WO2012084054A1

WO2012084054A1 - Power circuit for coupling a power consuming device to a power supply circuit

Info

Publication number: WO2012084054A1
Application number: PCT/EP2010/070667
Authority: WO
Inventors: Markus Neumann; Harald RAFFEL
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2010-12-23
Filing date: 2010-12-23
Publication date: 2012-06-28
Anticipated expiration: 2013-06-23

Abstract

A power circuit (114) for connecting a high-current-capable device (102) to a power supply circuit (104) comprising a plurality of current supplies (106, 108) is described. The power circuit (114) comprises a first input path (116) configured for being connectable to a first current supply (106) of the plurality of current supplies (106, 108), and a second input path (118) configured for being connectable to a second current supply (108) of the plurality of current supplies (106, 108). The power circuit (114) comprises a current combining unit (120) configured for generating a combined current by combining a first current to be provided by the first current supply (106) and a second current to be provided by the second current supply (108). The power circuit (114) comprises an output path (122) configured for supplying the combined current to the high-current-capable device (102), and a current negotiating unit (142) configured for negotiating a maximum amount of the second current with the power supply circuit (104).

Description

Title

Power circuit for coupling a power consuming device to a power supply circuit Technical Field

The invention relates to coupling a power consuming device to a power supply circuit.

Further, the invention relates to an adapting device for detachably connecting a high-current- capable device to a power supply circuit. Further, the invention relates to a high-current- capable device for being connectable to a power supply circuit. Further, the invention relates to a method of operating a power circuit.

Background High-current-capable devices may be operable at different amounts of a supply current, and may show optimum functionality at a maximum amount of the supply current.

For example, the high-current-capable device may be configured as a Universal Serial Bus (USB)-Long Term Evolution (LTE)-modem usable in association with a personal computer such as a laptop for data transmission. The USB-LTE -modem comprises a housing in which integrated circuits and a plug element electrically connected to the integrated circuits and configured for being detachably connected to a power supply circuit for the USB-LTE - modem are accommodated. The power supply circuit is accommodated in the personal computer and is connectable to the USB-LTE -modem via a respective socket element of the personal computer. When having plugged the plug element of the USB-LTE -modem into the socket element of the personal computer, the supply current is provided from the power supply circuit accommodated in the personal computer to the USB-LTE-modem via the plug- socket-connection. Both the USB-LTE-modem and the personal computer are configured in accordance with USB specifying the maximum amount of current to be provided by the personal computer to the USB-LTE -modem. Accordingly, the maximum amount of the supply current is negotiated between the USB-LTE -modem and the personal computer, for example using an enumeration procedure starting subsequent to connecting the USB-LTE -modem to the power supply circuit.

In the following, it will be assumed that the USB-LTE -modem may require a supply current of one Ampere (A), in order to show its optimum functionality, for example, with respect to its uplink and downlink data transmission rates or its range of a cell coverage. However, the USB specification may limit the maximum amount of the current to be provided, and is below the maximum amount of current required by the USB-LTE -modem for showing its optimum functionality. In particular, in a case in which a connected device may be enumerated as a high speed device a maximum amount of a supply current of 500 mA (milli- Ampere) and 900 mA may be provided by the power supply circuit of the personal computer in accordance with a USB2.0 specification and a USB3.0 specification, respectively. Consequently, the USB- LTE -modem may receive a supply current whose amount may be less than the amount of the supply current required for optimum functionality, and may operate at a lower data transmission rate than being possible or may comprise a smaller range of the cell coverage (caused by reduced radio output power) of the USB-LTE -modem than being possible. It is known to use an adapting device in the form of a Y-type cable, in order to increase the maximum amount of the current to be provided by the personal computer for the modem. The Y-type cable is configured for being detachably connecting the personal computer accommodating the power supply circuit and the USB-LTE -modem to one another. To this end, the Y-type cable comprises first and second portions each of which comprising a plug element to be pluggable into a respective socket element of the personal computer. The first and second portions of the Y-type cable are combined to a third portion at whose ending portion a socket element configured for detachably accommodating the plug element of the USB-LTE-modem is arranged. First and second currents are provided by first and second current supplies of the power supply circuit via the first and second plug elements. The first current is defined according to the USB specification to be either 500 mA or 900 mA when having enumerated the USB-LTE -modem as a high speed device, and is supplied to the modem via the first and the third portion of the Y-type cable. The second current to be provided by the second current supply of the power supply circuit comprises a maximum amount of 100 mA, which may particularly result from the USB-LTE -modem being not enumerated via the Y-type cable as a high speed device. Further, the personal computer may be configured in an undefined way regarding the USB socket connection towards the second portion of the Y-type cable. Further, the first and second currents to be provided by the first and second current supplies of the power source circuit may interfere along respective voltage lines accomodated in the first, second, and third portions of the Y-type cable such that the amount of the current to be supplied to the USB-LTE -modem may be less than a sum of the first and second currents. Consequently, the amount of current to be provided for the modem may be at most 600 mA at USB2.0 which is still less than the maximum amount of supply current required by the modem for showing optimum operational functionality.

