Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Can Cyclone IV JTAG VCC use separate 2.5V instead of VCCA?

The Cyclone IV handbook in section 8-47 says: --- Quote Start --- For device using VCCIO of 2.5, 3.0, and 3.3 V, refer to Figure 8–23. All I/O inputs must maintain a maximum AC volt...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

I'm referring to respective comments in the Cyclone III device handbook. I don't expect any problems as long as the supply rails power up regularly. I have mostly a switcher powered 3.3 V rail and 2.5 V VCCA and LVDS VCCIO generated by a small LDO. So you can expect both starting simultaneously. None of the fault scenarious discussed in the device handbook can take place here.