
SN54ALS646, SN54ALS648, SN54AS646
SN74ALS646A, SN74ALS648A, SN74AS646, SN74AS648
OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS
SDAS039F – DECEMBER 1983 – REVISED JANUARY 1995
15
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, VCC
7 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, VI: Control inputs
7 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I / O ports
5.5 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, TA: SN74AS648
0
°C to 70°C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range
– 65
°C to 150°C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
recommended operating conditions
SN74AS648
UNIT
MIN
NOM
MAX
UNIT
VCC
Supply voltage
4.5
5
5.5
V
VIH
High-level input voltage
2
V
VIL
Low-level input voltage
0.8
V
IOH
High-level output current
–15
mA
IOL
Low-level output current
48
mA
fclock
Clock frequency
0
90
MHz
t
Pulse duration
CLKBA or CLKAB high
5
ns
tw
Pulse duration
CLKBA or CLKAB low
6
ns
tsu
Setup time, A before CLKAB
↑ or B before CLKBA↑
6
ns
th
Hold time, A after CLKAB
↑ or B before CLKBA
0
ns
TA
Operating free-air temperature
0
70
°C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
SN74AS648
UNIT
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
VIK
VCC = 4.5 V,
II = – 18 mA
– 1.2
V
VCC = 4.5 V to 5.5 V,
IOH = – 2 mA
VCC –2
VOH
VCC =4 5V
IOH = – 3 mA
2.4
3.2
V
VCC = 4.5 V
IOH = – 15 mA
2
VOL
VCC = 4.5 V,
IOL = 48 mA
0.35
0.5
V
II
Control inputs
VCC =5 5V
VI = 7 V
0.1
mA
II
A or B ports
VCC = 5.5 V
VI = 5.5 V
0.1
mA
I
Control inputs
V5 5 V
V2 7 V
20
A
IIH
A or B ports§
VCC = 5.5 V,
VI = 2.7 V
70
A
I
Control input
V5 5 V
V0 4 V
– 0.5
mA
IIL
A or B ports§
VCC = 5.5 V,
VI = 0.4 V
– 0.75
mA
IO
VCC = 5.5 V,
VO = 2.25 V
–30
–112
mA
Outputs high
110
185
ICC
VCC = 5.5 V
Outputs low
120
195
mA
Outputs disabled
120
195
All typical values are at VCC = 5 V, TA = 25 °C.
§ For I/O ports, the parameters IIH and IIL include the off-state output current.
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.