Abstract:
An integrated power adapter system for a portable computer may include a power adapter for providing power to the portable computer, extractable elements for connection to an external socket, and a dissipation grid for reducing the temperature of the cover screen. The power adapter system may be a slim power adapter system being removable from and integrated with the cover screen of the portable computer.

Description:
FIELD OF THE INVENTION 
       [0001]    The present disclosure relates to an integrated power adapter system for portable computers, and in particular, relates to an integrated power adapter system for portable computers comprising an alternating current/direct current (AC/DC) adapter inside the computer. 
       BACKGROUND OF THE INVENTION 
       [0002]    With more and more people using portable computers, in particular, laptops or notebooks, there may be a desire for shrinking the sizes of such computers to improve their portability and to increase their manageability. Moreover, even if the life of the batteries supplying the portable computers is improved, when a battery is not charged, it is necessary to connect the portable computer to a power supply source, in particular providing a DC current. Up to now, portable computers thus typically involved an AC/DC adapter that extends from a plug (for plugging into a wall outlet of a power supply network or supply mains) to a case, usually in the form of a small brick, and then another plug from the case to a wire which leads to another plug for insertion into the portable computer. 
         [0003]    The computer sizes can be reduced by using an integrated power pack and as described in the U.S. Patent Application Publication No. 2009/243542 to Chai et al. In particular, this patent application discloses an apparatus comprising a power pack for providing power to a laptop computer. The power pack may be selectively removable from and integrated with a laptop computer housing; and the power pack may comprise: a power pack housing; a battery pack; and a AC/DC adapter; the battery pack and the AC/DC adapter both being housed within the power pack housing. 
         [0004]    This approach has a drawback in that the AC/DC adapter is not physically separated from the primary battery pack, and thus, it is not removable from the laptop housing without extracting also the battery pack. In addition, people may be obliged to carry an external adapter to supply the portable computer with a DC current when the battery is damaged, removed, or discharged. Moreover, the fact that this power pack is inside the laptop housing may increase the temperature of the housing itself. Furthermore, operating the portable computer adjacent the user&#39;s body during typical use may not be safe since the AC/DC adapter would be positioned in the bottom part of the laptop case, i.e. close to the user&#39;s body. 
       SUMMARY OF THE INVENTION 
       [0005]    The technical problem underlying the present invention is that of providing a power adapter system for portable computers having structural and functional characteristics that allow an approach to the limits affecting the power adapters according to the prior art. 
         [0006]    The approach underlying the present invention is that of providing a power adapter system for portable computers which is integrated in the computer, in particular in its cover screen and which is extractable from it, thus allowing to increase the portability and manageability of the computer itself for a final user. 
         [0007]    An aspect is directed to a power adapter system for a portable computer that may comprise a power adapter for providing power to portable computer, extractable elements for connection to an external socket, and a dissipation grid for avoiding the increasing of the temperature of the cover screen. The power adapter system may be a slim power adapter system being removable from and integrated with the cover screen of the portable computer. In this way, the portability and manageability of the computer itself for a final user are improved. 
         [0008]    More particularly, the following supplemental and optional features taken alone or in combination when needed are now disclosed. According to another embodiment, the power adapter system and the extractable elements can be housed in one of these regions in the cover screen of the portable computer, and in the case of the portable computer. 
         [0009]    According to another embodiment, the extractable elements can comprise a winding mechanism for a LAN cable and a grid wire connected with a plug. In this way, the winding mechanism would allow for handling, and connecting the laptop more easily. 
         [0010]    Furthermore, according to an aspect, the power adapter can be in direct contact with the dissipation grid. Also according to an aspect of the invention, the dissipation grid can occupy a region in a front side of the cover screen, wherein a screen of the portable computer is also placed, and a rear side of the cover screen. 
         [0011]    By positioning of the dissipation grid of the power adapter system and the winding mechanism on the front side of the cover screen, the dimensions of the screen are reduced. While the positioning of the dissipation grid of the power adapter system on the rear side of the cover screen may not reduce the dimensions of the screen. 
