Datasheet

SN54ABT657A, SN74ABT657A
OCTAL TRANSCEIVERS WITH PARITY GENERATORS/CHECKERS
AND 3-STATE OUTPUTS
SCBS192E – JANUARY 1991 – REVISED JUNE 1997
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
description (continued)
When V
CC
is between 0 and 2.1 V, the device is in the high-impedance state during power up or power down.
However, to ensure the high-impedance state above 2.1 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.
The SN54ABT657A is characterized for operation over the full military temperature range of –55°C to 125°C.
The SN74ABT657A is characterized for operation from –40°C to 85°C.
FUNCTION TABLE
NUMBER OF A OR B
INPUTS
I/O
OUTPUTS
INPUTS THAT ARE HIGH
OE T/R ODD/EVEN
PARITY
ERR OUTPUT MODE
L H H
H
Z Transmit
L HL
L
Z Transmit
02468
L LH
H
H Receive
0
,
2
,
4
,
6
,
8
L LH
L
L Receive
L LL
H
L Receive
L LL
L
H Receive
L H H
L
Z Transmit
L HL
H
Z Transmit
1357
L LH
H
L Receive
1
,
3
,
5
,
7
L LH
L
H Receive
L LL
H
H Receive
L LL
L
L Receive
Don’t care H X X Z Z Z