Summary

It is an object of the invention to provide an increased amount of a current to be supp liable to a high-current-capable device.

In order to achieve the object defined above, a power circuit for connecting a high-current- capable device to a power supply circuit, an adapting device for detachably connecting a high- current-capable device to a power supply circuit, a high-current-capable device for being connectable to a power supply circuit, and a method of operating a power circuit according to the independent claims are provided. According to an exemplary aspect of the invention, a power circuit for connecting a high- current-capable device to a power supply circuit is provided. The power supply circuit comprises a plurality of current supplies. The power circuit comprises a first input path configured for being connectable to a first current supply of the plurality of current supplies, a second input path configured for being connectable to a second current supply of the plurality of current supplies, and a current combining unit configured for generating a combined current by combining a first current to be provided by the first current supply and a second current to be provided by the second current supply. The power circuit comprises an output path configured for supplying the combined current to the high-current-capable device, and a current negotiating unit configured for negotiating a maximum amount of the second current with the power supply circuit.

According to another exemplary aspect of the invention, an adapting device for detachably connecting a high-current-capable device to a power supply circuit is provided. The adapting device comprises a power circuit as defined above.

According to another exemplary aspect of the invention, a high-current-capable device for being connectable to a power supply circuit is provided. The high-current-capable device comprises a power circuit as defined above.

According to another exemplary aspect of the invention, a method of operating a power circuit (particularly as defined above) is provided. The method comprises connecting a first input path of the power circuit to a first current supply of a plurality of current supplies of a power supply circuit, and connecting a second input path of the power circuit to a second current supply of a plurality of current supplies of the power supply circuit. The method comprises negotiating a maximum amount of a second current to be provided by the second current supply with the power supply circuit, generating a combined current by combining a first current to be provided by the first current supply and the second current to be provided by the second current supply, and supplying the combined current via an output path to a high-current-capable device.

In the context of the present application, the term "high-current-capable device" denotes a device that might consume a considerable amount of current (or power) within the scope of user devices, e.g. portable computers, mobile terminals etc, and especially is not negligible with respect to a current (power) consumption of associated devices, e.g. being connected to the high-current-capable device The term may particularly denote a current-driven device being operable at various amounts of a (supply) current. In particular, the high-current- capable device may show different levels of an operational functionality depending on an amount of a supply current for the high-current-capable device. In particular, the high-current- capable device may show an optimum operational functionality when being operated at a maximum amount of a supply current. In particular, the term "input path" and "output path" may particularly denote an electrical connection via which a respective supply current may be suppliable to a load in a flow direction of the current (from the input path towards the output path). In particular, the input path and/or the output path may comprise a respective voltage line or voltage bus and a respective ground line for the current supply. In particular, a data transmission may be bidirectionally transmittable along the input and/or output path, and may comprise media and/or signaling transmission. In particular, at least a portion of the input path and/or the output path may comprise respective signal (transmission) lines via which the media and/or the signaling may be transmittable. In particular, the term "negotiating an amount of a current with the power supply circuit" may particularly denote a communication with the power supply circuit during which respective control information may be exchanged between the power supply circuit and a respective communication partner (for example, in the case of the maximum amount of the second current with the current negotiating unit). The maximum amount of the current to be provided by the power supply circuit may be definable by the power supply circuit based on the communication. In particular, such control information may relate to characteristics of a functionality of a device (for example, a data transmission rate, or a range of a cell coverage), and/or a maximum amount of a supply current required for optimum functionality, and may be sent from the communication partner to the power supply circuit.

According to the exemplary aspects of the invention, the power circuit is interconnectable between a high-current-capable device and a power supply circuit for current negotiation such that an amount of a total supply current for the high-current-capable device may be significantly increased. In particular, a maximum amount of the second current to be provided by the second current supply may be negotiated between the current negotiating unit and the power supply circuit such that an increased amount of the second current may be provided and may be supplied to the high-current capable device via the second input path of the power circuit.

In particular, using a current combining unit for combining the first and second currents supplied via the first and second input paths may also at least increase or even optimize the amount of the generated combined current to be supplied to the high-current-capable device, since the first and second currents may be separately supplied along the first and second input paths and supplied along the output path in a combined way, thereby preventing leakage currents between the first and second currents along the first and second input paths and the output path. In particular, the current combining unit may help to at least reduce or even prevent a response of one of the first and second currents supplied along the first or second input paths back to the other one the first and second currents supplied along the first or second input paths in terms of leakage currents or any other interference. Next, further exemplary embodiments of the power circuit for connecting a high-current- capable device to a power supply circuit will be explained. However, these embodiments also apply to the respective adapting device, the respective high-current-capable device, and the respective method.

In particular, a maximum amount of a first current to be provided by the first current supply of the plurality of current supplies may be negotiable with the power supply circuit. Thus, an increased amount of the first current may be provided by the first current supply and may be supplied to the high-current capable device via the first input path of the power circuit. Thus, a total amount of the supply current for the high-capable device may be increased.

