A wide dynamic range self-biased fully differential operational amplifier for micro mechanical sensors and actuators circuitry

An all-new, self-biased, wide-range, high gain, fully differential folded cascode operational amplifier topology for interfacing with capacitive Micro Electro-Mechanical (MEMS) actuators interfaces designed in 45 nm technology is presented. The proposed topology shows seamless scalability across different technology nodes and low sensitivity to Vt & Le process variations. The designed amplifier is the first of its kind in the literature and is the first attempt to develop circuit interfaces for high impedance MEMS actuators on any advanced process technology. A new self-bias mechanism is used to limit the amplifier biasing requirements, eliminating the need of any additional bias circuitry. The amplifier average differential gain is about 35dB across process corners and across a 110°C temperature range.