Abstract:
The present invention provides an Ethernet module for a finished Ethernet device, said finished Ethernet device comprising: a host circuit board, and a connector jack mounted upon said host circuit board; wherein said Ethernet module comprises a circuit board vertically mountable upon the host circuit board, and wherein said Ethernet module is dimensioned to correspond to a rear face of said connector jack. By the innovative construction of space-saving Ethernet module, the present invention reduces the footprint of the Ethernet module on the host circuit board and increases the efficiency of utilization of the finished Ethernet device&#39;s internal volume.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates generally to Ethernet modules, including serial-to-Ethernet converter modules and programmable Ethernet modules. More particularly, this invention relates to an innovative construction of a space-saving Ethernet module occupying reduced area on a host circuit board of a finished Ethernet device and dimensioned to correspond to a rear face of a regular RJ connector jack. 
         [0003]    2. Description of the Prior Art 
         [0004]    Ethernet modules are well known in the industry. Such modules are used both in the design of new products, as well as for retrofitting existing products with the Ethernet interface. 
         [0005]    Ethernet modules are often said to “network-enable” their host products, meaning that the Ethernet module built into the host product gives the latter a network interface (in the form of the Ethernet interface). For the purpose of clarity, a host product incorporating an Ethernet module will hereinafter be referred to as a finished Ethernet device. 
         [0006]    Within the category of Ethernet modules, serial-to-Ethernet converter modules are extremely popular. The reason for this is that most products requiring network enablement have a CPU or microcontroller, and the majority of CPUs and microcontrollers are equipped with universal asynchronous receiver/transmitter (UART) circuits used for serial communications. 
         [0007]    A serial-to-Ethernet converter module allows to quickly and inexpensively network-enable such a CPU or microcontroller-equipped product by seamlessly converting between serial and Ethernet (TCP/IP) data. 
         [0008]    Another type of Ethernet modules will be referred to as programmable Ethernet modules. Such modules allow a developer to load a custom software program (application) into the module. The module can then serve as an intelligent processing block of the finished Ethernet device, thus offloading the main CPU or microcontroller of said device, or even completely eliminating the latter. 
         [0009]    For the purposes and goals of the present invention, the term “Ethernet module” will equally apply to all categories of such modules including serial-to-Ethernet converter modules and programmable Ethernet modules. 
         [0010]    A simplified block diagram of a typical Ethernet module and a finished Ethernet device incorporating such module are shown on  FIG. 1 . 
         [0011]    The Ethernet module  10  is typically installed on a host circuit board (not shown) of the finished Ethernet device  11 . Said Ethernet module  10  incorporates a CPU or microcontroller  12 , data bus  13 , an Ethernet controller  14 , and other hardware  15 . Said other hardware  15  may include RAM, flash memory, and other peripherals required for the operation of the Ethernet module  10 . The precise set of such peripherals is immaterial to the scope and spirit of the present invention. 
         [0012]    It is noteworthy, that some CPUs and microcontrollers on the market today incorporate Ethernet controllers, so blocks  12  and  14  may be realized as a single integrated circuit, with the data bus  13  existing within said integrated circuit. 
         [0013]    The Ethernet module  10  has a number of pins (leads)  16  through which it is coupled to other components on the host circuit board and/or finished Ethernet device  11 . Specifically, the Ethernet module  10  is coupled to an RJ connector jack  17 , Ethernet status LEDs  20 , module status LEDs  26 , as well as external (with respect to the Ethernet module  10 ) hardware  22 . 
         [0014]    The Ethernet controller  14  and the RJ connector jack  17  are linked by receive (Rx) and transmit (Tx) line pairs  18 . In addition, there are Ethernet status LED control lines  19  that drive Ethernet status LEDs  20  of the RJ connector jack  17 . 
         [0015]    The Ethernet status LEDs  20  are typically used to indicate the current link status and link mode of the Ethernet controller  14 . Of the two said LEDs, one is typically of green color, and another one is typically of yellow color. 
         [0016]    Although only two single-color Ethernet status LEDs  20  are shown, it is understood that there could be more LEDs and (or) multi-color LEDs built into the RJ connector jack  17 . Alternatively, the Ethernet status LEDs  20  may be implemented separately from said RJ connector jack  17 , or not implemented at all. All such variations are immaterial to the scope and spirit of the present invention. 
