EP2C5F256C7N Datasheet, PDF (89/168 Pages) Altera Corporation – Section I. Cyclone II Device Family Data Sheet

Hot Socketing & Power-On Reset
If you cannot meet the maximum V_CC ramp time requirement, you must
use an external component to hold nCONFIG low until the power supplies
have reached their minimum recommend operating levels. Otherwise,
the device may not properly configure and enter user mode.
Conclusion
Cyclone II devices are hot socketable and support all power-up and
power-down sequences with the one requirement that V_CCIO and V_CCINT
be powered up and down within 100 ms of each other to keep the I/O
pins from driving out. Cyclone II devices do not require any external
devices for hot socketing and power sequencing.
Document
Table 4–1 shows the revision history for this document.
Revision History
Table 4–1. Document Revision History
Date &
Document
Version
February 2007
v3.1
Changes Made
● Added document revision history.
● Updated “I/O Pins Remain Tri-Stated during Power-Up”
section.
● Updated “Power-On Reset Circuitry” section.
● Added footnote to Figure 4–3.
July 2005 v2.0
February 2005
v1.1
June 2004 v1.0
Updated technical content throughout.
Removed ESD section.
Added document to the Cyclone II Device Handbook.
Summary of Changes
● Specified V_CCIO and V_CCINT
supplies must be GND
when "not powered".
● Added clarification about
input-tristate behavior.
● Added infomation on V_CC
monotonic ramp.
Altera Corporation
February 2007
4–7
Cyclone II Device Handbook, Volume 1