OPAMP_AS_MILLIVOLT_REFERENCE

Published:2009/7/15 22:19:00 Author:Jessie | From:SeekIC

R4 at input of voltage-foilower opamp permits varying ref erence voltage from 0 up to limit of zener. A2 compensates for loading of zener by R4. Dual opamp cannot be used because negative supply terminal of A2, must be slightly more negative than -3 V common to permit linear output operation down to 0 V. If additional load current is required, NPN booster transistor can be used with A2.-W. G. Jung, IC Op-Amp Cookbook, Howard VV, Sams, Indianapolis, IN, 1974, p 155-157.



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