SN75ALS171A

Features:

 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 kΩ 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


Pinout




Specifications

Supply voltage, V_CC (see Note 1)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .          7 V
Voltage range at any bus terminal   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V to 12 V
Enable input voltage, V_I  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .       7 V
Continuous total power dissipation   . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Operating free-air temperature range, T_A  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0°C to 70°C
Storage temperature range, T_stg  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: DW package               260°C
Lead temperature 1,6 mm (1/16 inch) from case for 60 seconds: J package   . .             300°C

Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTE 1: All voltage values, except differential I/O bus voltage, are with respect to network ground terminal.


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.