A Novel High Performance CMOS Cascoded Operational Amplifier for Process Instrumentation Based Applications

In this contribution, a highly efficient CMOS based operational amplifier has been presented that uses the circuit arrangement so as to provide an extra bias current into a conventional CMOS differential input signal which is required for high performance of the system. The design of a high performance CMOS operational amplifier (op-amp) with level 3 parameters at 0.2ìm CMOS technology, that makes the use of stacked (cascode) current source techniques. This innovative approach benefits the chances operated by full complementary implementations of well known sub-circuits, to enhance the speed of such an operational amplifier and to better organize and economize layout generation. Unlike conventional techniques such as the cascoding, which increases the gain by increasing the output resistance, the replica-amp technique increases the gain by matching the main and the replica amps. Among the advantages of the replica op-amp technique are low supply, high swing, and effectiveness with resistive loads. The pSpice simulations of the op-amp shows a unity gain bandwidth of 30 MHz and a DC gain of 62 dB, when using a bias current of 90 ìA and a load capacitance of 10 pF.