SCBS081L − JANUARY 1991 − REVISED APRIL 2005
SN54ABT245A, SN74ABT245B
OCTAL BUS TRANSCEIVERS
WITH 3 STATE OUTPUTS
description/ordering information (continued)
To ensure the high-impedance state during power up or power down, OE should be tied to V
CC
through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
This device is fully specified for hot-insertion applications using I
off
and power-up 3-state. The I
off
circuitry
disables the outputs, preventing damaging current backflow through the device when it is powered down. The
power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down,
which prevents driver conflict.
SN74ABT245B . . . GQN OR ZQN PACKAGE
(TOP VIEW)
1
A
B
C
D
E
2
3
4
A
B
C
D
E
terminal assignments
1
A1
A3
A5
A7
GND
2
DIR
B2
A4
B6
A8
3
VCC
A2
B4
A6
B8
4
OE
B1
B3
B5
B7
FUNCTION TABLE
INPUTS
OE
L
L
H
DIR
L
H
X
OPERATION
B data to A bus
A data to B bus
Isolation
logic diagram (positive logic)
DIR
1
19
OE
A1
2
18
B1
To Seven Other Channels
Pin numbers shown are for the DB, DGV, DW, FK, J, N, NS, PW, RGY, and W packages.
2
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
