TRIPLE DIFFERENTIAL BUS TRANSCEIVERS
D Three Bidirectional Transceivers
D Driver Meets or Exceeds the Requirements
of ANSI EIA/TIA-422-B and RS-485 and ITU
D Two Skew Limits Available
D Designed to Operate Up to 20 Million Data
Transfers per Second (FAST-20 SCSI)
D High-Speed Advanced Low-Power Schottky
D Low Pulse Skew . . . 5 ns Max
D Designed for Multipoint Transmission on
Long Bus Lines in Noisy Environments
D Features Independent Driver Enables and
Combined Receiver Enables
D Wide Positive and Negative Input/Output
Bus Voltages Ranges
D Driver Output Capacity . . . ± 60 mA
D Thermal Shutdown Protection
D Driver Positive- and Negative-Current
D Receiver Input Impedances . . . 12 kΩ Min
D Receiver Input Sensitivity . . . ± 300 mV Max
D Receiver Input Hysteresis . . . 60 mV Typ
D Operates From a Single 5-V Supply
D Glitch-Free Power-Up and Power-Down
SLLS056D – AUGUST 1987 – REVISED SEPTEMBER 1995
DW OR J PACKAGE
The SN75ALS171 and the SN75ALS171A triple differential bus transceivers are monolithic integrated circuits
designed for bidirectional data communication on multipoint bus transmission lines. They are designed for
balanced transmission lines, and each driver meets ANSI Standards EIA/TIA-422-B and RS-485 and both the
drivers and receivers meet ITU Recommendation V.11. The SN75ALS171A is designed for FAST-20 SCSI and
can transmit or receive data pulses as short as 30 ns with a maximum skew of 5 ns.
The SN75ALS171 and the SN75ALS171A operate from a single 5-V power supply. The drivers and receivers
have individual active-high and active-low enables, respectively, which can be externally connected together
to function as a direction control. The driver differential output and the receiver differential input pairs are
connected internally to form differential input/output (I/O) bus ports that are designed to offer minimum loading
to the bus when the driver is disabled or VCC is at 0 V. These ports feature wide positive and negative
common-mode voltage ranges making the device suitable for party-line applications.
The SN75ALS171 and the SN75ALS171A are 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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