Chapter 1: Cyclone IV Device Datasheet
1–3
Operating Conditions
1
A DC signal is equivalent to 100% duty cycle. For example, a signal that overshoots to
4.3 V can only be at 4.3 V for 65% over the lifetime of the device; for a device lifetime
of 10 years, this amounts to 65/10ths of a year.
Table 1–2. Maximum Allowed Overshoot During Transitions over a 10-Year Time Frame for
Cyclone IV Devices
Symbol
Parameter
Condition (V)
VI = 4.20
VI = 4.25
VI = 4.30
VI = 4.35
VI = 4.40
VI = 4.45
VI = 4.50
VI = 4.55
VI = 4.60
Overshoot Duration as % of High Time
Unit
%
100
98
65
43
29
20
13
9
%
%
%
AC Input
Voltage
Vi
%
%
%
%
6
%
Figure 1–1 shows the methodology to determine the overshoot duration. The
overshoot voltage is shown in red and is present on the input pin of the Cyclone IV
device at over 4.3 V but below 4.4 V. From Table 1–2, for an overshoot of 4.3 V, the
percentage of high time for the overshoot can be as high as 65% over a 10-year period.
Percentage of high time is calculated as ([delta T]/T) × 100. This 10-year period
assumes that the device is always turned on with 100% I/O toggle rate and 50% duty
cycle signal. For lower I/O toggle rates and situations in which the device is in an idle
state, lifetimes are increased.
Figure 1–1. Cyclone IV Devices Overshoot Duration
4.4 V
4.3 V
3.3 V
DT
T
December 2013 Altera Corporation
Cyclone IV Device Handbook,
Volume 3
ALTERA [ ALTERA CORPORATION ]
