At 11:11 AM 10/19/99 -0400, Wagner wrote:
>LMC660 is a nice amplifier, low cost, low drift, low consume and more,
>works great in single +5V supply, one of the type that catch the eye for
>price/performance, but with the high impedance input CMOS there is a
>catch; is the crazy oscillation if configured as a follower (output
>connected to the negative input). The manufacturer recommend to install
>a RC network (see documentation) to avoid oscillations in this
>configuration.

I've looked up this problem. You're right: configuring the LMC660 as a
non-inverting voltage follower has a problem. It's due to the input voltage
range not being rail-rail although the output range is. Therefore a lot of
clipping and ringing will occur if the output voltage gets within 2 V of
rail, similar to that of non-rail-rail op-amps.

So connecting the LMC660 as a non-inverting unity gain follower on low
voltage supplies is not advisable.

================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral@lcfltd.com
Least Cost Formulations, Ltd.                   URL: http://lcfltd.com/
824 Timberlake Drive                            Tel: 757-467-0954
Virginia Beach, VA 23464-3239                   Fax: 757-467-2947

"Vere scire est per causae scire"
================================================================