SN65HVD77D - 3.3V 50Mbps Full-Duplex RS-485 | Texas Instruments
MPN： SN65HVD77D ✓ 啟用中SN65HVD77D 概覽
An RS-485 transceiver is an interface IC that converts logic-level signals into differential bus signals and converts received differential signals back into logic levels. RS-485 belongs to the differential data-interface hierarchy, where the voltage between the A and Y conductors carries the signal while common-mode noise is rejected. The SN65HVD77D is designed for robust, point-to-point, multidrop, and full-duplex industrial communication links.
The primary feature of the SN65HVD77D is its 50 Mbps signaling capability, making it suitable for high-speed data acquisition, factory automation, industrial control, and communications equipment. Its ±12 kV IEC-rated ESD protection improves system resilience when cables connect the transceiver to external equipment. Operating from a 3.3 V rail also simplifies integration with 3.3 V controllers, FPGAs, DSPs, and other digital logic.
Each device contains separate driver and receiver inputs and outputs, eliminating the shared bus direction controls commonly found on half-duplex transceivers. Full-duplex operation allows data to be transmitted and received at the same time. The transmitter drives a differential pair, while the receiver provides a complementary logic-level output. Because there are no external enable controls, the device is intended for continuous enabled operation rather than controlled low-power bus shutdown.
Typical implementations connect the logic-side data pins to a communications controller, connect the A and Y pins to a protected twisted-pair bus, and place the receiver output in the controller's receive path. Full-duplex systems use separate differential pairs for transmission and reception. The SOIC-8 package supports conventional surface-mount assembly and is suitable for industrial control boards, test equipment, motor-control systems, and embedded communications modules.
The principal design consideration is signal integrity. High-speed differential routing requires controlled impedance, a continuous return path, minimized stubs, and proper termination at the bus endpoints. External protection may still be required for severe industrial transients because the integrated ESD rating addresses electrostatic discharge rather than every surge or lightning event.
This product page combines the manufacturer's principal electrical and environmental specifications with same-package transceiver options, application guidance, and practical PCB-layout considerations. These engineering details help simplify device selection, footprint verification, and robust RS-485 implementation.
直接替換替代品，適用於 SN65HVD77D — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： SN65HVD77D （相同外形與佔位） — 差異在於 Product Type, Operating Temperature Range, Package, Supply Voltage, Maximum Data Rate.
SN65HVD78D
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →SN65HVD08D
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →SN65HVD10D
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →SN65HVD11D
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →SN65HVD12D
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →SN65HVD77D 規格
| Product Type | Full-duplex RS-485 transceiver |
| Supply Voltage Range | 3.0 V to 3.6 V |
| Nominal Supply Voltage | 3.3 V |
| Maximum Data Rate | 50 Mbps |
| Number of Drivers | 1 |
| Number of Receivers | 1 |
| Duplex Mode | Full duplex |
| Supported Standards | RS-485 and RS-422 |
| ESD Protection | ±12 kV IEC |
| 工作溫度範圍 | -40°C to 125°C |
| 封裝 | 8-pin SOIC (D) |
| Package Width | 3.90 mm |
| 安裝類型 | Surface mount |
| External Enable Controls | None |
| RoHS 狀態 | Compliant |
| Driver Output Type | Differential |
| Receiver Output Type | Single-ended logic output |
| Low-Power Standby Current | Less than 5 µA when driver and receiver are disabled |
| Termination Requirement | External termination required |
SN65HVD77D 腳位配置
| 腳位 1 | RO — Receiver output |
| 腳位 2 | RE — Receiver enable |
| 腳位 3 | DE — Driver enable |
| 腳位 4 | DI — Driver data input |
| 腳位 5 | GND — Ground |
| 腳位 6 | Y — Inverting driver output and receiver input |
| 腳位 7 | A — Non-inverting driver output and receiver input |
| 腳位 8 | VCC — Power supply |
典型應用
SN65HVD77D 適用於 6 應用s: Industrial Factory Automation Links, Industrial Data Acquisition, Motor Control and Positioning, Test and Measurement Equipment, Building and Facility Automation, Embedded Communications Modules.
Industrial Factory Automation Links
The SN65HVD77D fits high-speed factory automation links that require simultaneous command transmission and status reception. Its 50 Mbps maximum signaling rate provides ample bandwidth for machine-control traffic, while the 3.0 V to 3.6 V supply range supports 3.3 V industrial controllers. Place the transceiver between the controller and a protected twisted-pair cable, route the differential pair as a controlled-impedance net, and keep the logic and bus return paths continuous. The ±12 kV IEC ESD rating improves robustness at connector entry points, although separate surge protection may still be required for severe industrial transients.
