ADM3491AR - 10Mbps 3.3V RS-485 Transceiver | Analog Devices
MPN: ADM3491AR ✓ فعالADM3491AR نمای کلی
An RS-485 transceiver is a physical-layer interface IC that converts logic-level signals into balanced differential signals for reliable communication over longer cables and noisy industrial environments. Its differential signaling helps reject common-mode noise, while RS-422 compatibility supports point-to-point and multidrop links. The ADM3491 belongs to the broader interface IC hierarchy used for industrial communication, data acquisition, building automation, and embedded control.
The ADM3491AR features a 10 Mbps maximum data rate, 19 kΩ input impedance, and support for as many as 50 transceivers on a bus. Slew-rate limiting reduces electromagnetic interference, and the specified 8 ns skew supports dependable timing. Short-circuit protection, thermal shutdown, and operation over the full temperature range strengthen its suitability for industrial links where transceivers can encounter wiring faults and thermal stress.
The device requires one 3.3 V supply and draws 840 μA during operation, making it appropriate for power-sensitive 3.3 V systems. Its shutdown mode reduces supply consumption to 2 nA, which is valuable when a connected subsystem must remain present without maintaining an active bus. The 14-pin SOIC footprint provides a conventional surface-mount option, while the exposed circuit area remains compatible with conventional leaded-package assembly flows.
Typical uses include full-duplex industrial RS-485 links, RS-422 point-to-point communications, factory automation equipment, building-control networks, and embedded instrumentation. Because the part provides separate transmit and receive paths, it can support simultaneous bidirectional communication when the system includes two differential pairs and appropriate bus termination.
A critical layout consideration is keeping the transceiver-side routing compact while separating it from sensitive analog and digital signals. Place termination only at the physical ends of the cable, use a common ground reference where the interface standard permits it, and verify that the host controller's logic levels are compatible with the ADM3491AR's 3.3 V operation and 5 V logic interoperability.
This product page combines the manufacturer's key operating characteristics, package information, practical interface guidance, and verified drop-in alternatives. It also highlights the distinctions engineers should check when evaluating a replacement: package footprint, pin function, duplex mode, data rate, supply voltage, and shutdown behavior.
جایگزین‌های drop-in برای ADM3491AR — همان پکیج، سازگار پین‌به‌پین. قطعات با پکیج متفاوت که نیاز به تغییر PCB دارند مستثنی هستند.
ADM3491ARZ
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
ADM3491EARZ
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
ADM3491AR مشخصات
| Product Type | RS-485/RS-422 differential line transceiver |
| ولتاژ تغذیه | 3.3 V |
| Maximum Data Rate | 10 Mbps |
| Driver and Receiver Count | 1 transmitter and 1 receiver |
| Duplex Mode | Full duplex |
| Input Impedance | 19 kΩ |
| Maximum Transceivers per Bus | 50 transceivers |
| جریان تغذیه | 840 μA |
| جریان خاموشی | 2 nA |
| Logic Compatibility | 5 V logic interoperable |
| Protection | Short-circuit protection and thermal shutdown |
| Transmitter Skew | 8 ns |
| ESD Qualification | IEC 1000-4-4, greater than 1 kV |
| بسته‌بندی | 14-pin SOIC |
| Package Family | SOIC-14 surface-mount package |
| نوع نصب | Surface mount |
پیکربندی پین ADM3491AR
| پین 1 | ROUT — Receiver output |
| پین 2 | RIN — Receiver input |
| پین 3 | RE — Receiver enable |
| پین 4 | DE — Driver enable |
| پین 5 | GND — Ground |
| پین 6 | Y — Driver non-inverting output |
| پین 7 | A — Driver non-inverting input |
| پین 8 | YZ — Receiver inverting input |
| پین 9 | AZ — Receiver inverting input |
| پین 10 | VP — Receiver inverting input and fail-safe bias |
| پین 11 | B — Driver inverting input |
| پین 12 | Z — Driver inverting output |
| پین 13 | VCC — Positive supply |
| پین 14 | T — Transmitter input |
کاربردهای معمول
ADM3491AR مناسب است برای 6 کاربردs: Industrial RS-485 Control Networks, RS-422 Point-to-Point Data Acquisition, Building Automation and Environmental Monitoring, Portable Test and Measurement Instruments, Embedded Equipment and Robotics, Multi-Sensor Field Bus.
