U.S. patent application number 16/159291 was filed with the patent office on 2019-04-11 for system, method and apparatus for one-pair power over ethernet in an automotive application.
This patent application is currently assigned to AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED. The applicant listed for this patent is AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED. Invention is credited to Wael William DIAB, Sesha Thalpasai PANGULURI, Minh TRAN, James YU.
Application Number | 20190106066 16/159291 |
Document ID | / |
Family ID | 52667344 |
Filed Date | 2019-04-11 |
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United States Patent
Application |
20190106066 |
Kind Code |
A1 |
PANGULURI; Sesha Thalpasai ;
et al. |
April 11, 2019 |
SYSTEM, METHOD AND APPARATUS FOR ONE-PAIR POWER OVER ETHERNET IN AN
AUTOMOTIVE APPLICATION
Abstract
System, method and apparatus for one-pair power over Ethernet in
an automotive application. In one embodiment, a power sourcing
equipment transmits a forward path current to a powered device via
a single conductor pair and receives a return path current from the
powered device via a chassis of an automotive vehicle.
Inventors: |
PANGULURI; Sesha Thalpasai;
(San Jose, CA) ; TRAN; Minh; (San Jose, CA)
; YU; James; (Colorado Springs, CO) ; DIAB; Wael
William; (San Francisco, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE. LIMITED |
Singapore |
|
SG |
|
|
Assignee: |
AVAGO TECHNOLOGIES INTERNATIONAL
SALES PTE. LIMITED
Singapore
SG
|
Family ID: |
52667344 |
Appl. No.: |
16/159291 |
Filed: |
October 12, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14479938 |
Sep 8, 2014 |
10112558 |
|
|
16159291 |
|
|
|
|
61876294 |
Sep 11, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60R 16/03 20130101 |
International
Class: |
B60R 16/03 20060101
B60R016/03 |
Claims
1. A system, comprising: a first device configured to deliver power
to a load; and a second device configured to transmit a forward
path current to the first device via a single conductor pair, a
first portion of the forward path current carried over a first
conductor of the single conductor pair, a second portion of the
forward path current carried over a second conductor of the single
conductor pair, and a return path current carried by a body of a
vehicle, wherein the second device is coupled to a battery of the
vehicle, the battery coupled to the body of the vehicle, and the
body of the vehicle coupled to the first device, and wherein a
difference between a resistance of the body of the vehicle and a
resistance of the single conductor pair provides a predetermined
power loss attributable to a predetermined length of the single
conductor pair.
2. The system of claim 1, wherein the first device is a powered
device, and wherein the second device is a power sourcing
equipment.
3. The system of claim 1, wherein the battery is a 12V battery.
4. The system of claim 1, wherein the second device is coupled to a
positive terminal of the battery.
5. The system of claim 1, wherein the second device is coupled to
the single conductor pair via a transformer.
6. The system of claim 1, wherein the second device is coupled to
the single conductor pair via an inductor.
7. The system of claim 1, wherein the single conductor pair is a
single twisted wire pair.
8. An apparatus, comprising: a first port configured for coupling
to a battery of a vehicle, wherein the battery is coupled to a body
of the vehicle, and the body of the vehicle is coupled to a powered
device; a second port configured for coupling to a single conductor
pair; and control logic configured to control a delivery of power
to the powered device via the single conductor pair, a first
portion of a forward path current carried over a first conductor of
the single conductor pair, a second portion of the forward path
current carried over a second conductor of the single conductor
pair, and a return path current carried by the body of the vehicle,
wherein a difference between a resistance of the body and a
resistance of the single conductor pair provides a predetermined
power loss attributable to a predetermined length of the single
conductor pair.
9. The apparatus of claim 8, wherein the battery is a 12V
battery.
11. The apparatus of claim 8, wherein the first port is coupled to
a positive terminal of the battery.
12. The apparatus of claim 8, wherein the second port is coupled to
the single conductor pair via a transformer.
13. The apparatus of claim 8, wherein the second port is coupled to
the single conductor pair via an inductor.
14. The apparatus of claim 8, wherein the single conductor pair is
a single twisted wire pair.
15. An apparatus, comprising: a power transistor configured to
deliver power to a load, via a single conductor pair, a first
portion of a forward path current from a power sourcing equipment
carried over a first conductor of the single conductor pair, a
second portion of the forward path current from the power sourcing
equipment carried over a second conductor of the single conductor
pair, and a return path current carried by a body of a vehicle,
wherein the power sourcing equipment is coupled to a battery of the
vehicle, the battery coupled to the body of the vehicle, and the
body of the vehicle coupled to the apparatus, and wherein a
difference between a resistance of the body and a resistance of the
single conductor pair provides a predetermined power loss
attributable to a predetermined length of the single conductor
pair.
16. The apparatus of claim 15, further comprises a controller
configured to control the power transistor.
