ProASIC3 DC and Switching Characteristics
Table 2-25 • I/O Output Buffer Maximum Resistances1
Applicable to Standard Plus I/O Banks
Standard
Drive Strength
RPULL-DOWN
(Ω)2
RPULL-UP
(Ω)3
3.3 V LVTTL / 3.3 V LVCMOS
2 mA
100
300
4 mA
100
300
6 mA
50
150
8 mA
50
150
12 mA
25
75
16 mA
25
75
2.5 V LVCMOS
2 mA
100
200
4 mA
100
200
6 mA
50
100
8 mA
50
100
12 mA
25
50
1.8 V LVCMOS
2 mA
200
225
4 mA
100
112
6 mA
50
56
8 mA
50
56
1.5 V LVCMOS
2 mA
200
224
4 mA
100
112
3.3 V PCI/PCI-X
Per PCI/PCI-X specification
0
0
Notes:
1. These maximum values are provided for informational reasons only. Minimum output buffer
resistance values depend on VCCI, drive strength selection, temperature, and process. For
board design considerations and detailed output buffer resistances, use the corresponding
IBIS models located on the Actel website at http://www.actel.com/download/ibis/default.aspx.
2. R(PULL-DOWN-MAX) = (VOLspec) / IOLspec
3. R(PULL-UP-MAX) = (VCCImax – VOHspec) / IOHspec
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