Abstract:
The present invention is a system and method for sensing the voltage at multiple sense points. The present invention acquires optimal feedback from a plurality of sources including those integrated on the same motherboard, for populated or unpopulated connectors and for adapter cards plugged into the connectors, for the purpose of controlling the voltage regulator output. The voltage regulator, connected to a logic system, provides voltage to those connectors needing the voltage.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to voltage regulation and, more specifically, to improvements to systems and methods for sensing the voltage at multiple sense points. 
     BACKGROUND OF THE INVENTION 
     Large scale integration of electronic circuits continues to require lower voltages as the circuit dimensions keep dropping. Circuits that generally were designed with 5V circuits on early personal computers now are fed with circuits less than 1.5V, and the trend of lowering the voltage needs continues. As the frequency of operation continues to rise and circuit density increases, power needs have risen from a few watts per device to more than 100 watts for many devices. As voltage drops and power needs increase, current must go up. Future memory currents of  100 A or more will not be uncommon in servers. 
     When voltages were at 5V, the noise margin was typically 0.8V to ground or above 2V to power. Current voltage levels are now less than noise levels used to be, hence a requirement for better accuracy in delivery power. 
     Newer chip and adapter technology, including new memory technology, have more voltages, lower voltages, higher currents and more loads than previously but do not provide an improved power delivery mechanism to compensate. For example, current art senses the voltage on the power plane of the motherboard in the area of memory connectors for feedback control and does not accurately reflect the losses through the memory connectors or on the memory card or the ability to account for dynamic configuration changes. 
     There presently is a need for a system and method for sensing the voltage at multiple sense points. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is a system and method for sensing the voltage at multiple sense points. The system and method of the present invention acquires optimal feedback from a plurality of sources including those integrated on the same motherboard, for populated or unpopulated connectors and for adapter cards plugged into the connectors, for the purpose of controlling the voltage regulator output. In another embodiment, the system and method of the present invention continuously monitors voltage feedback from sense point pairs and determines, using logic, an optimal voltage for regulation and provides that optimal voltage to the voltage regulator. 
     The illustrative aspects of the present invention are designed to solve one or more of the problems herein described and/or one or more other problems not discussed. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       These and other features of the invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings that depict various embodiments of the invention, in which: 
         FIG. 1A  is a diagram which illustrates a basic system with probes at the power plane. 
         FIG. 1B  is a diagram which illustrates a basic system with a dedicated sense point pair on a single connector at the power plane. 
         FIG. 2  illustrates an embodiment of the present invention with remote sensors (sense pairs) at each connector for sensing voltage at each connector, selecting the sense pair closest to violation, and hard wiring the selected sense pair to a voltage regulator. 
         FIG. 3  illustrates the system of the present invention where the sense pairs are connected to a smart switch and the smart switch determines which sense pair is optimum for regulation and provides a single feedback to the voltage regulator for regulation. 
         FIG. 4  illustrates the system of the present invention for continuously sensing from multiple connectors having a smart circuit for determining, using a logic system, an optimum voltage for regulation and providing the optimum voltage to the regulator. 
         FIG. 5  illustrates the improved method of the present invention for sensing, by the smart circuit, from multiple connectors and, by the smart circuit, using a logic system to return an optimum voltage to the regulator. 
     
    
    
     The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represent like elements between the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides a system and method for sensing the voltage at multiple sense points. 
       FIG. 1A  shows a prior art System  100 A on a motherboard for sensing Voltage Feedback  104  near Connectors  102  utilizing Voltage Regulator  103 . A motherboard is the central or primary circuit board making up a complex electronic system, such as a modern computer. It could also be on a PDA or even a cell phone. It is also known as a mainboard, baseboard, system board, or, on Apple computers, a logic board. The basic purpose of the motherboard is to provide the electrical and logical connections by which the other components of the system communicate. A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. Voltage Regulator  103  accepts the positive and negative returns of Voltage Feedback  104  at Sensor+  105 , Sensor−  107  through Remote Sense Lines  108 A. Single Probe Points  106 A are taken from regions on the motherboard thought by previous engineers to give the best results but this is problematic as the Connectors  102  generally can be populated with adapters or other electronic devices. Also, Connectors  102  can have varying amounts of load and voltage drop because the adapters or other electronic devices can be built from different manufacturers with different power characteristics due to component type and quantity. For example, it is common in the industry for adapters or other electronic devices that can plug into the same connector to have cards which could be populated with any number of memory devices, plus a few extra components—all of which consume power. This causes the various power requirements. The Voltage Regulator  103  has a difficult time determining the power needs of the Connectors  102  and providing the power needs to the Connectors  102 . 
     Most systems of the prior art, have predetermined sense points without knowing ahead of time which connectors will be populated nor for those that will be populated with how much load. The electrical current (more information on electrical currents can be found at http://amasci.com/amateur/elecdir.html) passing through the remote sense lines is only a micro-Amp or so, yielding a negligible voltage drop. Voltage sensing on the adapter side of the connector will be much more accurate than the art of  FIG. 1A . 