The current negotiating unit may comprise an enumerating unit configured for

communicating with the power supply circuit for enumeration of the second input path. The term "enumeration" may particularly denote a Universal Serial Bus compatible procedure for setting the second current supply in a state controlled by the power supply circuit. In particular, respective control information may be exchangeable between the power supply circuit or any computer device comprising the power supply circuit (for example, a desktop computer or a laptop) and the enumerating unit during the enumeration procedure. Thus, the second input path of the power circuit may be recognized by the power supply circuit as a "device" which may require a particular amount of supply current, thereby the second current supply being enabled to provide a respective amount of the current to the second input path. Accordingly, the combined current for the high-current-capable device may be increased, since the amount of the second current may be increased and particularly optimized with respect to a maximum amount of the second current to be provided by the second current supply.

The current combining unit may comprise a connection node at which first ending portions of the first and the second input paths may be connected to one another, and wherein a first ending portion of the output path may be connected to the connection node. This constructively very simple design of the current combining unit may allow for generating the combined current in an easy and defined way. In particular, a voltage line and/or a ground line of the first ending portions of the first and second input paths may be connected to one another at respective connection points of the connection node, respectively. In particular, a suitable unit may be arranged at a connection point of the connection node.

The current combining unit may comprise a first diode arranged in the first input path and a second diode arranged in the second input path, wherein each of the first and second diodes may be (particularly continuously) operable in flow direction of the first and second currents. In particular, current losses of the first and second currents against the flow direction of the first and second currents may be minimized or may be prevented by using the first and second diodes. In particular, current losses owing to a presence of the first and second diodes may be minimized by using suitable diodes having a low forward voltage, for example, Schottky diodes. In particular, the first and second diodes may represent conventionally and

inexpensive electronic elements, thereby providing a cost-effective current combining unit.

The current combining unit may comprise a first transistor arranged in the first input path, a second transistor arranged in the second input path, and a dual power path (ideal diode) controller configured for controlling the first and second transistors. In particular, the dual power path controller may be configured for sensing a source voltage of the first and second transistors and may be configured for controlling a gate voltage of the first and second transistors in order to adapt a resistance of a source-drain channel of the first and second transistors. In particular, the first and second transistors may be field effect transistors which may be operated as small controllable resistances which may isolate the first and second input paths from one another. In particular, the first and second currents may be combined, particularly added, to one another depending on the kind of controlling of the first and second transistors, thereby providing a maximum achievable combined current for the high-current- capable device. In particular, the first and second transistors and the dual power path controller may represent conventionally and inexpensive electronic elements, thereby providing a cost-effective current combining unit. The current combining unit may comprise a (particularly dual input single output) switch mode power converter (SMPC) connected to first ending portions of the first and second input paths and to a first ending portion of the output path and being configured for converting the first and second currents into the combined current. Thus, the combining unit may be configured in a constructive simple and cost-effective way, since the current combining unit may comprise a single, commercially available and inexpensive electronic element.

In particular, a first capacitance may be arranged in the first input path (close or at a first input port of the SMPC), a second capacitance may be arranged in the second input path (close or at a second input port of the SMPC), and a third capacitance may be arranged in the output path (close or at an output port of the SMPC). In particular, the first and second capacitances may provide a constant and continuous current drain from the first and second input paths. In particular, the third capacitance may filter spurious signals generated in the SMPC.

In particular, the SMPC may be switched in an alternating way with respect to its first and second input ports.

The power circuit may further comprise a first (male) plug element configured for being pluggable into (particularly a respective (female) socket element of) the power supply circuit, and a second (male) plug element configured for being pluggable into (particularly a respective (female) socket element of) the power supply circuit, wherein a second ending portion of the first input path may be connected to (and partially accommodated in) the first plug element and wherein a second ending portion of the second input path may be connected to (and partially accommodated in) the second plug element. In particular, the first and second plug elements may comprise electrical contacts configured for electrically contacting the first and second current supplies and thus for connecting the first and second current supplies to the first and second input paths. In particular, the first and second plug elements may provide a secure but detachable connection between the power circuit and the power supply circuit, thereby the power circuit being versatile usable in association with different kinds of current supply circuits.

The current negotiating unit may be accommodated in the second plug element, thereby providing a mechanically stable and secure configuration of the power circuit. In particular, the power circuit may comprise a voltage line and a ground line connected between (the electrical contacts of) the second plug element and the current combining unit, and

additionally signal lines between (the electrical contacts of) the second plug element and the current negotiating unit. In particular, the current negotiating unit may be electrically fed via a voltage line and a ground line of the second input path.

The power circuit may further comprise a (female) socket element configured for being connectable to (a respective (male) plug element of) the high-current-capable device, wherein a second ending portion of the output path is connected to the socket element, thereby providing a secure but detachable connection between the power circuit and the high-current- capable device. In particular, the socket element may comprise electric contacts connected to a voltage line, a ground line and signal lines of the output path.

