N8T14, SN55122, SN75122
TRIPLE LINE RECEIVERS
SLLS075B – D1334, SEPTEMBER 1973 – REVISED FEBRUARY 1993
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Designed for Digital Data Transmission
Over Coaxial Cable, Strip Line, or Twisted
Pair
SN55122 . . . J PACKAGE
N8T14, SN75122 . . . D OR N PACKAGE
(TOP VIEW)
Designed for Operation With 50-Ω to 500-Ω
Transmission Lines
1A
1B
2R
2S
2A
2B
2Y
GND
TTL Compatible
Single 5-V Supply
Built-Input Threshold Hysteresis
High-Speed . . . Typical Propagation Delay
Time = 20 ns
Independent Channel Strobes
1
15
3
14
4
13
5
12
6
11
7
10
8
VCC
1S
1R
1Y
3A
3S
3R
3Y
16
2
9
SN55122 . . . FK PACKAGE
Input Gating Increases Application
Flexibility
(TOP VIEW)
1B
1A
NC
VCC
1S
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Fanout to 10 Series 54/74 Standard Loads
Can Be Used With Dual Line Drivers
SN55121 and SN75121
Interchangeable With Signetics N8T14
2R
2S
NC
2A
2B
The N8T14, SN55122, and SN75122 are triple
line receivers that are designed for digital data
transmission over lines having impedances from
50 Ω to 500 Ω. They are also compatible with
standard TTL-logic and supply voltage levels.
3 2 1 20 19
18
5
17
6
16
7
15
8
14
9 10 11 12 13
1R
1Y
NC
3A
3S
2Y
GND
NC
3Y
3R
description
4
NC – No internal connection
THE N8T14 AND SN75122 ARE NOT
RECOMMENDED FOR NEW DESIGN
The N8T14, SN55122, and SN75122 have receiver inputs with built-in hysteresis to provide increased noise
margin for single-ended systems. The high impedance of this input presents a minimum load to the driver and
allows termination of the transmission line in its characteristic impedance to minimize line reflection. An open
line will affect the receiver input as would a low-level voltage. The receiver can withstand a level of – 0.15 V with
power on or off. The other inputs are in TTL configuration. The S input must be high to enable the receiver input.
Two of the line receivers have A and B inputs that, if both are high, will hold the output low. The third receiver
has only an A input that, if high, will hold the output low.
The SN55122 is characterized for operation over the full military temperature range of – 55°C to 125°C. The
N8T14 and SN75122 are characterized for operation from 0°C to 70°C.
Copyright © 1993, 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
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