Design for improving linearity of transconductor by canceling effect of mobility degradation from vertical field

Summary form only given. A transconductor using the bias offset technique is known as a linear MOS transconductor. In practice, however, the transfer characteristic exhibits nonlinearity due to mobility degradation from the vertical field. This paper proposes a design for improving linearity of the transconductor by canceling the effect of mobility degradation from the vertical field. This technique is to design the transconductance factors of the transistors to cancel the effect of mobility degradation. The results of SPICE simulation show that under the condition where the mobility degradation factor is 0.2 or less, the transconductance error of the conventional design becomes less than 15%, while that of the proposed design becomes less than 2%. Even if the tail current is changed, the transconductance error hardly increases.