Objective of compensation is to achieve stable operation when negative feedback is applied around the op amp. Miller - Use of a capacitor feeding back around a high-gain, inverting stage. Miller capacitor only Miller capacitor with an unity-gain buffer to block the forward path through the compensation capacitor. Can eliminate the RHP zero.
Two capacitors are always used in the previously reported three-stage amplifiers for large capacitive loads. In this paper, the single Miller capacitor compensation approach is introduced to reduce the area and improve the small signal and large signal performance of the amplifiers.
Using a single Miller compensation ca-pacitor in three-stage amplifiers can significantly reduce the total capacitor value, and therefore, the overall area of the amplifiers without influencing their stability. Pole-splitting and feedforward techniques are effectively combined to achieve better small-signal and large-signal performances.
It is observed that as the size of the compensation capacitor is increased, the low-frequency pole location ω1 decreases in frequency, and the high-frequency pole ω2 increases in frequency. The poles appear to “split” in frequency.
output that helps in improving the transient response of the am-plifier . A single Miller compensation capacitor is used to split the first pole and the third pole . The position of the second nondominant pole is dictated by the gain of the second stage, which decides the stability of the amplifier.
Topology of single Miller capacitor feedforward frequency compensation amplifier (SMFFC) where Z = g + sC ; i = 1 ; 2 ;L . From (4), the order of the numerator of is less than that of the denominator, so the stability of the amplifier is basically determined by the denominator.