2-channel noise in both Acquisition and Mission Amplifiers
Spaceborne instruments are often fully redundant, designed as two identical instruments (channels) in one package. This allows one component failure to occur without compromising the mission. In this case, a redundant infrared instrument had unacceptably noisy outputs only when both channels were operating simultaneously. The designers of the instrument called us in after studying the problem for several man-months without success. We traced the problem to a digital clock signal, which was transmitted through the power and ground wiring, to the high gain sensor amplifiers. By slowing the slew rate of the clock edges, and making the amplifiers less sensitive to high frequencies, the problem was completely eliminated.
|