Abstract:
A print circuit board (PCB) includes a voltage regulator module (VRM), a plurality of loads, and a sense location for augmenting the voltage margin of the loads. The VRM is configured for charging the loads. Each load has a weight. The voltage value of the sense location equals to a summation of a corresponding weight value of a corresponding load multiplied by a corresponding voltage value of the load, for each of the plurality of loads on the PCB. An optimization method for the sense location on the PCB is also provided.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a printed circuit board (PCB), and particularly to an optimization method for a sense location on the PCB. 
         [0003]    2. Description of Related Art 
         [0004]    PCBs have played an important role in electrical production. Generally, a PCB can have a number of voltage regulator modules (VRMs) for charging one or more loads on the PCB. Each VRM has a sense location. A voltage of the sense location equals to a voltage of the corresponding VRM. The sense location acts as a mirror voltage source of the corresponding VRM, which affects voltage distribution on the PCB, and charges one or more loads on the PCB. The sense location affects performance of the corresponding VRM. An appropriate sense location of the VRM can augment voltage margins of the loads. PCB designers generally determine a sense location of a VRM manually, which generally cannot improve a performance of the corresponding VRM, and cannot augment the voltage margin of the loads. 
         [0005]    What is needed, therefore, is a PCB and an optimization method for a sense location on the PCB that can amend the aforementioned deficiency. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a schematic diagram of a PCB built in a simulation environment. 
           [0007]      FIG. 2  is a flowchart of an exemplary optimization method for a sense location on a PCB. 
           [0008]      FIG. 3  is a schematic diagram of an exemplary PCB. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Referring to  FIGS. 1-2 , an exemplary optimization method for a sense location on a printed circuit board (PCB) may include following blocks. Depending on the embodiment, additional blocks may be added, others deleted, and the ordering of the blocks may be changed. 
         [0010]    In block S 101 , a layout of a PCB  100  may be simulated using a simulation software. A detailed explanation of one exemplary embodiment of determining a sense location for the PCB  100  is detailed below. However, it may be understood that the embodiment is exemplary and may be used for other PCBs with different configurations. In the illustrated embodiment, the PCB  100  includes a sense location D, a voltage regulator module (VRM)  200 , and three loads C 1 , C 2 , and C 3 , such as a resistor, capacitor, inductor, and/or transistor, for example. The voltage of the VRM  200  is 1.5 volts (V) in one exemplary embodiment. The initialization position of the sense location D can be arbitrary. In one embodiment, the sense location D is positioned adjacent to the VRM  200 , however, the location of the sense location D is not limited thereto. An output voltage scope of the VRM  200  ranges from about 1.425V to about 1.575 V in one exemplary embodiment. The VRM  200  provides voltage for the loads C 1 , C 2 , and C 3 , and sets the voltage value of the sense location D as about 1.5V Parameters I 1 , I 2 , and I 3  act as current values of the loads C 1 , C 2 , and C 3  respectively. Parameters V 1 , V 2 , and V 3  act as voltage values of the loads C 1 , C 2 , and C 3  respectively. Afterwards, the current values I 1 , I 2 , and I 3  are set as about 2.6 amperes (A), about 9.6 A and about 2.38 A respectively, the voltage values V 1 , V 2 , and V 3  are equal to about 1.4697V, about 1.4599V, and about 1.4595V respectively. Therefore, a voltage margin of the load C 1  is a difference between the voltage value V 1  and the least voltage value 1.425V of the VRM  200 , i.e. about 44.7 millivolts (mV). A voltage margin of the load C 2  is a difference between the voltage value V 2  and the least voltage value about 1.425V of the VRM  200 , i.e. about 34.9 mV. A voltage margin of the load C 3  is a difference between the voltage value V 3  and the least voltage value about 1.425V of the VRM  200 , i.e. about 34.5 mV. 
         [0011]    In block S 102 , weight values for the loads C 1 , C 2 , and C 3  are calculated according to a weighted average method. In one embodiment, normalization values of the load current values I 1 , I 2 , and I 3  are set as the corresponding load weight values which are calculated as follows: 
         [0000]    
       
         
           
             
               
                 
                   
