Re: Low pass filter with chopper stabilized opamp

From: Larry Brasfield (donotspam_larry_brasfield_at_hotmail.com)
Date: 02/08/05 

Date: Tue, 8 Feb 2005 05:06:11 -0800

"Mook Johnson" <mook@mook.net> wrote in message
 news:S7WNd.19649$sr1.8331@fe2.texas.rr.com...
> I'm looking for a anti-alias filter for my sub-hertz filter discussed previously. (thanks for the responses)
>
> For this I need at least 2nd order to prevent aliasing down to the frequencies of interest to me. Looks like I wont be able to
> avoid an OP-amp in the signal chain so I'm looking for one with as little DC drift as possible.
>
> Chopper stabilized (like the linear tech "zero drift") appear to to be some of the betterones for low drift with temeprature.
> With the current non-chopper precision Analog Devices amps there is considerable drift with temperature.
>
> My question is if there are any special considerations for a chopper amplifier when configuring it as a low pass filter?

You need to be careful that the amplifier is not
asked to process signals near the chopping
frequency. This means getting at least that
part of the input spectrum reduced passively. 

-- 
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.
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