Patent ID: 6882185

Claim:
An apparatus for generating a current pair I p , I m wherein the ratio of the pair is exponentially related to a control signal, and wherein one of I p and I m is one of greater than a minimum value and less than a maximum value, the apparatus comprising: a differential amplifier including a first current source that generates a fixed current I fixed , a pair of BJTs, each BJT including a base and wherein the control signal is coupled to the bases of the BJTs, and a pair of FET current mirrors operatively coupled to the differential amplifier in combination with a feedback correction circuit, the differential amplifier generating the current pair I m , I p as a function of the control signal and a bias current I bias , where I bias is a function of a boost current I boost , wherein the sum of I p and I m equals I bias ; and the correction feedback circuit, coupled to the differential amplifier, for sensing one of I m and I p and generating the boost current I boost when one of I m and I p is one of less than the minimum value and greater than the maximum value, wherein I boost is proportional to a difference between one of the minimum value and the maximum value and one of I m and I p , and I bias is equal to the sum of I boost and the fixed current I fixed .