Three Bidirectional Transceivers

Driver Meets or Exceeds ANSI Standard

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

Designed for Multipoint Transmission on

Long Bus Lines in Noisy Environments

Wide Positive and Negative Input/Output

Bus Voltage 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

Operate From a Single 5-V Supply

Glitch-Free Power-Up and Power-Down

Protection

Feature Independent Direction Controls for

Each Channel

description

The SN75ALS170 and SN75ALS170A triple differential bus transceivers are monolithic integrated circuits

designed for bidirectional data communication on multipoint bus transmission lines. It is designed for balanced

transmission lines and the driver meets ANSI Standards EIA/TIA-422-B and RS-485 and both the driver and

receiver meet ITU Recommendation V.11. The SN75ALS170A 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 SN75ALS170 and SN75ALS170A operate from a single 5-V power supply. The drivers and receivers have

active-high and active-low enables, respectively, which are internally 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 when 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 SN75ALS170 and the SN75ALS170A are characterized for operation from 0°C to 70°C.