EP2C8T144C8N Datasheet, PDF (87/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

Cyclone II Architecture
Table 2–20. Cyclone II MultiVolt I/O Support (Part 2 of 2) Note (1)
V_CCIO (V)
3.3
1.5 V
Input Signal
1.8 V
2.5 V
v (4)
3.3 V
v
1.5 V
v (6)
Output Signal
1.8 V
2.5 V
v (6)
v (6)
3.3 V
v
Notes to Table 2–20:
(1) The PCI clamping diode must be disabled to drive an input with voltages higher than V_CCIO.
(2) These input values overdrive the input buffer, so the pin leakage current is slightly higher than the default value.
To drive inputs higher than V_CCIO but less than 4.0 V, disable the PCI clamping diode and turn on Allow voltage
overdrive for LVTTL/LVCMOS input pins option in Device setting option in the Quartus II software.
(3) When V_CCIO = 1.8-V, a Cyclone II device can drive a 1.5-V device with 1.8-V tolerant inputs.
(4) When V_CCIO = 3.3-V and a 2.5-V input signal feeds an input pin or when V_{C C I O} = 1.8-V and a 1.5-V input signal
feeds an input pin, the V_CCIO supply current will be slightly larger than expected. The reason for this increase is
that the input signal level does not drive to the V_CCIO rail, which causes the input buffer to not completely shut off.
(5) When V_CCIO = 2.5-V, a Cyclone II device can drive a 1.5-V or 1.8-V device with 2.5-V tolerant inputs.
(6) When V_CCIO = 3.3-V, a Cyclone II device can drive a 1.5-V, 1.8-V, or 2.5-V device with 3.3-V tolerant inputs.
Altera Corporation
February 2007
2–61
Cyclone II Device Handbook, Volume 1