SN75174DW - 4-Channel RS-422/RS-485 Driver | Texas Instruments
料号： SN75174DW ✓ 量产中SN75174DW 概述
A differential line driver is an interface IC that converts logic-level signals into balanced differential outputs for communication over cables or long printed-circuit-board traces. As a member of the RS-422 and RS-485 interface hierarchy, it translates a digital transmitter signal into noise-resistant differential voltage pairs. The four channels suit multipoint buses, industrial equipment, industrial-control systems, and legacy data ports where multiple bus nodes require controlled output states.
The SN75174 provides four differential drivers and common enable and ground pins. Each driver uses a positive and negative output, while the three-state outputs support shared party-line buses by placing unused transmitters in a high-impedance state. Its balanced outputs reduce sensitivity to common-mode noise, and the wide positive and negative output common-mode voltage ranges make it suitable for noisy industrial environments.
The device supports transmission rates up to 4 megabaud and is intended for balanced multipoint communication. This makes it appropriate for RS-422 and RS-485 systems where a transmitter must support multiple drivers on one bus. The common enable control can coordinate output states, but system design must prevent multiple drivers from actively driving the same pair simultaneously.
Typical uses include industrial RS-485 buses, data acquisition equipment, telecommunications interfaces, instrumentation, computer peripherals, and embedded control systems. The 20-pin SOIC package supports conventional surface-mount assembly and is available as the SN75174DW ordering option identified by DigiKey as a 20-SOIC device.
Designers should match cable termination, biasing, and transceiver direction-control requirements to the bus standard. Keep traces short where possible, provide a continuous ground reference where the interface standard permits it, and verify signal polarity and enable timing before enabling the outputs. The SN75174DW is a digital interface IC, so Safe Operating Area data do not apply.
直接替换替代料： SN75174DW ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
SN75174DWR
✅ 直接替换📋 参考替代料（不在目录中）
SN75174DWG4
✅ 直接替换📋 参考替代料（不在目录中）
SN75174DW 规格参数
| Device Type | Quadruple differential line driver |
| Number of Drivers | 4 |
| Logic Direction | 4/0 driver |
| Output State | 3-state |
| Supported Standards | ANSI EIA/TIA-422-B, RS-485, and ITU Recommendation V.11 |
| Maximum Data Rate | 4 megabaud |
| Supply Voltage Range | 4.75 V to 5.25 V |
| Output Common-Mode Range | Wide positive and negative range; exact limits not provided in the verified data |
| 拓扑 | Balanced multipoint bus |
| 封装 | 20-pin SOIC |
| Package Designation | 20-SOIC |
| 安装类型 | Surface mount |
| Enable Control | Common driver enable |
| Production Status | SN75174 listed as an active product on TI; SN75174DW listed as obsolete by TI carrier-option page |
SN75174DW 20-soic 引脚配置指南
SN75174DW（20-soic 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： SN75174DW.
请参阅 数据手册 以查看完整引脚配置。
典型应用
SN75174DW 适用于 6 应用s: Industrial RS-485 Bus, RS-422 Point-to-Point Links, Data-Acquisition Equipment, Instrumentation and Process Control, Telecommunications Peripherals, Legacy Computer and Peripheral Interconnects.
Industrial RS-485 Bus
The SN75174DW is well suited to an industrial RS-485 transmitter stage because it provides four differential drivers, common three-state control, and operation up to 4 megabaud. Use it when multiple nodes must share a balanced multipoint bus and only one transmitter should actively drive a pair at a time. The wide positive and negative output common-mode range supports noisy party-line environments, while the 20-pin SOIC package simplifies conventional surface-mount routing. Termination, fail-safe biasing, and protection still need to be designed around the cable and system grounding.
推荐
RS-422 Point-to-Point Links
Use the SN75174DW as the transmit side of an RS-422 interface when the system needs balanced differential signaling across cables or longer circuit-board interconnects. Its four channels can support several independent differential links, and its three-state outputs allow unused transmitters to stop driving when the link is not active. The manufacturer describes compliance with ANSI EIA/TIA-422-B and a maximum rate of 4 megabaud. Exact receiver, cable, termination, and logic-level compatibility must be verified in the complete interface design.
