Summary: | 碩士 === 長庚大學 === 電子工程研究所 === 95 === In an analog system , an operational amplifier is a both basic and important component. With the advancement of the semiconductor processing technology , low voltage design is often required in many circuits.
A rail-to-rail design can increase the operation range of the operational amplifier to avoid the signal distortion due to saturation . In the input stage , a constant-gm design can enhance the linearly of the circuit . These design points are very important for the low voltage OPAMP circuit .
In this thesis , a 1V OPAMP design is achieved by the “Current Driven Bulk “ (CDB) technique to reduce threshold voltages of MOS devices. Moreover, both constant-gm and rail-to-rail common range schemes are used to provide high circuit performance . Reduced working voltage also leads to more power saving . Furthermore, a programmable compensation circut is proposed to increase the stability of the amplifier.
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