When [absolute value of [T.sub.m]] > 1, the stability analysis should combine with the

phase margin. Due to the existence of grid impedance and other reactive elements, resonance and harmonic distortion is easy to appear in AC system, which is different from DC system.

The gain and

phase margin for the baseline controller and the closed-loop adaptive controller under the uncertain model are calculated as in Appendix B:

The designed folded op amp has a gain of 105 dB,

phase margin of 80[degrees], CMRR of 110 dB, slew rate of 2.0 V/[micro]s, input common-mode range (ICMR) of 2.0 V, gain bandwidth of 1k[OMEGA], averaged power supply rejection ratio (PSRR) of 118 dB, output swing of 1.8 V, input-referred noise of 10.8 nV/[square root of (Hz)] at 1 MHz, power consumption of 0.88 mW at a power supply of 1.8 V, and load capacitance of 10 pF in the TT design corner.

Namely, in [5], typical problems and corresponding solutions related to AC current controllers used with the three-phase back-EMF-type load are outlined: (i) the time delay related controller dynamic performance deterioration, (ii) the choice of the controller crossover frequency [[omega].sub.1] related to the PWM switching frequency and required

phase margin values, and (iii) the modeling of the load and the VSI.

The purpose of phase compensator design in the frequency domain generally is to satisfy specifications on steady-state accuracy and

phase margin. There may also be a specification on the gain crossover frequency or closed loop bandwidth.

where DGM and DPM represent disk gain margin and disk

phase margin, respectively, and [r.sub.min] is calculated with

This scheme effectively reduces the load capacitance of CMFB amplifier, which is conducive to improving the OTA

phase margin and frequency characteristics.

This is done to meet certain design specifications such as percentage overshoot, rise time, settling time,

phase margin, and a specified bandwidth [29-33].

The FRA can be used to make Bode plots to perform gain and

phase margin analysis of filters, operational amplifiers, and control loop response.

The

phase margin (colored part of the bit) is caused by several effects: quantization error, shift due to oscillator tolerance, bit asymmetry due to the above mentioned physical layer components, and instability of the RX signal due to ringing on the bus lines caused by impedance mis-matches [4.] The first two effects are bit-rate dependent and the other two effects do not depend on the bit-rate.

4(c) that the

phase margin is around 90[degrees] at the crossover frequency of the current loop Ti (s), and it has higher bandwidth when compared with the voltage loop Tv (s).

Here, three specifications to be met are applied [10, 16-19] from the loop-shaping perspective: namely, the

phase margin specification, the robustness to gain variations, and the gain crossover frequency specification, which will be detailed below.