17. The apparatus of claim 15, wherein the battery is a 12V
battery.
18. The apparatus of claim 15, wherein the apparatus is coupled to
the single conductor pair via a transformer.
19. The apparatus of claim 15, wherein the apparatus is coupled to
the single conductor pair via an inductor.
20. The apparatus of claim 15, wherein the single conductor pair is
a single twisted wire pair.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of and claims priority to
and the benefit of U.S. patent application Ser. No. 14/479,938,
filed Se. 8, 2014, which claims the benefit of and priority to U.S.
Provisional Application No. 61/876,294, filed Sep. 11, 2013, the
contents of which are hereby incorporated herein by reference in
their entirety for all purposes.
BACKGROUND
Field
[0002] The present disclosure relates generally to network powering
systems, methods and apparatus and, more particularly, to a system,
method and apparatus for one-pair power over Ethernet in an
automotive application.
Introduction
[0003] Power over Ethernet (PoE) provides a framework for delivery
of power from power sourcing equipment (PSE) to a powered device
(PD) over Ethernet cabling. Various types of PDs exist, including
voice over IP (VoIP) phones, wireless LAN access points, Bluetooth
access points, network cameras, computing devices, etc.
[0004] Conventionally, the power over Ethernet specifications are
designed to work on two-pair cabling using a pair of transformers.
Power over Ethernet is capable of running over a worst case
distance of 100 meters on two wire pairs of Category 3 Ethernet
cabling and higher power devices are capable of running on a worst
case distance of 100 meters on two pairs of Category 5 Ethernet
cabling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] In order to describe the manner in which the above-recited
and other advantages and features can be obtained, a more
particular description will be rendered by reference to specific
embodiments thereof which are illustrated in the appended drawings.
Understanding that these drawings depict only typical embodiments
and are not therefore to be considered limiting of its scope, the
disclosure describes and explains with additional specificity and
detail through the use of the accompanying drawings in which:
[0006] FIG. 1 illustrates an embodiment of a two-pair power over
Ethernet system.
[0007] FIG. 2 illustrates an example of a power over Ethernet
system that delivers power over one wire pair.
[0008] FIG. 3 illustrates an example embodiment of a power over
Ethernet system that delivers power over one wire pair in an
automotive application.
[0009] FIG. 4 illustrates another example embodiment of a power
over Ethernet system that delivers power over one wire pair in an
automotive application.
[0010] FIG. 5 illustrates a flowchart of an example process.
DETAILED DESCRIPTION
[0011] Various embodiments are discussed in detail below. While
specific implementations are discussed, it should be understood
that this is done for illustration purposes only. A person skilled
in the relevant art will recognize that other components and
configurations may be used without parting from the spirit and
scope of the present disclosure.
[0012] An approach for powering in a one-pair conductor Ethernet
transmission system is provided. In one application, the one-pair
conductor Ethernet transmission system can be applied to an
automotive vehicle environment. In one embodiment, a one-pair
powering approach includes transmitting, by a power sourcing
equipment, a forward path current to a powered device via a single
conductor pair, a first portion of the forward path current carried
over a first conductor of the single conductor pair, a second
portion of the forward path current carried over a second conductor
of the single conductor pair, and a return path current from the
powered device to the power sourcing equipment carried by a chassis
of an automotive vehicle.
[0013] In one embodiment, the power sourcing equipment is coupled
to a positive terminal of a battery (e.g., 12V) of the automotive
vehicle, wherein the battery is connected to the chassis of the
automotive vehicle. In one embodiment, the power sourcing equipment
is connected to the single conductor pair via a transformer. In
another embodiment, the power sourcing equipment is connected to
the single conductor pair via an inductor. In one embodiment, the
single conductor pair is a single twisted wire pair.
[0014] PoE can be used to deliver power over one or more wire pairs
that are used for data transmission. PoE can be applied to various
contexts and can be used alongside various data transmission
systems. Ethernet has an extensive, well-developed ecosystem that
has spanned various media specifications, including backplane,
twinax, twisted-pair, coaxial, optical fiber, etc. In that regard,
Ethernet has a vast amount and variety of proven physical layer
device (PHY) products, media access control (MAC) products, switch
products, etc.
[0015] FIG. 1 illustrates an example of a two-pair PoE system. As
illustrated, the two-pair PoE system includes PSE 120 that
transmits power to PD 140 over two conductor pairs such as two
twisted wire pairs. In the example illustration, the two twisted
wire pairs are referenced as transmit (TX) and receive (RX) wire
pairs.
[0016] Power delivered by PSE 120 to PD 140 is provided through the
application of a voltage across the center taps of a first data
transformer 112 that is coupled to the TX wire pair and a second
data transformer 114 that is coupled to the RX wire pair carried
within a twisted pair Ethernet cable. PD 140 receives the power
transmitted by PSE 120 at the center taps of a third data
transformer 132 that is coupled to the TX wire pair and a fourth
data transformer 134 that is coupled to the RX wire pair.
