A New High Drive Class-AB FVF-Based Second Generation Voltage Conveyor

摘要

A new low-voltage low-power class-AB second generation voltage conveyor (VCII) is presented. The proposed circuit is based on an improved class-AB flipped voltage follower (FVF) designed by adding a simple negative feedback loop to the conventional class-AB circuit. This modification ensures high current drive capability of at least 2 mA for both falling and rising edges of input signal along with very low 2-m Omega output impedance and high accuracy. Benefiting from the new class-AB FVF, the proposed VCII features a very simple implementation, extremely low impedance at Y and Z terminals (2 m Omega), high impedance at X terminal (370 k Omega) and high accuracy in current and voltage conveying (99% and 98%, respectively). Moreover, it exhibits current drive capability 117.6 times larger than its bias current (17 mu A). The circuit occupies 381.5 mu m x 197 mu m area. The application of the proposed VCII as a voltage integrator is also presented. Simulation results using PSpice and 0.35-mu m CMOS technology with +/- 1.65-V supply voltage are provided to demonstrate the presented theory. A comparison with the literature is also provided.