Abstract:
Power supply system for charging USB mini-B devices includes a charger and a USB mini-B device. The USB mini-B device includes a first pin receiving the DC current from the charger, a fourth pin receiving the DC current or identification data from the charger, a power management unit receiving DC current, a first switch transmitting the DC current from the first pin to the first input node of the power management when the first switch is on, a second switch transmitting the DC current from the first pin to the first input node of the power management when the second switch is on.

Description:
BACKGROUND OF THE INVENTION  
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a power system, and more particularly, to an USB mini B power supply system for quickly charging USB mini B devices. 
         [0003]    2. Description of the Prior Art 
         [0004]    Please refer to  FIG. 1 .  FIG. 1  is a diagram illustrating a USB mini B plug and a USB mini B socket. As shown in  FIG. 1 , the USB mini B plug has pins  1  to  6 , and the USB mini B socket has pins  1  to  6 . When the USB mini B plug is coupled to the USB mini B socket, pins  1  to  6  of the plug are coupled to pin  1  to  6  of the socket respectively. 
         [0005]    Please refer to  FIG. 2 .  FIG. 2  is a diagram illustrating the pin definition of a standard USB mini B connector. The USB mini B standard defines pin  1  for transmitting power, pin  2  and pin  3  for transmitting data, pin  4  for identity, pin  5  for grounding, and pin  6  for shielding. Additionally, pin  6  of the USB mini B connector is the housing of the connector. 
         [0006]    The USB mini B standard also defines the maximum current that a USB mini B socket device can sink. If the device coupled to the USB mini B socket device is a regular USB mini B plug device, then the maximum sink current is 500 milliamps. If the device coupled to the USB mini B socket device is a USB mini B power adaptor such as an ac/dc adaptor or a dc/dc adaptor, then the maximum sink current is 1 amp because the USB mini B connector only has one pin for transmitting power (pin  1 ) and one pin for grounding (pin  5 ) while each of them can be loaded with 1 amp at most under the hardware character of the USB mini B connector. 
         [0007]    Therefore, in order to differentiate the type of a USB mini B plug device, the USB mini B socket device uses the voltage of pin  4  of the USB mini B socket. Pin  4  of the USB mini B plug of the USB mini B power adaptor is coupled to ground so that the voltage of pin  4  is low. Pin  4  of the USB mini B plug of the regular USB mini B device is floating so that the voltage of pin  4  is also floating. Pin  4  of the USB mini B socket of a USB mini B socket device such as a cell phone is coupled to a high-leveled voltage through a resistor. 
         [0008]    Please refer to  FIG. 3 .  FIG. 3  is a diagram illustrating the situation when the USB mini B socket device  330  is coupled to the regular USB mini B plug device  310  or the USB mini B power adaptor  320 . When the USB mini B socket device  330  is coupled to the regular USB mini B plug device  310 , the voltage of pin  4  of the regular USB mini B plug device  310  is pulled up to the high-leveled voltage by the USB mini B socket device  330  because pin  4  of the regular USB mini B plug device  310  is floating so that the voltage of pin  4  of the USB mini B socket of the USB mini B socket device  330  is high. When the USB mini B socket device  330  is coupled to the USB mini B power adaptor, the voltage of pin  4  of the USB mini B power adaptor  320  is still at the ground-leveled voltage so that the voltage of pin  4  of the USB mini B socket of the USB mini B socket device  330  is low. Thus, the USB mini B socket device can determine if the USB mini B device coupled to it is a regular USB mini B plug device or an USB mini B power adaptor. If the USB mini B socket device determines the USB mini B device is a regular USB mini B plug device, then sinking current is limited to  500  milliamps. If the USB mini B socket device determines the USB mini B device is a USB mini B power adaptor, then sinking current is not limited. Nevertheless, the sinking current is still at most 1 amp because of the hardware character of the connector. 
         [0009]    However, from the description above, it is known that whatever the type of USB mini B plug device, the sinking current is only 1 amp at most, which is not enough for the USB mini B socket device to be charged with the sinking current very quickly. Thus, the user has to increase the charging time of the USB mini B socket device and that is an inconvenience. 
       SUMMARY OF THE INVENTION  
       [0010]    It is therefore an objective of the claimed invention to provide a power supply system for quickly charging USB mini B devices. 
