MM54HC245A MM74HC245A Octal TRI-STATE Transceiver
January 1988
MM54HC245A MM74HC245A
Octal TRI-STATE Transceiver
General Description
This TRI-STATE bidirectional buffer utilizes advanced sili-
con-gate CMOS technology and is intended for two-way
asynchronous communication between data buses It has
high drive current outputs which enable high speed opera-
tion even when driving large bus capacitances This circuit
possesses the low power consumption and high noise im-
munity usually associated with CMOS circuitry yet has
speeds comparable to low power Schottky TTL circuits
This device has an active low enable input G and a direction
control input DIR When DIR is high data flows from the A
inputs to the B outputs When DIR is low data flows from
the B inputs to the A outputs The MM54HC245A
MM74HC245A transfers true data from one bus to the oth-
er
This device can drive up to 15 LS-TTL Loads and does not
have Schmitt trigger inputs All inputs are protected from
damage due to static discharge by diodes to V
CC
and
ground
Features
Y
Y
Y
Y
Y
Y
Typical propagation delay 13 ns
Wide power supply range 2 鈥?6V
Low quiescent current 80
mA
maximum (74 HC)
TRI-STATE outputs for connection to bus oriented
systems
High output drive 6 mA (minimum)
Same as the 鈥?45
Connection Diagram
Dual-In-Line Package
TL F 5165 鈥?
Top View
Order Number MM54HC245A or MM74HC245A
Truth Table
Control
Inputs
G
L
L
H
DIR
L
H
X
B data to A bus
A data to B bus
Isolation
Operation
H
e
high level L
e
low level X
e
irrelevant
TRI-STATE is a registered trademark of National Semiconductor Corp
C
1995 National Semiconductor Corporation
TL F 5165
RRD-B30M105 Printed in U S A
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