A Fully Differential Three-Stage CMOS Operational Amplifier featuring Ultra High Bandwidth

Conference: ANALOG 2013 - Entwicklung von Analogschaltungen mit CAE-Methoden - Vorträge der 13. ITG/GMM-Fachtagung
03/04/2013 - 03/06/2013 at Aachen, Deutschland

Proceedings: ANALOG 2013 - Entwicklung von Analogschaltungen mit CAE-Methoden

Pages: 4Language: englishTyp: PDF

Personal VDE Members are entitled to a 10% discount on this title

Chen, Hong; Milovanovic, Vladimir; Zimmermann, Horst (Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria)
Giotta, Dario (Lantiq A GmbH, Villach, Austria)

A three-stage fully differential operational amplifier (OpAmp) design in 40 nm digital CMOS technology is presented. The proposed OpAmp is equipped with nested Miller compensation plus nulling resistor. Feed-forward topology is also applied to strengthen frequency compensation, as well as increasing unity-gain bandwidth. Under 1.1 V supply voltage and 1 kOmega + 4 pF load, postlayout simulation results show that 49 dB DC gain, 3.2 GHz GBW and 52 degrees phase margin are achieved with 17mA DC current consumption. The total harmonic distortion (THD) is -93 dB for a 50 MHz 0.6 V peak to peak sine wave input. The RMS input referred noise integrated from DC to 50 MHz is 14.2 muV. The fully-symmetric layout pattern minimizes the input offset. The circuit occupies about 0.011 mm2 chip area. All these features enable the proposed OpAmp to be used in high-speed applications.