Portable power source to provide power to an electronic device via an interface

A portable power source is configured for use with an electronic device. The portable power source cooperates and communicates with the electronic device via a peripheral bus to which the electronic device is attachable. The portable power source includes circuitry to process a power request signal from the electronic device to determine whether a device connected to a bus interface of the portable power source is requesting power from the portable power source.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is also related to: (i) U.S. Provisional Patent Application No. 60/642,276, filed Jan. 7, 2005, entitled “PORTABLE MEDIA DEVICE AND IMPROVED PLAYLIST PROCESSING ON MEDIA DEVICES,” which is hereby incorporated herein by reference; (ii) U.S. Provisional Patent Application No. 60/642,340, filed Jan. 7, 2005, entitled “ACCESSORY AUTHENTICATION FOR ELECTRONIC DEVICES,” which is hereby incorporated herein by reference; (iii) U.S. patent application Ser. No. 11/031,288 filed Jan. 7, 2005, entitled “METHOD AND SYSTEM FOR DISCOVERING A POWER SOURCE ON A PERIPHERAL BUS,” which is hereby incorporated herein by reference; (iv) U.S. patent application Ser. No. 11/031,301, filed Jan. 7, 2005, entitled “CONNECTOR SYSTEM,” which is hereby incorporated herein by reference; (v) U.S. patent application Ser. No. 10/833,689, filed Apr. 27, 2004, entitled “CONNECTOR INTERFACE SYSTEM FOR MULTI-COMMUNICATION DEVICE,” which is hereby incorporated herein by reference; (vi) U.S. patent application Ser. No. 10/278,752, filed Oct. 22, 2002, entitled “METHODS AND APPARATUS FOR CHARGING A BATTERY IN A PERIPHERAL DEVICE,” which is hereby incorporated herein by reference; (vii) U.S. patent application Ser. No. 10/125,893, filed Mar. 18, 2002, entitled “POWER ADAPTERS FOR POWERING AND/OR CHARGING PERIPHERAL DEVICES,” which is hereby incorporated herein by reference.

BACKGROUND

1. Technical Field

The present patent application relates to portable power sources and, in particular, relates to a portable power source operable to selectively provide power to a device connected to an interface of the portable power source.

2. Description of the Related Art

Portable electronic devices, such as Portable Digital Assistants and media players, typically include one or more rechargeable batteries housed permanently (or somewhat permanently) within the portable electronic device. These portable electronic devices sometimes also have peripheral bus ports that are able to support peripheral buses, such as Universal Serial Bus (USB) or FIREWIRE (IEEE 1394) bus ports. Peripheral buses are used to provide data communications with electronic devices as well as to provide limited amounts of power to the electronic devices. The power typically originates from a host computer to which the electronic device is connected via the peripheral bus.

In some situations, it can be impossible, or very inconvenient, to recharge the internally-housed batteries of a portable electronic device. This is typically due to lack of access to a suitable source of power. For example, many airliners do not have available a source of power suitable to recharge batteries of portable electronic devices.

On the other hand, external batteries (e.g., disposable AA batteries) can be somewhat easily obtained and carried to operate a portable electronic device in situations where the internally-housed rechargeable batteries are discharged and a source of recharge power is not conveniently available. However, configuring a portable electronic device to accommodate the use of both external batteries and internally-housed rechargeable batteries can be detrimental to the portability of the device.

Thus, there is a desire to accommodate the use of external batteries with portable electronic devices, while minimizing the detrimental effect to the portability of the electronic devices.

SUMMARY

Broadly speaking, in accordance with one aspect, a portable power source is configured for use with an electronic device.

The portable power source cooperates and communicates with the electronic device via an interface to which the electronic device is coupled. The portable power source includes circuitry to process a power request signal from the electronic device to determine whether a device connected to an interface of the portable power source is requesting power from the portable power source.

