Product details


Number of receivers 2 Number of transmitters 2 Duplex Full Supply voltage (Nom) (V) 5 Signaling rate (Max) (Mbps) 10 IEC 61000-4-2 contact (+/- kV) None Fault protection (V) -10 to 15 Common mode range -7 to 12 Number of nodes 32 Isolated No ICC (Max) (mA) 50 Rating Catalog Operating temperature range (C) 0 to 70 open-in-new Find other RS-485 & RS-422 transceivers

Package | Pins | Size

PDIP (N) 16 181 mm² 19.3 x 9.4 SOP (NS) 16 80 mm² 10.2 x 7.8 open-in-new Find other RS-485 & RS-422 transceivers


  • Meet or Exceed Standards TIA/EIA-422-B and TIA/EIA-485-A
  • Designed for Multipoint Bus Transmission on Long Bus Lines in Noisy Environments
  • Low Supply-Current Requirement 50 mA Max
  • Driver Positive- and Negative-Current Limiting
  • Driver Common-Mode Output Voltage Range of -7 V to 12 V
  • Thermal Shutdown Protection
  • Driver 3-State Outputs Active-High Enable
  • Receiver Common-Mode Input Voltage Range of -12 V to 12 V
  • Receiver Input Sensitivity...±200 mV
  • Receiver Hysteresis...50 mV Typ
  • Receiver High Input Impedance...12k Min
  • Receiver 3-State Outputs Active-Low Enable for SN75ALS1177 Only
  • Operate From Single 5-V Supply
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The SN75ALS1177 and SN75ALS1178 dual differential drivers and receivers are integrated circuits designed for bidirectional data communication on multipoint bus transmission lines. They are designed for balanced transmission lines and meet standards TIA/EIA-422-B and TIA/EIA-485-A.

The SN75ALS1177 combines dual 3-state differential line drivers and dual 3-state differential input line receivers, both of which operate from a single 5-V power supply. The drivers and receivers have active-high and active-low enables, respectively, which can be externally connected together to function as direction control. The SN75ALS1178 drivers each have an individual active-high enable. Fail-safe design ensures that when the receiver inputs are open, the receiver outputs are always high.

The SN75ALS1177 and SN75ALS1178 are characterized for operation from 0°C to 70°C.

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Technical documentation

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* Data sheet Dual Differential Drivers And Receivers datasheet (Rev. B) Feb. 23, 2001

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SO (NS) 16 View options

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