Abstract:
A low standby consumption power supply system having multi-channels for power supply is used to power first and second circuit blocks. The main supply module provides power to the first circuit-block, while the second supply module provides power to the second circuit-block. The enabling line is used to transmit an enabling signal to the main supply module to switch the main supply module from a power-off status to a power-on status. The enabling line operates under enabling mode and power-off mode. Under enabling mode, the enabling line transmit the enabling signal to the main supply module, such that the main supply module and the low-current supply module respectively provide power to the first circuit-block and the second circuit-block simultaneously. Under the power-off mode, the enabling signal is cut off and the main supply module stop providing power, so as to cut off standby current of the main supply module.

Description:
FIELD OF THE INVENTION  
       [0001]    The present invention relates to power supply devices, and more particularly, to a low standby consumption power supply system having multi-channels for power supply. 
       BACKGROUND OF THE INVENTION  
       [0002]    Referring to  FIG. 1 , a power supply system  2  is adapted to supplying power to an electronic circuit assembly  1  of an electronic device. The electronic circuit assembly  1  includes a functional circuit system  3  and the power supply system  2 . The technical features of the functional circuit system  3  shown as a simple block in  FIG. 1  depend on the type of the electronic device. 
         [0003]    The power supply system  2  is usually a DC-to-DC transformer, such as a low-dropout (LDO), adapted to convert a relatively high voltage of 3.3V into 1.2V to be supplied to the functional circuit system  3 . 
         [0004]    The power supply system  2  has to supply the power required by the functional circuit system  3  in its entirety. In the situation where the operating maximum load current of the power supply system  2  is relatively high, the standby current of the power supply system  2  is also relatively high. 
         [0005]    In the situation where the electronic circuit assembly  1  switches from an operation mode to a sleep mode or an idle mode, although the functional circuit system  3  is partially shut down, the power supply system  2  still has to stay in a standby state in order to wake up electronic circuit assembly  1  at any time. As mentioned above, the power supply system  2  with a high maximum load also has a high standby current; as a result, the electronic circuit assembly  1  in the sleep mode or idle mode still manifests overly high standby current consumption. The amplitude of the standby current of a conventional power supply system is not adjustable; as a result, the standby power consumption of a conventional power supply system cannot be reduced. 
       SUMMARY OF THE INVENTION  
       [0006]    In view of this, an embodiment of the present invention provides a low standby consumption power supply system having multi-channels for power supply to reduce the standby power consumption of the power supply system. 
         [0007]    In order to achieve the above and other objectives, an embodiment of the present invention provides a low standby consumption power supply system having multi-channels for power supply. The power supply system supplies power to an electronic circuit assembly. The electronic circuit assembly comprises a first circuit block and a second circuit block. The circuit blocks have their respective functions, so as to build the electronic circuit assembly with robust and complete functions. 
         [0008]    The power supply system comprises at least a main power supply unit, a low current supply unit, and an enable signal line. The main power supply unit supplies power to the first circuit block. The low-current power supply unit supplies power to the second circuit block. The enable signal line sends an enable signal to the main power supply unit, so as to switch the main power supply unit from a power-off status to a power-on status. 
         [0009]    The enable signal line operates in an enable mode and a shutdown mode. In an enable mode, the enable signal line sends an enable signal to the main power supply unit, such that the main power supply unit and the low-current power supply unit simultaneously supply power to the first circuit block and the second circuit block, respectively. In a shutdown mode, the enable signal interrupts, such that the main power supply unit shuts down and stops supplying output power to the first circuit block, so as to interrupt its standby current consumption. 
