1 introduction – Sundance SMT943 User Manual
Page 6
User Manual SMT943
Page 6 of 54
Last Edited: 23/08/2011 17:24:00
1 Introduction
The SMT943 is a single width expansion TIM that plugs onto a
base module,
(Virtex-5 LXT, SXT or even FXT FPGA) as an example and incorporates
1 Texas Instrument dual-channel Analog-to-Digital Converter
and 1
Texas Instrument dual-channel Digital-to-Analog Converter
The SMT943
implements a comprehensive clock circuitry based on a chip
from
Texas instrument that allows synchronisation among the converters and the use of
an external reference clock or sampling clock. It provides a complete conversion
solution and stands as a platform that can be part of a transmit/receive base
station. The SMT943 has an on-board VCXO of frequency 491.52MHz.
The DAC has a resolution of 16 bits and can update its outputs at up to
800MSamples per second. The converter is 1.8/3.3-Volt. Among the features of the
DAC5688 are integrated interpolation filters, a fine frequency mixer with a complex
NCO, a clock multiplier and IQ compensation. No DC-coupled version is currently
available on the DAC.
The ADC has a resolution of 14 bits and can update its outputs at up to 250MHz. All
converters are 1.8/3.3-Volt. ADCs internal gain and offset can be adjusted as well as
the data format. ADCs are AC-coupled on the board using a double-transformer
structure. No DC-coupled version is currently available on the ADC.
(Virtex-5 LXT or SXT series in the case of the SMT351T) on the base
module is responsible for handling data coming from one of the following sources:
Comports or Rocket Serial Link
These interfaces are compatible with a wide
range of Sundance’s modules.
The memory (DDR2) on the base module (still based on the case where using an
SMT351T SLB base module) can store samples.
Converter configuration, sampling and transferring modes are set via internal
control registers stored inside the FPGA and accessible via Comport.
The SMT943 module is well-suited for multi-carrier, wide bandwidth communication
applications.
The main features of the SMT943 are listed below:
● One Dual 14-bit 250MSPS ADC
● One Dual 16-bit 800MSPS DAC
● On-board low-jitter clock distribution chip
● On-board 491.52MHz VCXO,
● On-board 10MHz reference crystal,
● One external clock, one external trigger and one reference clock inputs via
connector,
● One external clock output vi
connector,
● One
connector to link SMT943 and SMT351T (set to 2.5-V FPGA IOs) as
an example,
● All Analogue inputs to be connected to 50-Ohm sources.
● All Analogue outputs to be connected to 50-Ohm loads.
● A fan.