[sdiy] uA726 transistor array

[Grant Richter]

> 
> The only difference between the THAT 1xx series of transistor arrays and
> others is that they used dialectric isolation.  I don't know what problems
> this
> might create or how it might perform thermally.  As far as I know, the new
> THAT
> 2xx series is going to be juntion issolated, or at least, that is what I
> thought
> I read about them.
> 
My guess is that dielectric isolation, also presents thermal isolation and
would decouple the transistors both thermally and electrically from the
common substrate. That means your heater transistor and sense transistor are
isolated and would make the temperature control loop very hard to stabilize.

It is hard enough to stabilize even in a CA3046.