A 0.35 μm CMOS Operational Amplifier Using Multi-Path Frequency Compensation

摘要

In this paper, the use of a multi-path frequency compensation into a general purpose operational amplifier is described. The need of multi-stage and multi-path architecture for a general purpose operational amplifier is introduced. Then, the design rules to properly integrate a multi-path architecture are developed and the signal transfer function is presented and compared to the classic ones (like Miller based compensation). A 0.35 μm CMOS implementation of a multi-path amplifier with nested Miller compensation is described. Simulation result and silicon measurement proves the efficiency of this compensation in comparison to state of the art operational amplifier. The presented work exhibits 36 uA of quiescent current, 57° of phase margin with 100 pF of capacitive load and 704 kHz of unity gain frequency. The factor of merit, which combines these characteristics under a scalar form, shows that the results are above the state of the art.