The Sum of Phase Margin and Effective Capacitance of Capacitors

Load capacitors may include all capacitors connected to the output and even all external capacitors or stray capacitors formed by the system, including circuit boards and probes. The capacitor adds phase difference to reduce the phase margin. By connecting the internal discharge resistor, the sum of the effective capacitors generates a pole of the moving gain and phase diagram. It is prudent to note that as the sum of capacitors increases, the phase margin begins to drop sharply. Capacitor 1000pf, or phase margin, is reduced to about 20-25 °, which is the minimum phase margin planned for a system according to Zhixu JEC's experience. For example, the sum of the small capacitors of the 30pf pushes the pole to a higher frequency in this lifting and phase diagram, and the lifting phase margin reaches 70 °.

In general, resistors with standard resistors in the range of 15 to 45 euros are used. The series circuit is essentially conducive to isolating the operational amplifier output and the capacitor, and the response is obtained from the operational amplifier output before the series circuit. The key to succession lies in series circuits rather than operational amplifiers.

Finally, some of the other ways to raise the phase margin are to strengthen the feedback network of the circuit. Due to the blocking effect of low output current, the unit gain is likely to be disturbed by instability.