Datasheet

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   
  
SCBS682G − MARCH 1997 − REVISED OCTOBER 2003
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
description/ordering information (continued)
Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of pullup or pulldown resistors
with the bus-hold circuitry is not recommended.
When V
CC
is between 0 and 1.5 V, the devices are in the high-impedance state during power up or power down.
However, to ensure the high-impedance state above 1.5 V, 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.
These devices are 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 devices when they are 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.
FUNCTION TABLE
INPUTS
OUTPUT
OE1 OE2 A
OUTPUT
Y
L L L L
L LH H
H XX Z
X H X Z
logic diagram (positive logic)
OE1
OE2
To Seven Other Channels
A1
Y1
1
19
218