Research And Design Of High Performance Integrated Amplifiers

Despite of many years' development, integrated operational amplifiers are still widely used in modern integrated circuit and system-on-chip (SOC) and are raised rigorous requests of performance to meet the need of application. So the research of high performance operational amplifier design technology is still a hot spot.This thesis analyzed the development of the integrated operational amplifiers and its trend. Combined with the actual needs, this thesis using "system design, input stage, mid stage, output stage" as the thread, combining with two actual design examples, this thesis discussed the high performance operational amplifier design technology.This thesis first discussed the mid stage and output stage. Taking a high-precision differential amplifier for example, in terms of the system, and at the aim of low voltage, high gain low distortion and wide common-mode output range, we designed a multi-stage gain stage, a rail-to-rail output stage with quiescent current control and a nested-miller compensation structure. With these structures, it can archive 130dB gain and only -95dB THD under 2.7V supply voltage. The simulation results showed that the designing lived up to the expectation.We further focused on the system design and input stage design to satisfy the special needs of some amplifiers. Using the High-side current-sense amplifier as an example, aiming at the need of wide input common-mode range of high-side current sense, we discussed the system design methodology. Based on the analysis of previous wide common-mode range input stage solutions; we proposed a novel input stage which combined two ways. It can get a 0-28V input common-mode range which is independent of supply voltage.the circuit level system simulation results proved the proposed design methodology could fulfill the demands.This thesis used the current sense amplifier as the example and finished the floorplan and layout of the amplifier under 1.5μmBCD process. The chip was fabricated and tested. The testing results showed the proposed amplifier met the requirements well and the proposed design methodology is effective.