Prototype readout module for hyper suprime-cam

The Hyper Suprime-Cam (HSC), the next generation wide-field camera proposed for the Subaru Telescope operated by the National Astronomical Observatory of Japan, employs ∼ 110 2k × 4k Charge Coupled Devices (CCDs) to cover a 1.5-degree diameter field of view. It is a requirement that the readout electronics are able to send ∼ 2 Gbytes of image data in 10 seconds while maintaining low noise. In addition, the readout system should be small and light in order to be mounted inside the camera. We have developed a prototype readout module for the Back End Electronics (BEE) of the readout system. The BEE provides a digital interface between the analog front end of the readout system and the data acquisition system (DAQ system). Two Gigabit Ethernet links are employed for data transfer between the BEE and the DAQ system. The size of our BEE module is 149 mm × 79 mm × 12 mm. We measured the data transfer rate from the readout module to the DAQ system and also estimated the noise. The data rate achieved full Gigabit Ethernet bandwidth and the noise was sufficiently low. Thus, we concluded our prototype readout module satisfied the required specification.