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New ContributorHi, I´m using a Cyclone 10 (10CL040YU484I7G) in a new design can I pull-up this pins CRC_error and INIT_DONE to a 5V rail
Hi,
These open drain pins can accept input voltages below the absolute maximum rating (Vi) for the device family.
For cyclone 10 LP it is 3.6 volts do we have to use some external circuitry to archive it.
Refer table 3 for vi value.
https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-10/c10lp-51002.pdf
Regards
Anand
Regular ContributorAbsolute Vi max for this family is 4.2V for pins, so the simple answer is no you cannot connect these pins to 10K pullups to 5V without causing possible device damage.
You will need some circuitry (diodes, resistive divider, voltage conversion buffer) to connect your 5V device input to what is basically a 3.3V compatible I/O.
Depending on your 5V device technology a pullup to 3.3V may, or may not, produce an acceptable high level. If it is 5VTTL, yes; if it is 5V CMOS, likely not.
Google '3.3 v to 5v level conversion circuit' there are lots of documented ways to do this with both off the shelf devices or discrete circuit components.
