Intrinsic MOS cascode differential input pair

Abstract

Methods and devices for a cascode differential input pair with low headroom voltage and high output impedance are presented. The cascode differential input pair includes first and second input (cascode) stages, each including a common-source regular transistor in series connection with a common-gate intrinsic transistor. Sources of the regular transistors are tied, and gates of the intrinsic transistors are tied. A gate voltage to the intrinsic transistors is provided by a source voltage at the sources of the regular transistors, the source voltage based on a common mode input voltage of the cascode differential input pair. According to one aspect, the cascode differential input pair is part of a differential amplifier that includes a current source coupled to the sources of the regular transistors, and a load coupled to drains of the intrinsic transistors.

Dependencies are inferred from the claim text.