Design of wideband CMOS current-mode operational amplifiers

This paper presents the design of CMOS current operational amplifiers for high frequency applications. A new design technique is proposed to enhance the frequency behavior of the current amplifier. This approach makes use of current steering to increase the non-dominant pole, and hence, the unity gain bandwidth of the amplifier. A single input differential output current amplifier is described but it can be easily modified for differential input operation. Simulations using HSPICE are presented to confirm the operation of the proposed circuits. The amplifies exhibits a unity gain bandwidth of 200 MHz and a settling time of 5 ns.