Micro-Digital Sun Sensor: An imaging sensor for space applications

Micro-Digital Sun Sensor is an attitude sensor which senses relative position of micro-satellites to the sun in space. It is composed of a solar cell power supply, a RF communication block and an imaging chip which is called APS+. The APS+integrates a CMOS Active Pixel Sensor (APS) of 512×512 pixels, a 12 bit Analogue to Digital Converter (ADC), digital Input and Output (I/O) circuits, timing signal generators and drivers, and digital signal processing circuits for centroid calculation. The paper describes the implementation of a prototype of the μDSS APS+ using a standard 0.18μm CMOS process. As a space application, it is particularly characterized by its low power consumption. The reduction of power consumption is mainly achieved by windowing, which is enabled by a specific active-pixel design in APS. The functions of the blocks in APS+ are tested. The test results of a test chip which contains 368×00368 pixel array will be discussed following in the paper.