A quad CMOS single-supply op amp with rail-to-rail output swing

The realization of a commercially viable, general-purpose quad CMOS amplifier is presented, along with discussions of the tradeoffs involved in such a design. The amplifier features an output swing that extends to either supply rail, together with an input common-mode range that includes ground. The device is especially well suited for single-supply operation and is fully specified for operation from 5 to 15 V over a temperature range of -55 to +125/spl deg/C. In the areas of input offset voltage, offset voltage drift, input noise voltage, voltage gain, and load driving capability, this implementation offers performance that equals or exceeds that of popular general-purpose quads or bipolar of Bi-FET construction. On a 5-V supply the typical V/SUB os/ is 1 Mv, V/SUB os/ drift is 1.3 /spl mu/V//spl deg/C, 1-kHz noise is 36 nV//spl radic/Hz, and gain is one million into a 600-/spl Omega/ load. This device achieves its performance through circuit design and layout techniques as opposed to special analog CMOS processing, thus lending itself to use on system chips built with digital CMOS technology.