1FEATURES
2• Meets EIA Standards RS-422-A, RS-423-A,
RS-485, and CCITT V.11
• Designed to Operate With Pulse Durations as
Short as 20 ns
• Designed for Multipoint Bus Transmission on
Long Bus Lines in Noisy Environments
• Input Sensitivity: ±200 mV
• Low-Power Consumption: 20 mA (Max)
• Open-Circuit Fail-Safe Design

DESCRIPTION
The SN55LBC173 is a monolithic quadruple differential line receiver with 3-state outputs designed to meet the
requirements of the EIA standards RS-422-A, RS-423-A, RS-485, and CCITT V.11. This device is optimized for
balanced multipoint bus transmission at data rates up to and exceeding 10 million bits per second. The four
receivers share two ORed enable inputs, one active when high, the other active when low. Each receiver
features high input impedance, input hysteresis for increased noise immunity, and input sensitivity of ±200 mV
over a common-mode input voltage range of 12 V to –7 V. Fail-safe design ensures that if the inputs are open
circuited, the output is always high. The SN55LBC173 is designed using the Texas Instruments proprietary
LinBiCMOS™ technology that provides low power consumption, high switching speeds, and robustness.