Operational Amplifier Bandwidth Extension Using Negative Capacitance Generation

A need for high bandwidth operational amplifiers, or op-amps, exists for certain applications. This need requires research in the area of op-amp bandwidth extension. The proposed method of this thesis uses Negative Capacitance Generation (NCG), which involves using the Miller effect to generate an equivalent negative capacitance at a given node in a circuit, to extend the bandwidth of an op-amp. This is accomplished by first applying NCG to the second stage of an op-amp, in which the op-amp has been compensated using Single Capacitor Miller Compensation (SCMC). Next, the Miller capacitor used to compensate the op-amp can be reduced and thus, the bandwidth of the op-amp is extended. The proposed method employed a 100dB, classic two-stage op-amp with a 7.7MHz gain-bandwidth product (GBW). It was discovered that after applying NCG to several places in the op-amp besides the second stage that the GBW was roughly doubled. The GBW of the second stage was improved by a factor of 9.3. This discrepancy in GBW improvements was researched and certain barriers were discovered. Although the barriers were not eliminated, research in overcoming them and obtaining greater improvements in op-amp bandwidth is encouraging.

Name thesis:degree_name

MS

Grantor dc:publisher

Brigham Young University - Provo

Author dc:creator

• Genz, Adrian P.

• operational amplifiers
• bandwidth extension
• op-amp compensation
• negative capacitance generation
• CMOS circuits
• Electrical and Computer Engineering

Language dc:language

English

Repository record dc:identifier

https://scholarsarchive.byu.edu/etd/459

OAI identifier oai:identifier

oai:scholarsarchive.byu.edu:etd-1458