At 03:53 AM 24/05/2013, you wrote:
>Hi all,
>
>I'm trying to power some MOSFET drivers (which can be powered from up to
>18V) with a battery pack(s) whose voltage may be anywhere from 16-24V. I
>can opt for the "correct"(?) design and just use a linear regulator, but
>I don't want to add a whole regulator just for the MOSFET driver. Is it
>considered acceptable engineering practice to use a Zener diode in
>series with the power supply rail, reverse biased, to act as a 10V (for
>example) drop to power the IC? That way, the IC supply voltage will be
>from 6-16V, which is acceptable. It seems I'd also need something like a
>10k resistor to GND in parallel with the IC to maintain a high enough
>current through the Zener to keep it in the intended reverse voltage range=
..
>
>SPICE simulation says it's okay, but I have a feeling there's something
>I don't know...

Sounds like you've got the bases covered.  A ~10V zener has a reasonably
sharp knee, and your 10K makes sure you're around it.

Note that using a zener increases the voltage range from to 1.5:1 to 2.7:1,
plus tolerances on the zener, but if you're okay with that, it should work.

The zener will conduct as a diode in the forward direction, so you'll
probably kill the MOSFET driver instantly if the battery gets reversed.

--sp =20

--=20
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