SL74HC640
Octal 3-State Inverting Bus Transceiver
High-Performance Silicon-Gate CMOS
The SL74HC640 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 SL74HC640 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
SL74HC640N Plastic
SL74HC640D SOIC
T
A
= -55° to 125° C for all packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Control Inputs
PIN 20=V
CC
PIN 10 = GND
Output
Enable
L
Direction
L
Operation
Data Transmitted
from Bus B to Bus
A (inverted)
Data Transmitted
from Bus A to Bus
B (inverted)
Buses Isolated
(High Impedance
State)
L
H
H
X
X = don’t care
System Logic
Semiconductor
SLS