EP1C4 ALTERA [Altera Corporation], EP1C4 Datasheet - Page 61

• Manufacturer Part Number: EP1C4
• Description: Cyclone FPGA Family Data Sheet
• Manufacturer: ALTERA [Altera Corporation]

Power
Sequencing &
Hot Socketing
Altera Corporation
January 2007
Notes to
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
Table 2–14. Cyclone MultiVolt I/O Support
The PCI clamping diode must be disabled to drive an input with voltages higher than V
When V
expected. Turn on Allow voltage overdrive for LVTTL / LVCMOS input pins in the Assignments > Device >
Device and Pin Options > Pin Placement tab when a device has this I/O combinations.
When V
When V
than expected.
When V
Cyclone devices can be 5.0-V tolerant with the use of an external resistor and the internal PCI clamp diode.
When V
When V
V
CCIO
1.5
1.8
2.5
3.3
Table
(V)
CCIO
CCIO
CCIO
CCIO
CCIO
CCIO
2–14:
= 1.5-V or 1.8-V and a 2.5-V or 3.3-V input signal feeds an input pin, higher pin leakage current is
= 1.8-V, a Cyclone device can drive a 1.5-V device with 1.8-V tolerant inputs.
= 3.3-V and a 2.5-V input signal feeds an input pin, the V
= 2.5-V, a Cyclone device can drive a 1.5-V or 1.8-V device with 2.5-V tolerant inputs.
= 3.3-V, a Cyclone device can drive a 1.5-V, 1.8-V, or 2.5-V device with 3.3-V tolerant inputs.
= 3.3-V, a Cyclone device can drive a device with 5.0-V LVTTL inputs but not 5.0-V LVCMOS inputs.
1.5 V
v
v
The Cyclone V
supply. If the V
and 3.3-V tolerant. The V
2.5-V, or 3.3-V power supply, depending on the output requirements. The
output levels are compatible with systems of the same voltage as the
power supply (i.e., when V
supply, the output levels are compatible with 1.5-V systems). When V
pins are connected to a 3.3-V power supply, the output high is 3.3-V and
is compatible with 3.3-V or 5.0-V systems.
Cyclone MultiVolt I/O support.
Because Cyclone devices can be used in a mixed-voltage environment,
they have been designed specifically to tolerate any possible power-up
sequence. Therefore, the V
powered in any order.
Signals can be driven into Cyclone devices before and during power up
without damaging the device. In addition, Cyclone devices do not drive
out during power up. Once operating conditions are reached and the
device is configured, Cyclone devices operate as specified by the user.
1.8 V
v
v
Input Signal
v
v
v
2.5 V
v
(2)
(2)
(4)
CCINT
CCINT
v
Note (1)
v
3.3 V
v
v
(2)
(2)
pins must always be connected to a 1.5-V power
level is 1.5 V, then input pins are 1.5-V, 1.8-V, 2.5-V,
CCIO
v
5.0 V
CCIO
CCIO
(6)
pins can be connected to either a 1.5-V, 1.8-V,
and V
pins are connected to a 1.5-V power
v
v
v
1.5 V
v
CCIO
(3)
(5)
(7)
CCINT
Power Sequencing & Hot Socketing
supply current will be slightly larger
v
v
1.8 V
Table 2–14
v
power supplies may be
(5)
(7)
Output Signal
v
2.5 V
v
CCIO
(7)
summarizes
.
3.3 V
v
Preliminary
v
5.0 V
2–55
CCIO
(8)