SN75LBC179, SN65LBC179, SN65LBC179Q
LOW-POWER DIFFERENTIAL LINE DRIVER AND RECEIVER PAIRS
SLLS173D – JANUARY 1994 – REVISED JUNE 2000
D
D
D
D
D
D
D
D
Designed for High-Speed Multipoint Data
Transmission Over Long Cables
Operates With Pulse Widths as Low
as 30 ns
Low Supply Current . . . 5 mA Max
Meets or Exceeds the Standard
Requirements of ANSI RS-485 and
ISO 8482:1987(E)
Common-Mode Voltage Range of – 7 V
to 12 V
Positive- and Negative-Output Current
Limiting
Driver Thermal Shutdown Protection
Pin Compatible With the SN75179B
D OR P PACKAGE
(TOP VIEW)
VCC
R
D
GND
The SN65LBC179, SN65LBC179Q,
and
SN75LBC179 combine a differential line driver
and differential line receiver and operate from a
single 5-V supply. The driver differential outputs
and the receiver differential inputs are connected
to separate terminals for full-duplex operation and
are designed to present minimum loading to the
bus when powered off (VCC = 0). These parts
feature a wide common-mode voltage range
making them suitable for point-to-point or
multipoint data bus applications. The devices also
provide positive- and negative-current limiting
and thermal shutdown for protection from line fault
conditions. The line driver shuts down at a junction
temperature of approximately 172°C.
8
2
7
3
6
4
5
A
B
Z
Y
Function Tables
DRIVER
INPUT
D
H
L
OUTPUTS
Y
Z
H
L
L
H
RECEIVER
description
The SN65LBC179, SN65LBC179Q,
and
SN75LBC179 differential driver and receiver pairs
are monolithic integrated circuits designed for
bidirectional data communication over long
cables that take on the characteristics of
transmission lines. They are balanced, or
differential, voltage mode devices that meet or
exceed the requirements of industry standards
ANSI RS-485 and ISO 8482:1987(E). Both
devices are designed using TI’s proprietary
LinBiCMOS™ with the low power consumption of
CMOS and the precision and robustness of
bipolar transistors in the same circuit.
1
DIFFERENTIAL INPUTS OUTPUT
A–B
R
VID ≥ 0.2 V
H
– 0.2 V < VID < 0.2 V
?
L
VID ≤ – 0.2 V
H
Open circuit
H = high level,
? = indeterminate
L = low level,
logic symbol†
R
D
8
2
7
6
3
5
A
B
Z
Y
† This symbol is in accordance with ANSI/IEEE Std 91-1984
and IEC Publication 617-12.
logic diagram (positive logic)
R
D
2
3
8
7
5
6
A
B
Y
Z
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.
LinBiCMOS is a trademark of Texas Instruments.
Copyright © 2000, 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
1
