1/10
July 2001
s
HIGH SPEED:
t
PD
= 10ns (TYP.) at V
CC
= 6V
s
LOW POWER DISSIPATION:
I
CC
= 4
A(MAX.) at T
A
=25C
s
HIGH NOISE IMMUNITY:
V
NIH
= V
NIL
= 28 % V
CC
(MIN.)
s
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 6mA (MIN)
s
BALANCED PROPAGATION DELAYS:
t
PLH
t
PHL
s
WIDE OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2V to 6V
s
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 240
DESCRIPTION
The M74HC240 is an advanced high-speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with silicon gate C
2
MOS technology.
G control input governs four BUS BUFFERs.
This device is designed to be used with 3 state
memory address drivers, etc.
All inputs are equipped with protection circuits
against static discharge and transient excess
voltage.
M74HC240
OCTAL BUS BUFFER
WITH 3 STATE OUTPUTS (INVERTED)
PIN CONNECTION AND IEC LOGIC SYMBOLS
ORDER CODES
PACKAGE
TUBE
T & R
DIP
M74HC240B1R
SOP
M74HC240M1R
M74HC240RM13TR
TSSOP
M74HC240TTR
TSSOP
DIP
SOP
M74HC240
2/10
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
TRUTH TABLE
X : Don't Care
Z : High Impedance
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
(*) 500mW at 65
C; derate to 300mW by 10mW/
C from 65
C to 85
C
RECOMMENDED OPERATING CONDITIONS
PIN No
SYMBOL
NAME AND FUNCTION
1
1G
Output Enable Input
2, 4, 6, 8
1A1 to 1A4
Data Inputs
9, 7, 5, 3
2Y1 to 2Y4
Data Outputs
11, 13, 15,
17
2A1 to 2A4
Data Inputs
18, 16, 14,
12
1Y1 to 1Y4
Data Outputs
19
2G
Output Enable Input
10
GND
Ground (0V)
20
V
CC
Positive Supply Voltage
INPUTS
OUTPUT
G
An
Yn
L
L
H
L
H
L
H
X
Z
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
-0.5 to +7
V
V
I
DC Input Voltage
-0.5 to V
CC
+ 0.5
V
V
O
DC Output Voltage
-0.5 to V
CC
+ 0.5
V
I
IK
DC Input Diode Current
20
mA
I
OK
DC Output Diode Current
20
mA
I
O
DC Output Current
35
mA
I
CC
or I
GND
DC V
CC
or Ground Current
70
mA
P
D
Power Dissipation
500(*)
mW
T
stg
Storage Temperature
-65 to +150
C
T
L
Lead Temperature (10 sec)
300
C
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
2 to 6
V
V
I
Input Voltage
0 to V
CC
V
V
O
Output Voltage
0 to V
CC
V
T
op
Operating Temperature
-55 to 125
C
t
r
, t
f
Input Rise and Fall Time
V
CC
= 2.0V
0 to 1000
ns
V
CC
= 4.5V
0 to 500
ns
V
CC
= 6.0V
0 to 400
ns
M74HC240
3/10
DC SPECIFICATIONS
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
V
IH
High Level Input
Voltage
2.0
1.5
1.5
1.5
V
4.5
3.15
3.15
3.15
6.0
4.2
4.2
4.2
V
IL
Low Level Input
Voltage
2.0
0.5
0.5
0.5
V
4.5
1.35
1.35
1.35
6.0
1.8
1.8
1.8
V
OH
High Level Output
Voltage
2.0
I
O
=-20
A
1.9
2.0
1.9
1.9
V
4.5
I
O
=-20
A
4.4
4.5
4.4
4.4
6.0
I
O
=-20
A
5.9
6.0
5.9
5.9
4.5
I
O
=-6.0 mA
4.18
4.31
4.13
4.10
6.0
I
O
=-7.8 mA
5.68
5.8
5.63
5.60
V
OL
Low Level Output
Voltage
2.0
I
O
=20
A
0.0
0.1
0.1
0.1
V
4.5
I
O
=20
A
0.0
0.1
0.1
0.1
6.0
I
O
=20
A
0.0
0.1
0.1
0.1
4.5
I
O
=6.0 mA
0.17
0.26
0.33
0.40
6.0
I
O
=7.8 mA
0.18
0.26
0.33
0.40
I
I
Input Leakage
Current
6.0
V
I
= V
CC
or GND
0.1
1
1
A
I
OZ
High Impedance
Output Leakage
Current
6.0
V
I
= V
IH
or V
IL
V
O
= V
CC
or GND
0.5
5
10
A
I
CC
Quiescent Supply
Current
6.0
V
I
= V
CC
or GND
4
40
80
A
M74HC240
4/10
AC ELECTRICAL CHARACTERISTICS (C
L
= 50 pF, Input t
r
= t
f
= 6ns)
CAPACITIVE CHARACTERISTICS
1) C
PD
is defined as the value of the IC's internal equivalent capacitance which is calculated from the operating current consumption without
load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. I
CC(opr)
= C
PD
x V
CC
x f
IN
+ I
CC
/8 (per circuit)
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
C
L
(pF)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
t
TLH
t
THL
Output Transition
Time
2.0
50
25
60
75
90
ns
4.5
7
12
19
18
6.0
6
10
13
15
t
PLH
t
PHL
Propagation Delay
Time
2.0
50
36
90
115
135
ns
4.5
12
18
23
27
6.0
10
15
20
23
2.0
150
51
130
165
195
ns
4.5
17
26
33
39
6.0
14
22
28
33
t
PZL
t
PZH
High Impedance
Output Enable
Time
2.0
50
R
L
= 1 K
48
125
155
190
ns
4.5
16
25
31
38
6.0
14
21
25
32
2.0
150
R
L
= 1 K
63
165
205
250
ns
4.5
21
33
41
50
6.0
18
28
35
43
t
PLZ
t
PHZ
High Impedance
Output Disable
Time
2.0
50
R
L
= 1 K
32
125
155
190
ns
4.5
15
25
31
38
6.0
14
21
26
32
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
C
IN
Input Capacitance
5.0
5
10
10
10
pF
C
OUT
Output
Capacitance
5.0
10
pF
C
PD
Power Dissipation
Capacitance (note
1)
5.0
31
pF
M74HC240
5/10
TEST CIRCUIT
C
L
= 50pF/150pF or equivalent (includes jig and probe capacitance)
R
1
= 1K
or equivalent
R
T
= Z
OUT
of pulse generator (typically 50
)
WAVEFORM 1: PROPAGATION DELAY TIME (f=1MHz; 50% duty cycle)
TEST
SWITCH
t
PLH
, t
PHL
Open
t
PZL
, t
PLZ
V
CC
t
PZH
, t
PHZ
GND
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