EP2S90F1020C5 Datasheet, PDF (223/768 Pages) Altera Corporation – Stratix II Device Handbook, Volume 1

DC & Switching Characteristics
Table 5–79. Maximum Output Clock Toggle Rate Derating Factors (Part 5 of 5)
I/O Standard
Drive
Strength
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 (2)
OCT
50 Ω
OCT
50 Ω
OCT
50 Ω
OCT
50 Ω
OCT
50 Ω
OCT
50 Ω
OCT
25 Ω
OCT
50 Ω
OCT
25 Ω
OCT
50 Ω
Maximum Output Clock Toggle Rate Derating Factors (ps/pF)
Column I/O Pins
Row I/O Pins
Dedicated Clock Outputs
-3
-4
-5
-3
-4
-5
-3 -4
-5
133 152 152 133 152 152 147 152 152
207 274 274 207 274 274 235 274 274
151 165 165 151 165 165 153 165 165
300 316 316 300 316 316 263 316 316
157 171 171 157 171 171 174 171 171
121 134 134 121 134 134 77 134 134
56
101 101
56
101 101 58 101 101
100 123 123 100 123 123 106 123 123
61
110 110
-
-
-
59 110 110
95
-
-
-
-
-
-
-
95
Notes to Table 5–79:
(1) 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 Table 5–78 for output toggle rates.
(2) 1.2-V HSTL is only supported on column I/O pins in I/O banks 4,7, and 8.
(3) Differential HSTL and SSTL is only supported on column clock and DQS outputs.
(4) LVPECL is only supported on column clock outputs.
Duty Cycle
Distortion
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 Figure 5–7. DCD is the deviation of the
non-ideal falling edge from the ideal falling edge, such as D1 for the
falling edge A and D2 for the falling edge B (Figure 5–7). The maximum
DCD for a clock is the larger value of D1 and D2.
Altera Corporation
April 2011
5–77
Stratix II Device Handbook, Volume 1