TECHNICAL DATA
IN74ACT640
Octal 3-State Inverting
Bus Transceiver
High-Speed Silicon-Gate CMOS
The IN74ACT640 is identical in pinout to the LS/ALS640,
HC/HCT640. The IN74ACT640 may be used as a level converter for
interfacing TTL or NMOS outputs to High Speed CMOS inputs.
The IN74ACT640 is a 3-state 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.
ORDERING INFORMATION
IN74ACT640N Plastic
IN74ACT640DW SOIC
TA = -40° to 85° C for all packages
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TTL/NMOS Compatible Input Levels
Outputs Directly Interface to CMOS, NMOS, and TTL
Operating Voltage Range: 4.5 to 5.5 V
Low Input Current: 1.0 µA; 0.1 µA @ 25°C
Outputs Source/Sink 24 mA
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Control Inputs
Output
Direction
Operation
Enable
L
L
Data Transmitted
from Bus B to
Bus A (inverted)
L
H
X
Data Transmitted
from Bus A to
Bus B (inverted)
PIN 20=VCC
PIN 10 = GND
H
Buses Isolated
(High Impedance
State)
X = don’t care
Rev. 00