         [0012]    According to this aspect, the extractable elements can be housed in a region being adjacent to the region which is occupied by the dissipation grid. According to an aspect, the side can have an increased thickness in correspondence of the region housing the extractable elements. 
         [0013]    Yet according to another aspect, the power adapter system can be placed in a physically separate area with respect to a battery of the portable computer. In this way, the power adapter system and the battery can be removed separately and no battery damage also impacts the power adapter system. 
         [0014]    Moreover, according to another aspect, the power adapter can be an integrated AC/DC power adapter circuit architecture comprising a boost circuit connected to an alternate voltage source being applied to a first and to a second input terminal of the power adapter circuit architecture, and a converter circuit connected to the boost converter circuit and providing a continuous output voltage at a first and a second output terminal to be applied to the portable computer. 
         [0015]    According to this aspect of the invention, the power adapter circuit architecture can further comprise a buffer circuit comprising diodes in series to straighten an input waveform and coupled to an electromagnetic interference (EMI) filter, being placed between the input terminals and the boost circuit to eliminate high frequency components of the alternate voltage source. Yet according to this aspect, the boost circuit can be also identified as a power factor control pre-regulator circuit. 
         [0016]    Moreover, according to this aspect, the boost circuit can comprise at least a first power metal-oxide semiconductor field effect transistor (MOSFET) having a control terminal connected to a power factor control circuit. In particular, according to a desired working mode, the power factor control circuit may drive the first power MOSFET in a different manner. 
         [0017]    Also, according to this aspect, the converter circuit can comprise at least a second power MOSFET having a control terminal connected to a pulse width modulation control circuit. Furthermore, yet according to this aspect, the pulse width modulation control circuit can be in full duplex communication with the power factor control circuit. According to a further aspect, the first and second power MOSFETs can be either an MDmesh™V or FDmesh™II or SuperMESH 5™ power MOSFET housed in a super slim package. Finally, according to an aspect, the converter circuit can comprise a first stage circuit and a second stage circuit coupled to each other by way of a transformer. 
         [0018]    The characteristics and advantages of the power adapter system according to the present disclosure will be apparent from the following description of an embodiment thereof given by way of indicative and non limiting example with reference to the annexed drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a schematic diagram of a portable computer with an integrated power adapter system, according to the present invention; 
           [0020]      FIGS. 2A-2B  and  2 C- 2 D are schematic diagrams of the dimensions of a screen of a portable computer according to the prior art, and a screen of a portable computer with an integrated power adapter system, according to the present invention, respectively and according to different embodiments; 
           [0021]      FIG. 3  is a schematic diagram of a view of the portable computer with an alternative embodiment of the integrated power adapter system of  FIG. 1 ; 
           [0022]      FIG. 4  is a schematic circuit diagram of an integrated power adapter architecture, according to the present invention; and 
           [0023]      FIGS. 5A-5C  are schematic diagrams of a top plan view, a 3D top plan view, and a 3D bottom view of a die package including a power MOSFET device, being used in the power adapter system, according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0024]    With reference to such figures, and in particular to  FIG. 1 , a portable computer comprising at least one slim power adapter system is shown. As will be clear from the following description, advantageously according to the present disclosure, the power adapter system is integrated in the cover screen of the computer and comprises extractable elements, like a winding mechanism, for a LAN cable, a power supply cable, and a plug also inserted into the cover screen. It should be noted that the figures show schematic views of the portable computer, of the power adapter system and of the die package including a power MOSFET device, being used in the power adapter system, and are not drawn in scale, being on the contrary drafted so as to emphasize the features of the invention. 
         [0025]    The portable computer, also briefly indicated as laptop  1 , comprising a case  2  and a cover screen  3  including a screen  3 A, also comprises a slim power adapter  4 , being placed inside the cover screen  3  of the laptop  1 , in the bottom side, and in direct contact with a dissipation grid  5 . In particular, the power adapter  4  and the dissipation grid  5  occupy a first region, for example, the region on the bottom-right of the front side of the cover screen  3  (the side comprising the screen  3 A), while a second region, for example, the region on the bottom-left comprises extractable elements or a winding mechanism  6  comprising a LAN cable  7  and a power supply cable connected with a plug  8 . 
