FG256 datasheet(24/108 Pages) ACTEL

24 / 108 page

SX-A Family FPGAs

2- 4

v5.3

Table 2-8 • AC Specifications (5 V PCI Operation)

Symbol

Parameter

Condition

Min.

Max.

Units

IOH(AC)

Switching Current High

0 < VOUT ≤ 1.4

–44

–

1.4

≤ V

OUT < 2.4

1, 2

(–44 + (VOUT – 1.4)/0.024)

–

3.1 < VOUT < VCCI

1, 3

–

EQ 2-1 on

page 2-5

–

(Test Point)

VOUT = 3.1

––142

IOL(AC)

Switching Current Low

VOUT ≥ 2.2

–

2.2 > VOUT > 0.55

(VOUT/0.023)

–

0.71 > VOUT > 0

1, 3

–

EQ 2-2 on

page 2-5

–

(Test Point)

VOUT = 0.71

–

206

ICL

Low Clamp Current

–5 < VIN ≤ –1

–25 + (VIN + 1)/0.015

–

slewR

Output Rise Slew Rate

0.4 V to 2.4 V load 4

V/ns

slewF

Output Fall Slew Rate

2.4 V to 0.4 V load 4

V/ns

Notes:

1. Refer to the V/I curves in Figure 2-1 on page 2-5. Switching current characteristics for REQ# and GNT# are permitted to be one half

of that specified here; i.e., half size output drivers may be used on these signals. This specification does not apply to CLK and RST#,

which are system outputs. “Switching Current High” specifications are not relevant to SERR#, INTA#, INTB#, INTC#, and INTD#,

which are open drain outputs.

2. Note that this segment of the minimum current curve is drawn from the AC drive point directly to the DC drive point rather than

toward the voltage rail (as is done in the pull-down curve). This difference is intended to allow for an optional N-channel pull-up.

3. Maximum current requirements must be met as drivers pull beyond the last step voltage. Equations defining these maximums (A

and B) are provided with the respective diagrams in Figure 2-1 on page 2-5. The equation defined maximum should be met by

design. In order to facilitate component testing, a maximum current test point is defined for each side of the output driver.

4. This parameter is to be interpreted as the cumulative edge rate across the specified range, rather than the instantaneous rate at any

point within the transition range. The specified load (diagram below) is optional; i.e., the designer may elect to meet this parameter

with an unloaded output per revision 2.0 of the PCI Local Bus Specification. However, adherence to both maximum and minimum

parameters is now required (the maximum is no longer simply a guideline). Since adherence to the maximum slew rate was not

required prior to revision 2.1 of the specification, there may be components in the market for some time that have faster edge

rates; therefore, motherboard designers must bear in mind that rise and fall times faster than this specification could occur and

should ensure that signal integrity modeling accounts for this. Rise slew rate does not apply to open drain outputs.

Output

Buffer

1/2 in. max.

50 pF

FG256 Datasheet(PDF) 24 Page - Actel Corporation

FG256 Datasheet(HTML) 24 Page - Actel Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL