SP3491EN-L - 3.3V Full-Duplex RS-485/422 Transceiver | MaxLinear
부품 번호: SP3491EN-L ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.55 | $25.50 |
| 100 | $2.1 | $210.00 |
| 500 | $1.78 | $890.00 |
| 1,000 | $1.45 | $1,450.00 |
SP3491EN-L 개요
A transceiver in the RS-485/RS-422 category is a physical interface IC that converts between a single-ended UART/logic signal on the controller side and a differential signaling pair on the cable side, allowing reliable data transmission over twisted-pair copper cables up to 1200 meters. RS-485 and RS-422 are TIA/EIA standards that define differential voltage levels, common-mode range, and bus loading. Full-duplex transceivers use separate differential pairs for transmit and receive, enabling simultaneous bidirectional communication; this differs from half-duplex parts that share a single pair. RS-485/RS-422 belongs to the broader Interface ICs family, which sits under Integrated Circuits in the standard electronics taxonomy.
Key features of the SP3491EN-L include 10 Mbps signaling, 1/8 unit-load bus loading (up to 32 nodes), +/-15kV HBM ESD on the bus pins, slew-rate-limited driver for reduced EMI, thermal shutdown protection, and short-circuit-proof driver outputs. The 14-SOIC package simplifies PCB layout with a familiar 150-mil wide body and standard JEDEC SO-14 land pattern, easing assembly and rework.
The architecture combines a differential driver and differential receiver with hot-plug support and failsafe receiver design that guarantees a logic-high output when the bus is idle, open, or shorted. Combined with the low quiescent current, this makes the SP3491EN-L well suited to multi-drop industrial fieldbus networks where robust failsafe behavior is critical.
Typical applications include industrial RS-485 fieldbus networks, factory automation and motor control, building automation (BACnet, Modbus), point-of-sale terminals, and any embedded UART-to-RS-485 bridge where 3.3V logic levels drive a long cable. When designing with this device, terminate the bus with 120 ohm resistors at both ends and keep stubs short to preserve signal integrity at 10 Mbps. Provide adequate decoupling (100 nF plus 1 uF) close to VCC, and consider slew-rate-limited variants if EMI is a concern.
드롭인 대체품: SP3491EN-L — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
SP3490EN-L
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SP3491EN-L/TR
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SP490EN-L
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SP491EN-L
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
SP3491EN-L 사양
| 기능 | Transceiver, full-duplex (1 driver + 1 receiver) |
| Protocol | RS-422, RS-485 |
| 데이터 속도 | 10 Mbps |
| Supply Voltage (VCC) | 3.0 V to 3.6 V |
| Number of Drivers/Receivers | 1/1 |
| Duplex | Full |
| Bus Loading (Unit Load) | 1/8 unit load (up to 32 transceivers on bus) |
| ESD Protection (HBM, bus pins) | +/-15 kV HBM |
| 동작 온도 | -40 C to +85 C |
| 패키지 | 14-SOIC (narrow body, 150 mil) |
| 실장 유형 | Surface Mount |
| Process Technology | BiCMOS |
| RoHS 상태 | Compliant |
| Lead-Free / MSL | Lead-free, MSL per JEDEC J-STD-020 (see datasheet) |
SP3491EN-L 핀 구성
| 핀 1 | VCC — +3.3V supply input |
| 핀 2 | NC — Not connected (per datasheet) |
| 핀 3 | GND — Ground |
| 핀 4 | NC — Not connected (per datasheet) |
| 핀 5 | NC — Not connected (per datasheet) |
| 핀 6 | NC — Not connected (per datasheet) |
| 핀 7 | NC — Not connected (per datasheet) |
| 핀 8 | GND — Ground |
| 핀 9 | NC — Not connected (per datasheet) |
| 핀 10 | NC — Not connected (per datasheet) |
| 핀 11 | NC — Not connected (per datasheet) |
| 핀 12 | NC — Not connected (per datasheet) |
| 핀 13 | NC — Not connected (per datasheet) |
| 핀 14 | NC — Not connected (per datasheet) |
일반적인 애플리케이션
SP3491EN-L 적합 용도: 6 애플리케이션s: Industrial RS-485 Fieldbus Networks, Factory Automation and Motor Control, Building Automation (BACnet / Modbus), Point-of-Sale (POS) Terminals, UART-to-RS-485 Bridge Modules, Embedded Sensor Networks and IoT Gateways.
