From: Joerg Hansmann (info_at_jhansmann.de)
Date: 2002-03-08 22:32:36
Hi,
----- Original Message -----
From: Sar Saloth <sarsaloth_at_yahoo.com>
To: <buildcheapeeg_at_yahoogroups.com>
Sent: Friday, March 08, 2002 5:56 PM
Subject: Re: [buildcheapeeg] New file uploaded to buildcheapeeg
> I uploaded a suggested change.
I have put your suggested changes into a simulation.
(with LTSPICE, a full featured SPICE freeware version made
available by Linear Technology)
On the left side you see the pulse response with the TLC272
opamp, on the right side with the LT1114.
The upper circuit is as you have suggested, the lower part is my
original design (which BTW was done with the TLC272 or TLC277).
> It adds 3 passives (the values are just crude guesses, it should be tuned
> by hand). If the parts are not needed at all, just putting jumpers in
> brings it back to the original circuit.
> This circuit I have used before.
Looks like figure 14.25.c on page 946 "The Art of Electronics", Horowitz, Hill, second edition, 1999,
except for the component values.
> The source resistance should be pretty
> low, depending on the opamp. The feedback components should be just slow
> enough to give stability. For load at those frequencies and above, the
> regulation has to come from the 47uF source capacitor.
> For the LT1114, the source series resistor could probably be 20ohms or
> less, I couldn't find any Cload tolerance info on the LT1114 data sheet
> except that at 10nF (much less that 47uF) overshoot would be quite
> significant.
>
> Was there a special reason for using the LT1114?
Ask Andreas ;-)
Regards,
Joerg
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:40 BST