2–32
Chapter 2: MAX II Architecture
Referenced Documents
Connect
VCCIO
pins 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 (that is, when
VCCIO
pins are connected to a 1.5-V
power supply, the output levels are compatible with 1.5-V systems). When
VCCIO
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.
summarizes MAX II MultiVolt I/O support.
Table 2–7.
MAX II MultiVolt I/O Support
Input Signal
VCCIO (V)
1.5
1.8
2.5
3.3
1.5 V
v
v
—
—
1.8 V
v
v
—
—
2.5 V
v
v
v
v
3.3 V
v
v
v
v
5.0 V
—
—
—
v
1.5 V
v
v
v
v
1.8 V
—
v
v
v
Output Signal
2.5 V
—
—
v
v
3.3 V
—
—
—
v
5.0 V
—
—
—
v
Notes to
(1) To drive inputs higher than V
CCIO
but less than 4.0 V including the overshoot, disable the I/O clamp diode. However, to drive 5.0-V inputs to the
device, enable the I/O clamp diode to prevent V
I
from rising above 4.0 V.
(2) When V
CCIO
= 1.8 V, a MAX II device can drive a 1.5-V device with 1.8-V tolerant inputs.
(3) When V
CCIO
= 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 V
CCIO
= 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 I/O clamp diode on the EPM1270 and EPM2210
devices.
(6) When V
CCIO
= 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 V
CCIO
= 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 I/O clamp diode (available only on EPM1270 and EPM2210 devices) and external resistor is required.
f
For information about output pin source and sink current guidelines, refer to the
Referenced Documents
This chapter referenced the following documents:
■
■
■
chapter in the
MAX II Device Handbook
chapter in the
MAX II Device
Handbook
chapter in the
MAX II Device Handbook
■
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