Op amp supplies

[Nir Goren]

I'd like to generate a stable negative voltage for my Op amp. The best I
could come up with is using a “Low Noise, Switched Capacitor-Regulated
Voltage Inverters”, but as far as I can see this low noise is pretty noisy…

Is there a better way of doing things?

Nir Goren

VLSI center

BGU University

Tel : 08-6477154

Fax : 08-6477620

Email : ni...@bgumail.bgu.ac.il

[Robert Baer]

One could use either the switched capacitor scheme, or a switched
inductor, or a dual voltage supply - if a negative voltage is absolutely
needed.
If you do not like the noise at the output of the switched supplies,
then use a filter and/or a second regulator.
One could also use a single supply and either "tap" it with resistors,
or use a device that TI announced years ago that does the same thing
(only a lot better).
If the signal in and out of the op-amp will never be negative, then
use a rail-to-rail device and no negative supply.

[Rich Grise]

"Nir Goren" <ni...@bgumail.bgu.ac.il> wrote in message news:<bg8paa$gdn$1...@news.iucc.ac.il>...

> I'd like to generate a stable negative voltage for my Op amp. The best I

> could come up with is using a ?Low Noise, Switched Capacitor-Regulated
> Voltage Inverters?, but as far as I can see this low noise is pretty noisy?
>
>
What's the current demand? Would a 9V battery work?

Good Luck,
Rich