N8T14, SN55122, SN75122
TRIPLE LINE RECEIVERS
SLLS075B – D1334, SEPTEMBER 1973 – REVISED FEBRUARY 1993
SN55122 . . . J PACKAGE
N8T14, SN75122 . . . D OR N PACKAGE
• Designed for Digital Data Transmission
Over Coaxial Cable, Strip Line, or Twisted
Pair
(TOP VIEW)
• Designed for Operation With 50-Ω to 500-Ω
V
1A
1B
1
2
3
4
5
6
7
8
16
15
14
CC
Transmission Lines
1S
1R
2R
• TTL Compatible
• Single 5-V Supply
• Built-Input Threshold Hysteresis
13 1Y
12 3A
2S
2A
11
10
9
3S
3R
3Y
2B
2Y
• High-Speed . . . Typical Propagation Delay
GND
Time = 20 ns
• Independent Channel Strobes
SN55122 . . . FK PACKAGE
(TOP VIEW)
• Input Gating Increases Application
Flexibility
• Fanout to 10 Series 54/74 Standard Loads
3
2
1
20 19
18
• Can Be Used With Dual Line Drivers
2R
2S
NC
2A
2B
1R
1Y
NC
3A
4
5
6
7
8
SN55121 and SN75121
17
16
15
• Interchangeable With Signetics N8T14
14 3S
9 10 11 12 13
description
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.
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.
2–1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265