[0017] As is further illustrated in FIG. 1, PD 140 includes PoE
module 142. PoE module 142 includes the electronics that would
enable PD 140 to communicate with PSE 120 in accordance with a PoE
specification such as IEEE 802.3af, 802.3at, legacy PoE
transmission, or any other type of PoE transmission. PD 140 also
includes controller 144 (e.g., pulse width modulation DC:DC
controller) that controls power transistor 146 (e.g., FET or
bipolar), which in turn provides constant power to load 150.
[0018] In the illustration of FIG. 1, power is delivered by PSE 120
to PD 140 via two conductor pairs through connection of PSE 120 to
the center taps of data transformers 112 and 114 and connection of
PD 140 to the center taps of data transformers 132 and 134.
[0019] FIG. 2 illustrates an example of an application of PoE to a
one-pair Ethernet system. An example of such a one-pair Ethernet
system is Broadcom's BroadR-Reach.RTM. technology that supports
both 100-meter traditional Ethernet services and other applications
that require longer than 100-meter reach or operation over a single
conductor pair. In various examples, the extended reach broadens
the range of cable installations and can be used for new IP
services and applications such as broadband access, voice over IP,
wireless access points, and surveillance cameras.
[0020] As illustrated in FIG. 2, power is injected onto the single
conductor pair by PSE 210 after blocking capacitors C1, C2.
Similarly, power is extracted from the single conductor pair by PD
220 before blocking capacitors C3, C4. In this framework, the
current "I" is carried along a first conductor of the single
conductor pair in the forward path from PSE 210 to PD 220 and is
carried along a second conductor of the single conductor pair in
the return path from PD 220 to PSE 210.
[0021] As further illustrated in FIG. 2, capacitors C1, C2 on the
PSE side and capacitors C3, C4 on the PD side are designed to block
or otherwise prevent DC current injected by PSE 210 from flowing
into data transformers of the PHYs. Significantly, capacitors C1,
C2 on the PSE side and capacitors C3, C4 on the PD side do not
impact the data transmission between the PHYs as AC current passes
through capacitors C1, C2, C3, C4.
[0022] One example area of application for PoE is automotive
networks. As evidenced by the increasing demand for in-vehicle
infotainment (e.g., video, navigation, etc,), control systems
(e.g., back-up cameras), etc., the networking challenges of
automotive networks continue to increase. Complex automotive
network management and domain control is needed in supporting
various network topologies within an automotive vehicle.
[0023] In the present disclosure, it is recognized that the
application of PoE to automotive networks can produce significant
benefits in further reducing the wiring needed within an automotive
vehicle. As would be appreciated, the sheer weight of a wiring
harness to support all of the network requirements within the
automotive vehicle can be substantial. Consider, for example, the
powering of a back-up camera that is located at the rear-end of an
automotive vehicle. Through PoE technology, the elimination of
separate wiring for powering of the back-up camera can greatly
simplify the implementation of such an application within the
automotive vehicle. The removal of excess cabling also reduced the
overall weight of the wiring harness.
[0024] In the present disclosure, it is recognized that the
application of PoE to an automotive network environment presents
unique implementation challenges. One of the issues is a reduced
voltage source. For example, a PSE in an automotive network can be
designed to source power from a 12V battery. This is in contrast to
48V power sources used in an enterprise environment. A consequence
of using a lower voltage source is the higher current levels that
are required to support a particular power level (e.g., 7W) at the
PD. The higher current levels can create higher power losses in the
cabling itself, as well as a higher voltage drop across the
cable.
[0025] For example, consider a 40 meter cable in an automotive
network that has a resistance of 10 .OMEGA.. For a current of 600
mA, the power loss attributable to each conductor would be
PL=I.sup.2*R=(600 mA).sup.2*10 .OMEGA.=3.6W. For the same current
of 600 mA, the voltage drop across the cable would be V=I*R=600 mA*
10 .OMEGA.=0.6V. As would be appreciated, The power loss
attributable to the cable as well as the magnitude of the voltage
drop would only increase as the current levels increase.
[0026] In the present disclosure, it is recognized that a reduction
in the adverse impact of the cable in an application of PoE to a
one-pair Ethernet system in an automotive network is desired. FIG.
3 illustrates an example embodiment of a power over Ethernet system
that delivers power over one wire pair in an automotive
application. As illustrated, both conductors of the single
conductor pair are used to carry current in the forward path from
PSE 310 to PD 320. As illustrated, the current I is split between
the first and second conductors of the single conductor pair.
Assuming that the two separate conductors in the single conductor
pair are balanced, the current I is split roughly equally such that
the current I/2 is carried over each of the two separate
conductors.
