X3-SDF Data Acquisition Board with 4x 5MSPS Adc and Spartan3 FPGA
The X3-SDF is an XMC IO module that can be fitted in a PC using a XMC to PCIe adapter or XMC to PCI adapter or a CompactPCI chassis using a XMC to CompactPCI adapter or a Standalone PC. Other hosting options include a standalone eInstrument and connection to a variety of PC hosts.
The data acquisition board has 4 channels of simultaneous 24 bit delta-sigma analogue to digital converters. The maximum adc can produce 24 bit samples at upto 5MSPS and 16 bit samples upto 20MSPS. The ADCs have built in lowpass filters which cutoff at half the samplerate, and an input range of +/-10V. The converter (AD7760) is a delta-sigma device which provides high quantisation linearity.
The X3-SDF has an onboard PLL which can be driven by an onboard reference oscillator or by an offboard reference clock. Alternately the user can supply an external clock. Triggering of the start of samples can be done by software or an external active high LVTTL signal.
The X3-SDF also has 44 bits of user digital IO. This can be read or written to as a 32 bit register from the host, or if the user modifies the logic, can be used to interface to a variety of digital devices such as serial, parallel ports, I2C devices etc. The Spartan3 device supports LVTTL.
Data acquisition control, signal processing, buffering, and system interface functions are implemented in a Xilinx Spartan3 FPGA, 1M gate device. Two 512Kx32 memory devices are used for data buffering and FPGA computing memory. The data acquisition board has a single lane PCI Express interface to the host which can sustain 160MB/s to the host.
The X3-SDF is supported by Malibu, a set of C++ libraries to use the board under Windows and Linux. This includes example programs to use the board to setup the logic, acquire samples and stream them to disk.
The logic can be fully customized using VHDL and MATLAB using the FrameWork Logic toolset. The MATLAB BSP supports real-time hardware-in-the-loop development using the graphical, block diagram Simulink environment with Xilinx System Generator.
