1/9
June 2001
s
HIGH SPEED: t
PD
= 3.6ns (TYP.) at V
CC
= 5V
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
POWER DOWN PROTECTION ON INPUTS
s
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 8 mA (MIN)
s
BALANCED PROPAGATION DELAYS:
t
PLH
t
PHL
s
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2V to 5.5V
s
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 240
s
IMPROVED LATCH-UP IMMUNITY
s
LOW NOISE: V
OLP
= 0.9V (MAX.)
DESCRIPTION
The 74VHC240 is an advanced high-speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with sub-micron silicon gate and
double-layer metal wiring C
2
MOS technology.
G output enable governs four BUS BUFFERs.
This device is designed to be used with 3 state
memory address drivers, etc.
Power down protection is provided on all inputs
and 0 to 7V can be accepted on inputs with no
regard to the supply voltage. This device can be
used to interface 5V to 3V.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
74VHC240
OCTAL BUS BUFFER
WITH 3 STATE OUTPUTS (INVERTED)
PIN CONNECTION AND IEC LOGIC SYMBOLS
ORDER CODES
PACKAGE
TUBE
T & R
SOP
74VHC240M
74VHC240MTR
TSSOP
74VHC240TTR
TSSOP
SOP
74VHC240
2/9
INPUT 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
RECOMMENDED OPERATING CONDITIONS
1) V
IN
from 30% to 70% of V
CC
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 +7.0
V
V
I
DC Input Voltage
-0.5 to +7.0
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
25
mA
I
CC
or I
GND
DC V
CC
or Ground Current
75
mA
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 5.5
V
V
I
Input Voltage
0 to 5.5
V
V
O
Output Voltage
0 to V
CC
V
T
op
Operating Temperature
-55 to 125
C
dt/dv
Input Rise and Fall Time (note 1) (V
CC
= 3.3
0.3V)
(V
CC
= 5.0
0.5V)
0 to 100
0 to 20
ns/V
74VHC240
3/9
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
3.0 to
5.5
0.7V
CC
0.7V
CC
0.7V
CC
V
IL
Low Level Input
Voltage
2.0
0.5
0.5
0.5
V
3.0 to
5.5
0.3V
CC
0.3V
CC
0.3V
CC
V
OH
High Level Output
Voltage
2.0
I
O
=-50
A
1.9
2.0
1.9
1.9
V
3.0
I
O
=-50
A
2.9
3.0
2.9
2.9
4.5
I
O
=-50
A
4.4
4.5
4.4
4.4
3.0
I
O
=-4 mA
2.58
2.48
2.4
4.5
I
O
=-8 mA
3.94
3.8
3.7
V
OL
Low Level Output
Voltage
2.0
I
O
=50
A
0.0
0.1
0.1
0.1
V
3.0
I
O
=50
A
0.0
0.1
0.1
0.1
4.5
I
O
=50
A
0.0
0.1
0.1
0.1
3.0
I
O
=4 mA
0.36
0.44
0.55
4.5
I
O
=8 mA
0.36
0.44
0.55
Ioz
High Impedance
Output Leakage
Current
5.5
V
I
= V
IH
or V
IL
V
O
= V
CC
or GND
0.25
2.5
2.5
A
I
I
Input Leakage
Current
0 to
5.5
V
I
= 5.5V or GND
0.1
1
1
A
I
CC
Quiescent Supply
Current
5.5
V
I
= V
CC
or GND
4
40
40
A
74VHC240
4/9
AC ELECTRICAL CHARACTERISTICS (Input t
r
= t
f
= 3ns)
(*) Voltage range is 3.3V
0.3V
(**) Voltage range is 5.0V
0.5V
Note 1 : Parameter guaranteed by design. t
soLH
= |t
pLHm
- t
pLHn
|, t
soHL
= |t
pHLm
- t
pHLn
|
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
PLH
t
PHL
Propagation Delay
Time
3.3
(*)
15
5.3
7.5
1.0
9.0
1.0
9.0
ns
3.3
(*)
50
7.8
11.0
1.0
12.5
1.0
12.5
5.0
(**)
15
3.6
5.5
1.0
6.5
1.0
6.5
5.0
(**)
50
5.1
7.5
1.0
8.5
1.0
8.5
t
PZL
t
PZH
Output Enable
Time
3.3
(*)
15
R
L
= 1K
6.6
10.6
1.0
12.5
1.0
12.5
ns
3.3
(*)
50
R
L
= 1K
9.1
14.1
1.0
16.0
1.0
16.0
5.0
(**)
15
R
L
= 1K
4.7
7.3
1.0
8.5
1.0
8.5
5.0
(**)
50
R
L
= 1K
6.2
9.3
1.0
10.5
1.0
10.5
t
PLZ
t
PHZ
Output Disable
Time
3.3
(*)
50
R
L
= 1K
10.3
14.0
1.0
16.0
1.0
16.0
ns
5.0
(**)
50
R
L
= 1K
6.7
9.2
1.0
10.5
1.0
10.5
t
OSLH
t
OSHL
Output to Output
Skew time (note 1)
3.3
(*)
50
1.5
1.5
1.5
ns
5.0
(**)
50
1.0
1.0
1.0
Symbol
Parameter
Test Condition
Value
Unit
T
A
= 25C
-40 to 85C
-55 to 125C
Min.