       FIG. 1B  shows prior art System  100 B with an improvement over System  100 A where a Dedicated Sense Pin Pair  106 B on a Connector  110 B can return the voltage read at a point on the adapter immediately at the side of the connector. This way, the voltage drop across the connector power pins can be taken into account. For adapter cards with heavy loads the voltage drop across the connector can be significant. However, the current passing through the remote sense lines  108 B is only a micro-Amp or so, yielding a negligible voltage drop. Voltage sensing on the adapter side of the connector will be much more accurate than the art of  FIG. 1A . 
     Not shown in  FIG. 1B  is an improved method over prior art where the sense signals are not connected to dedicated pins for this purpose but the motherboard wiring is changed to recover two power pins and convert them to sense lines for feedback control. In cases where sufficient power delivery pins allow this and where probing accuracy is the greater concern because of tight tolerances this invention is applicable. 
     A further improvement can be made by allowing the adaptor vendor to place remote remote sensors at a strategic point on the card, closer to the load. Even though many types of adapters may be plugged into a connector, each different adapter generally has a known static signature and the best place to locate the sensor is known and is accommodated. 
       FIG. 2  shows a System  200  of the present invention which is an improvement from the prior art where a dedicated sense Power Point Pair  202  on each Connector  102  utilizing Remote Sense Lines  204  can return the Voltage via Voltage Return  104  at a point immediately at the Sides  206  of each of the Connectors  102 . This way, the voltage drop across the Power Point Pair  202  can be taken into account. For adapter cards, with heavy loads, the voltage drop across the connector can be significant. 
       FIG. 2  further shows the System  200  of the present invention for sensing voltage utilizing Power Point Pairs  202  connected to the Connector Sides  206  of each of Connectors  102  and feeding the voltage readings to the Voltage Regulator  103 . A new system may be tested by inserting various adapters into the Connector Sides  206  to determine which sense point (using Remote Sense Lines  204 , Power Point Pairs  202  and Voltage Regulator  103 ) returns the highest voltage and which returns the lowest voltage and select the one closest to violation of a policy. It is determined which of the Connectors  102  has a high or low voltage requirement. The chosen remote sense pair of the Power Point Pairs  202  is then physically connected as input for the Voltage Regulator  103  to regulate with. There can be a load test against System  300  to select the optimal feedback that need only occur once in the life of the system. Load testing is the process of creating demand on a system or device and measuring its response. 
       FIG. 3  shows another embodiment  300  where a single feedback is provided to the Regulator  103  by way of a Smart Switch  303  comprising Analog MUX  306  and Logic  304 . The Smart Switch  303  monitors the various remote sense points (Remote Sense Lines  204 ) from the Connectors  102  as sensed at Connector Sides  206  and determines which pair is optimum for voltage regulation. The Smart Switch  303  then closes contact between the chosen sense point and Regulator  103  so it can regulate to that point. The Smart Switch  303  can monitor the various remote sense points every time the system is brought up, or, whenever there is a change in the number or location or type of adapter, and choose the appropriate remote sense pair. The advantage over the embodiment in  FIG. 2  is that there is no need to choose an optimal sense pair at first build. Rather, the system is now empowered to choose the correct sense pair. 
       FIG. 4  also shows the system of the present invention  400  where a single feedback is provided to the Regulator  103  by way of a Smart Circuit  402 . Smart Circuit  402 , along with Logic  304 , continuously monitors the various remote sense points from the Connectors  102  at Connector Sides  206  along the Remote Sense Lines  204  and, through algorithms stored in Logic  304 , or other logic, feeds the data for optimal voltage to the Voltage Regulator  103  so that it can feed the proper regulated voltage to that particular feed point. The sensed voltages are passed to an Analog MUX  401  which switches, one by one, the sensed voltage from each of the Connectors  102  to A/D Converter  404  which converts the sensed voltage to digital form and passes the digital form to the Smart Circuit  402 . The Smart Circuit  402  continuously monitors the voltage so that it can dynamically determine an optimum voltage to be regulated by Regulator  103  using Logic  304 . Once determined, Smart Circuit  402  passes the optimum voltage to D/A Converter  406  which passes the optimum voltage to Regulator  103 . 
       FIG. 5  illustrates the improved Method  500  of the present invention where the sense signals are connected to dedicated pins for the purpose of the present invention. However, the motherboard wiring is changed to recover two power pins and convert them to sense lines for feedback control. In cases where sufficient power delivery pins allow this and where probing accuracy is the greater concern because of tight tolerances this invention is applicable. The Method  500  starts at Step  502  and continues to Step  504  where, at a smart circuit, voltage feedback from components&#39; sense point pairs is received. At Step  506 , at the smart circuit, an optimal voltage for voltage regulation using logic is determined. At Step  508 , by the smart circuit, the optimal voltage for voltage regulation is provided to a voltage regulator. Because the voltage feedback from the components&#39; sense point pairs is continuously monitored, the Method  500  returns to Step  504  where, at a smart circuit, voltage feedback from components&#39; sense point pairs is received and the Method  500  continues as described above. 
     A further part of this invention is allowing the adaptor vendor to place remote sense at a strategic point on the card, closer to the load. Even though many types of adapters may be plugged into this connector, each different adapter generally has a known static signature and the best place to locate the sensor is known and is accommodated. 
     The foregoing description of various aspects of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to an individual in the art are included within the scope of the invention as defined by the accompanying claims.