Design of ultra-low voltage op amp based on quasi-floating gate transistors

The fundamental principle of quasi-floating gate (QFG) MOS transistors, along with the electrical characteristics and equivalent circuits, are discussed. Based on the PMOS quasi-floating gate transistors, an ultra-low voltage operational amplifier is proposed. With a single power supply of 0.8V, the maximal open-loop gain of the amplifier is 76.5dB, the phase margin is 62/spl deg/ and the unit gain-bandwidth is 2.98MHz with 9.45/spl mu/W power dissipation.