         [0010]    The present invention according to various embodiments is characterized in that, inter alia: the electronic circuit assembly is divided into a plurality of circuit blocks; and the power supply system is divided into a plurality of power supply units. In the electronic circuit assembly standby state, it is only necessary for a portion of the power supply system to stay standby and only necessary to supply a tiny current to a portion of the circuit blocks of the electronic circuit assembly. It is not necessary for the whole of the power supply system to stay standby; instead, the power supply system is partly power-off and partly standby, so as to reduce standby current and reduce standby power consumption. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]    Preferred embodiments and advantages of the present invention are hereunder described in conjunction with the accompanying drawings, in which: 
           [0012]      FIG. 1  (prior art) is a circuit block diagram of a conventional power supply system; 
           [0013]      FIG. 2  is a circuit block diagram of a low standby consumption power supply system having multi-channels for power supply according to an embodiment of the present invention, wherein an enable signal line operates in a shutdown mode; 
           [0014]      FIG. 3  is a circuit block diagram of the power supply system according to an embodiment of the present invention, wherein the enable signal line operates in an enable mode 
           [0015]      FIG. 4  is another circuit block diagram of the power supply system according to an embodiment of the present invention; 
           [0016]      FIG. 5  is yet another circuit block diagram of the power supply system according to an embodiment of the present invention; 
           [0017]      FIG. 6  is a circuit block diagram of the power supply system according to another embodiment of the present invention; 
           [0018]      FIG. 7  is a circuit block diagram of the power supply system according to yet another embodiment of the present invention; 
           [0019]      FIG. 8  is a circuit block diagram of the power supply system according to an embodiment of the present invention; and 
           [0020]      FIG. 9  is another circuit block diagram of the power supply system according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Referring to  FIG. 2 , there is shown a circuit block diagram of a low standby consumption power supply system  100  having multi-channels for power supply according to the first embodiment of the present invention. The power supply system  100  is adapted to supplying power to an electronic circuit assembly  200 . The electronic circuit assembly  200  comprises a first circuit block  210  and a second circuit block  220 . The first circuit block  210  and the second circuit block  220  have their respective functions so as to form the electronic circuit assembly  200  completely. The first circuit block  210  and the second circuit block  220  have their respective maximum consumption currents, and the sum of the two maximum consumption currents equals the maximum consumption current of the electronic circuit assembly  200 . The technical features of the first circuit block  210  and the second circuit block  220  depend on the type of the electronic circuit assembly  200 ; therefore, the first circuit block  210  and the second circuit block  220  are illustrated with the simple block diagram of  FIG. 2 , but the present invention is not restrictive of the type of the first circuit block  210  and the second circuit block  220 . 
         [0022]    Referring to  FIG. 2 , the power supply system  100  comprises a main power supply unit  110 , a low-current power supply unit  120 , and an enable signal line  130 . The main power supply unit  110  and the low-current power supply unit  120  are adapted to receiving an input power and convert the input power into an output power, respectively. The main power supply unit  110  is connected to the first circuit block  210 . The low-current power supply unit  120  is connected to the second circuit block  220 . 
         [0023]    The main power supply unit  110  and the low-current power supply unit  120  are each usually a DC-to-DC transformer, such as a low-dropout (LDO). In the first embodiment, the main power supply unit  110  and the low-current power supply unit  120  are adapted to receiving an input power of a voltage of 3.3V and convert the 3.3V input power into an output power of 1.2V, respectively. The maximum consumption current of the first circuit block  210  is relatively large; therefore, the main power supply unit  110  of relatively large maximum load current supplies the output power to the first circuit block  210 . As the maximum consumption power of the second circuit block  220  is relatively small, it is desirable for the low-current power supply unit  120  with a relatively small maximum load current to supply output power to the second circuit block  220 . 
         [0024]    Referring to  FIG. 2 , the main power supply unit  110  comprises a main power input end  112 , a main power output end  114 , and a switch pin  116 . The main power input end  112  receives 3.3V input power. The main power output end  114  outputs 1.2V output power. The switch pin  116  receives an enable signal ENB and thereby switches the main power supply unit  110  to a power-on status. 
         [0025]    The low-current power supply unit  120  comprises an auxiliary power input end  122  and an auxiliary power output end  124 . The auxiliary power input end  122  receives 3.3V input power. The auxiliary power output end  124  outputs 1.2V output power. The auxiliary power input end  122  and the main power input end  112  of the main power supply unit  110  are connected to the same power source and therefore receive input power from the same power source. 
         [0026]    The enable signal line  130  is connected to the switch pin  116  of the main power supply unit  110  to thereby send enable signal ENB to the main power supply unit  110 , so as to switch the main power supply unit  110  from a power-off status to a power-on status. 
         [0027]    Referring to  FIG. 2  and  FIG. 3 , the enable signal line  130  operates in an enable mode and a shutdown mode. 
