I/O Structure
Connect VCCIOpins to either a 1.5-V, 1.8 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 VCCIO
pins are connected to a 1.5-V power supply, the output levels are
compatible with 1.5-V systems). When VCCIOpins 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. Table 2–7 summarizes MAX II MultiVolt I/O support.
Table 2–7. MAX II MultiVolt I/O Support
Note (1)
VCCIO (V)
Input Signal
Output Signal
2.5 V
1.5 V
1.8 V
2.5 V
3.3 V
5.0 V
1.5 V
1.8 V
3.3 V
5.0 V
v
v
v
v
v
v
v
v
v
v
v
1.5
1.8
2.5
3.3
v (2)
v (3)
v (6)
v
v (3)
v (6)
v
v (6)
v (4)
v (5)
v
v (7)
Notes to Table 2–7:
(1) To drive inputs higher than VCCIO but less than 4.0 V including the overshoot, disable the PCI clamping diode.
However, to drive 5.0-V inputs to the device, enable the PCI clamping diode to prevent VI from rising above 4.0 V.
(2) When VCCIO = 1.8-V, a MAX II device can drive a 1.5-V device with 1.8-V tolerant inputs.
(3) When VCCIO = 2.5-V, a MAX II device can drive a 1.5-V or 1.8-V device with 2.5-V tolerant inputs.
(4) When VCCIO = 3.3-V and a 2.5-V input signal feeds an input pin, the VCCIO supply current will be slightly larger
than expected.
(5) MAX II devices can be 5.0-V tolerant with the use of an external resistor and the internal PCI clamp diode on the
EPM1270 and EPM2210 devices.
(6) When VCCIO = 3.3-V, a MAX II device can drive a 1.5-V, 1.8-V, or 2.5-V device with 3.3-V tolerant inputs.
(7) When VCCIO = 3.3-V, a MAX II device can drive a device with 5.0-V TTL inputs but not 5.0-V CMOS inputs. In the
case of 5.0-V CMOS, open-drain setting with internal PCI clamp diode (available only on EPM1270 and EPM2210
devices) and external resistor is required.
2–40
Core Version a.b.c variable
Altera Corporation
August 2006
MAX II Device Handbook, Volume 1
INTEL [ INTEL ]
