EP20K200C Datasheet, PDF (45/90 Pages) Altera Corporation – Programmable Logic

APEX 20KC Programmable Logic Device Data Sheet
Signals can be driven into APEX 20KC devices before and during power-
up without damaging the device. In addition, APEX 20KC devices do not
drive out during power-up. Once operating conditions are reached and
the device is configured, APEX 20KC devices operate as specified by the
user.
MultiVolt I/O
Interface
The APEX architecture supports the MultiVolt I/O interface feature,
which allows APEX devices in all packages to interface with systems of
different supply voltages. The devices have one set of VCC pins for
internal operation and input buffers (VCCINT), and another set for I/O
output drivers (VCCIO).
APEX 20KC devices support the MultiVolt I/O interface feature. The
APEX 20KC VCCINT pins must always be connected to a 1.8-V power
supply. With a 1.8-V V_CCINT level, input pins are 1.8-V, 2.5-V, and 3.3-V
tolerant. The VCCIO pins can be connected to either a 1.8-V, 2.5-V, or 3.3-V
power supply, depending on the I/O standard requirements. When the
VCCIO pins are connected to a 1.8-V power supply, the output levels are
compatible with 1.8-V systems. When VCCIO pins are connected to a 2.5-V
power supply, the output levels are compatible with 2.5-V systems. When
VCCIO pins are connected to a 3.3-V power supply, the output high is
3.3 V and compatible with 3.3-V or 5.0-V systems. An APEX 20KC device
is 5.0-V tolerant with the addition of a resistor and the PCI clamp diode
enabled.
f
For more information on 5.0-V tolerance, refer to the “5.0-V Tolerance in
APEX 20KE Devices White Paper,” as the information found therein also
applies to APEX 20KC devices.
Table 10 summarizes APEX 20KC MultiVolt I/O support.
Table 10. APEX 20KC MultiVolt I/O Support
V_CCIO (V)
Input Signals (V)
Output Signals (V)
1.8
2.5
3.3
5.0
1.8
2.5
3.3
5.0
1.8
v
v (1)
v (1)
v
2.5
v
v (1)
v
3.3
v
v
v (2)
v (3)
v
v
Notes to Table 10:
(1) The PCI clamping diode must be disabled to drive an input with voltages higher than V_CCIO, except for the 5.0-V
input case.
(2) An APEX 20KC device can be made 5.0-V tolerant with the addition of an external resistor and the PCI clamp diode
enabled.
(3) When V_CCIO = 3.3 V, an APEX 20KC device can drive a 2.5-V device with 3.3-V tolerant inputs.
Altera Corporation
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