[sdiy] Re: LVM

[TIm Daugard]

From: "Tony Clark" <clark at andrews.edu>

> that.  So I'd plan on making stuff that runs from 0-6V or something like
> that.  You can get near 0, but you still can't get right to the positive
> rail.

I currently run 0-12V and droool over some of the IC's I could use if I went to
5V. My designs could be scaled down to five volts with no problems - if the
opamps have the headroom.

>    OTOH, most chips for single-supply will run up to 5.5V-7V, so that
> should be good enough.

5.5V means I could use my huge stock pile of TTL chips!

>    And if it were me, I'd run it straight from 5V, not bipolar, and use a
> very good clean 2.5V reference for mid-biasing circuits.

All my designs use a reference between 0 and 12V. It's not always at 1/2 the
supply. I use a reference for each module that needs one. They range anywhere
from 1.5 V to one module that has a reference for 1/2 supply, 1/2 supply + 1.5
V, 1/2 supply - 1.5V. Another module has reference points at 1/3 rd supply and
2/3 rds supply.

I'm a beleiver in local references that keep noise of the reference lines. The
additional cost is minimal.

>    Just my comments on the topic.  :) . . . and mine . . .

Tim Daugard
AG4GZ 30.4078N 86.6227W
http://home.sprintmail.com/~daugard/synth.htm

. . . waiting for roofers who never show, and won't even answer their phone.