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Building a sigma-delta converter is a trival task, anything simpler??? perhaps a voltage-to-frequency converter?? But if a sigma-delta is used will it keep design digital???
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No, there is no way to measure an analog voltage with an FPGA without using some external components.
The sigma-delta method relies on an external RC filter and an LVDS receiver, so the external components are simple; Google "Lattice RD1066" for an example.
A voltage-to-frequency converter is essentially a VCO, i.e., it has an analog input and a logic output, at that point you may as well use an ADC.
Cheers,
Dave
Honored Contributor
