August 1986
Revised March 2000
DM74LS245
3-STATE Octal Bus Transceiver
General Description
Features
These octal bus transceivers are designed for asynchro-
nous two-way communication between data buses. The
control function implementation minimizes external timing
requirements.
■ Bi-Directional bus transceiver in a high-density 20-pin
package
■ 3-STATE outputs drive bus lines directly
■ PNP inputs reduce DC loading on bus lines
■ Hysteresis at bus inputs improve noise margins
■ Typical propagation delay times, port-to-port 8 ns
■ Typical enable/disable times 17 ns
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.
■ IOL (sink current)
24 mA
■ IOH (source current)
−15 mA
Ordering Code:
Order Number Package Number
Package Description
DM74LS245WM
DM74LS245SJ
DM74LS245N
M20B
M20D
N20A
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Function Table
Enable
G
Direction
Operation
Control
DIR
L
L
L
B Data to A Bus
A Data to B Bus
Isolation
H
H
X
H = HIGH Level
L = LOW Level
X = Irrelevant
© 2000 Fairchild Semiconductor Corporation
DS006413
www.fairchildsemi.com