[sdiy] mosfet/cmos opamp

[Ian Fritz]

At 09:20 PM 10/27/2010, dan snazelle wrote:
>i have plenty of 4069's/4049's but i was reading some articles saying that 
>mosfet opamps offer the advantages of mosfet with a regular opamp design.
>
>sounded great till i realized how few and far between they are

Yes, they are unique.

Intersil lists the CA3140 as in production.  Jameco has them for $1.  Their 
high input impedance is impossible to beat without paying a lot more.  I 
use them in my S/H module  -- at the time I developed it they were $.50 or 
so.  I recommend folks stock up on them now, while the price is reasonable.

Ian