Patent ID: 6555934
Filing Date: 2003-04-29
Classification: H05K

Abstract:
A ground voltage control system comprising:a working ground reference; an isolated ground reference connected to the working ground reference such that current flow in the isolated ground reference is reduced below a predetermined threshold; a first voltage controller comprising a first sense input connected to the isolated ground reference, a second sense input connected to the working ground reference, and a first controller output connected to the working ground reference, the first controller output carrying a voltage compensation signal to drive current into and out of the working ground reference to offset a voltage difference sensed between the isolated ground reference and the working ground reference; and a second voltage controller comprising a third sense input connected to the isolated ground reference, a fourth sense input connected to the working ground reference, and a second controller output connected to the working ground reference, the second controller output carrying an additional voltage compensation signal to drive the working ground reference to offset an additional voltage difference sensed between the isolated ground reference and the working ground reference.