         [0028]    Referring to  FIG. 2 , in the enable mode, the enable signal line  130  sends enable signal ENB to the main power supply unit  110 . The main power supply unit  110  receives enable signal ENB via the switch pin  116  and therefore switches from a power-off status to a power-on status. At this point in time, the main power supply unit  110  continuously receives input power and supplies output power to the first circuit block  210 . At this point in time, the main power supply unit  110  and the low-current power supply unit  120  supply power to the first circuit block  210  and the second circuit block  220  simultaneously. Even though at this point in time the first circuit block  210  is nearly in a power-off status and therefore does not consume any power, the main power supply unit  110  still consumes a standby current. Similarly, even though at this point in time the second circuit block  220  is nearly in a power-off status and therefore does not consume any power, the low-current power supply unit  120  still consumes a standby current. 
         [0029]    Referring to  FIG. 3 , in the shutdown mode which takes place, for example, when the electronic circuit assembly  200  enters the sleep mode or the standby mode, the first circuit block  210  is power-off and therefore does not need any consumption power, whereas the second circuit block  220  only needs to maintain standby power consumption in order to keep receiving a trigger signal at any time, so as to turn on the first circuit block  210  for waking up the electronic circuit assembly  200 . At this point in time, the enable signal line  130  stops outputting, such that enable signal ENB interrupts to thereby shut down the main power supply unit  110  fully, thereby interrupting its standby current consumption. The low-current power supply unit  120  only has to supply a tiny current to the second circuit block  220  to cause the second circuit block  220  to stay in the standby state. Take a computer motherboard as an example, the second circuit block  220  usually comes in the form of a combination of a BIOS and an embedded controller and is adapted to receiving and discerning a waking signal so as to wake up the first circuit block  210 . 
         [0030]    Referring to  FIG. 3 , in the shutdown mode, with the main power supply unit  210  being shut down, the power supply system  100  is partly power-off and partly standby. Unlike its conventional counterpart (shown in  FIG. 1 ), the standby current consumed by the partly power-off power supply system  100  is less than the standby current consumed by the fully standby power supply system  100 , thereby achieving low standby power consumption. If the second circuit block  220  is selected to be the least power-consuming block in the electronic circuit assembly  200 , the second circuit block  220  and the low-current power supply unit  120  with a relatively low standby current together will minimize the standby current of the power supply system  100  operating in a low standby consumption operation mode. 
         [0031]    For example, according to the prior art illustrated with  FIG. 1 , a transformer with a maximum load of 300 m A and a standby current of 50 uA is conducive to the operation of the electronic circuit assembly  200  in its entirety. In the first embodiment of the present invention, the main power supply unit  110  has a maximum load of 300 m A and a standby current of 50 uA, whereas the low-current power supply unit  120  has a maximum load of 50 m A and a standby current of 10 uA. 
         [0032]    In the normal operation mode of the electronic circuit assembly  200 , the actual load of the power supply system  100  depends on the electronic circuit assembly  200  but does not increase with the overall maximum load of the power supply system  100 . 
         [0033]    In the low standby consumption operation mode of the electronic circuit assembly  200 , the prior art illustrated with  FIG. 1  requires consuming a 50 uA standby current. By contrast, as regards the power supply system  100  of the present invention, only the low-current power supply unit  120  consumes a 10 uA standby current, whereas the main power supply unit  110  does not consume any standby current. Therefore, the power supply system  100  of the present invention achieves low standby power consumption. 
         [0034]    Referring to  FIG. 4 , after the second circuit block  220  has generated and sent feedback signal FB to the low-current power supply unit  120 , the low-current power supply unit  120  generates and sends enable signal ENB to the switch pin  116  of the main power supply unit  110 . Therefore, the enable signal line  130  is electrically connected to the low-current power supply unit  120  and the switch pin  116  of the main power supply unit  110 . 
         [0035]    Referring to  FIG. 5 , with the low-current power supply unit  120  supplying current regularly to maintain operation of the second circuit block  220 , enable signal ENB can also be generated by the second circuit block  220  and sent to the switch pin  116  of the main power supply unit  110 . That is to say, the enable signal line  130  is electrically connected to the second circuit block  220  and the switch pin  116  of the main power supply unit  110 . 
