Semiconductor Components Industries, LLC, 2000
March, 2000 – Rev. 8
1 Publication Order Number:
MC74HC245A/D
MC74HC245A
Octal 3-State Noninverting
Bus Transceiver
High–Performance Silicon–Gate CMOS
The MC74HC245A is identical in pinout to the LS245. The device
inputs are compatible with standard CMOS outputs; with pullup
resistors, they are compatible with LSTTL outputs.
The HC245A is a 3–state noninverting transceiver that is used for
2–way asynchronous communication between data buses. The device
has an active–low Output Enable pin, which is used to place the I/O
ports into high–impedance states. The Direction control determines
whether data flows from A to B or from B to A.
• Output Drive Capability: 15 LSTTL Loads
• Outputs Directly Interface to CMOS, NMOS, and TTL
• Operating Voltage Range: 2 to 6 V
• Low Input Current: 1 µA
• High Noise Immunity Characteristic of CMOS Devices
• In Compliance with the Requirements Defined by JEDEC Standard
No. 7A
• Chip Complexity: 308 FETs or 77 Equivalent Gates
LOGIC DIAGRAM
A
DATA
PORT
A8
A7
A6
A5
A3
A4
A2
A1
9
8
7
6
5
4
3
2
DIRECTION
OUTPUT ENABLE
1
19
PIN 10 = GND
PIN 20 = V
CC
18
17
16
15
14
13
12
11
B1
B2
B3
B4
B5
B6
B7
B8
B
DATA
PORT
FUNCTION TABLE
Control Inputs
Output
Enable
Direction
Operation
L L Data Transmitted from Bus B to Bus A
L H Data Transmitted from Bus A to Bus B
H X Buses Isolated (High–Impedance State)
X = don’t care
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MARKING
DIAGRAMS
1
20
A = Assembly Location
WL = Wafer Lot
YY = Year
WW = Work Week
SOIC WIDE–20
DW SUFFIX
CASE 751D
HC245A
AWLYYWW
PDIP–20
N SUFFIX
CASE 738
1
20
MC74HC245AN
AWLYYWW
1
20
1
20
Device Package Shipping
ORDERING INFORMATION
MC74HC245AN PDIP–20 1440 / Box
MC74HC245ADW SOIC–WIDE
38 / Rail
MC74HC245ADWR2 SOIC–WIDE 1000 / Reel
PIN ASSIGNMENT
A5
A3
A2
A1
DIRECTION
GND
A8
A7
A6
A4 5
4
3
2
1
10
9
8
7
6
14
15
16
17
18
19
20
11
12
13
B3
B2
B1
OUTPUT ENABLE
V
CC
B8
B7
B6
B5
B4
MC74HC245A
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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†
SOIC Package†
Lead Temperature, 1 mm from Case for 10 Seconds
(Plastic DIP or SOIC 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
SOIC Package: – 7 mW/_C from 65_ to 125_C
For high frequency or heavy load considerations, see Chapter 2 of the ON Semiconductor 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, All Package Types
Input Rise and Fall Time VCC = 2.0 V
(Figure 1) VCC = 4.5 V
VCC = 6.0 V
ns
DC ELECTRICAL CHARACTERISTICS (Voltages Referenced to GND)
Minimum High–Level Input
Voltage
V
out
= VCC – 0.1 V
|I
out
| v 20 µA
Maximum Low–Level Input
Voltage
V
out
= 0.1 V
|I
out
| v 20 µA
Minimum High–Level Output
Voltage
Vin = V
IH
|I
out
| v 20 µA
Vin = V
IH
|I
out
| v 2.4 mA
|I
out
| v 6.0 mA
|I
out
| v 7.8 mA
Maximum Low–Level Output
Voltage
Vin = V
IL
|I
out
| v 20 µA
Vin = V
IL
|I
out
| v 2.4 mA
|I
out
| v 6.0 mA
|I
out
| v 7.8 mA
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.
MC74HC245A
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DC ELECTRICAL CHARACTERISTICS (Voltages Referenced to GND)
Maximum Input Leakage
Current
Maximum Three–State
Leakage Current
Output in High–Impedance State
Vin = VIL or V
IH
V
out
= VCC or GND
Maximum Quiescent Supply
Current (per Package)
Vin = VCC or GND
I
out
= 0 µA
µA
NOTE: Infor mation on typ ical p arametr ic va lues and high frequency or heavy load considerations can be found in Chapter 2 of the ON
Semiconductor High–Speed CMOS Data Book (DL129/D).
AC ELECTRICAL CHARACTERISTICS (C
L
= 50 pF, Input tr = tf = 6 ns)
Maximum Propagation Delay, A to B, B to A
(Figures 1 and 3)
Maximum Propagation Delay, Direction or Output Enable to A or B
(Figures 2 and 4)
Maximum Propagation Delay, Output Enable to A or B
(Figures 2 and 4)
Maximum Output Transition Time, Any Output
(Figures 1 and 3)
Maximum Input Capacitance (Pin 1 or Pin 19)
Maximum Three–State I/O Capacitance
(I/O in High–Impedance State)
pF
NOTE: For propagation delays with loads other than 50 pF, and information on typical parametric values, see Chapter 2 of the ON
Semiconductor High–Speed CMOS Data Book (DL129/D).
Typical @ 25°C, VCC = 5.0 V
C
PD
Power Dissipation Capacitance (Per Transceiver Channel)*
40
pF
*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
ON Semiconductor High–Speed CMOS Data Book (DL129/D).