A Systematic Design Methodology for Class-AB-Style Ring Amplifiers

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 65; no. 9; pp. 1169 - 1173
• Main Authors: Megawer, Karim M., Hussien, Faisal A., Aboudina, Mohamed M., Mohieldin, Ahmed N.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-09-2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplification; Amplifier design; Amplifiers; Capacitance; Circuit stability; CMOS; CMOS process; Design engineering; Design methodology; Gain; low-voltage; Ring amplifier; scaling; Steady-state; switched-capacitor amplifier; Transistors
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2018.2815705

This brief introduces a design approach for Class-AB-style ring amplifiers which differs from the design of conventional amplifiers. The theory of operation of Class-AB-style ring amplifier is discussed as well as the different design tradeoffs that affect its design. Consequently, a systematic design methodology for Class-AB-style ring amplifier is introduced. A design example of a switched-capacitor gain amplifier with a closed-loop gain of 32, using a three-stage self-biased ring amplifier, is presented. This example has been designed and implemented in UMC 130-nm CMOS technology. It achieves an spurious-free dynamic range of 72 dB with a clock frequency of 25 MHz. It operates from a single 1.2-V supply and consumes 400 <inline-formula> <tex-math notation="LaTeX">\boldsymbol \mu \text{A} </tex-math></inline-formula>.