         [0036]    Referring to  FIG. 6 , in the second embodiment of the present invention, the power supply system  100  supplies power to the electronic circuit assembly  200 . The electronic circuit assembly  200  comprises a plurality of first circuit blocks  210   a ,  210   b,    210   c  and the second circuit block  220 . The first circuit blocks  210   a ,  210   b,    210   c  have their respective functions. The current load arising from the second circuit block  220  is usually less than any one of the first circuit blocks  210   a ,  210   b,    210   c.    
         [0037]    Referring to  FIG. 6 , the power supply system  100  comprises a plurality of main power supply units  110   a ,  110   b,    110   c , the low-current power supply unit  120 , and a plurality of enable signal lines  130   a ,  130   b,    130   c.    
         [0038]    The main power supply units  110   a ,  110   b,    110   c  and the low-current power supply unit  120  are rectifiers or any voltage or current converters, such as the low-dropouts (LDO) in the first embodiment. The main power supply units  110   a ,  110   b,    110   c  and the low-current power supply unit  120  differ in terms of the maximum loads they provide and their standby currents. The standby current of the low-current power supply unit  120  is usually lower than that of any one of the first circuit blocks  210   a ,  210   b,    210   c.    
         [0039]    Referring to  FIG. 6 , the main power supply units  110   a ,  110   b,    110   c  comprise main power input ends  112   a ,  112   b,    112   c  , main power output ends  114   a ,  114   b,    114   c  , and switch pins  116   a ,  116   b,    116   c,  respectively. The low-current power supply unit  120  comprises an auxiliary power input end  122  and an auxiliary power output end  124 . 
         [0040]    Referring to  FIG. 6 , the switch pins  116   a ,  116   b,    116   c  are each connected to an enable signal line  130 , and the enable signal lines  130  each operate in an enable mode and a shutdown mode. In the enable mode, the enable signal lines  130  each send enable signal ENB to a corresponding one of the switch pins  116   a ,  116   b,    116   c  to allow the corresponding one of the main power supply units  110   a ,  110   b,    110   c  to perform routine tasks, such that the main power supply unit  110  and the low-current power supply unit  120  supply power to the first circuit block  210  and the second circuit block  220  simultaneously. 
         [0041]    In the shutdown mode, the enable signal ENB interrupts, such that the main power supply unit  110  shuts down and stops supplying the output power to the first circuit block  210  to thereby interrupt standby current consumption thereof. Therefore, in the power supply system  100 , the standby current of at least one said main power supply unit  110  is interruptible, thereby reducing standby current consumption. 
         [0042]    In the second embodiment, it is feasible to switch between the modes of the enable signal lines  130  separately but unnecessary to enable or shut down all the main power supply units  110  simultaneously. 
         [0043]    For instance, when the electronic circuit assembly  200  is operating in the sleep mode, the enable signal lines  130  are concurrently set to the shutdown mode, such that in the power supply system  100  only the low-current power supply unit  120  stays in the standby state and consumes a standby current. 
         [0044]    When the electronic circuit assembly  200  is in the idle mode, a portion of the first circuit blocks  210   a ,  210   b,    210   c  shuts down, whereas the other portion of the first circuit blocks  210   a ,  210   b,    210   c  is enabled. At this point in time, only a portion of the enable signal lines  130   a ,  130   b,    130   c  is switched to the shutdown mode, whereas the other portion of the enable signal lines  130   a ,  130   b,    130   c  is switched to the enable mode. 
         [0045]    The first circuit blocks  210  which have shut down and the main power supply units  110  corresponding thereto stop standby current consumption. As soon as the electronic circuit assembly  200  switches to the normal operation mode, all the enable signal lines  130  switch to the enable mode to enable all the main power supply units  110   a ,  110   b,    110   c,  such that the power supply system  100  supplies power to all the first circuit blocks  210  and the second circuit block  220 . 
         [0046]    Referring to  FIG. 7 , in the third embodiment of the present invention, the power supply system  100  is adapted to supplying power to the electronic circuit assembly  200 . The electronic circuit assembly  200  comprises a plurality of first circuit blocks  210   a ,  210   b,    210   c  and the second circuit block  220 . 
