Patent ID: 8536946
Filing Date: 2013-09-17
Classification: H03F

Abstract:
1. An output error compensation method, adapted to a multi-input operational amplifier, wherein the multi-input operational amplifier has a plurality of differential pairs, and each of the differential pairs has a first input terminal coupled to an output terminal of the multi-input operational amplifier and a second input terminal for receiving an input voltage, wherein the input voltage is set at either of a plurality of levels, the output error compensation method comprising: regarding a specific combination of the input voltages received by the second input terminals of the differential pairs, executing following steps (i)-(iv): (i) obtaining a plurality of original transconductances of the differential pairs; (ii) obtaining a plurality of transconductance differences respectively corresponding to a plurality of adjustable differential pairs among the differential pairs according to the original transconductances; (iii) obtaining a plurality of adjusted transconductances respectively corresponding to the adjustable differential pairs according to the transconductance differences and the original transconductances; and (iv) respectively adjusting transconductances of the adjustable differential pairs according to the adjusted transconductances so that an output voltage matches a respective expected value when each of a plurality of combinations of the input voltages is received.