A second ending portion of the output path may be connected to another current negotiating unit configured for negotiating the maximum amount of the first current with the power supply circuit via the first input path. Thus, the power circuit may be configured as a self- contained circuit and may be usable for defining the maximum amount of the first current without requiring the high-current capable device comprising such functionality. In particular, the power circuit may form part of the high-current-capable device, thereby providing a mechanically stable configuration of the power circuit.

In particular, the second ending portion of the output path may be connectable to the another current negotiating unit which may particularly form part of the high-current-capable device. In particular, the power circuit may be a separate module with respect to the high-current- capable device. Thus, the first input path of the power circuit may provide a transparent channel between the power supply circuit and the high-current-capable device regarding a data exchange for the current negotiation procedure or for another purpose.

In particular, a respective current negotiation procedure between the another current negotiation unit and the power supply circuit via the input path may be executed prior to the current negotiation procedure between the current negotiating unit and the power supply circuit.

In particular, the another current negotiating unit may be configured as an enumerating unit configured for communicating with the power supply circuit via the first input path for enumeration of the (connectable) high-current-capable device. The power circuit may be configured according to a Universal Serial Bus specification, whereby the power circuit may be versatile usable in today's life in connection with standard connections of personal computers and/or telecommunication devices.

In particular, the power circuit may comprise a plurality of another input paths and a plurality of another current negotiating units. In particular, the term "plurality of objects" may particularly denote at least two objects. In particular, the plurality of another input paths may comprise the second input path. In particular, each one of the plurality of another input paths may be connectable to a respective another current supply of the plurality of current supplies. In particular, the plurality of another current negotiating units may comprise the current negotiating units. In particular, each one of the plurality of another current negotiating units may be configured for negotiating a maximum amount of another current to be provided by the respective another current supply with the power supply circuit. In particularly, the current combining unit may be configured for generating the combined current by combining the first current and the plurality of another currents.

In particular, each one of the plurality of another input paths may be configured in accordance with any (different one) of the embodiments of the second input path as defined above. In particular, each one of the plurality of another current negotiating units may be configured in accordance with any (different one) of the embodiments of the current negotiating unit and a respective arrangement thereof in the power circuit as defined above.

Next, further exemplary embodiments of the adapting device for detachably connecting a high-current-capable device to a power supply circuit will be explained. However, these embodiments also apply to the respective power circuit, the respective high-current-capable device, and the respective method. The adapting device may be configured as a Y-like shaped cable, wherein a first input path of the power circuit may be accommodated in a first portion of the Y-like shaped cable, wherein a second input path of the power circuit may be accommodated in a second portion of the Y- like shaped cable, and wherein an output path of the power circuit may be accommodated in a third portion of the Y-like shaped cable. In particular, the term "Y-like shaped cable" may particularly denote a cable comprising a shape which may be similar to a "Y". Thus, a conventionally designed adapting device may be used for detachably connecting the high- current-capable device and the power supply circuit, whereby handling of the adapting device by an operator of the adapting device may be facilitated. In particular, the first plug element may be arranged at an ending portion of the first portion of the Y-like shaped cable, the second plug element may be arranged at an ending portion of the second portion of the Y-like shaped cable, and the socket element may be arranged at an ending portion of the third portion of the Y-like shaped cable.

Next, further exemplary embodiments of the high-current-capable device for being connectable to a power supply circuit will be explained. However, these embodiments also apply to the respective power circuit, the respective adapting device, and the respective method.

In particular, the current negotiating unit, the current combining unit, at least a portion of the first and second input paths, the output path, and optionally integrated circuits of the high- current-capable device may be manufactured as an integrated circuit and/or may form part of another (higher) integrated circuit.

The high-current-capable device may be configured as a modem, a hard disk, a (particularly passive ethernet) hub, a battery charger or a loudspeaker or any similar device. In particular, uplink and downlink data transmission rates and ranges of a cell coverage of the modem may be increased when operating the modem at a maximum available supply current being (ideally) defined by the generated combined current. Arranging the power circuit in the high- current-capable device may provide for a compact and self-contained system.

In particular, the high-current-capable device may be configured for being communicatively coupled and/or may be configured as communication user equipment in accordance with Long Term Evolution (LTE), WideBand Code Division Multiple Access (WCDMA),

Extended Global System for Mobile Communications (EGSM), Wireless Local Area Network (WLAN) or Worldwide Interoperability for Microwave Access (WiMax) or any similar communication network or network protocol. In particular, the high-current-capable device may be configured as a LTE-(dongle) modem. Brief description of the drawings

The invention will be described in more detail hereinafter with reference to examples of embodiment, but to which the invention is not limited.

Fig. 1 illustrates an adapting device according to an exemplary embodiment of the invention,

Fig. 2 illustrates a second plug element of the adapting device in Fig. 1,

Figs. 3 - 6 illustrate further exemplary embodiments of a current combining unit of the adapting device in Fig. 1,

Fig. 7 illustrates a USB-LTE -modem according to an exemplary embodiment of the invention, and

Fig. 8 is a flow diagram illustrating an exemplary method of operating a power circuit according to an exemplary embodiment of the invention.

