I have been reviewing Maxim's Filter Primer application note for an idea to create my own 3D graphical utility. This goes in conjunction with the MFB derivation I posted a few weeks ago.
This work has certainly stressed the limits of my knowledge and understanding, so I need another set of brains to clarify a few things for me.
I want to start with a simple low pass filter per Maxim's app note, referring to figure 2b. I understand why they highlighted the jω axis in red as it is the frequency response of the filter and the 2D version as I am extremely familiar with regarding Bode plots (figure 2c). What I am confused about is the σ axis. Where did this comes from and how it is graphed especially since it is >0.
I can calculate the pole location of a simple RC filter (-1/RC), I know the cutoff frequency, time constant, and in my mind σ=0 during sinusoidal steady state.
What simple thing am I missing?
Thoughts and ideas will be greatly appreciated...especially at this hour.
This work has certainly stressed the limits of my knowledge and understanding, so I need another set of brains to clarify a few things for me.
I want to start with a simple low pass filter per Maxim's app note, referring to figure 2b. I understand why they highlighted the jω axis in red as it is the frequency response of the filter and the 2D version as I am extremely familiar with regarding Bode plots (figure 2c). What I am confused about is the σ axis. Where did this comes from and how it is graphed especially since it is >0.
I can calculate the pole location of a simple RC filter (-1/RC), I know the cutoff frequency, time constant, and in my mind σ=0 during sinusoidal steady state.
What simple thing am I missing?
Thoughts and ideas will be greatly appreciated...especially at this hour.