Patent ID: 7538614

Claim:
A differential amplifier having a differential input and a first output, the differential amplifier comprising: a differential input stage with an intermediate differential output driving a first resistor that defines a first current; wherein the first current is split into first and second input currents, a reference stage that defines a reference voltage, a second resistor functionally connected between the reference voltage and the first output that defines a feedback current, wherein the feedback current is split into first and second feedback currents, a first current summation circuit that accepts one of the split input currents and one of the split feedback currents and defines an error current, a second current summation circuit that accepts the other one of the split input currents and the other one of the split feedback currents and also defines the error current, a high transimpedance converter that accepts the error current outputs the first output, a first output voltage is a function of the error current times a transimpedance, wherein the transimpedance is very large, and wherein varying the reference voltage varies the first output voltage while largely leaving the performance of the differential amplifier unchanged.