Three-stage CMOS OTA for large capacitive loads with efficient frequency compensation scheme

A simple compensation strategy, which employs passive components only, is adopted to design a three-stage operational transconductance amplifier (OTA) suitable for driving high capacitive loads. Compared to the classical nested Miller compensation technique, the new solution exploits two additional resistors and allows a reduction in the values of the compensation capacitors of about an order of magnitude. The OTA was fabricated using 0.35-mu m CMOS technology and exhibits a 1.4-MHz gain-bandwidth with a load of 500 pF.