Three Bidirectional Transceivers

Driver Meets or Exceeds the Requirements

of ANSI EIA/TIA-422-B and RS-485 and ITU

Recommendation V.11

Two Skew Limits Available

Designed to Operate Up to 20 Million Data

Transfers per Second (FAST-20 SCSI)

High-Speed Advanced Low-Power Schottky

Circuitry

Low Pulse Skew . . . 5 ns Max

Designed for Multipoint Transmission on

Long Bus Lines in Noisy Environments

Features Independent Driver Enables and

Combined Receiver Enables

Wide Positive and Negative Input/Output

Bus Voltages Ranges

Driver Output Capacity . . . ±60 mA

Thermal Shutdown Protection

Driver Positive- and Negative-Current

Limiting

Receiver Input Impedances . . . 12 kW Min

Receiver Input Sensitivity . . . ±300 mV Max

Receiver Input Hysteresis . . . 60 mV Typ

Operates From a Single 5-V Supply

Glitch-Free Power-Up and Power-Down

Protection

description

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.