         [0017]    The Ethernet module  10  and the external hardware  22  are linked by input/output (I/O) lines  21 . In some cases, said external hardware  22  includes only simple non-intelligent components such as relays, opto-isolated inputs, analog-to-digital converters (ADC) or digital-to-analog converters (DAC). These non-intelligent components are then controlled by the CPU or microcontroller  12 . 
         [0018]    In other cases, the external hardware  22  may comprise a second CPU or microcontroller  23 , which is often the main (“master”) CPU or microcontroller of the finished Ethernet device  11 . 
         [0019]    The I/O lines  21  can be implemented in a multitude of ways and employ interfacing techniques suitable for a particular set of external hardware  22 . Said I/O lines  21  may comprise simple digital input/output lines, ADC and DAC lines, pulse-width modulated (PWM) signal lines, and so on. 
         [0020]    If the external hardware  22  comprised the second CPU or microcontroller  23 , I/O lines  21  often comprise serial port lines. In this case, the CPU or microcontroller  12  and the second CPU or microcontroller  23  use serial communications to interact with each other. 
         [0021]    It must be noted that in the majority of designs such serial communications conform to the timing of RS232 interface, but physical lines are of a CMOS or TTL type. Most modern CPUs and microcontrollers include one or more UART blocks  24 , so it is possible to interconnect the UARTs  24  of the CPU or microcontroller  12  and the second CPU or microcontroller  23  directly, without any additional “glue” components. 
         [0022]    Other serial port arrangements are possible. For example, the CPU or microcontroller  12  may not include or use the UART  24 . Instead, the other hardware  15  may include such an UART. The same applies to the second CPU or microcontroller  22 . All such variations are immaterial to the spirit and scope of the present invention. 
         [0023]    The Ethernet module  10  often includes a number of module status LED control lines  25  for driving a set of module status LEDs  26  used for indicating the current status of the Ethernet module. 
         [0024]    The function of module status LEDs  26  is not to be confused with the function of Ethernet status LEDs  20 . Ethernet status LEDs  20  display the current link status and link mode of the Ethernet controller  14 . Module status LEDs  26  provide indication of the overall state of the Ethernet module  10 . 
         [0025]    For example, module status LEDs  26  may indicate that the Ethernet module  10  is idle, or running in the setup mode, or has established a TCP/IP link with another device on the network, and so on. 
         [0026]    Physically, a typical Ethernet module may be implemented, for example, as a circuit board incorporating pins or leads for mounting on the host circuit board of the finished Ethernet device. A simplified drawing of such module is shown on  FIG. 2 . 
         [0027]    The Ethernet module  10  characteristically comprises a circuit board  100 , which is generally parallel to the host circuit board (not shown) upon which said circuit board  100  is installed. The circuit board  100  has two opposing sides  101  and  102  and both sides may be used for mounting electronic components. 
         [0028]      FIG. 2 . shows two such components: the CPU or microcontroller  12 , and the Ethernet controller  14 . The circuit board  100  typically includes other hardware as well (not shown). Two rows of pins (leads)  16  connect the Ethernet module  10  to the host circuit board. Pins (leads) of thru-hole type are shown, but SMT and pins (leads) of other shapes may be used. 
         [0029]    The Ethernet module  10  may include a housing or enclosure (not shown) that at least partially covers the circuit board  100  for decorative, protective, or heat dissipation purposes. 
         [0030]    For the purposes and goals of the present invention, the term “Ethernet module” will equally apply to Ethernet modules without the enclosure and Ethernet modules with enclosures. 
         [0031]    There are numerous other variants of physical implementation of the Ethernet module. For example, U.S. Pat. No. 6,881,096, discloses an Ethernet module incorporated directly into an RJ connector jack. 
         [0032]    Construction of a typical RJ connector jack  17  is of special importance to the present invention. 
         [0033]    RJ connectors are commonly used in telecommunications, data networking equipment, and devices having an ability to connect to data networks. RJ connectors employ a male connector plug and a female connector jack. 
         [0034]    For finished Ethernet devices, the female connector jack is typically mounted on the network-enabled device and is exposed in such a way as to allow the insertion of the male connector plug. A simplified drawing of a typical connector jack is shown on  FIG. 3 . 
         [0035]    RJ connector jack  17  characteristically comprises a generally rectangular dielectric housing  200 , said housing  200  having a front face  201  with a receptacle  202  for receiving the male connector plug (not shown), and a bottom face  203  adopted for mounting on the host circuit board (not shown). The housing  200  also defines a right face  204 , left face  205 , rear face  206 , and a top face  207 . 