Detailed description of the embodiments

The illustration in the drawing is schematic. It is noted that in different figures, similar or identical elements are provided with the same reference signs or with reference signs which are different from the corresponding reference signs only within the first digit. Fig. 1 illustrates an adapting device 100 configured for detachably connecting a high-current- capable device 102 to a power supply circuit 104, both of them being indicated by dashed lines. For example, the high-current-capable device 102 is configured as a USB-LTE modem, and the power supply circuit 104 forms part of a laptop. The power supply circuit 104 comprises a plurality of current supplies, in the shown embodiment, first and second current supplies 106, 108 configured for providing first and second currents for the adapting device 100 and thus the high-current-capable device 102, respectively.

The adapting device 100 is configured as a Y-like shaped cable comprising a cladding 112 in which a power circuit 114 for connecting the high-current-capable device 102 to the power supply circuit 104 is accommodated. The power circuit 114 comprises a first input path 116, a second input path 118, a current combining unit 120 configured for generating a combined current by combining the first and second currents, and an output path 122. The current combining unit 120 is connected to first ending portions 124, 126 of the first and second input paths 116, 118, and to a first ending portion 128 of the output path 122. The power circuit 114 further comprises first and second plug elements 130, 132, and a socket element 134. The first plug element 130 is connected to a second ending portion 136 of the first input path 116, the second plug element 132 is connected to a second ending portion 138 of the second input path 118, and the socket element 134 is connected to a second ending portion 140 of the output path 122. A current negotiating unit 142 of the power circuit 114 configured for negotiating a maximum amount of the second current with the power supply circuit 104 is arranged in the second input path 118 and is accommodated in the second plug element 132. Another current negotiating unit 144 configured for negotiating a maximum amount of the first current with the power supply circuit 104 via the first input path 116 and the output path 122 is

connectable to the output path 122 and is accommodated in the high-current-capable device 102. The current negotiating unit 142 is configured as an enumerating unit configured for enumeration of the second input path 118. The current negotiating unit 144 is also configured as an enumerating unit configured for enumeration of the high-current capable device 102. The reference numerals 142 and 144 will used in the following to refer to the enumerating unit and the another enumerating unit, respectively.

The Y-like shaped cable comprises a first portion 146a, a second portion 146b, and a third portion 146c. The first input path 1 16 and the current combining unit 120 are accommodated in the first portion 146a, the second input path 1 18 is accommodated in the second portion 146b, and the output path 120 is accommodated in the third portion 146c.

The power supply circuit 104, the adapting device 100, and the high-current-capable device 102 are configured in accordance with USB2.0. Thus, the first and second current supplies 106, 108 may provide a maximum amount of the first and second currents of up to 500 mA for the first and second input paths 116, 118 (when a respective enumeration procedure has been completed).

In operation of the adapting device 100 the first and second plug elements 130, 132 are electrically connected to the first and second current supplies 106, 108 by plugging the first and second plug elements 130, 132 into socket elements of the power supply circuit 104, and the socket element 134 is electrically connected to the high-current-capable device 102 by accommodating a plug element of the high-current-capable device 102. Thereupon, an enumeration procedures between the enumerating unit 144 and the power supply circuit 104 via the first input path 116 and the output path 122 and between the enumerating unit 142 and the power supply circuit 104 via the second input path 118 starts. During this enumeration procedure the first current to be provided by the first current supply 106 and the second current to be provided by the second current supply 108 are negotiated such that the maximum amount of the first current and the maximum amount of the second current is defined for being supplied by the power supply circuit 104. Thereupon, the first current and the second current are supplied to the first input path 116 and to the second input path 118, respectively, and are combined by the current combining unit 120 in that the current combining unit 120 generates the combined current to be supplied to the high-current-capable device 102 via the output path 122. In accordance with the USB 2.0 specification of the involved circuits and devices, the maximum amount of the first current and the maximum amount of the second current are defined to be equal to 500 mA such that a maximum available amount of the combined current of ideally 1 A is provided by the adapting device 100 to the high-current-capable device 102. In reality, the amount of the combined current may be less than 1 A owing to current losses in the first and second input paths 116, 118, the output path 122, the enumerating unit 142, and/or the current combining unit 120.

It is noted that data are also transmittable between the high-current-capable device 102 and the laptop comprising the power supply circuit 104 via the first plug element 130.

Referring to Fig. 2, the second plug element 132 is illustrated in more detail. The second plug element 132 comprises a housing 247 and four electrical contacts 248a-d (indicated by "GND", "D-2", "D+2", and "VBUS2", respectively). The electrical contacts 248d, 248a are connected to voltage and ground lines 250, 252 of the second input path 118 which connect the enumerating unit 142 to the current combining unit 120. The electrical contacts 248b, c are connected to signal lines 254, 256 which terminate in the enumerating unit 142. Thus, the second current to be provided by the second current supply 108 is supp liable from the electrical contacts 248a, d to the current combining unit 120 via the voltage and ground lines 250, 252 and the enumerating unit 142. Here, the enumerating unit 142 is electrically fed by the voltage line 248d. Media and signaling exchange is accomplished between the enumerating unit 142 and the power supply circuit 104 using the electrical contacts 248b, c and the signal lines 254, 256. Referring to Figs. 3 to 6, further exemplary embodiments of the current combining unit 120 of Fig. 1 will be explained.