Typically, even if the connected electronic device has an internally-housed rechargeable battery, the internally-housed battery may be completely discharged. Thus, in accordance with some aspects, under some conditions, the portable power source provides power to the electronic device for at least a predetermined amount of time without consideration of the power request signal. The electronic device can use the power provided from the portable power source during this predetermined amount of time to boot up or otherwise arrive at a steady state condition, if not already at a steady state condition, so the electronic device can definitively determine whether to provide the power request signal to the portable power source.

An example of a condition under which the portable power source may provide power to the electronic device without consideration of the power request signal includes an initialization condition, in which the portable power source is unaware of the state of the electronic device.

An initialization condition may include, for example, a condition when electronic device is first connected to the portable power source after being not connected or, regardless of whether the electronic device is already connected to the portable power source, when external batteries are first inserted into the portable power source.

This summary is not intended to be all-inclusive. Other aspects will become apparent from the following detailed description taken in conjunction with the accompanying drawings, as well as from the appended claims.

DETAILED DESCRIPTION

A portable power source, particularly suitable for use with an electronic device, is now described. Examples and aspects are discussed below with reference to FIGS.1,1A,2and3. However, it should be understood that the detailed description given herein with respect to these figures is for explanatory purposes only, and not by way of limitation.

FIG. 1is a block schematic diagram of a portable power source150in accordance with one aspect. Referring toFIG. 1, external batteries151provide a renewable source of power for the power generator154to generate a power signal156. The power signal156is provided to an interface152. A microcontroller158is configured to receive a “connect” signal that indicates whether an electronic device is connected to the power source150. The microcontroller158is also configured to receive a “request” signal that indicates whether a connected electronic device is requesting that the power signal156be provided to the electronic device. Based on the request signal160and the connect signal159, the microcontroller158controls the state of an enable signal162provided to the power generator154. The power generator154operates in consideration of the state of the enable signal162.

FIG. 1Ais a more detailed block schematic diagram of a portable power source100in accordance with an aspect. Before discussing the block schematic diagram ofFIG. 1A, however, it is useful to consider the system diagram inFIG. 3.

In particular,FIG. 3illustrates the power source100(referred to inFIG. 3by reference numeral302) in the context of an electronic device304that is connected to receive power from the power source to power the operation of the electronic device304. Looking first at the electronic device304, the electronic device receives a DC power signal322′ (which, as will be discussed in a moment, originates as DC power signal322from the power source302) via an interface connector310. The interface connector314is connected to a counterpart interface connector312in the power source302by a cable314.

Various configurations for the interface from the power source302may be employed. InFIG. 3, the configuration includes the interface connector314, the counterpart interface connector312and the cable314. In one example, either of the interface connectors312or314may not be present, and may be replaced by a more permanent connection.

Furthermore, in some examples, regardless of how many connectors are present, the interface may be a controlled interface, such as a Universal Serial Bus (USB) or Firewire (IEEE 1394) bus interface. In other examples, there may be little or no logic directly associated with it the interface.

Power consuming circuitry306in the electronic device304operates using the DC power signal322′. A power monitor308monitors the power requirements of the consuming circuitry306and, when appropriate, generates a request signal316to request the power source302to provide the DC power signal322. The request signal316is provided to the power source302via the interface connector310and cable314.

A microcontroller318in the power source302receives the power request signal316as power request signal316′, via the interface connector312of the power source302. In response to the power request signal316′, the microcontroller302provides an enable signal324to power generation circuitry320of the power source302, which provides the generated power signal322to the interface connector312. The power generation circuitry320generates the power signal322using power supplied from external batteries319connected to the power generation circuitry320, and the power signal322is provided to the electronic device304via the cable314and interface connector310.

Having considered theFIG. 3system diagram of a power source and connected electronic device, we now consider theFIG. 1Ablock circuit diagram of the portable power source100. In the manner discussed above with reference toFIG. 3, the portable power source100is connectable to an electronic device (not shown) via a connector110. The connecter110provides an interface from the portable power source100to a port of a detachable electronic device.

The portable power source100includes a microcontroller102configured to control and coordinate the operation of various components of the portable power source100. The portable power source further includes terminal circuitry104(terminals and associated circuitry) to receive power from, in theFIG. 1example, two replaceable AA batteries. In theFIG. 1Aexample, circuitry106is provided to generate 5V power from the battery output, and circuitry108is provided to generate a 1.9V output from the battery output. The circuitry106and circuitry108operate based on the state of enable output signals from the microcontroller102.

