74LS245 Datasheet, PDF (1/6 Pages) National Semiconductor (TI) – TRI-STATE Octal Bus Transceiver

June 1989
54LS245 DM54LS245 DM74LS245
TRI-STATE Octal Bus Transceiver
General Description
These octal bus transceivers are designed for asynchro-
nous two-way communication between data buses The
control function implementation minimizes external timing
requirements
The device allows data transmission from the A bus to the B
bus or from the B bus to the A bus depending upon the logic
level at the direction control (DIR) input The enable input
(G) can be used to disable the device so that the buses are
effectively isolated
Features
Y _{Bi-Directional bus transceiver in a high-density 20-pin}
package
Y _{TRI-STATE outputs drive bus lines directly}
Y _{PNP inputs reduce DC loading on bus lines}
Y _{Hysteresis at bus inputs improve noise margins}
Y _{Typical propagation delay times port-to-port 8 ns}
Y _{Typical enable disable times 17 ns}
Y _{IOL (sink current)}
54LS 12 mA
74LS 24 mA
Y _{IOH (source current)}
54LS b12 mA
74LS b15 mA
Y _{Alternate Military Aerospace device (54LS245) is avail-}
able Contact a National Semiconductor Sales Office
Distributor for specifications
Connection Diagram
Dual-In-Line Package
Order Number 54LS245DMQB 54LS245FMQB 54LS245LMQB
DM54LS245J DM54LS245W DM74LS245WM or DM74LS245N
See NS Package Number E20A J20A M20B N20A or W20A
Function Table
Enable
G
Direction
Control
DIR
Operation
L
L
B data to A bus
L
H
A data to B bus
H
X
Isolation
H e High Level L e Low Level X e Irrelevant
TRI-STATE is a registered trademark of National Semiconductor Corporation
C1995 National Semiconductor Corporation TL F 6413
TL F 6413 – 1
RRD-B30M105 Printed in U S A