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.
ORDERING INFORMATION
SL74HC640N Plastic
SL74HC640D SOIC
TA = -55° to 125° C for all packages
·
·
·
·
Outputs Directly Interface to CMOS, NMOS, and TTL
Operating Voltage Range: 2.0 to 6.0 V
Low Input Current: 1.0 mA
High Noise Immunity Characteristic of CMOS Devices
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Control Inputs
Output
Enable
Direction
Operation
PIN 20=VCC
PIN 10 = GND
L
L
Data Transmitted
from Bus B to Bus
A (inverted)
L
H
X
Data Transmitted
from Bus A to Bus
B (inverted)
H
Buses Isolated
(High Impedance
State)
X = don’ t care
System Logic
SLS
Semiconductor
SLS [ SYSTEM LOGIC SEMICONDUCTOR ]
