The term
FPAA was first used in 1991 by Lee and Gulak. They put forward the concept of CABs that are connected via a routing network and configured digitally. Subsequently, in 1992 and 1995 they further elaborated the concept with the inclusion of op-amps, capacitors, and resistors. This original chip was manufactured using 1.2 μm CMOS technology and operates in the 20 kHz range at a power consumption of 80 mW. However, the concept of a user-definable analog array dates back 20 years earlier, to the mask-programmable analog "Monochip" invented by the designer of the famous 555 timer chip, Hans Camenzind, and his company Interdesign (later acquired by Ferranti in 1977). The Monochip was the basis for a pioneering line of chips for music synthesizers, sold by Curtis Electromusic (CEM). Pierzchala et al introduced a similar concept named
electronically-programmable analog circuit (
EPAC). It featured only a single integrator. However, they proposed a local interconnect
architecture in order to try to avoid the bandwidth limitations. The
reconfigurable analog signal processor (
RASP) and a second version were introduced in 2002 by Hall et al. Their design incorporated high-level elements such as second order
bandpass filters and 4 by 4 vector matrix multipliers into the CABs. Because of its architecture, it is limited to around 100 kHz and the chip itself is not able to support independent reconfiguration. In 2004 Joachim Becker picked up the
parallel connection of OTAs (operational transconductance amplifiers) and proposed its use in a hexagonal local interconnection architecture. It did not require a routing network and eliminated switching the signal path that enhances the frequency response. In 2005 Fabian Henrici worked with Joachim Becker to develop a switchable and invertible OTA which doubled the maximum FPAA bandwidth. This collaboration resulted in the first manufactured FPAA in a
0.13 μm CMOS technology. In 2016 Dr. Jennifer Hasler from Georgia Tech designed a FPAA system on a chip that uses analog technology to achieve unprecedented power and size reductions. ==See also==