LTC2862AIS8-2 - ±60V RS485/RS422 Transceiver | Analog Devices
MPN: LTC2862AIS8-2 ✓ Hoạt độngLTC2862AIS8-2 Tóm tắt
An RS485/RS422 transceiver is a physical-layer device that converts between a single-ended UART/CMOS logic signal on the microcontroller side and a robust differential signal on the bus side, enabling reliable serial communication over twisted-pair cables at distances up to 1200 meters. RS485 is the de-facto standard for industrial multipoint buses (Modbus RTU, Profibus, DMX512) while RS422 is used for point-to-point high-speed links; the LTC2862 family supports both. Half-duplex means one differential pair is shared between transmit and receive, with direction controlled by a logic pin.
Key features include ±60V fault tolerance on the bus pins, IEC 61000-4-2 Level 4 ESD protection (typically 8 kV contact, 15 kV air per the manufacturer's IEC ESD rating), current-limited drivers, thermal shutdown, and a fully balanced differential receiver threshold for low duty-cycle distortion. The 8-pin SOIC package is pin-compatible with legacy LT1785/LT1791 footprints and the original LTC2862 family, enabling direct board replacement.
The LTC2862A uses a CMOS process with switched-capacitor charge pump to generate the ±60V fault-tolerant driver supply. The architecture delivers low quiescent current during idle while still maintaining high drive strength during bus arbitration, and the receiver exhibits 250 mV typical hysteresis with a 50 mV worst-case offset to meet TIA/EIA-485-A.
Typical applications include industrial fieldbus networks (Modbus, Profibus), solar inverter monitoring, building automation (BACnet), motor control encoder links, and any 3V-5V MCU interface that must survive miswiring, ESD strikes, or transient overvoltage events on long cable runs. The wide 3V-5.5V supply range also supports battery-powered remote sensor nodes.
When designing with this device, place 100 nF decoupling close to VCC and use twisted-pair cable with proper termination (120 Ω) at the bus ends. The -2 suffix denotes 20 Mbps high-speed grade; the -1 variant is 250 kbps low-EMI grade - select based on your data rate and EMI budget.
Bộ thay thế dễ dàng lắp đặt cho LTC2862AIS8-2 — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
LTC2862AIS8-2#WPBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC2862IS8-2
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC2862AIS8-1
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC2862AIS8-2 Thông số kỹ thuật
| Chức năng | RS485/RS422 Transceiver (Half-Duplex) |
| Tốc độ dữ liệu | 20 Mbps (high-speed grade, -2 suffix) |
| Number of Drivers/Receivers | 1/1 |
| Protocol | RS422, RS485 |
| Điện áp cung cấp | 3 V to 5.5 V |
| Fault Protection (Bus Pins) | ±60 V overvoltage |
| ESD Protection | IEC 61000-4-2 Level 4 |
| Receiver Hysteresis | 250 mV typical |
| Nhiệt độ hoạt động | -40 °C to +85 °C (industrial, A suffix) |
| Hộp | 8-SOIC (S8) |
| Kiểu lắp đặt | Surface Mount |
| Duplex | Half |
| Số chân | 8 |
| Trạng thái RoHS | Compliant (PBF suffix) |
| Compliance | TIA/EIA-485-A |
Cấu hình chân LTC2862AIS8-2
| Chân 1 | RO — Receiver Output (logic-level signal to MCU UART RX) |
| Chân 2 | RE — Receiver Enable (active-low, tie to GND to enable receiver) |
| Chân 3 | DE — Driver Enable (logic high enables driver for transmit) |
| Chân 4 | DI — Driver Input (logic-level signal from MCU UART TX) |
| Chân 5 | GND — Ground |
| Chân 6 | A — Non-inverting differential bus line |
| Chân 7 | B — Inverting differential bus line |
| Chân 8 | VCC — Supply Voltage (3 V to 5.5 V) |
Ứng dụng tiêu biểu
LTC2862AIS8-2 phù hợp cho 6 Áp dụngs: Industrial Modbus RTU Fieldbus, Solar Inverter Monitoring (RS485), Building Automation (BACnet MS-TP), Motor Encoder / Servo Drive Link, DMX512 Stage Lighting Control, Battery-Powered Remote Sensor Node.
Industrial Modbus RTU Fieldbus
The LTC2862AIS8-2 is ideal for Modbus RTU networks operating on 3.3V or 5V MCUs in factory automation. Its ±60V fault tolerance survives accidental contact with 24V control wiring on the shop floor, while the 20 Mbps data rate handles 115.2 kbaud Modbus and higher-speed proprietary protocols. Place the part between the MCU UART and the isolated bus-side transceiver, with 120Ω termination at cable ends. The IEC Level 4 ESD rating eliminates external TVS diodes and reduces BOM cost. Differential signaling over twisted pair rejects common-mode noise from VFD drives and motor starters that share the same cable tray.
Được đề xuất
Solar Inverter Monitoring (RS485)
In solar inverter monitoring systems, the LTC2862AIS8-2 connects the inverter's MPPT controller to a string-monitoring data logger over RS485. The 3V-5.5V supply range supports direct connection to 3.3V DSP/MCU without level shifters. ±60V fault protection is critical because DC bus voltages up to 1500V can induce destructive transients on long PV cable runs during grid disturbances. The 20 Mbps speed supports inverter-to-inverter daisy-chained communications, while IEC Level 4 ESD survives installer handling and lightning-induced coupling. The 8-SOIC package fits compact inverter power modules with thermal headroom up to 85°C.