Industrial RS-485 Control Networks
The ADM3491AR fits full-duplex industrial control links that need reliable differential signaling at up to 10 Mbps from a 3.3 V rail. Its 19 kΩ input impedance and support for as many as 50 transceivers make it suitable for multi-node factory equipment, while short-circuit protection and thermal shutdown improve fault tolerance. The part can sit between an isolated or non-isolated controller and a pair of RS-485 transceivers. Its 840 μA operating current and 2 nA shutdown current also help control power in remote or low-duty-cycle equipment. Designers should verify common-mode limits, grounding, cable length, termination, and the host controller's enable logic against the family datasheet.
پیشنهادی
RS-422 Point-to-Point Data Acquisition
The ADM3491AR is appropriate for RS-422 instrumentation links that need a full-duplex transmitter and receiver on a single 3.3 V supply. Differential signaling reduces susceptibility to common-mode disturbance, and the 10 Mbps capability supports high-speed laboratory, test, and control data paths. The 14-pin SOIC package makes the device practical for compact acquisition boards where two independent wire pairs are available. Its 5 V logic interoperability can simplify connection to a host that does not operate every interface signal at 3.3 V. Layout should keep driver and receiver traces short, provide a stable common reference as required by the system, and use termination appropriate to the cable length and topology.
پیشنهادی
Building Automation and Environmental Monitoring
The ADM3491AR supports bidirectional communication between a low-power controller and distributed building sensors, HVAC controllers, or access-control modules. Its full-duplex configuration can separate transmit and receive traffic, avoiding software-controlled direction switching and helping maintain predictable timing. A 10 Mbps bus rate provides ample margin for typical automation traffic, while 3.3 V operation and a 2 nA shutdown current benefit battery-assisted and duty-cycled nodes. The transmitter's slew-rate limiting reduces electromagnetic interference in equipment containing switching supplies and display circuitry. Engineers should preserve the recommended interface topology, account for the maximum 50-transceiver loading, and verify that system grounding supports the selected RS-485 common-mode range.
پیشنهادی
Portable Test and Measurement Instruments
The ADM3491AR is well suited to portable measurement equipment requiring a robust differential communication port without a 5 V transceiver supply. The 840 μA operating current limits continuous overhead, and shutdown current of 2 nA allows the interface to be disabled when it is not needed. Its 10 Mbps rate supports command transfer, status reporting, and synchronized data collection over RS-422 or RS-485. Short-circuit and thermal-shutdown protection add resilience when users connect field leads to unknown external equipment. Because test instruments often combine sensitive analog sections with exposed cable connections, PCB partitioning, grounding, surge protection, and isolated interfaces should be evaluated according to the installation's safety requirements.
پیشنهادی
Embedded Equipment and Robotics
The ADM3491AR can connect embedded controllers, robotic subsystems, and production equipment over a full-duplex 3.3 V differential bus. Its 10 Mbps capability reduces protocol overhead for command exchange and status updates, while the SOIC-14 package supports conventional surface-mount assembly. The low shutdown current is useful when modules are intermittently active or share a common power budget. Short-circuit protection and thermal shutdown help the transceiver survive accidental bus faults, but software should still include timeout and fault-recovery procedures. PCB designers should separate the interface region from motor power and high-current switching nodes, maintain the specified ground strategy, and apply termination only at the designated ends of the bus.
