Two custom analog VLSI chips are currently in development for scientific payloads
of NASA's Advanced Composition Explorer. One chip will be fabricated in the radiation
hard 1.2 um CMOS process of the United Technologies Microelectronics Center (UlMC),
and will contain 16 complete discriminator/12 bit pulse-height-analysis chains for the
readout of heavy ion Si strip detectors. The second chip will be fabricated by Harris
Semiconductor in their dielectrically isolated bipolar VHF process. This chip will contain
the active elements of a single precision pulse-height-analysis chain and several precision
discriminator chains. The chips designed in this effort and the techniques employed are
expected to be applicable in science payloads of future missions, especially those which
place extraordinary premiums on weight, power, and/or performance.