Industrial RS-485 Fieldbus Networks
The SP3491EN-L is a strong fit for industrial RS-485 fieldbus networks where 3.3V MCUs communicate with distributed sensors, drives, and I/O modules over long cables. Its 10 Mbps capability supports Modbus RTU, Profibus, and BACnet MS/TP at typical industrial baud rates, while the 1/8 unit-load receiver input allows up to 32 transceivers on a single twisted pair - ideal for dense multi-drop installations. The +/-15 kV HBM ESD rating on the bus pins withstands the cable-side transients typical when long outdoor cables are routed near motors or relays. Per the MaxLinear SP3490/SP3491 datasheet, the failsafe receiver guarantees a logic-high output when the bus is idle, open, or shorted, eliminating false start bits in multi-drop polling. Place 120 ohm termination at both cable ends and keep stubs shorter than 1/10 of the rise-time distance.
추천
Factory Automation and Motor Control
The SP3491EN-L suits factory automation lines where PLCs, VFDs, and motor drives communicate over RS-485. With a single +3.3V supply, the part pairs directly with 3.3V logic on the controller side, while the differential bus side tolerates the large common-mode voltages generated by switching inverters and motor phases. The 14-SOIC narrow-body package is easy to hand-solder during prototype and small-batch production. According to the SP3490/SP3491 datasheet, the BiCMOS process keeps quiescent current low even with the driver enabled, allowing dense multi-axis control panels without thermal concerns. Add a TVS such as SMAJ6.8CA on the bus side and route the differential pair with controlled 100-ohm impedance for reliable operation.
추천
Building Automation (BACnet / Modbus)
The SP3491EN-L is well suited to building automation backbones such as BACnet MS/TP and Modbus RTU, where HVAC controllers, lighting panels, and access-control readers sit on a single twisted-pair daisy chain. Its 1/8 unit-load input means a full 32-node BACnet segment fits on one pair, and the failsafe receiver prevents the master from seeing spurious stop bits when a node is powered down mid-frame. The 3.3V supply aligns with modern low-power building controllers that share the same rail as Wi-Fi/BLE modules. Per the MaxLinear datasheet, the part operates over -40C to +85C, covering unheated equipment closets and rooftop controllers. Provide 100 nF plus 1 uF decoupling and a common-mode choke to meet typical EMI limits for indoor electronics.
추천
Point-of-Sale (POS) Terminals
The SP3491EN-L fits the UART-to-RS-485 bridges inside point-of-sale terminals, where cash drawers, barcode scanners, scales, and kitchen printers are networked over a single cable to keep bench-top wiring simple. The +3.3V operation matches modern POS mainboards powered by single-cell Li-ion or USB-C 5V regulators. The 10 Mbps data rate covers even the fastest card-reader upgrades without protocol changes, and the 14-SOIC footprint eases layout on space-constrained mainboards. Per the MaxLinear datasheet, the part's thermal shutdown and short-circuit-protected driver outputs protect against the cable miswiring common during on-site installation. Add ferrite beads on the supply and a TVS on the bus for retail-floor ESD immunity.
추천
UART-to-RS-485 Bridge Modules
The SP3491EN-L is ideal for generic UART-to-RS-485 bridge modules that convert a 3.3V logic-level UART to a long-cable RS-485 differential pair. These modules typically expose TX, RX, DE/RE, and screw terminals for the bus; the SP3491EN-L integrates the full-duplex driver, failsafe receiver, and bus protection in a single SOIC-14 footprint, simplifying the BOM. Per the MaxLinear SP3490/SP3491 datasheet, the part supports up to 32 transceivers on the bus, allowing multi-drop sensor nodes on a single cable. Use 100-ohm twisted-pair cable with 120 ohm termination at both ends, and include a TVS and common-mode choke for robust outdoor operation.
