Automatic Calibration of a Reference Voltage

Abstract

A voltage calibration system includes three main units, which are a voltage level trimming unit, a trim detection unit, and a trim control unit. The three units work in conjunction with each other during a trimming operation in order to identify a tap voltage that is closest to a target voltage. In one embodiment, the voltage calibration system may be used to calibrate a voltage regulator. Upon commencement of calibration, the voltage regulator's feedback loop is open, and the target voltage is selected as the input for the feedback port of the amplifier. The voltage regulator serves as a voltage comparator that compares each tap voltage to the target voltage. When the calibration is complete, regulator's feedback loop is closed and the closest tap voltage to the target voltage is used as the regulator's input.

1 . (canceled) 
   
   
       2 . (canceled) 
   
   
       3 . (canceled) 
   
   
       4 . (canceled) 
   
   
       5 . (canceled) 
   
   
       6 . (canceled) 
   
   
       7 . (canceled) 
   
   
       8 . A system comprising:
 reference voltage logic effective to:   identify a target voltage;   increment a trim control counter value, wherein each incremented trim control counter value selects one of a plurality of tap voltages;   use each of the incremented trim control counter values to compare each of the plurality of tap voltages to the target voltage;   in response to comparing each of the plurality of tap voltages to the target voltage, detect whether one or more of the plurality of tap voltages is at a higher voltage level than the target voltage, the detecting resulting in a plurality of comparison values;   store the plurality of comparison values in a shift register;   determine which one of the plurality of tap voltages correlates to the target voltage based upon the plurality of comparison values, the determining resulting in a trimmed reference voltage; and   provide the trimmed reference voltage to one or more devices.   
   
   
       9 . (canceled) 
   
   
       10 . (canceled) 
   
   
       11 . The system of  claim 8  wherein the logic is further effective to:
 detect when the trim control counter has reached its maximum value;   identify a point at which the stored comparison values change value in response to detecting that the trim control counter has reached its maximum value, the identified point corresponding to a final trim setting value; and   use the final trim setting value as the trimmed reference voltage.   
   
   
       12 . The system of  claim 8  wherein the trimmed reference voltage regulates an unregulated power supply, the logic further effective to:
 select the target voltage as a feedback reference voltage;   identify that the trim control counter has reached its maximum value;   use a final trim setting value to select the trimmed reference voltage in response to identifying that the trim control counter has reached its maximum value; and   select the trimmed reference voltage as the feedback reference voltage in response to identifying that the trim control counter has reached its maximum value.   
   
   
       13 . The system of  claim 8  wherein the logic is further effective to:
 identify a reference voltage generator range;   identify a voltage range system requirement; and   calculate a number of plurality of tap voltages based upon the reference voltage generator range and the voltage range system requirement.   
   
   
       14 . The system of  claim 8  wherein the trimmed reference voltage is provided to a processing element architecture. 
   
   
       15 . A program product comprising:
 computer readable code stored in computer memory, the computer readable code being effective to:   increment a trim control counter value, wherein each incremented trim control counter value selects one of a plurality of tap voltages;   use each of the incremented trim control counter values to compare each of the plurality of tap voltages to the target voltage;   in response to comparing each of the plurality of tap voltages to the target voltage, detect whether one or more of the plurality of tap voltages is at a higher voltage level than the target voltage, the detecting resulting in a plurality of comparison values;   store the plurality of comparison values in a shift register;   determine which one of the plurality of tap voltages correlates to the target voltage based upon the plurality of comparison values, the determining resulting in a trimmed reference voltage; and   provide the trimmed reference voltage to one or more devices.   
   
   
       16 . (canceled) 
   
   
       17 . (canceled) 
   
   
       18 . The program product of  claim 15  wherein the computer readable code is further effective to:
 detect when the trim control counter has reached its maximum value;   identify a point at which the stored comparison values change value in response to detecting that the trim control counter has reached its maximum value, the identified point corresponding to a final trim setting value; and   use the final trim setting value as the trimmed reference voltage.   
   
   
       19 . The program product of  claim 15  wherein the trimmed reference voltage regulates an unregulated power supply, the computer readable code further effective to:
 select the target voltage as a feedback reference voltage;   identify that the trim control counter has reached its maximum value;   use a final trim setting value to select the trimmed reference voltage in response to identifying that the trim control counter has reached its maximum value; and   select the trimmed reference voltage as the feedback reference voltage in response to identifying that the trim control counter has reached its maximum value.   
   
   
       20 . The program product of  claim 15  wherein the computer readable code is further effective to:
 identify a reference voltage generator range;   identify a voltage range system requirement; and calculate a number of plurality of tap voltages based upon the reference voltage generator range and the voltage range system requirement.