Lvds_io

[Altera_Forum]

Hi, 

I am working on a project and a part from it is using LVDS_IO with the buffer as a comparator to compare 2-input signals. My question is how we send the analog signal to the FPGA even though it is a digital device. Is there any way that we can simulate this part (Please see the attachment for more details).

[Altera_Forum]

LVDS input buffers aren't designed as analog comparators and have limited common mode range, please refer to the datasheet section of the device manual for details. 

 They nevertheless may work as comparators, there's nothing to do but assigning an LVDs IO-standard to the input.  It's not clear what you want to simulate and with which tool?

[Altera_Forum]

hi does altera DE1 cyclonII has LVDS? i want to implement sigma delta ADC on this FPGA board... i think i need LVDS

[Altera_Forum]

u do need LVDS_IO to implement the ADC. I am not sure about altera DE1 but most of the FPGAs have LVDS_IO and some of them have built_in ADCs.

[Altera_Forum]

--- Quote Start ---  u do need LVDS_IO to implement the ADC. I am not sure about altera DE1 but most of the FPGAs have LVDS_IO and some of them have built_in ADCs.  --- Quote End ---    thanks icd. but i got that even without LVDS-IO we can implement the sigma delta ADC on FPGA with both analog comparator and RC network out of the FPGA. and do the rest of the circuit inside the FPGA.