
SEMICONDUCTOR TECHNICAL DATA
1
REV 6
Motorola, Inc. 1995
10/95
High–Performance Silicon–Gate CMOS
The MC74HC242 is identical in pinout to the LS242. The device inputs
are compatible with Standard CMOS outputs; with pullup resistors, they
are compatible with LSTTL outputs.
This quad bus transceiver is designed for asynchronous two–way
communications between data buses. The states of the Output Enables
(A–to–B Enable and B–to–A Enable) determine both the direction of data
flow (from A to B or from B to A) and the modes of the Data Ports (input,
output, or high–impedance).
• Output Drive Capability: 15 LSTTL Loads
• Outputs Directly Interface to CMOS, NMOS and TTL
• Operating Voltage Range: 2 to 6V
• Low Input Current: 1µA
• High Noise Immunity Characteristic of CMOS Devices
• In Compliance With the JEDEC Standard No. 7A Requirements
• Chip Complexity: 130 FETs or 32.5 Equivalent Gates
LOGIC DIAGRAM
Pin 14 = VCC
Pin 7 = GND
Pins 2, 12 = No Connection
A1
3
Output
EnableS
B Data
Port
A2
4
A3
5
A4
6
A–TO–B ENABLE
1
B–TO–A ENABLE
13
B1
11
B2
10
B3
9
B4
8
A Data
Port
Pinout: 14–Lead Plastic Package (Top View)
1314 12 11 10 9 8
21 3 4 5 6 7
V
CC
B–to–A
Enable
NC B1 B2 B3 B4
A–to–B
Enable
NC A1 A2 A3 A4 GND
NC = No Connection
H
L
H
L
H
H
L
L
O
Z
Z
I
I
Z
Z
O
I = Input; O = Output, O = Inverting Output
Z = High Impedance
FUNCTION TABLE
Control Inputs Data Port Status
A–to–B
Enable
B–to–A
Enable
A
B
N SUFFIX
PLASTIC PACKAGE
CASE 646–06
1
14
ORDERING INFORMATION
MC74HCXXXN Plastic

MC74HC242
MOTOROLA High–Speed CMOS Logic Data
DL129 — Rev 6
2
DC Supply Voltage (Referenced to GND)
DC Input Voltage (Referenced to GND)
DC Output Voltage (Referenced to GND)
DC Input Current, per Pin
DC Output Current, per Pin
DC Supply Current, VCC and GND Pins
Power Dissipation in Still Air Plastic DIP†
Lead Temperature, 1 mm from Case for 10 Seconds
Plastic DIP Package
_
C
*Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
†Derating — Plastic DIP: – 10 mW/_C from 65_ to 125_C
For high frequency or heavy load considerations, see Chapter 2 of the Motorola High–Speed CMOS Data Book (DL129/D).
RECOMMENDED OPERATING CONDITIONS
DC Supply Voltage (Referenced to GND)
DC Input Voltage, Output Voltage (Referenced to GND)
Operating Temperature Range, All Package Types
Input Rise/Fall Time VCC = 2.0 V
(Figure 1) VCC = 4.5 V
VCC = 6.0 V
ns
DC CHARACTERISTICS (Voltages Referenced to GND)
Guaranteed Limit
Symbol Parameter Condition
–55 to 25°C ≤85°C ≤125°C Unit
V
IH
Minimum High–Level Input Voltage V
out
= 0.1V or VCC –0.1V
|I
out
| ≤ 20µA
2.0
4.5
6.0
1.50
3.15
4.20
1.50
3.15
4.20
1.50
3.15
4.20
V
V
IL
Maximum Low–Level Input Voltage V
out
= 0.1V or VCC – 0.1V
|I
out
| ≤ 20µA
2.0
4.5
6.0
0.3
0.9
1.2
0.3
0.9
1.2
0.3
0.9
1.2
V
V
OH
Minimum High–Level Output
Voltage
Vin = VIH or V
IL
|I
out
| ≤ 20µA
2.0
4.5
6.0
1.9
4.4
5.9
1.9
4.4
5.9
1.9
4.4
5.9
V
Vin =VIH or VIL|I
out
| ≤ 6.0mA
|I
out
| ≤ 7.8mA
4.5
6.0
3.98
5.48
3.84
5.34
3.70
5.20
V
OL
Maximum Low–Level Output
Voltage
Vin = VIH or V
IL
|I
out
| ≤ 20µA
2.0
4.5
6.0
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
V
Vin = VIH or VIL|I
out
| ≤ 6.0mA
|I
out
| ≤ 7.8mA
4.5
6.0
0.26
0.26
0.33
0.33
0.40
0.40
I
in
Maximum Input Leakage Current Vin = VCC or GND 6.0 ±0.1 ±1.0 ±1.0 µA
I
OZ
Maximum Three–State Leakage
Current
Output in High–Impedance State
Vin = VIL or V
IH
V
out
= VCC or GND
6.0 ±0.5 ±5.0 ±10.0 µA
I
CC
Maximum Quiescent Supply
Current (per Package)
Vin = VCC or GND
I
out
= 0µA
6.0 8 80 160 µA
NOTE: Information on typical parametric values can be found in Chapter 2 of the Motorola High–Speed CMOS Data Book (DL129/D).
This device contains protection
circuitry to guard against damage
due to high static voltages or electric
fields. However, precautions must
be taken to avoid applications of any
voltage higher than maximum rated
voltages to this high–impedance circuit. For proper operation, Vin and
V
out
should be constrained to the
range GND v (Vin or V
out
) v VCC.
Unused inputs must always be
tied to an appropriate logic voltage
level (e.g., either GND or VCC).
Unused outputs must be left open.

