Philips Semiconductors
Product specification
Buffers
74F240/74F240A/
74F241/74F241A
FEATURES
•
Octal bus interface
•
3-State buffer outputs sink 64mA
•
15mA source current
•
Guaranteed output skew less than 2.0ns
(74F240A/74F241A)
•
Reduced ground bounce (74F240A/74F241A)
DESCRIPTION
The 74F240 and 74F241 are octal buffers that are ideal for
driving bus lines of buffer memory address registers. The
outputs are all capable of sinking 64mA and sourcing up to
15mA. The device features two output enables, each
controlling four of the 3–state outputs.
The 74F240A and 74F241A are functionally equivalent to
their non–A counterparts. They have been designed to
reduce effects of ground noise. Other advantages are noted
in the features.
•
Reduced I
CC
(74F241A only)
•
Reduced loading (74F240A I
IL
= 100µA,
74F241A I
IL
= 40µA)
TYPE
74F240
74F240A
74F241
74F241A
TYPICAL PROPAGATION DELAY
4.3ns
3.8ns
5.0ns
4.5ns
TYPICAL SUPPLY CURRENT (TOTAL)
37mA
40mA
53mA
32mA
ORDERING INFORMATION
ORDER CODE
DESCRIPTION
20–pin plastic DIP
20–pin plastic SOL
20-pin plastic SSOP II
COMMERCIAL RANGE
V
CC
= 5V
±
10%, T
amb
= 0
°
C to +70
°
C
N74F240N, N74F240AN, N74F241N, N74F241AN
N74F240D, N74F240AD, N74F241D, N74F241AD
N74F240DB
PKG DWG #
SOT146-1
SOT163-1
SOT339-1
INPUT AND OUTPUT LOADING AND FAN OUT TABLE
PINS
Data inputs (74F240)
Ian, Ibn
Data inputs (74F240A)
Data inputs (74F241)
Data inputs (74F241A)
OEa, OEb
Output enable inputs (active low) (74F240)
Output enable inputs (active low) (74F240A)
OEa, OEb
Output enable input (74F241)
Output enable input (74F241A)
Yan, Ybn
Data outputs (74F241, 74F241A)
DESCRIPTION
74F (U.L.)
HIGH/LOW
1.0/1.67
1.0/0.167
1.0/2.67
1.0/0.067
1.0/0.33
1.0/0.167
1.0/1.67
1.0/0.067
750/106.7
750/106.7
LOAD VALUE
HIGH/LOW
20µA/1.0mA
20µA/100µA
20µA/1.6mA
20µA/40µA
20µA/0.2mA
20µA/100µA
20µA/1.0mA
20µA/40µA
15mA/64mA
15mA/64mA
Yan, Ybn
Data outputs (74F240, 74F240A)
Note to input and output loading and fan out table
One (1.0) FAST unit load is defined as: 20µA in the high state and 0.6mA in the low state.