         [0036]    The front face  201  often includes or exposes a pair of Ethernet status LEDs  20 . 
         [0037]    The receptacle  202  includes latching shoulders  208  which, in conjunction with the latching shoulder on the plug (not shown), form a mechanism for reliable engagement between the plug and the jack. 
         [0038]    The RJ connector jack  17  also incorporates pins or leads  209 . These pins or leads conduct electrical signals between the jack and the host circuit board. 
         [0039]    Many RJ connector jacks also have a Faraday shield  210  that envelops the housing  200 . Said shield  210  often has spring biased grounding tabs  211  located on the left right face  204 , right left face  205 , and top face  207 . Said grounding tabs  211  connect the Faraday shield to chassis (Earth) ground by contacting the enclosure of the finished Ethernet device. Grounding tabs protrude from the right, left, and top faces of the jack and slightly increase effective jack dimensions. 
         [0040]    One inescapable fact of the RJ connector jack&#39;s construction is that its height  211  and width  212  can&#39;t be reduced substantially, even as rapid technical progress has led to a dramatic miniaturization of other electronic components. This is because the male connector plug has standard dimensions that dictate the minimum possible dimensions of the jack. 
         [0041]    Several attempts has been made to somewhat decrease the overall dimensions of the RJ connector jack. Most of these attempts have concentrated on decreasing the height  211  of the jack. For example, U.S. Pat. No. 4,497,526 discloses a jack of reduced height, and the height reduction is achieved by moving the latching mechanism off the jack and onto the bottom side of the housing of the finished Ethernet device. 
         [0042]    U.S. Pat. No. 5,378,172 discloses a low-profile jack, in which the reduction in the jack height is achieved by delegating the latching function of the jack to the host circuit board. 
         [0043]    It must be noted that the above improvements have only had a marginal effect on the industry and the majority of RJ connector jacks are still built in the image of the jack shown on  FIG. 3 . The market has even produced a de-facto “standard” for the RJ connector jack&#39;s dimensions. Accounting for tolerances and excluding grounding tabs  210 , this de-facto standard sets the height  211  at approximately 14 mm, and the width  212  at 16 mm. Including the grounding tabs  210 , the “standard” height  211  is around 15 mm, and the “standard” width  212  is around 17.5 mm. An overwhelming number of RJ connector jacks manufactured today have the above width and height. 
         [0044]    Since most RJ connector jacks have a “standard” height, this often dictates the height of the finished Ethernet device incorporating RJ connector jacks. Taking into account that most modern electronic components are low-profile, this leaves RJ connector jack “towering high” above the rest of the electronic circuits. A large portion of the finished Ethernet device&#39;s internal volume, typically behind the RJ connector jack, is then left unused. 
         [0045]    Continuous miniaturization of electronic devices demands an ever-increasing density of component placement on printed circuit boards. As network-enabled electronic devices shrink in size, the pressure is placed on the manufacturers of Ethernet modules to reduce the footprint occupied by said modules on host circuit boards. 
         [0046]    This happens at a time when Ethernet modules are starting to hit a “size reduction ceiling”, with some modules being barely large enough to fit a single integrated circuit incorporating the CPU or microcontroller, the Ethernet controller, memory, UART(s) and almost all other components necessary for module&#39;s operation. 
       SUMMARY OF THE INVENTION 
       [0047]    In view of the above, it is an object of the present invention to reduce the footprint of the Ethernet module on the host circuit board. It is another object of the present invention to increase the efficiency of utilization of the finished Ethernet device&#39;s internal volume. 
         [0048]    The present invention provides an Ethernet module for a finished Ethernet device, said finished Ethernet device comprising: a host circuit board, and a connector jack mounted upon said host circuit board; wherein said Ethernet module comprises a circuit board vertically mountable upon the host circuit board, and wherein said Ethernet module is dimensioned to correspond to a rear face of said connector jack. 
         [0049]    In the preferred embodiment of the present invention, the circuit board of the Ethernet module is not oriented in a generally parallel fashion with respect to the host circuit board. In the preferred embodiment of the present invention, said circuit board is oriented in a generally perpendicular fashion with respect to the host circuit board. 
         [0050]    According to the preferred embodiment of the present invention, the Ethernet module uses an integrated circuit that contains the CPU or microcontroller, the Ethernet controller, memory, UART(s), and I/O lines. Said integrated circuit is mounted upon a first side of the Ethernet module&#39;s circuit board. 