         [0026]    According to another aspect, the winding mechanism  6  is integrated in the case  2  and the power adapter  4  is a slim integrated device. Moreover, the winding mechanism  6  of the LAN cable  7  and a grid wire connected to the plug  8  are extractable elements and are placed in a portion, for example, an end portion of the bottom side of the cover screen  3 , a left part, or a right portion of the cover screen  3 . 
         [0027]    According to an aspect, the new dimensions of the screen  3 A, indicated with the arrows Ad 1  and Al 1  in  FIG. 1 , are reduced between 5 and 20 percent with respect to the dimensions of an original screen, indicated with the arrows Ad 2  and Al 2  in  FIG. 1 . It is clear that the lengths indicated by the arrows Ad 1 , Al 1  as well as by the arrows Ad 2  and Al 2  depend on the actual sizes of the laptop  1  and in particular of the sizes of its cover screen  3 . 
         [0028]    In particular, according to an aspect of the present disclosure and to the embodiment shown in  FIG. 1 , the reduction of the sizes of the screen  3 A of the computer  1  are due to the positioning of the dissipation grid  5 , which is attached on the front side of the cover screen  3 , in particular in the region on the right of the bottom side of such cover screen  3 . 
         [0029]      FIGS. 2A-2D  schematically show the dimensions of a screen of two different embodiments of a computer being realized according to the prior art ( FIGS. 2A and 2B ) and according to the present disclosure ( FIGS. 2C and 2D ). In particular, according to a first embodiment, a screen of 18.4″ (46.74 cm) has a diagonal D 1 =18.4″ (46.74 cm), a length L 1 =16″ (40.64 cm), and a height H 1 =9″ (22.86 cm), as shown in  FIG. 2A . 
         [0030]    According to the present disclosure, by positioning of the dissipation grid  5  of the power adapter  4  and the winding mechanism  6  on the front side of the cover screen  3 , the dimensions of the screen  3 A are reduced to a diagonal D 3 =17.4″ (44.2 cm) due to the reduction of the height to H 3 =7″ (17.78 cm), the length L 1 =16″ (40.64 cm) being left unchanged. This reduction is due to the height H 4 =2″ (5.08 cm) of the power adapter  4  and the winding mechanism  6 , which have lengths L 4  and L 6 , respectively, whose sum is equal to L 1 , as shown in  FIG. 2C . 
         [0031]    A similar reduction is obtained by starting from a screen of 15″ (38.1 cm), which has a diagonal D 2 =15″ (38.1 cm), a length L 2 =12″ (30.48 cm) and a height H 2 =H 1 =9″ (22.86 cm), as shown in  FIG. 2B . In this case, due to the height H 4 =2″ (5.08 cm) of the power adapter  4  and the winding mechanism  6 , the new screen diagonal is D 3 =14″, its height being reduced to H 3 =7″ (17.78 cm) and its length L 2 =12″ (30.48 cm) being left unchanged, as shown in  FIG. 2D . Also, in this embodiment, the power adapter  4  and the winding mechanism  6  should have lengths L 4  and L 6 , respectively, whose sum is equal to L 2 . 
         [0032]    According to an alternative embodiment, as shown in  FIG. 3 , the power adapter  4  and the winding mechanism  6  are housed in a bottom portion of a rear side  3 B of the cover screen  3 . More in particular, the power adapter  4  and the dissipation grid  5  occupy a first region A 1 , for example, the region on the bottom-right of the rear side  3 B of the cover screen  3 , while a second region A 2 , for example, the region on the bottom-left comprises the winding mechanism  6 . 
         [0033]    It is evident that the housing of the power adapter  4  and of the winding mechanism  6  according to this alternative embodiment does not reduce the dimensions of the screen  3 A. However, in order to correctly house the power adapter  4  and the winding mechanism  6 , the rear side  3 B of the cover screen  3  has an increased thickness. More particularly, according to the embodiment shown in  FIG. 3 , the thickness of this rear side  3 B increases from a first value Tc 1  to a second value Tc 2 , for example, equal to 0.4″ (1.02 cm) and 1″ (2.54 cm), respectively. Also according to the embodiment shown in  FIG. 3 , the front side, i.e. the screen  3 A has a constant thickness Ts, for example, equal to 0.6″ (1.52 cm). 