Được đề xuất
Building Automation (BACnet MS-TP)
The LTC2862AIS8-2 supports BACnet MS-TP (Master-Slave Token Passing) networks used in HVAC controllers, VAV boxes, and lighting control panels. Operating from a single 3.3V or 5V rail simplifies power design in space-constrained building automation enclosures. The ±60V bus tolerance handles miswiring during installation where electricians may accidentally connect the MS-TP pair to a 24V thermostat circuit. The 20 Mbps capability exceeds the 76.8 kbps BACnet requirement, leaving bandwidth headroom for diagnostics. Wide industrial temperature range (-40°C to +85°C) supports unheated rooftop equipment rooms.
Được đề xuất
Motor Encoder / Servo Drive Link
The LTC2862AIS8-2 provides robust serial communication between servo drives and central motion controllers over RS485. Differential signaling rejects EMI from PWM-driven motor phases and switching power supplies in the drive cabinet. The 20 Mbps rate supports high-speed encoder feedback and drive parameter updates from the controller to multiple drives on a shared bus. ±60V fault tolerance protects against DC bus transients and motor regen events. Half-duplex operation matches the typical drive-to-controller topology where one pair carries both command and telemetry.
Được đề xuất
DMX512 Stage Lighting Control
The LTC2862AIS8-2 is well-suited for DMX512 lighting consoles and dimmer racks, where RS485 differential signaling on XLR-3 cables connects fixtures up to 300 meters from the controller. The 20 Mbps capability exceeds the 250 kbps DMX512 standard, providing ample margin for derivative protocols and future bandwidth needs. ±60V fault protection prevents damage when stage power cables accidentally short to DMX lines during setup. IEC Level 4 ESD survives the frequent connector mating/unmating in touring environments. The 8-SOIC package fits into the compact fixture and dimmer-pack form factors.
Được đề xuất
Battery-Powered Remote Sensor Node
The LTC2862AIS8-2 enables low-power RS485 communication in battery-powered remote sensor nodes for environmental monitoring, agriculture, or pipeline telemetry. The 3V-5.5V supply supports direct connection to a 3.6V LiSOCl2 or 3.7V Li-ion cell without boost converters. Low quiescent current during idle preserves battery life; the device only draws significant current when actively transmitting sensor data. ±60V fault protection is essential because remote nodes are often installed near power lines or motor control cabinets where ground faults can induce high common-mode voltages on the bus. The wide temperature range supports outdoor deployment.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LTC2862AIS8-2 — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | LTC2862AIS8-2#WPBF | LTC2862IS8-2 | LTC2862AIS8-1 | LTC2862AIDD-2 |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 8-SOIC (S8) | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-DFN (different footprint) |
| Data Rate | 20 Mbps | 20 Mbps | 20 Mbps | 250 kbps | 20 Mbps |
| Supply Voltage | 3 V to 5.5 V | 3 V to 5.5 V | 3 V to 5.5 V | 3 V to 5.5 V | 3 V to 5.5 V |
| Bus Fault Protection | ±60 V | ±60 V | ±60 V | ±60 V | ±60 V |
| Automotive Grade (AEC-Q100) | No | Yes (AEC-Q100 qualified) | No | No | No |
| Duplex | Half | Half | Half | Half | Half |
| Drivers/Receivers | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 |
Bảo phân biệt quan trọng
- ±60 V bus fault tolerance across all operating modes including power-down (vsLTC2862IS8-2 (first generation))
- AEC-Q100 automotive qualified variant available in same footprint (vsLTC2862AIS8-2#WPBF)
- 20 Mbps data rate for high-speed fieldbus applications (vsLTC2862AIS8-1 (250 kbps))
Ghi chú thiết kế
Place a 100 nF decoupling capacitor as close as possible to the VCC pin (pin 8) of the LTC2862AIS8-2 to suppress supply transients during bus driver switching. Add a 10 µF bulk capacitor if the VCC trace is longer than 25 mm or shares inductance with high-current digital logic. Keep the bus traces (A, B) matched in length and routed as a differential pair with 100 Ω characteristic impedance on twisted-pair cable. Place the 120 Ω termination resistor at the physical ends of the bus only, never at stub nodes, to prevent reflection artifacts.
Do not connect the LTC2862AIS8-2 A and B pins directly to external TVS diodes in parallel - the part's internal ±60 V fault protection already handles transient suppression, and external TVS capacitance can degrade the 20 Mbps signal integrity. Do not leave the DE (driver enable) pin floating; tie DE low for receive-only mode or high for transmit. Do not operate with VCC below 3 V or above 5.5 V; the bus fault protection is independent of VCC state but the logic interface requires a valid supply. Always use twisted-pair cable (not parallel wires) to meet the EIA-485 common-mode rejection spec.
Separate the bus-side differential traces (A, B) from the logic-side CMOS traces (DI, DE, RE, RO) on the PCB to prevent noise coupling from the bus into the MCU UART. Use a ground guard trace or copper pour between the two regions for additional isolation. The exposed pad (if using the DFN variant) must be soldered to a continuous ground plane for thermal dissipation - in 8-SOIC variants, the GND pin handles the return path. Avoid routing the bus traces near switching power supply inductors or motor phase traces, which inject common-mode noise that can exceed the receiver's common-mode range (-25 V to +25 V).
Thông tin tuân thủ
RoHS compliant per #PBF suffix. AEC-Q100 qualified only on the #WPBF automotive suffix variant; standard LTC2862AIS8-2 is industrial grade. Halogen-free status not explicitly stated in available data - marked unknown per data authenticity rules.