         [0051]    It is envisioned that a second side of the Ethernet module&#39;s circuit board is occupied by small(er) components that are typically necessary to complete the circuit of the Ethernet module. 
         [0052]    It is further envisioned that the second side of the Ethernet module&#39;s circuit board contains a connector comprising pins or leads that are generally parallel to the circuit board of the Ethernet module and generally perpendicular to the host circuit board. Said pins or leads are used to install the Ethernet module on the host circuit board and conduct electric signals between the Ethernet module and the host circuit board. 
         [0053]    According to the preferred embodiment of the present invention, the height and width of this innovative Ethernet module can be made to not exceed, or only slightly exceed the “standard” width and height of the RJ connector jack when said height and width account for grounding tabs. 
         [0054]    It is envisioned that the Ethernet module of the present invention will be mounted on the host circuit board directly behind the RJ connector jack. Having the height and width dimension to correspond to the rear face of the RJ connector jack, the innovative Ethernet module will utilize the internal space of the finished Ethernet device in a highly efficient manner. 
         [0055]    Namely, the innovative Ethernet module will occupy a very small space on the host circuit board, and utilize an empty space typically available behind the RJ Ethernet jack. 
         [0056]    In the alternative embodiment of the present invention, the Ethernet module does not use an integrated circuit packaged in a standard housing with leads. In the alternative embodiment of the present invention, the Ethernet module utilizes a chip-on-board technology to mount one or more silicon dies upon the first and the second sides of the Ethernet module&#39;s circuit board. 
         [0057]    Other objects, features and advantages of the present invention will be apparent from the following detailed description taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0058]      FIG. 1  is a simplified block diagram of a typical Ethernet module according to the prior art and a finished Ethernet device based on said Ethernet module. 
           [0059]      FIG. 2  is a simplified drawing of a typical Ethernet module according to the prior art. 
           [0060]      FIG. 3  shows a simplified construction of a typical RJ connector jack according to the prior art. 
           [0061]      FIG. 4  is a drawing of the Ethernet module according to the preferred embodiment of the present invention. 
           [0062]      FIG. 5  is a drawing of a host circuit board, a “standard” RJ connector jack, and the Ethernet module according to the preferred embodiment of the present invention mounted behind said RJ connector jack. 
           [0063]      FIG. 6  is a drawing of the Ethernet module according to the alternative embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0064]    In the following detailed description, reference is made to the accompanying drawings that form a part thereof, and in which are shown by way of illustration, specific embodiments in which the invention may be practiced. 
         [0065]    The embodiments of the present invention are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized. It is also to be understood that changes can be made without departing from the spirit and scope of the present invention. The following detailed description, therefore, is not to be taken in the limiting manner, and the scope of the present invention is defined by the following claims and their equivalents. 
         [0066]    Referring to  FIG. 4-6 , the embodiments of the present invention are shown. 
         [0067]    Referring particularly to  FIG. 4 , there shown a front, side, and back views of the Ethernet module according to the preferred embodiment of the present invention. 
         [0068]    The Ethernet module according to the preferred embodiment of the present invention is realized using an integrated circuit  300 , which incorporates the CPU or microcontroller and the Ethernet controller. The integrated circuit may also incorporate flash memory for storing the program (firmware) of the CPU, SRAM for storing variables and data, general I/O lines, and UART(s). 
         [0069]    An example of the integrated circuit  300  is an LM3S8930 part from Luminary Micro (currently owned by Texas Instruments). This integrated circuit incorporates all blocks listed above. The circuit is available in a 100-pin LQFP package with outline dimensions of 16×16 mm or 108-ball BGA package with outline dimensions of 10×10 mm. 
         [0070]    According to the preferred embodiment of the present invention, the integrated circuit  300  is mounted upon the first side  101  of the circuit board  100  of the Ethernet module  10 . The first side  101  of the circuit board  100  may or may not have other electronic parts mounted atop said first side. 
         [0071]    Looking at  FIG. 5  those skilled in the art will recognize that the height  301  and width  302  of the circuit board  100 , and, hence, the overall height and width of the Ethernet module  10  constructed according the preferred embodiment of the present invention, are dictated largely by the outline dimensions of the integrated circuit  300 . 