         [0034]    More particularly, the slim integrated power adapter  4  works in order to charge a computer battery, not showed in the figures, and being placed in physically separated areas. In particular, according to an embodiment, the slim integrated power adapter  4  is placed in the cover screen  3  while the battery is usually placed inside the case  2 . 
         [0035]    A detailed block diagram of a circuit architecture implementing a slim integrated power adapter  4  according to the present disclosure is shown in  FIG. 4 . In particular, the block diagram is an AC/DC circuit architecture, also indicated as power adapter circuit architecture  10 , comprising a boost circuit  11 , for example, a power factor control (PFC) pre-regulator circuit, and a converter circuit  12 , for example, a flyback converter. The boost circuit  11  is connected, via a buffer circuit  13 , comprising, for example, a parallel coupling of two diodes in series, to an EMI filter  14 , which is coupled with an alternate source of a voltage Vinac being applied to a first and to a second input terminal, IN 1  and IN 2  respectively, of the power adapter circuit architecture  10  and which attenuates possible noise signal affecting the alternate source of the voltage Vinac. 
         [0036]    In particular, the EMI filter  14  allows for elimination of the high frequency components of the alternate source of the voltage Vinac, which could resonate within the power adapter circuit architecture  10  while the buffer circuit  13  allows smoothing of the input waveform, the diodes only leaving the positive half-waves and the capacitor transforming it into a continuous waveform. 
         [0037]    The boost circuit  11  is a DC/DC converter that comprises at least an inductor L 1  and a boost diode D 1  being series connected between an input terminal I 1  and an output terminal O 1 , which terminals are in turn connected to a voltage reference, in particular ground GND, by way of input and output capacitors Cin, Cout respectively. The boost circuit  11  provides an output voltage across the output capacitor Cout being higher than the input one across the input capacitor Cin. According to the present disclosure, the boost circuit  11  also comprises, as a switch, a first power MOSFET PM 1 , and in particular either a MDmesh™V or FDmesh™II or SuperMESH 5™ power MOSFET, being connected to an intermediate node between the inductor L 1  and the boost diode D 1  and ground GND and having a control or gate terminal connected to a PFC control circuit (PFC CTL)  15 . 
         [0038]    Also according to an aspect of the present disclosure, the first power MOSFET PM 1  is housed in a super slim PowerFLAT™ 8×8 HV package  20 , as shown in  FIGS. 5A-5C  in its top view (FIG.  5 A), 3D top view ( FIG. 5B ) and 3D bottom view with one gate contact G, one drain contact D and three source contacts S ( FIG. 5C ). 
         [0039]    According to an aspect of the present disclosure the PowerFLAT™ 8×8 HV package  20  has a thickness equal to 1 mm standard flat. A slim package, such as the STMicroelectronics&#39; PowerFLAT™ 8×8 HV package, except for the similar Infineon&#39;s ThinPAK package, can be found in the market. Due to the energy accumulated by the inductance L 1  of the boost circuit  11 , during the phase ON, the current flowing through the inductor L 1  cannot go to zero instantaneously. The consequence of this phenomenon is an extra voltage applied to the boost diode D 1 , in particular, to its anode terminal, with a sign able to oppose to the decreasing current. Due to the extra voltage, the anode of the boost diode D 1  will be brought to a voltage higher than the output one, permitting to the current to flow through it. 
         [0040]    Moreover, according to the present disclosure, the first power MOSFET PM 1  is driven, in a typical manner, by the PFC control circuit  15 , which is turned off when a load applied to the power adapter circuit architecture  10  is light to obtain an easy compliance with the energy saving requirements of the power adapter  4 . More particularly, the PFC control circuit  15  acts on the duty cycle or on the frequency of the first power MOSFET PM 1  commutation to build a sinusoidal current shape. 