推荐
Data-Acquisition Equipment
The four-channel architecture of the SN75174DW can consolidate transmitter-side connections in data-acquisition and test equipment that must communicate with remote sensors or controllers. Balanced outputs reduce susceptibility to ground potential differences and radiated noise compared with single-ended links, which is useful when the equipment is connected through external cables. The device’s common three-state enable helps the system avoid contention during bus direction changes. Add appropriate surge protection and grounding at the connector because interface robustness depends on the complete board-level protection network.
推荐
Instrumentation and Process Control
The SN75174DW can provide the balanced driver section of an industrial instrumentation interface when remote sensors, actuators, or controllers communicate over an RS-422 or RS-485 bus. Four channels offer a practical way to support several driver pairs in a compact 20-pin SOIC, while three-state operation supports shared-bus access. Its stated common-mode capability is useful in electrically noisy environments, but process-control installations also require careful isolation or surge protection where cables leave the enclosure. Validate the complete electrical budget against the selected bus standard and cable length.
推荐
Telecommunications Peripherals
The SN75174DW is appropriate for legacy telecommunications and peripheral interfaces requiring multiple balanced differential outputs. A single package can provide four driver channels, reducing the number of discrete transmit elements needed for a multi-port controller. The common enable control simplifies coordinated bus-state management, while the 3-state outputs permit unused channels to avoid active contention. Actual telecommunications use requires review of isolation, protection, connector pinout, return path, and regulatory requirements that are outside the driver’s basic RS-422/RS-485 function.
推荐
Legacy Computer and Peripheral Interconnects
The SN75174DW can be evaluated for legacy computer peripherals or embedded controllers that expose balanced differential communications rather than single-ended logic. The four independent driver channels can serve multiple external ports, and the common enable structure is useful when a system needs predictable bus release states. Because legacy systems may combine RS-422, RS-485, and unrelated serial interfaces, the system designer must verify connector mapping, voltage levels, timing, and shutdown behavior rather than assuming the SN75174DW replaces a generic serial transceiver.
推荐
推荐产品汇总
工程参考数据： SN75174DW ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | SN75174DWR | SN75174DWG4 |
|---|---|---|---|
| Device Type | Quadruple differential line driver | Related SN75174 quadruple driver ordering option | Related SN75174 quadruple driver ordering option |
| Package | 20-SOIC | 20-SOIC related ordering option; exact package verification required | 20-SOIC related ordering option; exact package verification required |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Availability Status | SN75174DW listed obsolete by TI carrier-option page | Related TI ordering option; current status not verified | Related TI ordering option; current status not verified |
关键差异点
- Four-channel differential output in one package （对比 SN75174DWR)
- Three-state outputs for shared-bus release （对比 SN75174DWG4)
- Supports 4-megabaud balanced multipoint communication （对比 SN75174DWR)
设计说明
Do not enable two SN75174DW drivers onto the same differential pair at the same time. The three-state output is useful for releasing a bus, but contention can produce excessive current and invalid data. Define enable polarity and bus ownership in the system controller, and include a fail-safe state that leaves unused transmitters high impedance. Confirm the final logic mapping against the manufacturer pin diagram before laying out the PCB.
Route each differential pair as a closely coupled pair with continuous reference to the appropriate ground plane. Keep the driver close to the connector or bus entry when practical, and keep external protection components close to the connector so surge current is diverted before reaching the IC. Avoid splitting the pair around unrelated traces or changing reference planes beneath the pair, because those discontinuities can degrade differential signal integrity.
Provide a stable 5 V rail within the verified 4.75 V to 5.25 V supply range and place bypass capacitance near the device power pins according to the manufacturer layout guidance. The supplied data does not provide the exact recommended capacitor values or current limits, so those values must be taken from the datasheet rather than inferred. Check supply startup behavior and enable sequencing across the entire bus system.
Use cable termination and biasing appropriate to the selected RS-422 or RS-485 topology, and place surge protection at the exposed connector. Balanced signaling helps reject common-mode noise, but it does not eliminate radiated emissions or eliminate the need for controlled return-current paths. Validate the complete board with the intended cable length and termination because edge rates and common-mode transients can change system behavior.
合规信息
The verified web data confirms ANSI EIA/TIA-422-B, RS-485, and ITU Recommendation V.11 compatibility, but does not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. Those values remain unknown rather than inferred.
