Feedforward compensation techniques for high-frequency CMOS amplifiers

Two circuit techniques for broadbanding the gain bandwidth product (GBW) of CMOS amplifiers are presented. The conventional feedforward technique using an AC bypass capacitor is reviewed. Compared to the conventional technique, the new techniques offer the advantage of exact cancellation of the low-frequency pole-zero pair. Furthermore, the position of the pole-zero pair occurs at higher frequencies than with the conventional technique. Calculations and computer simulations suggest that using the new techniques. CMOS amplifiers with a unity stable GBW of 160 MHz can be obtained in a standard 3-μm CMOS technology