推薦
Industrial Data Acquisition
The SN65HVD77D is suitable for distributed data-acquisition systems that move sensor and control information across a factory floor. Full-duplex operation allows a central controller to request data and receive measurements concurrently, removing the need to reverse a shared half-duplex bus. The 50 Mbps capability supports high-throughput acquisition buses, while the 3.3 V operating range integrates directly with modern processors and FPGAs. Use separate transmit and receive differential pairs, place termination only at physical bus endpoints, and maintain a low-impedance ground reference beneath the pairs to minimize differential-mode and common-mode conversion.
推薦
Motor Control and Positioning
The SN65HVD77D can support high-speed position, speed, and drive-status communication in motor-control equipment. Full-duplex operation lets the controller transmit motion commands while simultaneously receiving encoder or drive feedback. Its 50 Mbps rating provides low communication latency, and the ±12 kV IEC ESD protection helps protect the interface when motor-control boards connect to external cables. Place the transceiver close to the cable connector, use short controlled-impedance routes, and provide common-mode protection based on the cable environment. Differential routing and a solid ground reference are essential when the motor system contains high dv/dt switching nodes.
推薦
Test and Measurement Equipment
The SN65HVD77D is appropriate for remote instrumentation, automated test equipment, and high-speed measurement fixtures that exchange commands and results over RS-485 or RS-422. The 3.3 V supply operation reduces interface complexity in modern instrument electronics, while the 50 Mbps data rate supports dense or fast data transfers. Full-duplex operation separates command and response traffic, simplifying protocol timing. Use short differential traces near the transceiver, maintain a continuous reference plane, and add termination at the far end of the cable. Shielded twisted-pair cabling can reduce radiated emissions in laboratory environments.
推薦
Building and Facility Automation
The SN65HVD77D supports high-speed building-control, access-control, and sensor-network links where full-duplex communication and a 3.3 V interface simplify controller integration. Its 50 Mbps capability provides substantial headroom for aggregated building data, and its ESD protection is useful near external panels and cable connections. Route each differential pair over a continuous reference plane, avoid branch stubs, and terminate the cable according to its length and topology. Because building systems may span multiple floors, evaluate galvanic isolation or additional surge protection when ground-potential differences or severe transients are expected.
推薦
Embedded Communications Modules
The SN65HVD77D is suitable for compact embedded modules that add a robust differential bus interface to a 3.3 V processor. The 8-pin SOIC package simplifies surface-mount routing, and the transceiver's full-duplex architecture allows command traffic and responses to coexist. Its 50 Mbps capability supports high-throughput local links, while ±12 kV IEC ESD protection strengthens the interface when the module is connected through an external harness. Keep the differential pair short and symmetrical, provide a solid ground plane, and place optional protection components near the connector rather than near the logic controller.
推薦
推薦產品摘要
工程參考資料，適用於 SN65HVD77D — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | SN65HVD78D | SN65HVD08D | SN65HVD10D | SN65HVD11D | SN65HVD12D |
|---|---|---|---|---|---|---|
| Package | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Product Type | Full-duplex RS-485 transceiver | Full-duplex transceiver | Full-duplex transceiver | Full-duplex transceiver | Full-duplex transceiver | Full-duplex transceiver |
| Nominal Supply Voltage | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V |
| Number of Drivers | 1 | 1 | 1 | 1 | 1 | 1 |
| Number of Receivers | 1 | 1 | 1 | 1 | 1 | 1 |
主要差異化特點
- High-speed full-duplex operation in a compact 8-pin SOIC (對比SN65HVD12D)
- Defined industrial ESD protection (對比SN65HVD10D)
- Simple 3.3 V system integration without external enable controls (對比SN65HVD08D)
設計說明
Route the A and Y conductors as a tightly coupled differential pair over a continuous reference plane. Keep the pair length matched, avoid test pads and unnecessary stubs, and connect the transceiver ground pins with low-impedance vias. At 50 Mbps, component placement, connector transitions, and cable return-path discontinuities can affect signal quality even when the DC bus voltage is correct.
Place the transceiver close to the external connector and termination components so that the high-frequency A and Y paths remain short. Keep logic-side DI and RO routing away from the differential pair where practical. Provide a solid ground plane beneath the bus traces, use a common ground reference, and verify the stack-up with the PCB fabrication specification before defining controlled-impedance dimensions.
Do not treat the ±12 kV IEC ESD rating as complete protection against lightning, switching spikes, or severe industrial surges. Select external TVS, surge-protection, or isolation components according to the actual cable environment and required standards. Also confirm termination placement: excessive termination loads the driver, while an unterminated long cable can create reflections that degrade the 50 Mbps signal.
合規資訊
The SN65HVD77D is identified as RoHS compliant. No separate automotive qualification is stated for this ordering option.