[sdiy] best way to convert bipolar to Cmos compatible square/gate?

[Colin Hinz]

On Fri, 21 Sep 2012, Oscar Salas wrote:

> A common op-amp as comparator followed by a 30K resistor to the CMOS input
> does the job.
> CMOS input has clamping diodes to its rails. Maximum Rating is I think (
> see your data-sheet) 10mA. So for a +/-15V supply a 30K will limit the
> current through the clamping diodes about 5mA.

Basing a design on a protection circuit (and in particular an on-die
circuit which one can only hope is up to spec, and will remain up to
spec despite being exercised continually) seems unnecessarily risky,
especially when alternate approaches are readily available.

- Colin