| 摘要 |
<p>An operational amplifier provides independent trimming of Vos for both high and low common mode input voltages. The amplifier includes complementary input pairs (MP1/MP2, MN1/MN2), and employs a steering circuit (24) which provides a tail current Itail to one pair when Vcm is less than a threshold voltage Vth, and provides Itail to the other pair when Vcm > Vth. The input pairs drive a load stage (14) which includes one or more trim inputs (TRIM1, TRIM2) that enable Vos to be varied with one or more trim signals applied to the trim inputs. A first trim signal generating circuit (26) provides a first trim signal (ΔI1) only when Vcm < Vth, and a second trim signal generating circuit (28) provides a second trim signal (ΔI2) to a trim input only whenVcm > Vth. This allows the input offset voltages at high and low Vcm to be adjusted independently.</p> |