A current combining unit 320 illustrated in Fig. 3 electrically connects the first and second input paths 116, 118 to the output path 122. The first input path 116 comprises a voltage line 354, a ground line 356, and signal lines 358, 360, and the output path 122 comprises a voltage line 362, a ground line 364, and signal lines 366, 368. The current combining unit 320 comprises a connection node 370 (indicated by a dashed line) having a connection point at which the ground line 356 of the first ending portion 124 of the first input path 116 and the ground line 252 of the first ending portion 126 of the second input path 118 are connected to one another. Similarly, the voltage line 354 of the first ending portion 124 of the first input path 116 and the voltage line 250 of the first ending portion 126 of the second input paths 118 are connected to one another at another connection point of the connection node 370. Further, the voltage line 362 and the ground line 364 of the first ending portion 128 of the output path 122 are connected to the respective connection points of the connection node 370. The signal lines 358, 360 of the ending portion 124 of the first input path 116 are directly connected to the signal lines 366, 368 of the ending portion 128 of the output path 122 and bypass the connection node 368. Here, the signal lines 358 and 366 and the signal lines 360 and 268 are integrally formed, respectively.

In operation of the current combining unit 320, the first and second currents provided by the first and second current supplies 106,108 are supplied by the first and second input paths 116, 118 and are merged at the connection node 370 of the current combining unit 320. The first current supplied along the voltage line 354 and the second current supplied along the voltage line 250 are defined by USB2.0 to be equal to 500 mA after enumeration such that the combined current supplied along the voltage line 362 is equal to almost 1 A. Another current combining unit 420 illustrated in Fig. 4 is similarly designed with respect to the current combining unit 320 illustrated in Fig. 3. However, a first diode 472 is arranged in the voltage line 354 of the first ending portion 124 of the first input path 116, and a second diode 474 is arranged in the voltage line 250 of the first ending portion 126 of the second input path 118. Accordingly, the first and second diodes 472, 474 are arranged upstream of the connection node 370. Further, the first and second diodes 472, 474 are operable in flow direction of the first and second currents to be supplied along the voltage lines 250, 354.

In operation of the current combining unit 420, the first and second diodes 472, 474 are operated in flow direction of the first and second currents 118. The first and second currents provided by the first and second current supplies 106,108 are supplied by the first and second input paths 116, 1 18 such that the first and second currents passing through the first and second diodes 472, 474 are added at the connection node 370 of the current combining unit 420.

Another current combining unit 520 illustrated in Fig. 5 is similarly designed with respect to the current combining unit 420, however, the first and second diodes 472, 474 are replaced by first and second transistors 576, 578. Further, the current combining unit 520 comprises a dual power path controller 580 configured for controlling the first and second transistors 576, 578. To this end, the dual power path controller 580 is configured for sensing a source voltage of each of source contacts of the first and second transistors 576, 578 via voltage lines connecting ports "VI", "V2" of the dual power path controller 580 and the respective voltage line 250, 354 upstream of the respective first or second transistors 576, 578. The dual power path controller 580 is also configured for controlling a gate voltage of each of gate contacts of the first and second transistors 576, 578 via voltage lines connecting ports "Gl", "G2" of the dual power path controller 580 and the respective gate contact of the first and second transistors 576, 578. Further, the dual power path controller 580 is configured for driving the generated combined current via a voltage line connected between a port "VO" of the dual power path controller 580 and a connection point of the connection node 370 at which the voltage lines 250, 354 are connected to one another. Here, a drain contact of the second transistor 578 is connected to the voltage line via which the dual power path controller is configured for driving the combined current such that the voltage line 250 is provided across the second transistor 578 to the latter mentioned connection point of the connection node 370.

In operation of the current combining unit 520, the source voltage of the first and second transistors 576, 578 are sensed by the dual power path controller 580. Further, the gate contacts of the first and second transistors 576, 578 are simultaneously supplied with a respective gate voltage such that the first and second transistors 576, 578 are operated in such a way by the dual power path controller 580 that the first and second transistors 576, 578 simultaneously and continuously supply the first and second currents to the connection node 370 at which the first and second currents are added to one another. Accordingly, the first and second transistors 576, 578 represent a resistance which is controllable by the amount of the gate voltages and which prevent a response of one of the first and second currents back to the other one of the first and second currents in terms of leakage currents via the first and second input paths 116, 118.

