Design and implementation of an area-efficient MEMS-based IR static earth sensor

This paper introduces a complete design of a static earth sensor, used for satellite attitude determination. Our design approach offers high area efficiency, high resolution (10 arc minutes), and modularity relative to previous designs. This sensor is made up of four separate identical chips; each chip represents a complete System on Chip (SoC) including the following main components: the sensor, the electronic read-out sub-circuit, the decision sub-circuit, and the serial interface to the On-Board Computer (OBC). Each chip has two staggered arrays of MEMS bulk-micromachined thermopiles, which sense the IR radiation incident on the chip and convert it into an electrical voltage. A complete design of the IR detector is introduced and its characteristics are estimated. A novel block diagram of one chip is presented including both analog and digital sub-circuits. A low offset amplifier (LOA), based on the Auto-zeroing technique, is used as a front-end to the analog part of the circuit. Finally, a complete layout or the SoC is given.