One of the most important goals in every light source is to achieve
orbit stability for the electron beam within the required specifications
for the stability of the photon beam in the experimental stations.
Several technical challenges make the task of achieving sub-micrometer
stability really demanding in terms of mechanical and electrical
engineering. Fast feedback systems are employed to dump orbit
distortions through accurate measurements of the beam positions, fast
computation of the corrections and actuation back to the beam through
fast power supplies and steering magnets. To realize this task in the
*SIRIUS*http://www.lnls.br, the new brazilian synchrotron light
source, a digital platform to measure the beam position is required.
Inside this plattaform a key part is the analog to digital conversion.
This text will describe the main specification for an FMC
Analog-to-digital conversion board.
There are several commercial off-the-shelf digitizers covering a wide
range of speed, bandwidth and resolution, but there is no board that
cover all features required for the LNLS
Four Channel 16 bit 130 MSPS ADC. Required ADC: LTC2208IUP
Internal ADC clock circuit: Phase locked to the external reference
clock input with fine frequency tuning capability. See specific
section. Hold mode in case of loss of external reference is a
Internal high frequency PLL oscillator output with amplitude control
and locked to external reference.
External ADC clock input (50 MHz up to 130 MHz, 0 dBm typ.)