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         [0000]    wherein W 1  is the weight value for the load C 1 , W 2  is the weight value for the load C 2 , and W 3  is the weight value for the load C 3 . Thus, when the current value I 1  equals to about 2.6 A, the current value I 2  equals to about 9.6 A, and the current value I 3  equals to about 2.38 A, the weight value W 1  is about 0.18, the weight value W 2  is about 0.66, and the weight value W 3  is about 0.16. 
         [0012]    In block S 103 , the summation of the load weight values W 1 , W 2 , and W 3  multiply the corresponding load voltage values V 1 , V 2 , and V 3  respectively is calculated. In one embodiment, the calculation can be denoted as follows: 
         [0000]        VD=W 1 *V 1+ W 2* V 2+ W 3* V 3   (4) 
         [0000]    wherein VD is a voltage value for optimal sense locations on the PCB  100 . Thus, the voltage value VD equals to about 1.46V based on the voltage values V 1 , V 2 , V 3 , and the weight values W 1 , W 2 , and W 3  described above. All locations with the voltage value 1.46V on the PCB  100  can be set as the optimal sense locations, and form a distributing area for the optimal sense locations. 
         [0013]    In block S 104 , an optimal sense location in the distributing area is determined based on the layout convenience and feasibility. The VRM  200  sets the sense location voltage value as 1.5V, which changes voltage distribution on the PCB  100 . The voltage value V 1  of the load C 1  becomes about 1.5062V The voltage value V 2  of the load C 2  becomes about 1.4963V The voltage value V 3  of the load C 3  becomes about 1.4959V Therefore, the voltage margin of the load C 1  becomes a difference between the new voltage value V 1  and the most voltage value about 1.575V of the VRM  200 , i.e. about 68.8 mV. The voltage margin of the load C 2  becomes a difference between the new voltage value V 2  and the least voltage value about 1.425V of the VRM  200 , i.e. about 71.3 mV. The voltage margin of the load C 3  becomes a difference between the new voltage value V 3  and the least voltage value about 1.425V of the VRM  200 , i.e. about 70.9 mV. It can be seen that the voltage margins of the loads C 1 , C 2 , and C 3  can be augmented by the exemplary optimization method. 
         [0014]    Applying the above-mentioned exemplary optimization method on a PCB  300  as shown in  FIG. 3 , wherein the optimal sense location is D 1 . The position of D 1  is chosen because the voltage of this point is the voltage value VD (1.46V) based on the voltage values V 1 , V 2 , V 3 , and the weight values W 1 , W 2 , and W 3 . The PCB  300  includes a sense location D 1 , a VRM  400 , and three loads R 1 , R 2 , and R 3 . The sense location D 1  is located far from the VRM  400  however the sense location D 1  may be located on other positions of the PCB  100  depending on the voltage value VD (1.46V), layout convenience, and feasibility. The VRM  400  provides voltage for the loads R 1 , R 2 , and R 3 , and sets the voltage value of the sense location D 1  as about 1.5V may be understood that the voltage value about 1.5V of the sense location is because the voltage of the VRM  400  is about 1.5V. After determining the sense location, the voltage of the sense location is set as the voltage of the VRM to change voltage distribution on the PCB  300  and augment the voltage margins of the loads. That is to say, the sense location acts as a mirror voltage source of the VRM  400 . 
         [0015]    It is be understood that the VRM  400  of the PCB  300  can also be other types of direct current sources or alternating current sources, and the number of loads can also be adjusted. The weight values W 1 , W 2 , and W 3  can be determined by other types of weighted average methods. For example, the weight values W 1 , W 2 , and W 3  are square normalization values of the current values I 1 , I 2 , and I 3 , which can be denoted as follows: 
         [0000]    
       
         
           
             
               
                 
                   
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         [0000]    or, are simple average values of the number of the loads, which can be denoted as follows: 
         [0000]    
       
         
           
             
               
                 
                   
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         [0000]    wherein, n is the number of the loads. 
         [0016]    The foregoing description of the certain inventive embodiments of the disclosure has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in light of the above everything. The embodiments were chosen and described in order to explain the principles of the disclosure and their practical application so as to enable others of ordinary skill in the art to utilize the disclosure and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those of ordinary skill in the art to which the present disclosure pertains without departing from its spirit and scope. Accordingly, the scope of the present disclosure is defined by the appended claims rather than the foregoing description and the embodiments described therein.