         [0047]    The power supply system  100  comprises a plurality of main power supply units  110   a ,  110   b,    110   c  , the low-current power supply unit  120 , a plurality of enable signal lines  130   a ,  130   b,    141   a , an auxiliary power supply unit  141 , and at least a hub switch  142 . 
         [0048]    The auxiliary power supply unit  141  is connected to one of the first circuit block  210   a  by means of the hub switch  142 . The hub switch  142  is adapted to switching selectively to a pass or a break between the auxiliary power supply unit  141  and the first circuit block  210   a,  such that the auxiliary power supply unit  141  and the main power supply unit  110  simultaneously supply power to the corresponding one of the first circuit blocks  210 . 
         [0049]    If the first circuit block  210   a  operates at a high speed and therefore has a heavy load, the hub switch  142  will switch to a pass between the auxiliary power supply unit  141  and the first circuit block  210   a,  whereas the auxiliary power supply unit  141  will receive enable signal ENB from the enable signal line  130  and therefore start to operate, thereby supplying the auxiliary power to the corresponding one of the first circuit blocks  210 . 
         [0050]    If the first circuit block  210   a  operates at a low speed and therefore is loaded, the hub switch  142  will switch to a break between the auxiliary power supply unit  141  and the first circuit block  210   a,  whereas enable signal ENB will interrupt transmission to the auxiliary power supply unit  141  and therefore stop supplying the auxiliary power, and the auxiliary power supply unit  141  will shut down and stop the standby current consumption. 
         [0051]    From the perspective of the first circuit block  210   a  which generates heavy loads, the low-power-consuming main power supply unit  110  supplies power in a general operation state, and it is only when heavy-load operation is to begin that the auxiliary power supply unit  141  capable of supplying a high current starts. Therefore, the auxiliary power supply unit  141  is prevented from consuming unnecessary power in a general operation state. 
         [0052]    Referring to  FIG. 8 , in the fourth embodiment of the present invention, the power supply system  100  is adapted to supplying power to the electronic circuit assembly  200 . The electronic circuit assembly  200  comprises a plurality of first circuit blocks  210   a ,  210   b,    210   c , the second circuit block  220 , and third circuit block  230 . 
         [0053]    The power supply system  100  comprises a plurality of main power supply units  110   a ,  110   b,    110   c , a low-current power supply unit  120 , and at least a branched switch  150 . 
         [0054]    The third circuit block  230  is connected to one of the main power supply unit  110   b  by the branched switch  150 . The branched switch  150  selectively switches a pass or a break between the third circuit block  230  and the main power supply unit  110   b,  such that the main power supply unit  110   b  supplies power to a corresponding one of the first circuit blocks  210  and the third circuit block  230  simultaneously. 
         [0055]    In the situation where the third circuit block  230  is going to operate, the branched switch  150  switches to a pass between the third circuit block  230  and the main power supply unit  110   b,  so as for the main power supply unit  110   b  to not only supply power to a corresponding one of the first circuit blocks  210  but also supply power to the third circuit block  230 . 
         [0056]    In the situation where the third circuit block  230  is ready to shut down, the branched switch  150  switches to a break between the third circuit block  230  and the main power supply unit  110   b,  such that the third circuit block  230  shuts down completely and does not consume any standby current. 
         [0057]    Preferably, the load of the first circuit block  210  is less than the maximum allowable load thereof to ensure that the main power supply unit  110   b  can supply sufficient current to the first circuit block  210  and the third circuit block  230  simultaneously. 
         [0058]    Referring to  FIG. 9 , the hub switch  142  and the branched switch  150  are not necessarily used in different power supply systems  100 ; instead, the hub switch  142  and the branched switch  150  can also be used in the same power supply system  100  so as to perform optimal management of unnecessary standby power. 
         [0059]    The technical features of the present invention are disclosed above by preferred embodiments. However, persons skilled in the art should understand that the preferred embodiments are illustrative of the present invention only, but should not be interpreted as restrictive of the scope of the present invention. Therefore, slight changes and modifications made to the aforesaid embodiments by any persons skilled in the art should fall within the scope of the present invention, provided that the changes and modifications made do not depart from the spirit embodied in the present invention. Accordingly, the legal protection for the present invention should be defined by the appended claims.