A current combining unit 620 illustrated in Fig. 6 comprises a connection node 370 at which the voltage lines 250, 354, 362 and the ground lines 252, 356, 364 of the first and second input paths 116, 118 and the output path 122 are connected to one another. A switch mode power converter (SMPC) 682 is arranged at a respective connection point of the connection node 370 and is connected to the first ending portions 124, 126 of the first and second input paths 116, 118. Accordingly, the voltage lines 354, 250 of the first and second input paths 116, 118 terminate in respective input ports "INI", "IN2" of the SMPC 682. An output port "OUT" of the SMPC 682 is connected to the voltage line 362 of the output path 122. Further, the ground lines 252, 356 of the first and second input paths 116, 118 are connected to one another at a connection point 684 of the connection node 370 to which the ground line 364 of the output path 122 is also connected.

In operation of the current combining unit 620, the SMPC 682 is activated. The first and second currents are supplied by the first and second input paths 116, 118 to the first and second input ports "INI", "IN2", and a combined current is generated by the SMPC 682 and is outputted at the output port "OUT".

Owing to the switching mode operation of the SMPC 682 the two available first and second currents are combined, and a respective combined current is available on the output port of the SMPC 682 without current interference between the two input ports of the SMPC 682.

Further, a first capacitor 685 is arranged at in the first input path 116 at the input port "INI "of the SMPC 682, and a second capacitor 686 is arranged in the second input path 118 at the input port "IN2"of the SMPC 682. Here, the first and second capacitors 685, 686 are connected to the voltage line 354, 250 and the ground line 356, 252 of the first and second input path 116, 118, respectively. The first and second capacitances 685, 686 serve to realize a constant and continuous current drain from the first and second input paths 116, 118, respectively. A third capacitor 687 is arranged in the output path 122 at the output port "OUT" of the SMPC 682 in that the third capacitor 687 is connected to the voltage line 362 and the ground line 364 of the output path 122. The third capacitor 687 filters spurious signals potentially generated by a switching operation of the SMPC 682. A switching timing inside the SMPC 682 with respect to the two input ports may be configured according to any timing scheme. In an operation mode the switching of the SMPC 682 is executed in an alternating way inside the SMPC 682 with respect to the two input ports.

Referring to Fig. 7 a high-current-capable device 702 according to another exemplary embodiment of the invention is shown. The high-current-capable device 702 is configured as a USB-LTE -modem being connectable to a laptop or personal computer in which the power supply circuit 104 is accommodated. The high-current-capable device 702 comprises a housing 788 in which a substrate is accommodated. Portions of the first and second input paths 116, 118, the current negotiating unit 142, the current combining unit 120, a USB controlling circuit 790 comprising an another current negotiating unit 143, and a device function circuit 792 are arranged on the substrate forming an integrated circuit. Further, the modem 786 comprises first and second cable portions 793a, 793b in which a remaining portion of the first and second input path 116, 118 and the first and second plug elements 130, 132 are accommodated. The current negotiating unit 142 and the another current negotiating unit 144 are configured as enumerating units.

Alternatively, the current combining unit 120 may be configured as one of the current combining units 320, 420, 520, 620 illustrated in Fig. 3 to 6. The first input path 116 comprises a voltage line, a ground line, and signal lines between the first plug element 130 and the current combining unit 120, as illustrated, for example, in Fig. 3. The second input path 118 comprises a voltage line and a ground line between the second plug element 132 and the current combining unit 120, and signal lines between the second plug element 132 and the enumerating unit 142. A line connection of the enumerating unit 142 in Fig. 7 is identical to a line connection of the enumerating unit 142 in Fig. 2. The output path 122 comprises a voltage line, a ground line, and signal lines between the current combining unit 120 and the USB controlling circuit 790. The device function circuit 792 is connected to the output path 122 via a voltage line and a ground line, and is connected to the USB controlling circuit 790 via signal lines, mainly used for data exchange of the information originated from or dedicated for the personal computer or the laptop.

An operation of the modem 786 is similar to an operation of the adapting device 100 of Fig. 1, however, the maximum amount of the first and second currents to be provided by the first and second current supplies 106, 108 is negotiated between the power supply circuit 104 and the enumerating unit 144 of the USB controlling circuit 790 and the enumerating unit 142 arranged in the second input path 118. Further, the device functional circuit 792 is communicatively coupled to the USB controlling circuit 790 and is electrically fed by the combined current supplied along the output path 122 and a respective connection line between the output path 122 and the device functional circuit 792.

Referring to Fig. 8, an exemplary method of operating a power circuit will be explained. The method comprises a step 894 of connecting a first input path of the power circuit to a first current supply of a plurality of current supplies of a power supply circuit, (and negotiating a maximum amount of first current between the power supply circuit and the high-current- capable device), a step 895 of connecting a second input path of the power circuit to a second current supply of a plurality of current supplies of the power supply circuit. The method comprises a step 896 of negotiating a maximum amount of a second current to be provided by the second current supply with the power supply circuit, a step 897 of generating a combined current by combining a first current to be provided by the first current supply and the second current to be provided by the second current supply, and a step 898 of supplying the combined current via an output path to a high-current-capable device. The method may also comprise a step of negotiating a maximum amount of the first current to be provided by the first current supply with the power supply circuit.