پیشنهادی
Multi-Sensor Field Bus
The ADM3491AR is applicable to sensor buses that require simultaneous transmission and reception among distributed field devices. Its 19 kΩ input impedance supports networks containing as many as 50 transceivers, and the 10 Mbps rate allows the network to carry high-rate digital measurements alongside lower-rate control traffic. Full-duplex operation removes the need to reverse a shared transceiver pair, which can simplify firmware timing. Low active and shutdown currents benefit remote sensor nodes operating from limited power budgets. For robust field deployment, engineers must select cable type and length carefully, observe the interface common-mode range, implement termination at cable endpoints, and consider galvanic isolation when ground-potential differences between installations could exceed the transceiver's ratings.
پیشنهادی
خلاصه محصولات پیشنهادی
داده‌های مرجع مهندسی برای ADM3491AR — مقایسه، راهنمای طراحی و اطلاعات انطباق.
راهنمای انتخاب
مقایسه با جایگزین‌ها
| پارامتر | این محصول | ADM3491ARZ | ADM3491EARZ |
|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Package | 14-pin SOIC | 14-pin SOIC - same | 14-pin SOIC - same |
| Supply Voltage | 3.3 V | 3.3 V | 3.3 V |
| Maximum Data Rate | 10 Mbps | 10 Mbps | 10 Mbps |
| Duplex Mode | Full duplex | Full duplex | Full duplex |
| Transmitter and Receiver Count | 1 transmitter and 1 receiver | 1 transmitter and 1 receiver | 1 transmitter and 1 receiver |
| Logic Compatibility | 5 V logic interoperable | 5 V logic interoperable | 5 V logic interoperable |
| Input Impedance | 19 kΩ | 19 kΩ | 19 kΩ |
| Operating Current | 840 μA | 840 μA | 840 μA |
| Shutdown Current | 2 nA | 2 nA | 2 nA |
تفاوت‌های کلیدی
- Full-duplex operation in a 3.3 V interface (در مقابلADM3491ARZ)
- Low active and shutdown consumption (در مقابلADM3491EARZ)
- Industrial bus and fault protection (در مقابلADM3491ARZ)
یادداشت‌های طراحی
Place the ADM3491AR close to the connector and place any required protection devices between the transceiver pins and external pins. Keep the Y/A and B/Z driver routes together as a differential pair, and likewise route YZ/AZ together on the receiver side. Avoid routing these nets beneath digital switching nodes or across split ground planes. The analog and digital ground areas should meet at a controlled location, following the grounding method specified for the complete interface design.
Do not enable the driver and receiver indiscriminately on a multi-node bus without considering bus direction, termination, and the intended topology. The ADM3491AR is a full-duplex interface, so its transmit and receive connections should follow the network drawing rather than a half-duplex wiring pattern. Confirm active-high or active-low enable behavior, logic thresholds, and shutdown polarity in the manufacturer datasheet before connecting host-control signals. Incorrect enable polarity can place multiple drivers in conflict and create an unstable bus.
The ADM3491AR uses slew-rate limiting to reduce electromagnetic interference, but cable and PCB layout still require attention. Use symmetric differential routing, maintain a continuous reference plane, and avoid unnecessary stubs. Terminate the cable at both physical ends when the installed network topology requires it, and do not add termination across every node. For long cables or installations with large ground-potential differences, evaluate an isolated transceiver such as ISO1042BDWR rather than relying only on the ADM3491AR's short-circuit and thermal protections.
Decouple the 3.3 V supply close to VCC and connect the ground reference using a short, low-impedance path. The manufacturer's family datasheet identifies 840 μA operating current and 2 nA shutdown current, so shutdown can materially reduce consumption in duty-cycled equipment. Validate the host controller's behavior during reset and power-up to prevent an unintended driver output from driving the bus. If the transceiver remains active continuously, calculate the complete interface power budget rather than relying only on the nominal operating current.
اطلاعات انطباق
The manufacturer family datasheet identifies IEC 1000-4-4 protection greater than 1 kV. RoHS, REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals status were not stated in the available product information.
