Patent ID: 7733179

Claim:
A differential amplifier comprising: (a) an input stage including first and second input transistors and first and second load devices, each of the first and second input transistors including a control electrode and first and second electrodes, the first electrodes of the first and second input transistors being coupled together, the second electrode of the first input transistor being coupled by a first conductor to a terminal of the first load device, the second electrode of the second input transistor being coupled by a second conductor to a terminal of the second load device; and (b) a combined CMFB (common mode feedback) and offset correction circuit including an offset correction section and a CMFB section, the CMFB section including first, second and third transistors each including a control electrode and first and second electrodes, the first electrodes of the first and second transistors being coupled together by a third conductor, the second electrode of the first transistor being coupled to a first reference voltage, the second electrode of the second transistor being coupled to the first conductor, a common mode output reference voltage being provided on the control electrode of the first transistor, the offset correction section including an offset generator circuit and the third transistor, a first output of the offset generator circuit being coupled to a control electrode of the third transistor, a first electrode of the third transistor being coupled to the third conductor, a second electrode of the third transistor being coupled to the second conductor, a second output of the offset generator circuit being coupled to the control electrode of the second transistor; and the third conductor being coupled by the first tail current source to a second reference voltage.