LLRF electronics for the CNAO synchrotron

International audience; CNAO, The Italian National Centre for Oncological hAdrontherapy in Pavia will start its test phase in 2008. Treatment is based on beams of proton and carbon ion provided by a 78 meters circumference synchrotron. Particle acceleration is done by a unique VITROVAC load RF cavity operating at a frequency ranging from 0.3 to 3MHz and up to 3kV peak amplitude. In order to control this cavity a digital LLRF system has been designed at LPSC. It is based mainly on Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGA) and Direct Digital Synthesizers (DDS). The LLRF system implements both cavity control and beam control capabilities in a compact, remotely programmable and configurable, Ethernet controlled electronic module. It also allows an easy regulation loop tuning, thanks to an embedded acquisition system that stores all input and output signals during a given acceleration cycle.