SN75ALS121_08 Datasheet, PDF (1/7 Pages) Texas Instruments – DUAL LINE DRIVER

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SN75ALS121
DUAL LINE DRIVER
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SLLS030A − D1334, SEPTEMBER 1987 − REVISED AUGUST 1989
• Permits Digital Data Transmission Over
Coaxial Cable, Strip Line, or Twisted Pair
• Operates With 50-Ω to 500-Ω Transmission
Lines
• TTL Compatible With 5-V Supply
• 2.4-V Output at I_OH = −75 mA
• Uncommitted Emitter-Follower Output
Structure for Party-Line Operation
• IMPACT Low-Power Schottky Technology
• Improved Replacement for the SN75121
and Signetics 8T13
• Glitchless Power Up/Power Down
• Short-Circuit Protection
• AND-OR Logic Configuration
• High Speed . . . Maximum Propagation
Delay Time of 14 ns at C_L = 15 pF
description
The SN75ALS121 dual line driver is designed for
digital data transmission over lines having
impedances from 50 to 500 Ω. It is compatible with
standard TTL logic and supply voltage levels.
D OR N PACKAGE
(TOP VIEW)
1A 1
1B 2
1C 3
1D 4
1E 5
1F 6
1Y 7
GND 8
16 V_CC
15 2F
14 2E
13 2D
12 2C
11 2B
10 2A
9 2Y
NOT RECOMMENDED FOR NEW DESIGN
FUNCTION TABLE
INPUTS
OUTPUT
A BC DE F
Y
H HH HX X
H
X XX
XHH
H
All other input combinations
L
H = high level, L = low level, X = irrelevant
The low-impedance emitter-follower outputs drive terminated lines such as coaxial cable, strip line, or twisted
pair. Having the outputs uncommitted allows wired-OR logic to be performed in party-line applications. Output
short-circuit protection is provided by an internal clamping network that turns on when the output voltage drops
below approximately 1.5 V. All inputs are in conventional TTL configuration. Gating can be used during power-up
and power-down sequences to ensure that no noise is introduced on the line.
The SN75ALS121 employs the IMPACT process to achieve fast switching speeds, low power dissipation, and
reduced input current requirements.
The SN75ALS121 is characterized for operation from 0°C to 70°C.
IMPACT 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.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
• POST OFFICE BOX 1443 HOUSTON, TEXAS 77001
Copyright  1989, Texas Instruments Incorporated
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