         [0011]    The claimed invention provides a power charger for quickly charging USB mini B devices and includes a power converter for converting an input power source into a direct current, and a USB mini B plug, of which a first pin and a fourth pin are coupled to an output node of the power converter for receiving direct current from the output node of the power converter. 
         [0012]    The claimed invention also provides a USB mini B device for quickly being charged and includes a USB mini B socket having a first pin for receiving a direct current, and a fourth pin for receiving a direct current or a identity; a power management unit having a first input node for receiving a direct current; a first switch coupled between the first pin of the USB mini B socket and the first input node of the power management unit for transmitting the direct current of the first pin of the USB mini B socket to the first input node of the power management unit when the first switch is turned on; and a second switch coupled to the fourth pin of the USB mini B socket and the first input node of the power management unit for transmitting the direct current of the fourth pin of the USB mini B socket to the first input node of the power management unit when the first switch is turned on. 
         [0013]    The claimed invention also provides a power supply system for quickly charging USB mini B devices and includes a charger having a power converter for converting an input power source into a direct current and a USB mini B plug having a first pin and a fourth pin coupled to an output node of the power converter for receiving a direct current from the output node of the power converter; a USB mini B device including a USB mini B socket having a first pin coupled to the first pin of the USB mini B plug for receiving the direct current from the first pin of the USB mini B plug and a fourth pin coupled to the fourth pin of the USB mini B plug for receiving the direct current or an identity from the fourth pin of the USB mini B plug; a power management unit having a first input node for receiving a direct current; a first switch coupled between the first pin of the USB mini B socket and the first input node of the power management unit for transmitting the direct current of the first pin of the USB mini B socket to the first input node of the power management unit when the first switch is turned on; and a second switch coupled between the fourth pin of the USB mini B socket and the first input node of the power management unit for transmitting the direct current of the fourth pin of the USB mini B socket to the first input node of the power management unit when the second switch is turned on. 
         [0014]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]      FIG. 1  is a diagram illustrating a USB mini B plug and a USB mini B socket. 
           [0016]      FIG. 2  is a diagram illustrating the pin definition of a standard USB mini B connector. 
           [0017]      FIG. 3  is a diagram illustrating the situation when the USB mini B socket device is coupled to the regular USB mini B plug device or the USB mini B power adaptor. 
           [0018]      FIG. 4  is a diagram illustrating the definition of the USB mini B connector of the present invention. 
           [0019]      FIG. 5  is a diagram illustrating a USB mini B power adaptor of the present invention. 
           [0020]      FIG. 6  is a diagram illustrating the USB mini B socket device of the present invention. 
           [0021]      FIG. 7  is a diagram illustrating the situation when the USB mini B socket device of the present invention is coupled to the power adaptor of the present invention. 
           [0022]      FIG. 8  is a diagram illustrating the situation when the USB mini B socket device of the present invention is coupled to a regular USB mini B plug device or a regular USB mini B power adaptor. 
       
    
    
     DETAILED DESCRIPTION  
       [0023]    Please refer to  FIG. 4 .  FIG. 4  is a diagram illustrating the definition of the USB mini B connector of the present invention. The difference between the USB mini B connector of the prior art and the present invention is that the USB mini B connector of the present invention uses pin  1  and pin  4  for transmitting power while the present invention is also compatible with the regular USB mini B devices. As shown in  FIG. 4 , the USB mini B power adaptor of the present invention uses pin  1  and pin  4  for providing the power, and pin  5  and pin  6  for grounding. Additionally, the USB mini B socket device of the present invention uses pin  1  for receiving the power, pin  4  for both identifying the type of the USB mini B device and receiving the power, and pin  5  and pin  6  for grounding. Thus, the USB mini B device of the present invention can transmit current up to 2 amps because the USB mini B connector of the present invention uses 2 pins for transmitting the power and 2 pins for grounding. 
         [0024]    Please refer to  FIG. 5 .  FIG. 5  is a diagram illustrating a USB mini B power adaptor  500  of the present invention. The USB mini B power adaptor  500  comprises an ac/dc adaptor  510 . The ac/dc adaptor  510  comprises an output node and a ground node. The output node of the ac/dc adaptor outputs a direct current and is coupled to pin  1  and pin  4  of the USB mini B plug. The ground node of the ac/dc adaptor is coupled to pin  5  and pin  6  of the USB mini B plug. In this way, the ac/dc adaptor  510  uses the USB mini B plug defined by the present invention to provide the current up to 2 amps. Likewise, a dc/dc adaptor can be used for the USB mini B power adaptor  500  to provide direct current in the present invention. 
