SN54AHCT245, SN74AHCT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCLS233I – OCTOBER 1995 – REVISED JANUARY 2000
D
EPIC
(Enhanced-Performance Implanted
CMOS) Process
D
Inputs Are TTL-Voltage Compatible
D
Latch-Up Performance Exceeds 250 mA Per
JESD 17
D
ESD Protection Exceeds 2000 V Per
MIL-STD-883, Method 3015; Exceeds 200 V
Using Machine Model (C = 200 pF, R = 0)
D
Package Options Include Plastic
Small-Outline (DW), Shrink Small-Outline
(DB), Thin Very Small-Outline (DGV), Thin
Shrink Small-Outline (PW), and Ceramic
Flat (W) Packages, Ceramic Chip Carriers
(FK), and Standard Plastic (N) and Ceramic
(J) DIPs
description
These octal bus transceivers are designed for
asynchronous two-way communication between
data buses. The control-function implementation
minimizes external timing requirements.
The ’AHCT245 devices allow 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 output-enable
(
OE) input can be used to disable the device so
that the buses are effectively isolated.
SN74AHCT245 . . . DB, DGV, DW, N, OR PW PACKAGE
SN54AHCT245 ...J OR W PACKAGE
(TOP VIEW)
1
20
B8
19
18
17
16
15
14
13
12
11
V
CC
B7
V
OE
B1
B2
B3
B4
B5
B6
B7
B8
18
17
16
15
14
B6 OE
CC
B1
B2
B3
B4
B5
DIR
2
A1
3
A2
4
A3
5
A4
6
A5
7
A6
8
A7
9
A8
GND
SN54AHCT245 . . . FK PACKAGE
10
(TOP VIEW)
A2A1DIR
A3
A4
A5
A6
A7
3212019
4
5
6
7
8
9
10 11 12 13
A8
GND
T o ensure the high-impedance state during power up or power down, OE should be tied to V
through a pullup
CC
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54AHCT245 is characterized for operation over the full military temperature range of –55°C to 125°C.
The SN74AHCT245 is characterized for operation from –40°C to 85°C.
FUNCTION TABLE
(each transceiver)
INPUTS
OE DIR
L L B data to A bus
L H A data to B bus
H X Isolation
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
EPIC is a trademark of Texas Instruments Incorporated.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright 2000, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
1
SN54AHCT245, SN74AHCT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCLS233I – OCTOBER 1995 – REVISED JANUARY 2000
logic symbol
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
†
OE
DIR
A1
A2
A3
A4
A5
A6
A7
A8
19
1
2
3
4
5
6
7
8
9
G3
3 EN1 [BA]
3 EN2 [AB]
1
2
logic diagram (positive logic)
1
DIR
18
17
16
15
14
13
12
11
B1
B2
B3
B4
B5
B6
B7
B8
A1
19
OE
2
18
B1
To Seven Other Channels
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265