[sdiy] Outputs grounded! Re: SSI2164 datasheet updated

[Neil Johnson]

KD KD wrote:
> Many contradictions in this so far from 2015 and 2018 debate but a general
> path in the dark forest emerges from it for a quick proposal such as for a
> unused cell/s:
> 1: Input is directly to GND but can also be left open.
> 2: Control pin gets min +3V as to shut off any current in mirrors and
> internal feedback loop.
> 3: Output left open.

Putting +3V on the control pin does not shut off the current mirrors,
it just causes current to flow in a different internal path.

> Else, leaving all pins open proofed working for 10k units (DIXON) without
> any adverse effects no matter compliance or other data sheet figures.

Oh well, must be right then.  After all ten thousand is a big number indeed.

*shrug*

> 1: Output cant be tied via resistor to a potential like GND as LM13700 like
>     current to voltage conversion due to bad compliance figures in 2164.
>
> So where does it leave the datasheet statement "output to GND" on unused cells?

Where indeed.  I guess on the one hand you could take the advice of
analog chip design industry veterans who's IC designs have shipped in
billions of parts and about whose design we are discussing, or on the
other hand some bloke off the interwebs who says otherwise.  But feel
free to cast your vote as you feel appropriate.

Neil
-- 
http://www.njohnson.co.uk