Low pass filter - LC or RC phase response better for specific attenuation level?

[julian1]

I know that LC can have much sharper attenuation response.

But what about phase differences at a specific attenuation level?

Does an LC circuit have less phase change than an RC circuit - or are they the same for a given attenuation level?

I'm thinking about the case of frequency compensation, where the goal is to roll-off the gain, between amplifier sections, before negative feedback turns into positive feedback due to phase lag in the different sections.

Most of the filters seem to be RC rather than LC - ie in the internal compensation of an op-amp between diff-amp and output section.

[danadak]

RC basically a one pole solution, LC two, therefore phase contribution is greater in
LC. LC also exhibits resonance behavior, so in this case of LPF examples show greater
G and phase change. Attached, you will see great phase change with LC.

RC single pole are inherently loss, but its possible to get G out of a purely passive
RC. See attached.

Regards, Dana.

[danadak]

"Normally" active filters employ just RC and OpAmps. This allows the
generation of L type characteristics for use in the filter. There are
a number of issues using L, T dependence, size, microphonics, sens-
itivities to component changes....

Regards, Dana.