Stability Analysis of Feedback Circuits in Analog Multiplier Designs

Feedback technique based on amplifier is widely used in analog circuit designs. However, it may introduce instability. Thus it is important to analyze the stability of feedback circuits based on amplifier. In this paper, the stability analysis of feedback circuits in analog multiplier designs considering the influence of parasitic capacitance is given. Additionally, the stable conditions for feedback circuits are shown. Based on the stability analysis, an improved feedback circuit fabricated under CMOS 0.6 mum process is proposed to avoid oscillation, and the experimental results show that this proposed method can improve the stability of feedback circuits very well.