January 2, 1991
2
853–0355 01345
Philips Semiconductors
Product specification
Buffers
74F240/74F240A/
74F241/74F241A
PIN CONFIGURATION FOR 74F240/74F240A
OEa
Ia0
Yb0
Ia1
Yb1
Ia2
Yb2
Ia3
Yb3
1
2
3
4
5
6
7
8
9
20 V
CC
19 OEb
18 Ya0
17 Ib0
16 Ya1
15 Ib1
14 Ya2
13 Ib2
IEC/IEEE SYMBOL FOR 74F240/74F240A
1
19
EN1
EN2
18
16
14
12
2
3
5
7
9
2
4
6
8
17
15
2D
1
12 Ya3
13
11 Ib3
11
GND 10
SF00320
SF00322
LOGIC SYMBOL FOR 74F240/74F240A
2
4
6
8
17
15
13
11
LOGIC DIAGRAM FOR 74F240/74F240A
Ia0
2
18
Ya0
Ib0
17
3
Yb0
Ia0
1
19
OEa
Ia1
Ia2
Ia3
Ib0
Ib1
Ib2 Ib3
Ia1
4
16
Ya1
Ib1
15
5
Yb1
Ia2
OEb
Ya0 Ya1 Ya2 Ya3 Yb0 Yb1 Yb2 Yb3
Ia3
6
14
Ya2
Ib2
13
7
Yb2
8
12
Ya3
Ib3
11
9
Yb3
18
V
CC
= Pin 20
GND = Pin 10
16
14
12
3
5
7
9
OEa
1
OEb
10
SF00321
V
CC
= Pin 20
GND = Pin 10
SF00323
FUNCTION TABLE FOR 74F240/74F240A
INPUTS
OEa
L
L
H
Ia
L
H
X
OEb
L
L
H
Ib
L
H
X
OUTPUTS
Ya
H
L
Z
Yb
H
L
Z
Notes to function table for 74F240/74F240A
H = High voltage level
L = Low voltage level
X = Don’t care
Z = High impedance ”off” state
January 2, 1991
3
Philips Semiconductors
Product specification
Buffers
74F240/74F240A/
74F241/74F241A
PIN CONFIGURATION FOR 74F241/74F241A
OEa
Ia0
Yb0
Ia1
Yb1
Ia2
Yb2
Ia3
Yb3
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
OEb
Ya0
Ib0
Ya1
IEC/IEEE SYMBOL FOR 74F241/74F241A
1
19
EN1
EN2
18
16
14
12
2
3
5
7
9
2
4
6
2D
1
Ib1
Ya2
Ib2
Ya3
Ib3
8
17
15
13
11
SF00324
SF00326
LOGIC SYMBOL FOR 74F241/74F241A
2
4
6
8
17
15
13
11
LOGIC DIAGRAM FOR 74F241/74F241A
Ia0
2
18
Ya0
Ib0
17
3
Yb0
Ia0
1
19
OEa
Ia1 Ia2
Ia3 Ib0
Ib1 Ib2
Ib3
Ia1
4
16
Ya1
Ib1
15
5
Yb1
Ia2
OEb
Ya0 Ya1 Ya2 Ya3 Yb0 Yb1 Yb2 Yb3
Ia3
6
14
Ya2
Ib2
13
7
Yb2
8
12
Ya3
Ib3
11
9
Yb3
18
V
CC
= Pin 20
GND = Pin 10
16
14
12
3
5
7
9
OEa
1
OEb
10
SF00325
V
CC
= Pin 20
GND = Pin 10
SF00327
FUNCTION TABLE FOR 74F241/74F241A
INPUTS
OEa
L
L
H
Ia
L
H
X
OEb
H
H
L
Ib
L
H
X
OUTPUTS
Ya
L
H
Z
Yb
L
H
Z
Notes to function table for 74F241/74F241A
H = High voltage level
L = Low voltage level
X = Don’t care
Z = High impedance ”off” state
January 2, 1991
4
Philips Semiconductors
Product specification
Buffers
74F240/74F240A/
74F241/74F241A
ABSOLUTE MAXIMUM RATINGS
(Operation beyond the limit set forth in this table may impair the useful life of the device. Unless otherwise noted these limits are over the
operating free air temperature range.)
SYMBOL
V
CC
V
IN
I
IN
V
OUT
I
OUT
T
amb
T
stg
Supply voltage
Input voltage
Input current
Voltage applied to output in high output state
Current applied to output in low output state
Operating free air temperature range
Storage temperature range
PARAMETER
RATING
–0.5 to +7.0
–0.5 to +7.0
–30 to +5
–0.5 to V
CC
128
0 to +70
–65 to +150
UNIT
V
V
mA
V
mA
°
C
°
C
RECOMMENDED OPERATING CONDITIONS
SYMBOL
PARAMETER
MIN
V
CC
V
IH
V
IL
I
Ik
I
OH
I
OL
T
amb
Supply voltage
High–level input voltage
Low–level input voltage
Input clamp current
High–level output current
Low–level output current
Operating free air temperature range
0
4.5
2.0
0.8
–18
–15
64
+70
LIMITS
NOM
5.0
MAX
5.5
V
V
V
mA
mA
mA
UNIT
°
C
January 2, 1991
5
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