Title :
A high-speed CMOS amplifier with dynamic frequency compensation
Author :
Lee, Bang ; Sheu, Bing
Author_Institution :
Dept. of Electr. Eng., Univ. of Southern California, Los Angeles, CA, USA
Abstract :
High-performance CMOS operational amplifiers with advanced frequency compensation, dynamic biasing, and enhanced slew rate are presented. Prototyping amplifiers with three design techniques have been fabricated by the MOSIS service using a 2-μm scalable CMOS technology. Experimental results show a significant speed-up on amplifier transient responses. The dynamic biasing technique is used to enhance the slew rate by increasing the bias current of the input differential pair when the differential-mode input voltage is large. Another differential pair is added to sense the input voltage. The additional circuitry increases the input capacitance of an MOS amplifier, which can degrade power supply rejection ratio characteristics. Since the slew rate enhancement factor is proportional to the ratio of bias current and additional dynamic biasing current, a large improvement on slew rate always generates additional ripples on the power lines
Keywords :
CMOS integrated circuits; compensation; operational amplifiers; 2 micron; MOSIS service; amplifier transient responses; bias current; differential-mode input voltage; dynamic biasing; dynamic frequency compensation; high-speed CMOS amplifier; input capacitance; input differential pair; operational amplifiers; power supply rejection ratio characteristics; ripples; scalable CMOS technology; slew rate; CMOS technology; Capacitance; Circuits; Degradation; Dynamic voltage scaling; Frequency; Operational amplifiers; Power amplifiers; Power supplies; Prototypes;
Conference_Titel :
Custom Integrated Circuits Conference, 1990., Proceedings of the IEEE 1990
Conference_Location :
Boston, MA
DOI :
10.1109/CICC.1990.124689