The circuitry106is coupled to provide the 5V power to a supply voltage pin (for example, to carry a “supply voltage” as defined by a USB interface standard) of the connector110. The circuitry108is coupled to provide the 1.9V power on an additional power line pin of the connector110. The “additional power line pin” may be, for example, a pin to carry a signal that is supplemental to the signals defined by the USB interface standard. For additional details on connectors having additional functionality, see U.S. patent application Ser. No. 10/031,301, filed Jan. 7, 2005, entitled ‘CONNECTOR SYSTEM,” referred to above in the “CROSS-REFERENCE TO RELATED APPLICATIONS” section.

While theFIG. 1Ablock schematic diagram illustrates two power generation circuitry106and108, generating 5V and 1.9V, respectively, the number of voltages, and their values, would generally be compatible with particular electronic devices expected to be connected to receive power from the power source100to power the operation of the electronic device304

Referring still toFIG. 1A, circuitry112generates signal(s) coupled to data lines (for example, the “data lines” defined by the USB interface standard) in the connector110. The generated signal(s) characterize the portable power source100to a connected electronic device. The generated signal(s) may comprise, for example, an “available power indicator” of the type disclosed in related patent application Ser. No. 10/961,776, which was converted to U.S. Provisional Application No. 60/608,959 on Dec. 23, 2004.

Circuitry114processes a request signal from the electronic device, provided to the portable power source100via the connector110, and provides an indication thereof to a “request” input of the microcontroller102. The request signal from the electronic device indicates whether the electronic device is requesting power (i.e., the 5V and 1.9 V power generated by circuitry106and108, respectively) from the portable power source100.

Circuitry118generates a signal, to a “connect” input of the microcontroller102, that indicates whether an electronic device is connected to the connector110. While an electronic device is connected to the portable power source100, the circuitry118generates a signal indicating such a connection and provides the signal to the microcontroller102. Otherwise, a signal indicating such a connection is not provided to the microcontroller102.

In one particular example, the circuitry118cooperates with complementary circuitry nominally present in the electronic device. That is, it is assumed that, the electronic device includes complementary circuitry in which the chassis ground and digital ground are connected. At the microcontroller102, when the electronic device having the complementary circuitry is not connected to the connector110, the “connect” pin of the microcontroller102is normally pulled high (through a resistor to Vcc). When the electronic device having the complementary circuitry is connected to the connector110, the “connect” pin of the microcontroller102is pulled to digital ground.

Circuitry116is low power detection circuitry. Circuitry116evaluates the power available in the external batteries (connected to the terminal circuitry104) and, when the available power falls below a particular threshold, generates a low-power indication signal to a reset input of the microcontroller102. The thus-generated low-power indication signal holds the microcontroller102in a reset condition, resulting in the power generation circuitry106and108being controlled to cease generating power. This protects against the microcontroller102operating erratically due to a lower power condition, as well as minimizing the chance of damage (from leaking, for example) resulting from the external batteries being excessively discharged.

Having described the circuitry of the portable power source100with reference toFIG. 1A, we now refer toFIG. 2to describe how theFIG. 1Aportable power source100may operate in accordance with one example. In particular, program memory associated with the microcontroller102holds one or more programs which, when executed by the microcontroller102, controls a process to operate the portable power source100, including the interoperation of the portable power source100with a connected electronic device.

Referring toFIG. 2, a process200to operate the portable power source100is now described. The process stays at step210until external batteries are connected to the terminal circuitry104. In step210, the microcontroller is in an unpowered condition. When external batteries are connected to the terminal circuitry104, the microcontroller102powers up, leaves a reset condition, and begins to execute program instructions.

At step220, the microcontroller102waits (if necessary) for an electronic device to be connected to the connector110. As discussed above, in theFIG. 1Aexample, circuitry118of the portable power source100generates a signal indicating such a connection and provides the indication signal to the “connect” input of the microcontroller102. When step220is first reached, an electronic device may already be connected, in which case processing proceeds to step230.

