 He started work in the early 1960s at George A. Philbrick Researches (GAP-R).GAP-R pioneered the first reasonable-cost, mass-produced operational amplifier (op-amp), the K2-W. At GAP-R, Pease developed many high-performance op-amps, built with discrete solid-state components.In 1976, Pease moved to National Semiconductor Corporation (NSC) as a designer and applications engineer, where he began designing analog monolithic integrated circuits, as well as design reference circuits using these devices.