His father, Arthur S. Jensen, was a physicist who earned his PhD at the University of Pennsylvania in 1941.
In 1961, he was chief studio engineer for the student-run radio station, WXPN-FM.
[2] Jensen developed a low-noise, high-performance operational amplifier called the 990 in the late 1970s and was awarded a patent for it September 1, 1981 [3] Following the granting of the patent, Jensen published the circuit so that it could be the basis of further, public development.
[4] The circuit has gone on to be popular with both professional equipment manufacturers as well as Hobbyists.
In 2018, the 990 op amp was inducted into the TEC Awards Hall of Fame.