         [0041]    As is known, the boost circuit  11  works in two modes: a discontinuous conduction mode (DCM), in which the current flowing in the inductor L 1  reaches zero; and a continuous conduction mode (CCM), in which the current flowing in the inductor L 1  never reaches zero. According to a desired working mode, the PFC control circuit  15  drives the first power MOSFET PM 1  in a different manner. 
         [0042]    The flyback converter  12  in turn comprises a first stage circuit  16  inserted between the output terminal O 1  of the boost circuit  10  and ground GND, and a second stage circuit  17  coupled to the first stage circuit  16  through a transformer  1 B. In particular, the first stage circuit  16  comprises, in series with a primary winding L 2  of the transformer  18 , a second power MOSFET PM 2 , as a switch, being for example, of the same type of the first power MOSFET PM 1  (and thus either a MDmesh™V or FDmesh™II or SuperMESH 5™ power MOSFET), as all available from STmicroelectronics of Geneva, Switzerland, and suitably having a different breakdown voltage BV. For example, the breakdown voltage BV of the first power MOSFET PM 1  is chosen in the range between 525 and 650 Volts while the breakdown voltage BV of the second power MOSFET PM 2  is chosen equal to or higher than 800 Volt. The second power MOSFET PM 2  is connected in series with the primary winding L 2  between the output terminal O 1  of the primary winding L 2  and a further ground GND 2  and is driven by a pulse width modulation or PWM control circuit (PWM CTL)  19 , which is connected to a control or gate terminal of the second power MOSFET PM 2  and in full duplex communication with the PFC control circuit  15 . In particular, in order to maintain safety conditions, the PWM control circuit  19  is turned off if the PFC control circuit  15  operates in an anomalous way. 
         [0043]    The second stage circuit  17  comprises a synchronous rectification circuit, in particular, a freewheeling diode D 2 , which is connected to a secondary winding L 3  of the transformer  18  and to a first output terminal OUT 1  of the flyback converter  12  (which corresponds to the output terminal of the power adapter circuit architecture  10 ) as well as an output capacitance C 2 , which is connected between the first output terminal OUT 1  and a further ground GND 2 . 
         [0044]    The flyback converter  12  has two operating phases, depending on the working conditions of the second power MOSFET PM 2 : a switch on phase, in which the energy is stored on the primary winding L 2  of the transformer  18  and on the output of the secondary winding L 3 . The freewheeling diode D 2  is blocked and a load, being connected to the first output terminal OUT 1  and to a second output terminal OUT 2  of the flyback converter  12 , is supplied by way of the output capacitance C 2 . The second phase is a switch off phase, in which, as soon as the second power MOSFET PM 2  turns off, the stored energy on the primary winding L 2  is transferred to the secondary winding L 3  by magnetic coupling. The freewheeling diode D 2  is forward biased, thus the energy is supplied to the output capacitance C 2  and to the load of flyback converter  12 . The output voltage of the second stage circuit  17  is a DC voltage Voutdc to be provided to the load, in particular, to the portable computer  1 . 
         [0045]    According to a first aspect of the present disclosure, the power provided from the slim integrated power adapter architecture  10  is comprised between 0 Watt and 90 Watt. In essence, the power adapter system according to the present disclosure allows portable computers, in particular laptops, to be more compact, manageable and portable. Another advantage is that the winding mechanism for power supply cable and LAN cable allows for easy handling, and connecting of the laptop. 
         [0046]    Moreover, the power adapter system, being integrated inside the cover screen of the portable computer may contribute to increase in the heat dissipation capability versus the approach of the prior art, in which the power adapter is integrated with the battery in the battery pack, contained in the case on the bottom of the portable computer. 
         [0047]    In addition, being that the power adapter system is physically separated from the battery, they can be removed separately and battery damage does not also impact the power adapter system. In addition, the integration of the power adapter system according to the present disclosure comprising also the integration of a dissipation grid may avoid the increasing of the temperature of the cover screen. Even when the dissipation grid is housed on the front side, i.e. the screen side of the cover screen of the portable computer, it reduces the screen dimensions a minimum quantity, while the integration of the power adapter system with the dissipation grid in the rear side of the cover screen does not involve any reduction of the screen dimensions.