A Novel Low-Voltage Differential Double Flipped Voltage Follower Structure and Its Derivatives
Abhishek Shrivastava, Gaurav Musalgaonkar and Akshi
This paper proposes the low-voltage differential double flipped voltage follower (DDFVF) structure. Flipped voltage follower cell is used to reduce the voltage supply requirement and to stabilization of DC point in order to achieve desirable gain, when used as an amplifier. Using the basic DDFVF structure, various low-voltage analog cells such as differential amplifiers and two-stage operational amplifier are derived and their applications like integrator and differentiator are designed to validate the low-voltage cell designs. The differential amplifier obtained from the basic structure exhibits the bandwidth of 26 GHz, which is recorded as the most attracting feature of the design.The stability of two-stage operational amplifier has also been discussed by the mean of phase margin and is shown in the results. The results are simulated using SPICE in TSMC 0.18μm CMOS technology and with operating voltage supply of +1V. All the derivatives are designed to prove the effectiveness of the DDFVF structure.
Keywords: Flipped voltage follower, Low-voltage, Two-stage operational amplifier, Differential amplifier, Common mode rejection Ratio, Dominant pole, Unity-gain bandwidth.