At step230, the microcontroller102executes instructions to control the circuitry106and the circuitry108to provide the 5.0V and 1.9 V output, respectively. In one example, this comprises asserting an enable line from separate output pins of the microcontroller102to respective enable inputs of the respective power generation circuitry106and108. In one example, the microcontroller102executes the instructions such that there is a time delay of 100 msec between controlling the circuitry106to provide the 5.0V output and subsequently controlling the circuitry108to provide the 1.9V output.

Step240is essentially a “waiting” step, and step240is executed only each time in the process200that step220is executed. In particular, at step240, the microcontroller102executes instructions to wait an appropriate amount of time (for example, five seconds) for the connected electronic device to “boot up.” This wait is to accommodate a connected electronic device whose internal battery may itself insufficient for the electronic device to be operating. In such a case, the connected electronic device has to rely on the power being provided from the portable power source100to boot up and to begin to operate.

Step240is typically executed only one time after an electronic device is determined to be connected at step220since, at this time, the state of the internal battery of the connected electronic device is unknown. Subsequently, when step240is reached, it is known that the connected electronic device is already booted up and operating, so step240is skipped in this instance.

While not shown explicitly inFIG. 2, at any time it is detected (typically, asynchronously) that the electronic device is no longer connected to the port of the portable power source100, processing returns to step220to wait until the electronic device is again connected.

At step250(after waiting at step240, as appropriate), the microcontroller102executes instructions to determine whether the connected electronic device is asserting a signal to indicate a request by the connected electronic device, processed by the circuitry114of the portable power source100(as discussed above), for power from the portable power source100. Using theFIG. 1Aexample, the microcontroller102executes instructions to inspect the “request” input to the microcontroller102.

As long the microcontroller102determined that the connected electronic device is requesting power from the portable power source100, and assuming the power generation circuitry106and108is not disabled due to the low power detection circuitry116detecting a low power condition of the batteries (which, as discussed above, puts the microcontroller102into a reset condition, in one example), processing stays at step250. While processing stays at step250, the microcontroller continues to control the power generation circuitry106and108to provide power to the connected electronic device.

On the other hand, when the connected electronic device discontinues requesting power from the portable power source100, processing goes to step260. At step260, the microcontroller102executes instructions to go into a “sleep mode.” In the sleep mode, the microcontroller102executes instructions to disable the power generation circuitry106and108, which conserves the charge in the external batteries. If the connected electronic device again requests power from the portable power source100, then processing returns to step230.

Having now described a process200to operate the portable power source100, it is noted that, in a normal operating state, the operation of the power generation circuitry106and108is at the request of the connected electronic device. Typically, a connected electronic device would not employ the portable power source100as a power source to charge the internal battery of the connected electronic device.

However, the configuration of the portable power source100does not prevent the electronic device from employing the portable power source100in such a manner. In fact, in some examples, such as a particular example of a portable media player, the electronic device is designed to preserve certain information in its internal memory even when “powered off.” Such information may include, for example, an indication of which song was playing when the electronic device was powered off. The electronic device requires a minimum amount of power to its internal memory to preserve the information. Thus, the electronic device may employ a small amount of power from the portable power source100to raise its internal battery to a minimum level of charge, to power its internal memory to preserve the information.

The various described aspects, examples, implementations or features can be used separately or in any combination.

The invention is preferably implemented by hardware, software or a combination of hardware and software. As an example, processing of certain signals may be accomplished in some cases by polling a signal state and, in other cases, using a combination of interrupt hardware and interrupt handler software.

One example of an ornamental design for a portable power source is provided in U.S. Design Patent Application No.: 29/220,307, filed Dec. 23, 2004, entitled “BATTERY PACK,” which is hereby incorporated herein by reference.

The advantages of the invention are numerous. Different aspects, embodiments or implementations may yield one or more advantages. One advantage that an embodiment of the invention may have is that an electronic device may be conveniently powered using a portable power source.