Typ.
Max.
Min.
Max.
Min.
Max.
C
IN
Input Capacitance
6
10
10
10
pF
C
OUT
Output
Capacitance
8
pF
C
PD
Power Dissipation
Capacitance
(note 1)
17
pF
74VHC240
5/9
DYNAMIC SWITCHING CHARACTERISTICS
1) Worst case package.
2) Max number of outputs defined as (n). Data inputs are driven 0V to 5.0V, (n-1) outputs switching and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to 5.0V. Inputs under test switching: 5.0V to threshold (V
ILD
), 0V to threshold
(V
IHD
), f=1MHz.
TEST CIRCUIT
C
L
=15/ 50pF or equivalent (includes jig and probe capacitance)
R
L
= R
1
= 1K
or equivalent
R
T
= Z
OUT
of pulse generator (typically 50
)
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
OLP
Dynamic Low
Voltage Quiet
Output (note 1, 2)
5.0
C
L
= 50 pF
0.6
0.9
V
V
OLV
-0.9
-0.6
V
IHD
Dynamic High
Voltage Input
(note 1, 3)
5.0
3.5
V
V
ILD
Dynamic Low
Voltage Input
(note 1, 3)
5.0
1.5
V
TEST
SWITCH
t
PLH
, t
PHL
Open
t
PZL
, t
PLZ
V
CC
t
PZH
, t
PHZ
GND
74VHC240
6/9
WAVEFORM 1 : PROPAGATION DELAYS (f=1MHz; 50% duty cycle)
WAVEFORM 2: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle)
74VHC240
7/9
DIM.
mm.
inch
MIN.
TYP
MAX.
MIN.
TYP.
MAX.
A
2.65
0.104
a1
0.1
0.2
0.004
0.008
a2
2.45
0.096
b
0.35
0.49
0.014
0.019
b1
0.23
0.32
0.009
0.012
C
0.5
0.020
c1
45 (typ.)
D
12.60
13.00
0.496
0.512
E
10.00
10.65
0.393
0.419
e
1.27
0.050
e3
11.43
0.450
F
7.40
7.60
0.291
0.300
L
0.50
1.27
0.020
0.050
M
0.75
0.029
S
8 (max.)
SO-20 MECHANICAL DATA
PO13L
74VHC240
8/9
DIM.
mm.
inch
MIN.
TYP
MAX.
MIN.
TYP.
MAX.
A
1.2
0.047
A1
0.05
0.15
0.002
0.004
0.006
A2
0.8
1
1.05
0.031
0.039
0.041
b
0.19
0.30
0.007
0.012
c
0.09
0.20
0.004
0.0089
D
6.4
6.5
6.6
0.252
0.256
0.260
E
6.2
6.4
6.6
0.244
0.252
0.260
E1
4.3
4.4
4.48
0.169
0.173
0.176
e
0.65 BSC
0.0256 BSC
K
0
8
0
8
L
0.45
0.60
0.75
0.018
0.024
0.030
TSSOP20 MECHANICAL DATA
c
E
b
A2
A
E1
D
1
PIN 1 IDENTIFICATION
A1
L
K
e
0087225C
74VHC240
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of STMicroelectronics.
The ST logo is a registered trademark of STMicroelectronics
2001 STMicroelectronics - Printed in Italy - All Rights Reserved
STMicroelectronics GROUP OF COMPANIES
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