Sundance SMT350 - Manual (Page 11)

Version 1.9 Page 11 of 45 SMT350 User Manual
the inter-module connector ( SLB – Sundance LVDS Bus, used in this case as
‘single-ended’).
DAC: Digital samples are routed from the FPGA to the DAC via the inter-module
connector. Internal interpolation scheme allows reaching 500 Mega Samples per
Second. The DAC shows other modes such as Dual DAC, Single side-band,
Quadrature or up conversion. Both outputs are AC-coupled. By default they are
single-ended but can optionally be differential. The DAC mode is selected via Jumper
J1, that enables or disables the DAC Internal PLL (see DAC5686 datasheet for more
details).
Clock generator and distribution: All samplings clocks are generated by the same
chip. It allows having them all synchronized to a single reference clock.
Multi-module Synchronization: There are two types of synchronization available on
the SMT350. The first one is frequency synchronization, by passing the external
reference clock to an other module. It first goes through a 0-delay buffer and is then
output. Note that the synchronization is in frequency and not in phase. The second
type is register synchronization between DACs. It is achieved by the way of an extra
link between several modules to synchronize DAC internal registers (DAC signal
PHSTR passed from one module to the other and driven by the master FPGA – it
resets the internal VCO).
Inter-module Connector: it is made of a power (33 pins) and data connectors (120
pins). It is called Sundance LVDS Bus. Please refer to
the SLB specifications for
more details. In the case of the SMT350, the SLB is used as ‘single-ended’.
A global reset signal is mapped to the FPGA from the bottom TIM connector.
External Clock signals, used to generate Sampling clocks. There is one external
clock, common to ADCs and DAC When used, the CDCM7005 is used as a clock
multiplexer. Also available, an external reference clock that can be passed to an
other SMT350 module with ‘0-delay’.
External Trigger: passed directly to base module. There are two, one for the ADCs
and one for the DAC.
Temperature Sensor: available for constant monitoring. Not part of default firmware
provided.