SN75ALS1178NSR

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.

Applications

• Multipoint bus bidirectional data communication
• Long bus line data transmission in noisy environments

Key features

• Compliant with TIA/EIA-422-B and TIA/EIA-485-A standards
• Designed for multipoint bus transmission over long bus lines in noisy environments
• Supply current max 50mA
• Driver with positive and negative current limiting
• Driver common-mode output voltage range: -7V to 12V
• Thermal shutdown protection
• Three-state driver output with active-high enable
• Receiver common-mode input voltage range: -12V to 12V
• Receiver input sensitivity: ±200mV
• Receiver typical hysteresis: 50mV
• Receiver input impedance min 12kΩ
• SN75ALS1177 only: receiver three-state output with active-low enable
• Single 5V supply
• SN75ALS1177 integrates dual three-state differential line drivers and dual three-state differential-input line receivers, with active-high and active-low enables respectively for drivers and receivers, externally connectable for direction control
• SN75ALS1178: each driver has an independent active-high enable
• Fail-safe design: receiver output remains high when inputs are open
• Available in N and NS packages; NS package available in tape and reel with suffix "R" in part number
• Absolute maximum ratings: supply VCC max 7V; DE, RE, and D input voltage max 7V; driver output voltage range -9V to 14V; receiver input voltage range -14V to 14V; receiver differential input voltage range -14V to 14V; receiver low-level output current max 50mA; N package thermal resistance 67°C/W; NS package thermal resistance 64°C/W; soldering temperature max 260°C for 10 seconds at 1.6mm from case; storage temperature range -65°C to 150°C