Patent ID: 6081106
Filing Date: 2000-06-27
Classification: G05F,Y10S

Abstract:
A precision power supply having an input terminal, an output terminal, and a common terminal, said power supply comprising:an adjustable regulator having a voltage input coupled to said power supply input terminal, a voltage output coupled to said power supply output terminal, and an adjustment input, said adjustable regulator producing an output terminal voltage equal to said adjustment input voltage added to a reference voltage,a voltage divider having a divider output coupled to said power supply output terminal, a divider common coupled to said power supply common terminal, and a divider adjustment output coupled to said adjustable regulator adjustment input;said voltage divider comprising a plurality n of individual resistors of equal values fabricated on a common substrate having a center wherein n/2 resistors are on one side of said center, and n/2 resistors are on the other side of said center, m of said resistors connected in parallel to form a first resistor connected between said voltage divider output and said voltage divider adjustment output, n-m of said resistors connected in parallel to form a second resistor connected between said voltage divider adjustment output and said divider commons;said m first resistors and said n-m second resistors distributed equally on each side of said center and thermally coupled to each other such that thermal gradients across the area of said m first resistors and said n-m second resistors have minimum effect on the divider ratio formed by dividing said divider adjustment output by said divider output,wherein said n is an integer larger than said m.