Chapter 1: Cyclone III Device Datasheet

1–3

Electrical Characteristics

July 2012

Altera Corporation

Cyclone III Device Handbook

Volume 2

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.

Figure 1–1 shows the methodology to determine the overshoot duration.

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

AC Input

Voltage

100

%

95.67

%

55.24

%

31.97

%

18.52

%

10.74

%

6.23

%

3.62

%

2.1

%

1.22

%

0.71

%

0.41

%

0.14

%

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. Cyclone III Devices Overshoot Duration

3.3 V

4.1 V

4.2 V

T

ΔT