Spacecraft require all manner of both digital and analog circuits.
Onboard digital systems are constructed almost exclusively from
field-programmable gate array (FPGA) circuits providing numerous
advantages over discrete design including high integration density,
high reliability, fast turn-around design cycle time, lower mass,
volume, and power consumption, and lower parts acquisition and flight
qualification costs. Analog and mixed-signal circuits perform tasks
ranging from housekeeping to signal conditioning and processing.
These circuits are painstakingly designed and built using discrete
components due to a lack of options for field-programmability. FPAA
(Field-Programmable Analog Array) and FPMA (Field-Programmable
Mixed-signal Array) parts exist [
1] but not in
radiation-tolerant technology and not necessarily in an architecture
optimal for the design of analog circuits for spaceflight applications.
This paper outlines an architecture proposed for an FPAA fabricated
in an existing commercial digital CMOS process used to make
radiation-tolerant antifuse-based FPGA devices. The primary
concerns are the impact of the technology and the overall array
architecture on the flexibility of programming, the bandwidth
available for high-speed analog circuits, and the accuracy of the
components for high-performance applications.