         [0025]    Please refer to  FIG. 6 .  FIG. 6  is a diagram illustrating the USB mini B socket device  600  of the present invention. The USB mini B socket device  600  comprises a power management unit  610 , a current-limiting unit  630 , 3 transistors Q 1 , Q 2 , Q 3 , an inverter U 1 , and a resistor R 1 . The resistor R 1  is coupled between ground and the USB mini B plug  620  for pulling the voltage of pin  4  of the USB mini B plug  620  down to ground. Thus the voltage of pin  4  of the USB mini B plug  620  holds ground-leveled voltage when not coupled to any external devices. The transistor Q 1  is coupled between pin  4  of the USB mini B plug  620  and the power management unit  610 . The signal  X  at the gate of the transistor Q 1  determines whether pin  4  of the USB mini B plug  620  is coupled to the input node of the power management unit  610 . The transistor Q 2  is coupled between pin  1  of the USB mini B plug  620  and the power management unit  610 . The signal  X  at the gate of the transistor Q 2  determines whether pin  1  of the USB mini B plug  620  is coupled to the input node of the power management unit  610 . The transistor Q 3  is coupled between pin  1  of the USB mini B plug  620  and the power management unit  610 . The signal X at the gate of the transistor Q 3  determines whether pin  1  of the USB mini B plug  620  is coupled to the input node of the current-limiting unit  630  of the power management unit  610 . The input node of the inverter U 1  is coupled to pin  4  of the USB mini B plug  620 . The signal on the input node of the inverter U 1  is taken as signal X and also serves as the controlling signal of the transistor Q 3  by coupling to the gate of the transistor Q 3 . Then the inverter U 1  inverts the signal X of the input node to the signal  X  output to the gates of the transistors Q 1  and Q 2 . 
         [0026]    Please refer to  FIG. 7 .  FIG. 7  is a diagram illustrating the situation when the USB mini B socket device  600  of the present invention is coupled to the power adaptor  500  of the present invention. As shown in  FIG. 7 , when the USB mini B power adaptor  500  is coupled to the USB mini B socket device  600 , pin  4  of the USB mini B plug of the power adaptor  500  pulls the voltage of pin  4  of the USB mini B socket to a high-leveled voltage because pin  4  of the USB mini B plug is the direct current output of the USB mini B power adaptor  500 . Thus, the signal X is high and the signal  X  is low. Consequently, the transistors Q 1  and Q 2  are turned on and the transistor Q 3  is turned off so that the direct current is transmitted from pin  1  and pin  4 , through the transistors Q 1  and Q 2 , to the input node of the power management unit  610 . In this way, the power can be transmitted through 2 pins and thus the maximum current can be up to 2 amps. 
         [0027]    Please refer to  FIG. 8 .  FIG. 8  is a diagram illustrating the situation when the USB mini B socket device  600  of the present invention is coupled to a regular USB mini B plug device or a regular USB mini B power adaptor. Pin  4  of the USB mini B plug of the regular USB mini B device is floating so that when the regular USB mini B plug device is coupled to the USB mini B socket device  600  of the present invention, the voltage of pin  4  of the plug is pulled down to the ground-leveled voltage through the resistor R 1  and the voltage of pin  4  of the socket of the USB mini B socket device  600  is low. Pin  4  of the regular USB mini B power adaptor is coupled to ground so that when the regular USB mini B power adaptor is coupled to the USB mini B socket device  600 , pin  4  of the USB mini B socket of the USB mini B socket device  600  is also low. Thus, whether the device coupled to the USB mini B socket device  600  is a regular USB mini B plug device or a regular USB mini B power adaptor, pin  4  of the USB mini B socket of the USB mini B socket device  600  is low. Consequently, the signal X is also low and the signal  X  is high. According to the signals X and X, the transistors Q 1  and Q 2  are turned off and the transistor Q 3  is turned on respectively. As shown in  FIG. 8 , through the transistor Q 3 , pin  1  of the USB mini B socket is coupled to the current-limiting unit  630  of the power management unit  610  so that the power output from the regular USB mini B plug device or the regular USB mini B power adaptor can be transmitted to the current-limiting unit  630 . 
         [0028]    Therefore, by using the power supply system of the present invention, the USB mini B devices can be charged quickly, save the charging time, and use the extra current for the need of the operation of the USB mini B devices, which increases the convenience. 
         [0029]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.