Re: 3 dB bandwidth

In article <1LXve.32948$Vo6.19836@xxxxxxxxxxxxxxxxxxxxxxxxx>,
Kevin Aylward <see_website@xxxxxxxxxxxxx> wrote:

> Tony Williams wrote:
> > IMO, CMRR is an example of the use of dB which has no
> > technical justification, merely used as a convenient way
> > of printing large numbers in specs. If you use a diff
> > amp and want to see the effect of CMRR the first thing
> > you have to do is unconvert it anyway.

> I disagree completely. It far easier, in my book to go 80dB, or
> 120db then 10000000. There are less zeros to count and confuse
> one with.

1E6 is an easier ratio to see in a spec.

[snip]
> You need to move on mate.

20Log(Q1/Q2) to express large numbers is from the
slide rule days. It is more appropriate these days
to simply use 1E6, or whatever.

Using dB is also a less accurate use of the numbers.
Each 1dB change is about a 12% change in the linear
number..... that might be ok for audio, but for
linear instrumentation it can disguise large errors.

--
Tony Williams.
.

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