SN75ALS1177NS Texas Instruments Integrated Circuit (Small Outline Packages) In Stock
The SN75ALS1177NS is a dual half-duplex RS-422/RS-485 line transceiver from Texas Instruments, integrating 2 drivers and 2 receivers with differential Schmitt trigger inputs in a 16-pin PDIP package. It supports EIA-422-B, TIA-422-B, EIA-485-A, and TIA-485-A standards for robust industrial communications. Available in lead-free PDIP-16 with worldwide shipping.
- Manufacturer
- Texas Instruments
- Package
- Small Outline Packages
- Pin Count
- 16
- Lifecycle
- OBSOLETE
- Datasheet
- SN75ALS1177NS Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- ?°C to 70.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- Half-duplex 2-driver/2-receiver RS-422/RS-485 transceiver with differential Schmitt trigger inputs for high noise immunity
- Compliant with EIA-422-B, TIA-422-B, EIA-485-A, and TIA-485-A standards enabling multi-drop bus architectures
- High-level input current up to 100 µA with differential output drive for long-line industrial communication networks
Applications
The SN75ALS1177NS is used in industrial automation networks, programmable logic controllers, and building management systems requiring RS-422 or RS-485 half-duplex serial communication. Its dual transceiver configuration enables bidirectional data exchange over balanced twisted-pair cables spanning hundreds of meters. The device is also common in process control instrumentation and SCADA systems where reliable multi-drop communication is essential.
Specifications
| Pbfree Code | Yes |
| YTEOL | 0 |
| Differential Output | YES |
| Driver Number of Bits | 2 |
| High Level Input Current-Max | 0.0001A |
| Input Characteristics | DIFFERENTIAL SCHMITT TRIGGER |
| Interface IC Type | LINE TRANSCEIVER |
| Interface Standard | EIA-422-B; TIA-422-B; EIA-485-A; TIA-485-A |
| JESD-30 Code | R-PDSO-G16 |
| JESD-609 Code | e4 |
| Number of Functions | 2 |
| Out Swing-Min | 1.5V |
| Output Characteristics | 3-STATE |
| Output Low Current-Max | 0.06A |
| Output Polarity | COMPLEMENTARY |
| Package Body Material | PLASTIC/EPOXY |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Qualification Status | Not Qualified |
| Receive Delay-Max | 37ns |
| Receiver Number of Bits | 2 |
| Supply Current-Max | 50mA |
| Supply Voltage-Max | 5.25V |
| Supply Voltage-Min | 4.75V |
| Supply Voltage-Nom | 5V |
| Supply Voltage1-Max | 5.25V |
| Supply Voltage1-Min | 4.75V |
| Supply Voltage1-Nom | 5V |
| Surface Mount | YES |
| Technology | TTL |
| Temperature Grade | COMMERCIAL |
| Terminal Finish | Nickel/Palladium/Gold (Ni/Pd/Au) |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time@Peak Reflow Temperature-Max (s) | 30 |
| Transmit Delay-Max | 22ns |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.60 |
| Country of Origin | Malaysia |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for SN75ALS1177NS:
Frequently Asked Questions
Which communication standards does the SN75ALS1177NS support, and how many nodes can share an RS-485 bus?
The SN75ALS1177NS supports EIA-422-B, TIA-422-B, EIA-485-A, and TIA-485-A standards. On an RS-485 bus, up to 32 unit loads can be connected, allowing multiple nodes to share a single twisted-pair cable over distances up to 1,200 meters at lower data rates.
How does the differential Schmitt trigger input improve noise rejection in the SN75ALS1177NS?
The differential Schmitt trigger receivers in the SN75ALS1177NS add hysteresis to the input threshold, rejecting common-mode noise and slow signal transitions on the bus. This ensures reliable data recovery even when the differential input signal is corrupted by electromagnetic interference, which is common in industrial environments with motors and switching power supplies operating at high voltages.
Can the SN75ALS1177NS be used as a replacement for older RS-422 transceivers in legacy SCADA equipment?
Yes. The SN75ALS1177NS is pin-compatible with many classic 16-pin RS-422/RS-485 transceiver ICs and supports both EIA-422-B and EIA-485-A standards. Its 2-driver/2-receiver architecture with a high-level input current of up to 100 µA makes it a practical drop-in replacement in legacy SCADA, PLC, and industrial serial communication hardware.
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About Texas Instruments
Texas Instruments (TI) is a global semiconductor company headquartered in Dallas, Texas. TI designs and manufactures analog and embedded processing chips used in industrial, automotive, consumer, communications, and enterprise systems.
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