EP2S15 ALTERA [Altera Corporation], EP2S15 Datasheet - Page 213

• Manufacturer Part Number: EP2S15
• Description: Stratix II Device Family
• Manufacturer: ALTERA [Altera Corporation]

Duty Cycle
Distortion
Altera Corporation
May 2007
Notes to
(1)
(2)
(3)
(4)
3.3-V LVTTL
2.5-V LVTTL
1.8-V LVTTL
3.3-V LVCMOS
1.5-V LVCMOS
SSTL-2 Class I
SSTL-2 Class II
SSTL-18 Class I
SSTL-18 Class II
1.2-V HSTL
Table 5–79. Maximum Output Clock Toggle Rate Derating Factors (Part 5 of 5)
I/O Standard
For LVDS and HyperTransport technology output on row I/O pins, the toggle rate derating factors apply to loads
larger than 5 pF. In the derating calculation, subtract 5 pF from the intended load value in pF for the correct result.
For a load less than or equal to 5 pF, refer to
1.2-V HSTL is only supported on column I/O pins in I/O banks 4,7, and 8.
Differential HSTL and SSTL is only supported on column clock and DQS outputs.
LVPECL is only supported on column clock outputs.
Table
(2)
5–79:
Strength
Drive
OCT
OCT
OCT
OCT
OCT
OCT
OCT
OCT
OCT
OCT
50 Ω
50 Ω
50 Ω
50 Ω
50 Ω
50 Ω
25 Ω
50 Ω
25 Ω
50 Ω
Duty cycle distortion (DCD) describes how much the falling edge of a
clock is off from its ideal position. The ideal position is when both the
clock high time (CLKH) and the clock low time (CLKL) equal half of the
clock period (T), as shown in
non-ideal falling edge from the ideal falling edge, such as D1 for the
falling edge A and D2 for the falling edge B
DCD for a clock is the larger value of D1 and D2.
133
207
151
300
157
121
100
56
61
95
-3
Column I/O Pins
Maximum Output Clock Toggle Rate Derating Factors (ps/pF)
152
274
165
316
171
134
101
123
110
-4
-
Table 5–78
152
274
165
316
171
134
101
123
110
-5
-
for output toggle rates.
133
207
151
300
157
121
100
56
-3
-
-
Figure
Row I/O Pins
152
274
165
316
171
134
101
123
-4
-
-
5–7. DCD is the deviation of the
Stratix II Device Handbook, Volume 1
DC & Switching Characteristics
152
274
165
316
171
134
101
123
-5
-
-
(Figure
Dedicated Clock Outputs
147
235
153
263
174
106
77
58
59
-3
-
5–7). The maximum
152
274
165
316
171
134
101
123
110
-4
-
152
274
165
316
171
134
101
123
110
95
-5
5–77