FAIL-SAFE DIFFERENTIAL BUS TRANSCEIVER
D Bidirectional Transceiver With Fail-Safe
D Meets or Exceeds the Requirements of ITU
D Electrically Compatible With ANSI
Standards TIA/EIA-422-B and TIA/EIA-485-A
D Designed for Multipoint Transmission on
Long Bus Lines in Noisy Environments
D 3-State Driver and Receiver Outputs
D Individual Driver and Receiver Enables
D Wide Positive and Negative Input/Output
Bus Voltage Ranges
D Driver Output Capability . . . ± 60 mA Max
D Thermal Shutdown Protection
D Driver Positive and Negative Current
D Receiver Input Impedance . . . 12 kΩ Min
D Receiver Input Sensitivity . . . – 300 mV/0 mV
D Operates From Single 5-V Supply
D Pin-to-Pin Compatible With SN75176A
SLLS212B – SEPTEMBER 1995 – REVISED APRIL 1998
D OR P PACKAGE
The SN75276 differential bus transceiver is a monolithic, integrated circuit designed for bidirectional data
communication on multipoint bus transmission lines. It is designed for balanced transmission lines and is
electrically compatible with ANSI Standards TIA/EIA-422-B and TIA/EIA-485-A, and meets ITU
The fail-safe operation ensures a known level on the circuit output under bus fault conditions. The circuit
provides a high-level output under floating-line, idle-line, open-circuit, and short-circuit bus conditions (see
The SN75276 combines a 3-state, differential line driver and a differential input line receiver, both of which
operate from a single, 5-V power supply. The driver and receiver have active-high and active-low enables,
respectively, that can be externally connected together to function as a direction control. The driver differential
outputs and the receiver differential inputs are connected internally to form differential input/output (I/O) bus
ports that are designed to offer minimum loading to the bus whenever the driver is disabled or
VCC = 0. These ports feature wide positive and negative common-mode voltage ranges making the device
suitable for party-line applications.
The driver is designed for up to 60 mA of sink or source current. The driver features positive- and
negative-current limiting and thermal shutdown for protection from line fault conditions. Thermal shutdown is
designed to occur at a junction temperature of approximately 150°C. The receiver features a minimum input
impedance of 12 kΩ.
The SN75276 can be used in transmission line applications employing the SN75172 and SN75174 quadruple
differential line drivers and SN75173 and SN75175 quadruple differential line receivers.
SN75276 is characterized for operation from 0°C to 70°C.
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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.
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