The block computes the loop gain and phase margins and checks that:- The gain margin is greater than 30 dB
- The phase margin is greater than 60 degrees
When computing the margins, the loop feedback sign must be specified. To determine the
feedback sign, check if the path defined by the IOs includes the feedback summation:- If the path includes the summation block, use positive feedback.
- If the path does not include the summation block, use the feedback defined by the
summation block.
The linearization IOs specified in the Check Gain and Phase Margins block includes
the summation block with negative feedback. Therefore, the feedback sign used to
compute the gain and phase margins must be positive.14 Model Verification