode, setting the first control signal to, at the same time, alternately open and close the first switch and the second switch, keeping only one switch open or closed at a time. The step of regulating may be performed, for example, by regulator 700 and the step of switching may be as explained in Figs. 7A-7C.

[0092] In one embodiment of the method, the step of selectively coupling may further include coupling said output to the regulator when the second control signal is set to the first mode, and coupling said output to the second voltage output and to the regulator when the second control signal is set to the second mode. The step of coupling may be performed, for example, by coupling circuit 880 or 980.

[0093] In one embodiment of the method, the step of regulating may be performed by a buck regulator, the regulating step further including switching a first switch and a second switch within the regulator responsive to the first control signal. The step of regulating may be performed, for example, by regulator 970.

[0094] In one embodiment of the method, the step of switching may further include, when the second control signal is set to the second mode, setting the first control signal to open the first switch and the second switch. The step of regulating may be performed, for example, by regulator 700 and the step of switching may be as explained in the description of Figs. 8D and 9.

[0095] In one embodiment of the method, the step of switching may further include, when the second control signal is set to the first mode, setting the first control signal to at the same time, alternately open and close the first switch and the second switch, keeping only one switch open or closed at a time. The step of regulating may be performed, for example, by regulator 970 and the step of switching may be as explained in Figs. 7B-7C.

[0096] In one embodiment, the method may further include coupling, at step 1060, to at least one functional component. In at least one embodiment of the method, the step of coupling to at least one functional component may be bypassed. The step of coupling may be performed by, for example, controller 630. The functional components may be components 640-648. [0097] In one embodiment of the method, the step of selectively coupling may further include using FET transistors as switches.

[0098] It is to be understood that any of the embodiments of the method 1000 described above may be implemented by the apparatus described in FIG. 6 and its respective embodiments described in FIGs. 7 A to 9. It is to be further understood that additional embodiments of the voltage source 610, regulator 620, coupling circuit 650, controller 630 and functional components 640-648, as previously described in the present disclosure, may also implement their respective steps of the method of flowchart 1000.

[0099] According to one aspect of the present disclosure, an apparatus 600 is described for providing an output voltage including a voltage source means 610 including a first voltage output at a first voltage level 612 and a second voltage output at a second voltage level 614 lower than said first voltage level, means for regulating 620 said second voltage level responsive to a first control signal to output a third voltage level not higher than said second voltage level, and means for selectively coupling 630 an output to at least one of said second voltage output 612 and said means for regulating 620 responsive to a second control signal to provide a voltage output.

[00100] As noted before, the functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. Also, when provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared.

[00101] It is to be further understood that, because some of the constituent system components and methods depicted in the accompanying drawings are preferably implemented in software, the actual connections between the system components or the process function blocks may differ depending upon the manner in which the present disclosure is programmed. Given the teachings herein, one of ordinary skill in the pertinent art will be able to contemplate these and similar implementations or configurations of the present disclosure.

[00102] Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the present disclosure is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one of ordinary skill in the pertinent art without departing from the scope of the present disclosure. In addition, individual embodiments can be combined, without departing from the scope of the present disclosure. All such changes and modifications are intended to be included within the scope of the present disclosure as set forth in the appended claims.

Claims

1. An apparatus (600) comprising:

a voltage source (610, 860) including a first voltage output (612, 862, 910) at a first voltage level (VI) and a second voltage output (614, 864, 983) at a second voltage level (V2) lower than said first voltage level;

a regulator (620, 970) coupled to said first voltage output (612, 862, 910) that outputs a third voltage level (V3) (652, 960) not higher than said second voltage level (V2) (614, 864, 983) responsive to a first control signal (632); and

a coupling circuit (650, 870, 880) that selectively couples a coupling circuit output (654, 874, 884, 984) to at least one of said second voltage output (614, 864, 983) and said regulator (620, 700, 870) responsive to a second control signal (634) to provide an output voltage.

2. The apparatus of claim 1 further comprising:

a controller (630) coupled to said coupling circuit (650) that receives said output voltage and provides said first (632) and second (634) control signals to said regulator (620) and said coupling circuit (650), respectively.

3. The apparatus of claim 1 wherein said voltage source (610) is a battery pack.

4. The apparatus of claim 3 wherein said battery pack is a plurality of batteries coupled in series (860).

5. The apparatus of claim 4 wherein said second voltage output (614, 864) is an output voltage of a subset of said plurality of batteries (860C, 860D) of said battery pack (860).

6. The apparatus of claim 1 wherein said second control signal (634) is one of a first mode and a second mode.

7. The apparatus of claim 6 wherein said first mode is a normal mode and said second mode is a sleep mode, said sleep mode being a lower current mode than said normal mode.

8. The apparatus of claim 6 or 7 wherein said coupling circuit output (654, 874) is coupled to said regulator (620) when said second control signal (634, 8772, 8782) is set to said first mode and coupled to said second voltage output (614) when said second control signal (634, 8772, 8782) is set to said second mode.

