
SN74BCT25240
25-Ω OCTAL BUFFER/DRIVER
WITH 3-STATE OUTPUTS
SCBS101B – JUNE 1990 – REVISED NOVEMBER 1993
• State-of-the-Art BiCMOS Design
Significantly Reduces I
CCZ
• ESD Protection Exceeds 2000 V Per
MIL-STD-883C, Method 3015; Exceeds
200 V Using Machine Model (C = 200 pF,
R = 0)
• Designed to Facilitate Incident-Wave
Switching for Line Impedances of 25 Ω
or Greater
• Distributed V
and GND Pins Minimize
CC
Noise Generated by the Simultaneous
Switching of Outputs
• Package Options Include Plastic
Small-Outline (DW) Packages and Standard
Plastic 300-mil DIPs (NT)
DW OR NT PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
1Y1
GND
1Y2
1Y3
GND
1Y4
2Y1
GND
2Y2
2Y3
GND
2Y4
1OE
1A1
1A2
V
CC
1A3
1A4
2A1
2A2
V
CC
2A3
2A4
2OE
description
This 25-Ω octal buffers and line driver is designed specifically to improve both the performance and density of
3-state memory address drivers, clock drivers, and bus-oriented receivers and transmitters.
The SN74BCT25240 is capable of sinking 188-mA IOL, which facilitates switching 25-Ω transmission lines on
the incident wave. The distributed VCC and GND pins minimize switching noise for more reliable system
operation.
When the output-enable (1OE and 2OE) inputs are low, the device transmits the inverted A-input data to the
Y outputs. When 1OE
and 2OE are high, the outputs are in the high-impedance state. 1OE affects only the 1Y
outputs; 2OE affects only the 2Y outputs.
The SN74BCT25240 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
(each buffer/driver)
INPUTS
OE
L H L
L LH
H X Z
OUTPUT
A
Y
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.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 1993, Texas Instruments Incorporated
2–1

SN74BCT25240
25-Ω OCTAL BUFFER/DRIVER
WITH 3-STATE OUTPUTS
SCBS101B – JUNE 1990 – REVISED NOVEMBER 1993
24
23
22
20
19
13
18
17
15
14
†
EN
1
EN
1
logic symbol
1OE
1A1
1A2
1A3
1A4
2OE
2A1
2A2
2A3
2A4
†
This symbol is in accordance with ANSI/IEEE Std 91-1984
and IEC Publication 617-12.
10
12
logic diagram (positive logic)
1OE
1
1Y1
3
1Y2
4
1Y3
6
1Y4
7
2Y1
9
2Y2
2Y3
2Y4
1A1
1A2
1A3
1A4
2OE
2A1
2A2
24
23
22
20
19
13
18
17
1
1Y1
3
1Y2
4
1Y3
6
1Y4
7
2Y1
9
2Y2
2A3
2A4
15
14 12
10
2Y3
2Y4
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage range, V
CC
Input voltage range, VI (see Note 1) –0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage applied to any output in the disabled or power-off state, V
Voltage applied to any output in the high state, V
Input clamp current, I
Current into any output in the low state, I
(V
< 0) –30 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IK
I
O
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
O
O
Operating free-air temperature range 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
‡
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: The input negative-voltage rating may be exceeded if the input clamp-current rating is observed.
–0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
–0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . . . . .
–0.5 V to V
376 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
‡
CC
2–2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265