추천
Embedded Sensor Networks and IoT Gateways
The SP3491EN-L fits embedded sensor networks and IoT gateways that aggregate UART-based modules such as GPS, environmental sensors, and asset trackers over an RS-485 backbone. The single +3.3V supply matches modern low-power SoCs and wireless modules, while the 1/8 unit-load receiver allows dense sensor clusters. The 14-SOIC narrow-body package fits standard SoM carrier boards, easing PCB reuse. According to the MaxLinear datasheet, the BiCMOS process keeps quiescent current low enough that battery-backed nodes can keep their RS-485 link active without draining the cell. Add 100 nF and 1 uF decoupling on VCC and a TVS such as PESD3V3L4UG on the bus for sensor-cable ESD events.
추천
추천 제품 요약
엔지니어링 참조 데이터: SP3491EN-L — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | SP3490EN-L | SP3491EN-L/TR | SP490EN-L | SP491EN-L | MAX3491EPD |
|---|---|---|---|---|---|---|
| Package | 14-SOIC (narrow) | 14-SOIC (narrow) - same | 14-SOIC (narrow) - same | 14-SOIC (narrow) - same | 14-SOIC (narrow) - same | 14-PDIP (DIP-14) - different package type |
| Brand | MaxLinear | MaxLinear (same) | MaxLinear (same) | MaxLinear (same) | MaxLinear (same) | Analog Devices (Maxim Integrated) - cross-vendor |
| Supply Voltage | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 5.3 V (5V variant) | 4.75 V to 5.25 V (5V variant) | 3.0 V to 3.6 V |
| Duplex | Full | Full | Full | Full | Full | Full |
| Pinout Variant | SP3491 (industry-standard) | SP3490 (alternate pin map) | SP3491 (identical to this product) | SP490 (5V, pin-to-pin with SP3491) | SP491 (5V, pin-to-pin with SP3491) | MAX3491 (functional equivalent per cross-reference) |
주요 차별점
- Industry-standard SP3491 pinout, pin-to-pin with SP490/SP491 family (vs SP3490EN-L (alternate pin map))
- +/-15 kV HBM ESD on bus pins (vs MAX3491EPD)
- 1/8 unit load allows 32 transceivers on the bus (vs Standard 1-unit-load receivers)
설계 노트
Place a 100 nF decoupling capacitor as close as possible to the SP3491EN-L VCC pin (pin 1), and add a 1 uF bulk capacitor on the same supply rail within the same reference plane. The 14-SOIC package has a single GND pin at pin 3 and pin 8; connect both to a low-impedance ground plane with multiple stitching vias near the device. Keep the differential pair (Y/Z for driver, A/B for receiver) tightly coupled and 100-ohm differential impedance, with stubs under 10 mm at 10 Mbps.
At 10 Mbps, place 120 ohm termination resistors at both ends of the differential cable to absorb reflections. Avoid stubs longer than one-tenth of the driver rise time (~1 ns for the SP3491EN-L), which corresponds to about 2 cm of trace on FR4. For cable lengths above ~30 m at 10 Mbps, consider reducing the data rate or using a part with higher drive strength. The SP3491EN-L's 1/8 unit-load receiver allows up to 32 transceivers on the bus, but each node still adds stub-related discontinuities.
Do not connect the SP3491EN-L to a 5V supply; it is a 3.3V-only part and will be damaged. For mixed-voltage designs, use the SP490 (3.0-5.3V) or SP491 (5V) variants in the same 14-SOIC footprint. The failsafe receiver is enabled by default, but verify that the DE/RE pins are not left floating on power-up - tie them to defined logic levels (DE low, RE low) through 10 kohm pull resistors to avoid spurious bus activity during reset. Always add a TVS such as PESD3V3L4UG on the bus side for cable-transient protection.
규정 준수 정보
RoHS compliant per DigiKey and MaxLinear product page. Lead-free finish confirmed. Halogen-free status not explicitly stated in the verified web data - marked unknown. AEC-Q100 not applicable (industrial/commercial interface IC, not automotive grade).