9. The apparatus of claim 8 wherein said regulator (620) is a buck regulator (700) further comprising:

a first switch (720) and a second switch (730), said first and second switches responsive to said first control signal (632, 722, 732).

10. The apparatus of claim 9 wherein, when said second control signal (634, 8772, 8782) is set to said second mode, said first control signal (632, 722, 732) closes said first switch

(720) and opens said second switch (730).

11. The apparatus of claim 9 wherein, when said second control signal (634) is set to said first mode, said first control signal (632, 722, 732) alternately opens and closes said first switch (720) while alternately closing and opening said second switch (730), respectively, keeping only one switch open or closed at a time.

12. The apparatus of claim 6 or 7 wherein said coupling circuit output (654, 884, 984) is coupled to said regulator (620, 970) when said second control signal (634, 8872, 9872) is set to said first mode and coupled to said second voltage output (614, 983) and to said regulator (620, 970) when said second control signal (634, 8872, 9872) is set to said second mode.

13. The apparatus of claim 12 wherein said regulator (620) is a buck regulator (970) further comprising:

a first switch (720, 920) and a second switch (730, 930), said first and second switches responsive to said first control signal (632, 722, 922, 732, 932).

14. The apparatus of claim 13 wherein, when said second control signal (634, 8872, 9872) is set to said second mode, said first control signal (632, 722, 922, 732, 932) opens said first switch (720, 920) and said second switch (730, 930).

15. The apparatus of claim 13 wherein, when said second control signal (634, 8872, 9872) is set to said first mode, said first control signal (632, 722, 922, 732, 932) alternately opens and closes said first switch (720, 920) while alternately closing and opening said second switch (730, 930), respectively, keeping only one switch open or closed at a time.

16. The apparatus of claim 2 further comprising at least one functional component (640-648) coupled to said controller (630).

17. The apparatus of claim 1 wherein said coupling circuit (650) comprises FET transistors.

18. A method comprising:

providing (1010) a first voltage and a second voltage lower than said first voltage; regulating (1020) in a regulator said first voltage responsive to a first control signal to output a third voltage not higher than said second voltage; and

selectively coupling (1030) an output to at least one of said second voltage and said regulator responsive to a second control signal to provide an output voltage.

19. The method of claim 18 further comprising:

receiving said output voltage (1040); and

generating (1050) said first control signal and said second control signal in a controller.

20. The method of claim 18 wherein said first and second voltages are provided by a battery pack.

21. The method of claim 20 wherein said battery pack is a plurality of batteries coupled in series.

22. The method of claim 21 wherein said second voltage is an output voltage of a subset of said plurality of batteries of said battery pack.

23. The method of claim 18 wherein said second control signal is one of a first mode and a second mode.

24. The method of claim 23 wherein said first mode is a normal mode and said second mode is a sleep mode, said sleep mode being a lower current mode than said normal mode.

25. The method of claim 23 or 24 wherein said selectively coupling further comprises:

coupling said output to said regulator when said second control signal is set to said first mode; and

coupling said output to said second voltage output when said second control signal is set to said second mode.

26. The method of claim 25 wherein said regulating is performed by a buck regulator, said regulating further comprising:

switching a first switch and a second switch within said regulator responsive to said first control signal.

27. The method of claim 26 wherein said switching further comprises:

when said second control signal is set to said second mode, setting said first control signal to close said first switch and open said second switch.

28. The method of claim 26 wherein said switching further comprises:

when said second control signal is set to said first mode, setting said first control signal to alternately open and close said first switch while alternately opening and closing said second switch, keeping only one switch open or closed at a time.

29. The method of claim 23 or 24 wherein said selectively coupling further comprises: coupling said output to said regulator when said second control signal is set to said first mode; and

coupling said output to said second voltage output and to said regulator when said second control signal is set to said second mode.

30. The method of claim 29 wherein said regulating is performed by a buck regulator, said regulating further comprising:

31. The method of claim 30 wherein said switching further comprises:

when said second control signal is set to said second mode, setting said first control signal to open said first switch and said second switch.

32. The method of claim 30 wherein said switching further comprises:

when said second control signal is set to said first mode, setting said first control signal to alternately open and close said first switch while alternately closing and opening said second switch, keeping only one switch open or closed at a time.

33. The method of claim 19 further comprising:

coupling (1060) to at least one functional component.

34. The method of claim 18 wherein said selectively coupling further comprises:

using FET transistors as switches.

35. An apparatus comprising:

a voltage source means (610) including a first voltage output at a first voltage level (612) and a second voltage output at a second voltage level (614) lower than said first voltage level; means for regulating (620) said second voltage level responsive to a first control signal to output a third voltage level not higher than said second voltage level; and means for selectively coupling (630) an output to at least one of said second voltage output (612) and said means for regulating (620) responsive to a second control signal to provide a voltage output.