A Two-Stage Weighted Capacitor Network for D/A-A/D Conversion

A two-stage weighted capacitor network for A/D and D/A conversion utilizing a feedback amplifier is described. The two-stage weighted capacitor DAC requires a smaller range of capacitor values than the conventional weighted capacitor DAC and is not subject to the nonlinear effects of parasitic capacitance. Experimental results of such a DAC implemented using a conventional n-channel metal-gate MOS process are presented. A discussion of the comparative accuracy and area of one-and two-stage weighted capacitor DAC's on the basis of capacitor tracking is given. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.