IOTA: the array controller for a gigapixel OTCCD camera for Pan- STARRS Peter Onaka, John Tonry, Gerard Luppino, Charles Lockhart, Aaron Lee, Gregory Ching, Sidik Isani, Robin Uyeshiro Institute for Astronomy 2680 Woodlawn Drive Honolulu HI 96822 ABSTRACT The PanSTARRS project has undertaken an ambitious effort to develop a completely new array controller architecture that is fundamentally driven by the large 1gigapixel, low noise, high speed OTCCD mosaic requirements as well as the size, power and weight restrictions of the PanSTARRS telescope. The result is a very small form factor next generation controller scalar building block with 1 Gigabit Ethernet interfaces that will be assembled into a system that will readout 512 outputs at ~1 Megapixel sample rates on each output. The paper will also discuss critical technology and fabrication techniques such as greater than 1MHz analog to digital converters (ADCs), multiple fast sampling and digital calculation of multiple correlated samples (DMCS), ball grid array (BGA) packaged circuits, LINUX running on embedded field programmable gate arrays (FPGAs) with hard core microprocessors for the prototype currently being developed. Keywords: Digital multiple correlated sampling, Analog to Digital Converter, array controller, FPGA, LINUX. INTRODUCTION The requirements imposed on the array controller for the PanSTARRS Orthogonal Transfer Array (OTA) 1 in an 8x8 mosaic presents a formidable challenge to any existing design. Despite the presence of an ongoing array controller development program at the Institute for Astronomy, a completely new effort was undertaken to produce a next generation design that could scale up to the needs of a gigapixel focal plane instrument. The team that was assembled to produce this design consisted of 2 scientists, 3 hardware/firmware engineers and 2 software engineers each with specific expertise and experience in critical areas. DEVELOPMENT AND INFRASTRUCTURE PLAN A multiphase plan has been developed to produce the IOTA array controller. A distinct infrastructure and prototype phase was identified as critical for success and the Institute for Astronomy has acquired new CAD development tools, Ball Grid Array (BGA) integrated circuit package rework and inspection capability, clean room, and a wire bonder. The BGA rework and inspection tools were especially important because the small form factor requirements for the controller required the use of BGA packages. Optical and X-ray BGA inspection microscopes have already proved valuable in troubleshooting. The end goal of the Development phase is to design and produce a detector controller capable of running a 1 x 4 assembly of OTAs in a form factor suitable for testing in a laboratory and on a telescope. The goal of the Production phase is to fabricate electronics for four fully functional gigapixel OTA cameras. Production schedule will allow the systems to be produced in a serial fashion. REQUIREMENTS 1.1. Modes of Operation