The M74HC240 is an advanced high-speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with silicon gate C
control input governs four BUS BUFFERs.
G
2
MOS technology.
TSSOPDIPSOP
ORDER CODES
PACKAGETUBET & R
DIPM74HC240B1R
SOPM74HC240M1RM74HC240RM13TR
TSSOPM74HC240TTR
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.
PIN CONNECTION AND IEC LOGIC SYMBOLS
1/10July 2001
Page 2
M74HC240
INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION
PIN NoSYMBOLNAME AND FUNCTION
11G
2, 4, 6, 81A1 to 1A4 Data Inputs
9, 7, 5, 32Y1
11, 13, 15, 172A1 to 2A4 Data Inputs
to 2Y4 Data Outputs
Output Enable Input
18, 16, 14, 121Y1
192G
to 1Y4 Data Outputs
Output Enable Input
10GNDGround (0V)
20V
CC
Positive Supply Voltage
TRUTH TABLE
INPUTSOUTPUT
G
AnYn
LLH
LHL
HXZ
X : Don’t Care
Z : High Impedance
ABSOLUTE MAXIMUM RATINGS
SymbolParameterValueUnit
V
V
V
I
I
OK
I
I
or I
CC
P
T
T
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
1) CPD 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
Input Capacitance
IN
Output
OUT
Capacitance
Power Dissipation
PD
Capacitance (note 1)5.031pF
5.05101010pF
5.010pF
= 25°C
A
Min.Typ. Max.Min.Max. Min. Max.
-40 to 85°C -55 to 125°C
= CPD x VCC x fIN + ICC/8 (per circuit)
CC(opr)
Unit
4/10
Page 5
TEST CIRCUIT
TESTSWITCH
t
, t
PLH
PHL
, t
t
PZL
PLZ
t
, t
PZH
PHZ
CL = 50pF/150p F or equivalen t (includes ji g and probe capa ci t ance)
R
= 1KΩ or equivalent
1
R
= Z
of pulse generator (typically 50Ω)
T
OUT
M74HC240
Open
V
CC
GND
WAVEFORM 1: PROPAGATION DELAY TIME (f=1 MHz; 50% duty cycl e )
5/10
Page 6
M74HC240
WAVEFORM 2 :OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50 % duty cycle )
6/10
Page 7
M74HC240
Plastic DIP-20 (0.25) MECHANICAL DATA
mm.inch
DIM.
MIN.TYPMAX.MIN.TYP.MAX.
a10.2540.010
B1.391.650.0550.065
b0.450.018
b10.250.010
D25.41.000
E8.50.335
e2.540.100
e322.860.900
F7.10.280
I3.930.155
L3.30.130
Z1.340.053
P001J
7/10
Page 8
M74HC240
SO-20 MECHANICAL DATA
DIM.
MIN.TYPMAX.MIN.TYP.MAX.
A2.650.104
a10.10.20.0040.008
a22.450.096
b0.350.490.0140.019
b10.230.320.0090.012
C0.50.020
c145° (typ.)
D12.6013.000.4960.512
E10.0010.650.3930.419
e1.270.050
e311.430.450
F7.407.600.2910.300
L0.501.270.0200.050
M0.750.029
S8° (max.)
mm.inch
8/10
PO13L
Page 9
M74HC240
TSSOP20 MECHANICAL DATA
mm.inch
DIM.
MIN.TYPMAX.MIN.TYP.MAX.
A1.20.047
A10.050.150.0020.0040.006
A20.811.050.0310.0390.041
b0.190.300.0070.012
c0.090.200.0040.0089
D6.46.56.60.2520.2560.260
E6.26.46.60.2440.2520.260
E14.34.44.480.1690.1730.176
e0.65 BSC0.0256 BSC
K0°8°0°8°
L0.450.600.750.0180.0240.030
A2
A
A1
b
e
K
c
L
E
D
E1
PIN 1 IDENTIFICATION
1
0087225C
9/10
Page 10
M74HC240
Information furnished is bel ieved to be accurate and reliable. However, STMicroe lectronics 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 li cense is granted by imp lication or otherwise under a ny patent or patent rig hts of STMicroelectronics. Spec ific at ions
mentioned in this publication ar e subject to change without notice. This publication supersedes and replaces all information
previously supplied. S TMicroelectronics products are not authorized for use as critica l components in life suppo rt devices or
systems without express written approval of STMicroelectronics.
Australi a - Brazil - Chi na - Finland - F rance - Germany - Hong Kon g - I ndia - Italy - Japan - Malay sia - Malta - Morocco