[0027] On the return path from PD 320 to PSE 310, the current I is
carried over a chassis of the automotive vehicle that connects the
power source (e.g., 12V battery) to PD 320. In the present
disclosure, it is recognized that the resistance of the chassis of
the automotive vehicle is very small and could be neglected since
the space of the chassis of the automotive vehicle is very
large.
[0028] As illustrated, PSE 310 is connected to the positive
terminal of the battery. It is recognized that the control by PSE
310 of the current loop on the high side of the battery would
enable PSE 310 to provide proper protection should the cable or
load short to the chassis of the automotive vehicle. Here, it
should be recognized that other implementation-dependent protection
mechanism can be implemented such that the PSE control can be
placed on the low side of the battery.
[0029] As noted, the resistance of the chassis of the automotive
vehicle in the return path from PD 320 to PSE 310 is negligible in
comparison to the resistance of the single conductor pair used in
the forward path from PSE 310 to PD 320. In the same example of a
40 meter cable having 10 .OMEGA. of resistance, the power loss
attributable to each conductor would be PL=(I/2).sup.2*R=(600
mA/2).sup.2*10 .OMEGA.=0.9 W. Notably, the power loss attributable
to the cable would represent 1/4 of the power loss. The voltage
drop across the cable would be V=I/2*R, or 1/2 of the voltage drop
in comparison.
[0030] As further illustrated in FIG. 3, PSE 310 and PD 320 are
connected to center taps of transformers T1 and T2, respectively.
This enables DC blocking for the PHYs, while enabling a passage of
AC signals between the PHYs. In another embodiment illustrated in
FIG. 4, the PSE and PD are connected to inductors L1, L2,
respectively, while blocking capacitors C1, C2, C3, C4 are
used.
[0031] Having described a framework for implementing one-pair PoE
in an automotive application, reference is now made to FIG. 5,
which illustrates a flowchart of an example process. As
illustrated, the process begins at step 502 where a first port of a
PSE is coupled to a forward path to the PD using a single conductor
pair. As noted, the particular mechanism for coupling of the first
port of the PSE to the single conductor pair can vary. In one
example, the PSE can be coupled to the high side of the battery of
an automotive vehicle such that the PSE is directly coupled to the
single conductor pair (e.g., using a transformer, inductor, or
other coupling mechanism). In another example, the PSE can be
coupled to the low side of the battery of an automotive vehicle,
wherein the high side of the battery is directly coupled to the
single conductor pair (e.g., using a transformer, inductor, or
other coupling mechanism). In general, the particular mechanism of
coupling of the PSE to the forward path can vary.
[0032] Next, at step 504, a second port of the PSE is coupled to a
return path from the PD using a chassis of the automotive vehicle.
Again, the particular mechanism for coupling of the second port of
the PSE to the chassis of the automotive vehicle can vary. In one
example, the PSE can be coupled to the low side of the battery of
an automotive vehicle such that the PSE is directly coupled to the
chassis of the automotive vehicle. In another example, the PSE can
be coupled to the high side of the battery of an automotive
vehicle, wherein the low side of the battery is directly coupled to
the chassis of the automotive vehicle. In general, the particular
mechanism of coupling of the PSE to the return path can vary.
[0033] After the coupling of the PSE at steps 502 and 504 to the
forward and return paths, respectively, the PSE can then transmit
power to the PD at step 506 using the established forward and
return paths. In this power-delivery process, a first portion of
the forward path current is carried over a first conductor of the
single conductor pair, a second portion of the forward path current
is carried over a second conductor of the single conductor pair,
and a return path current from the PD to the PSE is carried by a
chassis of the automotive vehicle.
[0034] Those of skill in the relevant art would appreciate that the
various illustrative blocks, modules, elements, components, and
methods described herein may be implemented as electronic hardware,
computer software, or combinations of both. To illustrate this
interchangeability of hardware and software, various illustrative
blocks, modules, elements, components, methods, and algorithms have
been described above generally in terms of their functionality.
Whether such functionality is implemented as hardware or software
depends upon the particular application and design constraints
imposed on the overall system. Those of skill in the relevant art
can implement the described functionality in varying ways for each
particular application. Various components and blocks may be
arranged differently (e.g., arranged in a different order, or
partitioned in a different way) all without departing from the
scope of the subject technology.
[0035] These and other aspects of the present disclosure will
become apparent to those skilled in the relevant art by a review of
the preceding detailed disclosure. Although a number of salient
features of the present disclosure have been described above, the
principles in the present disclosure are capable of other
embodiments and of being practiced and carried out in various ways
that would be apparent to one of skill in the relevant art after
reading the present disclosure, therefore the above disclosure
should not be considered to be exclusive of these other
embodiments. Also, it is to be understood that the phraseology and
terminology employed herein are for the purposes of description and
should not be regarded as limiting.
* * * * *