We plan to condense the functionality of the NGC front-end in two Eurocard PCBs (see Fig. 4). These PCBs will contain the high-speed highvoltage clock driver to control the L3Vision chip, the 8 fast 14-bit ADCs (for scientific applications we are currently using 18-bit ADCs) and a Xilinx Virtex-II Pro as the only digital electronics on the board.
The AO head must be compact and the electronics must be in close proximity of the CCD to avoid reflections on the high-speed clock lines driving the chip. Similarly, the fast ADCs input tracks must be shielded and as close as possible to the output ports of the CCD to avoid pick-up noise and interference from the high-speed electronics in the surrounding. Especially challenging is the generation of phase voltages close to 50 V and currents peaks of several amps .
From an electronics point of view, the challenges in driving an L3CCD can be summarized as [1,7]:
• Fast reading of up to 10 Mlines per second,
• High-voltage, high-speed clock driver generation,
• Sampling of high-speed video with RON < 1 (0.1) e-/pixel.
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