OpAmp - easy question

[Mark Haase]

Hey--

9V is a weird voltage in a lot of projects. We used OpAmps in an
entry-level EE course where we had access to bench power supplies and
could dial in 9V.

Now I'm working at home, and the project that I am designing will have
an AC adapter which will provide 12V and 5V to the board. I'm wondering,
can I provide the OpAmp (probably an LM7414) with 9V by using a simple
voltage divider circuit? Or does the OpAmp have an internal resistance
thats significant, and if so, is it constant or variable?

Thanks in advance

--
|\/| /| |2 |<
mehaase(at)sas(dot)upenn(dot)edu

 

[Jim Thompson]

On Sat, 29 May 2004 14:56:19 -0400, Mark Haase <mehaase@earthlink.net>
wrote:

Hey--

9V is a weird voltage in a lot of projects. We used OpAmps in an
entry-level EE course where we had access to bench power supplies and
could dial in 9V.

Now I'm working at home, and the project that I am designing will have
an AC adapter which will provide 12V and 5V to the board. I'm wondering,
can I provide the OpAmp (probably an LM7414) with 9V by using a simple
voltage divider circuit? Or does the OpAmp have an internal resistance
thats significant, and if so, is it constant or variable?

Thanks in advance

Most OpAmps are (nearly) constant current, as far as quiescent current
is concerned. I'd just use the +12V supply for the OpAmps.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
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