Prefabricated design experience for CMOS op amps

In courses that teach analog integrated circuit design, it is difficult to provide an opportunity to practice what is taught because of time required to design and fabricate an integrated circuit. This paper introduces a design approach to CMOS op amps which uses a prefabricated integrated circuit and yet maintains the flexibility of building almost 90% of the existing op amps. Building blocks that are repeated used in op amp design are identified that allow different architectures to be implemented. The performance is designed through the combination of building blocks and the current selected. The W/L values are not a variable in this approach. Examples are given with simulation results of using the building blocks to design various types of CMOS op amps.