MC74HC242
High–Speed CMOS Logic Data
DL129 — Rev 6
3 MOTOROLA
AC CHARACTERISTICS (C
L
= 50 pF, Input tr = tf = 6 ns)
Guaranteed Limit
Symbol Parameter
–55 to 25°C ≤85°C ≤125°C Unit
t
PLH
,
t
PHL
Maximum Propagation Delay, A to B or B to A
(Figures 2 and 4)
2.0
4.5
6.0
100
20
17
125
25
21
150
30
26
ns
t
PLZ
,
t
PHZ
Maximum Propagation Delay, Output Enable to Output A or B
(Figures 3 and 5)
2.0
4.5
6.0
150
30
26
190
38
33
225
45
38
ns
t
PZL
,
t
PZH
Maximum Propagation Delay, Output Enable to Output A or B
(Figures 3 and 5)
2.0
4.5
6.0
150
30
26
190
38
33
225
45
38
ns
t
TLH
,
t
THL
Maximum Output Transition Time, Any Output
(Figures 2 and 4)
2.0
4.5
6.0
60
12
10
75
15
13
90
18
15
ns
C
in
Maximum Input Capacitance 10 10 10 pF
C
out
Maximum Three–State Output Capacitance (Output in High Impedance
State)
15 15 15 pF
NOTE: For propagation delays with loads other than 50 pF, and information on typical parametric values, see Chapter 2 of the Motorola High–
Speed CMOS Data Book (DL129/D).
Typical @ 25°C, VCC = 5.0 V
C
PD
Power Dissipation Capacitance (Per Transceiver)*
*Used to determine the no–load dynamic power consumption: PD = CPD V
CC
2
f + ICC VCC. For load considerations, see Chapter 2 of the
Motorola High–Speed CMOS Data Book (DL129/D).
PIN DESCRIPTIONS
DATA PORTS
A1–A4 (Pins 3,4,5,6) and B1–B4 (Pins 11,10,9,8)
Data on these pins may be transferred between d ata
buses. Depending upon the states of the Output Enables,
these pins may be inputs, outputs or open circuits (high–impedance).
CONTROL INPUTS
A–to–B Enable (Pin 1) and B–to–A Enable (Pin 13)
Data on these Output Enables determine both the direction of the data flow (from A to B or from B to A) and the
states of the outputs (standard or high impedance), according to the Function Table.

MC74HC242
MOTOROLA High–Speed CMOS Logic Data
DL129 — Rev 6
4
Figure 1. Expanded Logic Diagram
One of Four
Transceivers
A (I/O)
V
CC
B (I/O)
V
CC
A–to–B
Enable
B–to–A
Enable
1
13
SWITCHING WAVEFORMS
Figure 2.
V
CC
GND
Input A or B
Output A or B
t
PHL
CL*
*Includes all probe and jig capacitance
TEST
POINT
Output
Enable
50%
V
CC
GND
Output A or B
t
PZL
Output A or B
t
PZH
High
Impedance
V
OL
V
OH
High
Impedance
10%
90%
t
PLZ
t
PHZ
50%
50%
t
PLH
90%
50%
10%
t
r
t
THL
t
f
t
TLH
Figure 3.
DEVICE
UNDER
TEST
OUTPUT
TEST CIRCUITS
Figure 4. Figure 5.
CL*
*Includes all probe and jig capacitance
TEST
POINT
DEVICE
UNDER
TEST
OUTPUT
1k
Ω
CONNECT TO VCC WHEN
TESTING t
PLZ
AND t
PZL
.
CONNECT TO GND WHEN
TESTING t
PHZ
and t
PZH
.
90%
50%
10%
50%

MC74HC242
High–Speed CMOS Logic Data
DL129 — Rev 6
5 MOTOROLA
OUTLINE DIMENSIONS
N SUFFIX
PLASTIC DIP PACKAGE
CASE 646–06
ISSUE L
NOTES:
1. LEADS WITHIN 0.13 (0.005) RADIUS OF TRUE
POSITION AT SEATING PLANE AT MAXIMUM
MATERIAL CONDITION.
2. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.
3. DIMENSION B DOES NOT INCLUDE MOLD
FLASH.
4. ROUNDED CORNERS OPTIONAL.
1 7
14 8
B
A
F
H G D
K
C
N
L
J
M
SEATING
PLANE
DIM MIN MAX MIN MAX
MILLIMETERSINCHES
A 0.715 0.770 18.16 19.56
B 0.240 0.260 6.10 6.60
C 0.145 0.185 3.69 4.69
D 0.015 0.021 0.38 0.53
F 0.040 0.070 1.02 1.78
G 0.100 BSC 2.54 BSC
H 0.052 0.095 1.32 2.41
J 0.008 0.015 0.20 0.38
K 0.115 0.135 2.92 3.43
L 0.300 BSC 7.62 BSC
M 0 10 0 10
N 0.015 0.039 0.39 1.01
_ _ _ _
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the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit,
and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “T ypical” parameters can and do vary in different
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MC74HC242/D
*MC74HC242/D*
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