IN74HC640A
O
CTAL
3-S
TATE
I
NVERTING
B
US
T
RANSCEIVER
High-Performance Silicon-Gate CMOS
The IN74HC640A is identical in pinout to the LS/ALS640. The
device inputs are compatible with standard CMOS outputs; with
pullup resistors, they are compatible with LS/ALSTTL outputs.
The IN74HC640A 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.
Outputs Directly Interface to CMOS, NMOS, and TTL
Operating Voltage Range: 2.0 to 6.0 V
Low Input Current: 1.0
µA
High Noise Immunity Characteristic of CMOS Devices
•
•
•
•
ORDERING INFORMATION
IN74HC640AN Plastic
IN74HC640ADW SOIC
T
A
= -55° to 125° C for all
packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
PIN 20=V
CC
PIN 10 = GND
Control Inputs
Output
Direction
Enable
L
L
L
H
H
X
Operation
Data Transmitted
from Bus B to Bus
A (inverted)
Data Transmitted
from Bus A to Bus
B (inverted)
Buses
Isolated
(High Impedance
State)
X = don’t care
1
INTEGRAL [ INTEGRAL CORP. ]
