EP3C5E144C8N Datasheet, PDF (283/348 Pages) Altera Corporation – Ability to disable external JTAG port

Chapter 1: Cyclone III Device Data Sheet
1–3
Electrical Characteristics
1 A DC signal is equivalent to 100% duty cycle. For example, a signal that overshoots to
4.2 V can only be at 4.2 V for 10.74% over the lifetime of the device; for device lifetime
of 10 years, this amounts to 10.74/10ths of a year.
Table 1–2. Cyclone III Devices Maximum Allowed Overshoot During Transitions over a 10-Year
Time Frame ⁽¹⁾
Symbol Parameter
Condition
Overshoot Duration as % of High Time Unit
V_I = 3.95 V
100
%
V_I = 4.0 V
95.67
%
V_I = 4.05 V
55.24
%
V_I = 4.10 V
31.97
%
V_I = 4.15 V
18.52
%
V_I = 4.20 V
10.74
%
V_i
AC Input
Voltage
V_I = 4.25 V
V_I = 4.30 V
6.23
%
3.62
%
V_I = 4.35 V
2.1
%
V_I = 4.40 V
1.22
%
V_I = 4.45 V
0.71
%
V_I = 4.50 V
0.41
%
V_I = 4.60 V
0.14
%
V_I = 4.70 V
0.047
%
Note to Table 1–2:
(1) Figure 1–1 shows the methodology to determine the overshoot duration. In the example in Figure 1–1, overshoot
voltage is shown in red and is present on the input pin of the Cyclone III device at over 4.1 V but below 4.2 V. From
Table 1–1, for an overshoot of 4.1 V, the percentage of high time for the overshoot can be as high as 31.97% over
a 10-year period. Percentage of high time is calculated as ([delta T]/T) × 100. This 10-year period assumes 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 shows the methodology to determine the overshoot duration.
Figure 1–1. Cyclone III Devices Overshoot Duration
4.2 V
4.1 V
3.3 V
ΔT
T
December 2011 Altera Corporation
Cyclone III Device Handbook
Volume 2