1 Introduction

Operational amplifiers (op amps) employed in various applications may be called upon to amplify very small signals, requiring them to operate with high closed-loop gains in the hundreds, or thousands of volts per volt (V/V). If the required gain is in the range of tens to a few hundred V/V, a single precision op amp can provide the desired electrical performance. However, once the gain requirements become significantly higher, a single-stage approach mght not provide adequate levels of performance.