Exponential current generator and method

pm p m m pboost p m boost p mAn apparatus and method of generating a current pair I, Iwhere the ratio of the pair is exponentially related to a control signal, and where either Ior Iis greater than or less than a minimum or maximum value includes a feedback correction circuit used to sense the value of Ior I. The correction circuit supplies a boost current Iwhen the sensed value of Ior Iis less than or greater than the minimum or maximum value. Iis preferably maintained proportional to the difference of the desired value and Ior I.