The steps of connecting the first and second input paths may be executed simultaneously to one another or may be executed subsequently to one another with a sequence of the steps being interchangeable. The steps of negotiating a maximum amount of the first and second currents may be executed simultaneously to one another or may be executed subsequently to one another with a sequence of the steps being interchangeable. The step of the connecting the first input path and the second input path may be executed prior the step of negotiating the maximum amount of the first current and the second current, respectively.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the use of indefinite articles "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A power circuit (114) for connecting a high-current-capable device (102, 702) to a power supply circuit (104) comprising a plurality of current supplies (106, 108), the power circuit (114) comprising:

a first input path (116) configured for being connectable to a first current supply (104) of the plurality of current supplies (106, 108),

a second input path (118) configured for being connectable to a second current supply (108) of the plurality of current supplies (106, 108),

- a current combining unit (120, 320, 420, 520, 620) configured for generating a

combined current by combining a first current to be provided by the first current supply (106) and a second current to be provided by the second current supply (108),

an output path (122) configured for supplying the combined current to the high- current-capable device (102, 702), and

a current negotiating unit (142) configured for negotiating a maximum amount of the second current with the power supply circuit (104).

2. The power circuit (114) according to claim 1, wherein the current negotiating unit (142) comprises an enumerating unit (142) configured for communicating with the power supply circuit (104) for an enumeration of the second input path (118).

3. The power circuit (114) according to claim 1 or 2, wherein the current combining unit (120, 320, 420, 520, 620) comprises a connection node (370) at which first ending portions (124, 126) of the first and second input paths (116, 118) are connected to one another, and wherein a first ending portion (128) of the output path (122) is connected to the connection node (370).

4. The power circuit (114) according to claim 3, wherein the current combining unit (420) comprises a first diode (472) arranged in the first input path (116) and a second diode (474) arranged in the second input path (118), wherein each of the first and second diodes (472, 474) is operable in flow direction of the first and second currents.

5. The power circuit (114) according to claim 3, wherein the current combining unit (520) comprises a first transistor (576) arranged in the first input path (116), a second transistor (578) arranged in the second input path (118), and a dual power path controller (580) configured for controlling the first and second transistors (576, 578).

6. The power circuit (114) according to claim 3, wherein the current combining unit (620) comprises a switch mode power converter (682) connected to first ending portions (124, 126) of the first and second input paths (116, 118) and to a first ending portion (128) of the output path (122) and being configured for converting the first and second currents into the combined current.

7. The power circuit (114) according to anyone of claims 1 to 6, the power circuit (114) further comprising:

a first plug element (130) configured for being pluggable into the power supply circuit (104), and

a second plug element (132) configured for being pluggable into the power supply circuit (104),

wherein a second ending portion (136) of the first input path (116) is connected to the first plug element (130) and wherein a second ending portion (138) of the second input path (118) is connected to the second plug element (132).

8. The power circuit (114) according to anyone of claims 1 to 7, wherein the current negotiating unit (142) is accommodated in the second plug element (132).

9. The power circuit (114) according to anyone of claims 1 to 8, the power circuit (114) further comprising:

a socket element (134) configured for being connectable to the high-current-capable device (102),

wherein a second ending portion (140) of the output path (122) is connected to the socket element (134).

10. The power circuit (114) according to anyone of claims 1 to 9, wherein a second ending portion (140) of the output path (122) is connected to another current negotiating unit (144) configured for negotiating the maximum amount of the first current with the power supply circuit (104) via the first input path (116).

11. The power circuit (114) according to claim 1 to 10, wherein the power circuit (114) is configured according to a Universal Serial Bus specification.

12. An adapting device (100) for detachably connecting a high-current-capable-device (102) to a power supply circuit (104), the adapting device (100) comprising a power circuit (114) according to anyone of claims 1 to 11.

13. The adapting device (100) according to claim 12, wherein the adapting device (146) is configured as a Y-like shaped cable, wherein a first input path (116) of the power circuit

(114) is accommodated in a first portion (146a) of the Y-like shaped cable, wherein a second input path (118) of the power circuit (114) is accommodated in a second portion (146b) of the Y-like shaped cable, and wherein an output path (122) of the power circuit (114) is accommodated in a third portion (146c) of the Y-like shaped cable.

14. A high-current-capable device (702) for being connectable to a power supply circuit (104), the high-current-capable device (702) comprising a power circuit (114) according to anyone of claims 1 to 11, wherein the high-current-capable device (702) is preferably configured as a modem (786), a hard disk circuit, a hub, a battery charger or a loudspeaker.

15. A method of operating a power circuit (114), the method comprising:

connecting (894) a first input path (116) of the power circuit (114) to a first current supply (106) of a plurality of current supplies (106, 108) of a power supply circuit (104), connecting (895) a second input path (118) of the power circuit (114) to a second current supply (108) of a plurality of current supplies (106, 108) of the power supply circuit (104),

negotiating (896) a maximum amount of a second current to be provided by the second current supply (108) with the power supply circuit (104),

generating (897) a combined current by combining a first current to be provided by the first current supply (106) and the second current to be provided by the second current supply (108), and

supplying (898) the combined current via an output path (118) to a high-current- capable device (102, 702).