Hi all, We are building a low-frequency array for the observation of the deuterium hyperfine line at 327.4 MHz with a bandwidth of 250 kHz. We intend to use SNAPs for acquisition. The boards will operate at full 12 channels input, thus the ADCs at 250 MSps. We will subsequently decimate the data rate, as our working bandwidth is narrow.
Concerning the clock input for the SNAP, https://casper.berkeley.edu/wiki/SNAP states the following: *Digital 1 PPS: 50 ohm single-ended LVTTL logic levels * - * SMATP13 * - * Vin-high 2.0 to 3.3 Volts. Low current drive sources, such as typical LVTTL or CMOS gates, probably can not supply the 40mA required to supply the 2.0V into the 50ohm load. * - * Vin-low 0.0 to 0.8 Volts* Actually we considered buying the GPS-disciplined Meinberg M500 LANTIME ( https://www.meinbergglobal.com/english/products/modular-railmount-ntp-server-ieee-1588-solution.htm), which is advertised to output 1 PPS *TTL* levels. Now, our first question is whether the SNAP can work with this? Also, the note about low current drive sources is a little confusing, can anyone shed some light here. Secondly, we would like suggestions from anyone who has experience with clocking the SNAP. You see, we run a very tight budget and the M500 LANTIME clock is expensive. We would like to know if there is a less costly way to clock the SNAP and synchronise several boards. Thanks. Best regards, Nitish Ragoomundun Department of Physics University of Mauritius -- You received this message because you are subscribed to the Google Groups "casper@lists.berkeley.edu" group. To unsubscribe from this group and stop receiving emails from it, send an email to casper+unsubscr...@lists.berkeley.edu. To post to this group, send email to casper@lists.berkeley.edu.
