Hi! I'm a student and doing a project to construct an Oversampling Delta-Sigma DAC. I planned to build the system using Cadence, Verilog HDL and FPGA which are totally new to me, I don't know whether the FPGA can be programmed to build functions like oversampling and interpolation, or should I make that part by other electronic components and connect to the FPGA containing the delta-sigma modulator only? Hope someone can answer my question. Thanks in advance!
Best Regards, Eva
Hi Eva, You can use AN221E04 from Anandigm. AN221E04 is a FPAA (Field Programmable Analog Arrays). Visit
For delta-sigma modulator in digital domain,you may use a Xilinx FPGA--- Virtex-II family device.
You get a nice programmable system.A convergence of Analog and Digital programmabilty. Regards, SANKET.
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Depends on the precision you are chasing.
A straight FPGA pin -> RC will have 50% of the power/ground noise at idle. ( ie lousy PSRR, and crosstalk) but would be OK for mono shortwave radio audio. For higher presisons 12/16/24 bit regions, external TinyLogic Buffer or analog switches should be used, to 'clean/low noise' +ve/Gnd lines.
Keeps the FPGA for digital stuff, and separate, but very simple parts for the analog stuff.
Highest presisions should also use a true integrator, for the charge balancing.
-jg
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