         [0072]    For the 100-pin LQFP package with outline dimensions of 16×16 mm, the height  301  and width  302  of the circuit board  100  can be made as small as 17×17 mm. This only marginally exceeds the “standard” height  211  and width  212  of the RJ connector jack (including the spring tabs). Thus, according to the preferred embodiment of the present invention, although the height  301  and width  302  may be larger than the respective height  211  and width  212  of the RJ connector jack, the difference in corresponding dimensions is small and will not substantially increase the height and width of the finished Ethernet device. 
         [0073]    If the 108-ball BGA package is used, the overall dimensions of the circuit board  100  can be further substantially reduced and become smaller than corresponding dimensions of the RJ connector jack. Thus, according to the preferred embodiment of the present invention, the height  301  and width  302  may be smaller than the respective height  211  and width  212  of the RJ connector jack. 
         [0074]    In both cases, the dimensions of the Ethernet module  10  can be achieved by choosing a fitting package for the integrated circuit  300  and dimensioning the circuit board  100  to have a height and width either substantially equal to the respective height and width of the RJ connector jack, or smaller than the respective height and width of the RJ connector jack, or larger than the respective height and width of the RJ connector jack without substantially increasing the height and width of the finished Ethernet device. 
         [0075]    It must be noted that the particular integrated circuit part number and package type are used herein solely for the illustration purposes and shall not be viewed as limiting the present invention in any way. A number of other integrated circuits in existence today can be used and said integrated circuits are available in a multitude of packaging options. 
         [0076]    The majority of other electronic components required to complete the circuit of the Ethernet module  10  are mounted upon the second side  102 . Also mounted upon the second side  102  is the connector  303 . Said connector  303  comprises a plurality of pins or leads  16  that are used to mount the Ethernet module  10  on the host circuit board (not shown) and conduct electric signals between the Ethernet module  10  and the host circuit board. Said pins or leads  16  are positioned in a generally parallel fashion with respect to the circuit board  100 , and in a generally perpendicular fashion to the host circuit board. 
         [0077]    The connector  303  is designed for surface mounting on the second side  102  of the circuit board  100 . The plastic part  304  of the connector  303  is designed in such a way, and the whole connector  303  is positioned on the circuit board  100  in such a fashion as to allow the plastic part  304  reside completely within the boundaries of the circuit board  100 . This minimizes the overall height  301  of the circuit board  100 . 
         [0078]    It must be noted that the Ethernet module according to the preferred embodiment of the present invention may comprise an enclosure (not shown). Such an enclosure can be made of plastic, stamped out of sheet metal, or manufactured in some other suitable way. 
         [0079]    The primary function of the enclosure may be to serve as a Faraday shield, function as a heat sink for the circuit board and components thereof, or simply exist for decorative purposes. Said enclosure may envelope the circuit board  100  completely or only partially cover said circuit board. All such variations are within the scope and the spirit of the present invention. 
         [0080]    Looking now at  FIG. 5 , there shown a host circuit board  400 , a “standard” RJ connector jack  17 , and the Ethernet module  10  according to the preferred embodiment of the present invention, said Ethernet module  10  mounted behind said RJ connector jack  17 . 
         [0081]    Those skilled in the art will immediately appreciate that the Ethernet module  10  built according to the preferred embodiment of the present invention minimizes its footprint on the host circuit board  400 , while taking advantage of the empty space available behind the RJ connector jack  17 . The height  301  and width  302  of the Ethernet module  10  correspond closely to the height  211  and width  212  of the RJ connector jack  17 . 
         [0082]    Looking now at  FIG. 6 , there shown a front, side, and back views of the Ethernet module according to the alternative embodiment of the present invention. 
         [0083]    In the alternative embodiment of the present invention, the Ethernet module  10  does not use an integrated circuit  300 . In the alternative embodiment of the present invention, the Ethernet module  10  utilizes chip-on-board technology to mount one or more encapsulated silicon dies  500  upon the first side  101  and, if necessary, the second side  102  of the circuit board  100 . 
         [0084]    Those skilled in the art will recognize that the use of the chip-on-board technology will allow to further reduce the cost and size of the Ethernet module  10 . 
         [0085]    It should be noted that the number of silicon dies used, their position on the circuit board  100 , number of dies encapsulated together, as well as the shape and material used for the die encapsulation may vary widely and the particular die arrangement presented on  FIG. 6 . should not be viewed as limiting the scope of the present invention in any way. 
         [0086]    While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention needs not be limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.