Phase Margin Rule of Thumb
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1 Phase Margin Rule of Thumb
The phase margin is one of the robustness measures of a closed loop system under control. A low phase margin will lead to undesirable oscillations in the step response.
The phase margin can be determined from a:
 Bode Plot of the open loop transfer function magnitude crosses 0 dB
 Nichols Plot where the open loop transfer function magnitude crosses 0 dB
1.1 Minimum Recommended Phase Margin
A good rule of thumb for the phase margin is
Application  Minimum Phase Margin (deg)  

Tracking 
40 
Please feel free to add the recommended minimum phase margin for the applications you are familiar with.