SPRUHJ1I January 2013 – October 2021 TMS320F2802-Q1 , TMS320F28026-Q1 , TMS320F28026F , TMS320F28027-Q1 , TMS320F28027F , TMS320F28027F-Q1 , TMS320F28052-Q1 , TMS320F28052F , TMS320F28052F-Q1 , TMS320F28052M , TMS320F28052M-Q1 , TMS320F28054-Q1 , TMS320F28054F , TMS320F28054F-Q1 , TMS320F28054M , TMS320F28054M-Q1 , TMS320F2806-Q1 , TMS320F28062-Q1 , TMS320F28062F , TMS320F28062F-Q1 , TMS320F28068F , TMS320F28068M , TMS320F28069-Q1 , TMS320F28069F , TMS320F28069F-Q1 , TMS320F28069M , TMS320F28069M-Q1
Classic control design models the system and derives the linear expressions close to the operating point, and uses Bode analysis to assess the stability through the gain margin and phase margin. Gain margin is the negative of the magnitude curve value at the frequency where the phase curve crosses -180°. Phase margin is the phase curve value above -180° at the frequency where the magnitude curve crosses 0 dB.
In order to allow the system to tolerate some non-linearity and model mismatch, typically 6- to 12-dB gain margin and 30- to 45-degree phase margin are needed.