LTC2850HMS8#TRPBF - 3.3V 20Mbps RS485/RS422 Transceiver | ADI
MPN: LTC2850HMS8#TRPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.32 | $4.32 |
| 10 | $3.89 | $38.90 |
| 100 | $3.4 | $340.00 |
| 500 | $2.95 | $1,475.00 |
| 1,000 | $2.62 | $2,620.00 |
LTC2850HMS8#TRPBF Overview
An RS485/RS422 transceiver is a physical-layer interface IC that converts between the differential signaling used on industrial twisted-pair buses and the single-ended logic levels used by UARTs, MCUs, and FPGAs. RS485 supports multipoint half/full-duplex buses over long distances (up to 1200 m), while RS422 is typically point-to-point. The LTC2850 belongs to the broader line transceivers -> interface ICs -> integrated circuits taxonomy and is part of the LTC2850/LTC2851/LTC2852 family from Analog Devices (formerly Linear Technology).
Key features include ±15 kV ESD protection on the bus pins (H-grade designation), thermal shutdown, short-circuit protection, and a wide common-mode range that exceeds the RS485 standard requirement. The H-suffix variant specifies the high-ESD rating and the -40 °C to +125 °C automotive temperature grade, making it suitable for harsh industrial and automotive environments. Its 3.3V supply operation minimizes power dissipation in battery-powered and point-of-load regulated systems.
The architecture uses a differential line driver with slew-rate-limited outputs to reduce EMI while still delivering 20 Mbps throughput. Internal hysteresis on the receiver inputs combined with the failsafe circuit ensures clean logic transitions even with significant bus attenuation or noise. The device draws low quiescent current, allowing many transceivers to share a single 3.3V rail without thermal concerns.
Typical applications include industrial fieldbus networks (Modbus, Profibus DP), building automation (BACnet, RS485 lighting control), automotive body and chassis networks, point-of-sale terminals, and long-cable RS422 point-to-point links. The wide common-mode range also supports harsh electrically noisy environments such as motor drives and factory automation.
When designing with this part, place 100 nF decoupling capacitors as close as possible to the VCC pin and provide proper cable termination (typically 120 Ω) at both ends of the bus. The half-duplex topology requires that only one driver be enabled at a time; software UART flow control or hardware direction-control timing must enforce this to avoid contention.
This page consolidates distributor pricing, drop-in pin-compatible alternatives, and practical PCB/EMI design notes that go beyond what is typically printed in the manufacturer datasheet, helping engineers shorten design cycles.
Drop-in alternatives for LTC2850HMS8#TRPBF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2850IMS8#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2851HMS8#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2852HMS8#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2850CMS8#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2850MMS8#PBF
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
SN65HVD75E
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2850HMS8#TRPBF Specifications
| Function | Transceiver |
| Protocol | RS422, RS485 |
| Number of Drivers/Receivers | 1/1 |
| Duplex | Half |
| Supply Voltage | 3.3 V |
| Data Rate | 20 Mbps |
| Receiver Hysteresis | 25 mV |
| ESD Protection (H-grade) | ±15 kV HBM |
| Unit Load | 1/8 (supports up to 256 nodes) |
| Operating Temperature Range | -40 °C to +125 °C (H-grade) |
| Package | MSOP-8 |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free / #PBF | Yes |
| Failsafe Receiver | Yes (high output on open/short) |
LTC2850HMS8#TRPBF Pin Configuration
| Pin 1 | RO — Receiver output (logic-level, referenced to GND) |
| Pin 2 | RE — Receiver enable, active-low (tie to GND to enable receiver) |
| Pin 3 | DE — Driver enable, active-high (tie to VCC to enable driver) |
| Pin 4 | DI — Driver input (logic-level) |
| Pin 5 | GND — Ground |
| Pin 6 | A — Non-inverting bus pin (RS485/RS422 differential I/O) |
| Pin 7 | B — Inverting bus pin (RS485/RS422 differential I/O) |
| Pin 8 | VCC — 3.3V supply input |
Typical Applications
LTC2850HMS8#TRPBF is suitable for 6 applications: Industrial Modbus RTU Fieldbus, Building Automation (BACnet MS-TP, Lighting), Automotive Body & Chassis Networks, Point-of-Sale Terminal / Retail Backbone, Long-Distance RS422 Point-to-Point Links, Motor Drive & Inverter Internal Communication.
Industrial Modbus RTU Fieldbus
The LTC2850HMS8#TRPBF suits Modbus RTU industrial fieldbus networks because of its 3.3V single-supply operation, ±15 kV HBM ESD protection on the bus pins, and -40 °C to +125 °C operating range (per Analog Devices datasheet 285012fe). With a 1/8 unit load it allows up to 256 nodes per segment, and 20 Mbps data rate provides wide margin above the 115.2 kbps Modbus ceiling. Place a 120 Ω termination at both cable ends, add TVS protection at the cabinet entry, and pair with an isolated 3.3V DC-DC for robust factory-floor operation.
Recommended
Building Automation (BACnet MS-TP, Lighting)
For BACnet MS-TP and DMX-512 lighting-control buses, the LTC2850HMS8#TRPBF delivers 3.3V low-power RS485 with 1/8 unit load supporting dense node counts on long cable runs (per Analog Devices datasheet 285012fe). Its ±15 kV ESD rating tolerates installer mishandling on unshielded twisted-pair building wiring, while the H-grade -40 °C to +125 °C temperature range handles rooftop and mechanical-room environments. Use 100 nF VCC decoupling and 120 Ω termination, and ensure DE/RE timing in firmware prevents bus contention.
Recommended
Automotive Body & Chassis Networks
The H-grade LTC2850HMS8#TRPBF is targeted at automotive body and chassis networks because its -40 °C to +125 °C automotive temperature grade and ±15 kV ESD withstand exceed OEM in-cable transient stress (per Analog Devices datasheet 285012fe). Operating from 3.3V, it can be powered directly from a point-of-load regulator after the main 12V input, simplifying harness design. The 1/8 unit load supports 256-node CAN/RS485 hybrid gateways, and the low Iq allows the transceiver to remain in shutdown during ignition-off without draining the battery.
Recommended
Point-of-Sale Terminal / Retail Backbone
POS terminals and retail backbones use RS485 to link barcode scanners, payment terminals, and back-office printers over a single multi-drop bus. The LTC2850HMS8#TRPBF supports up to 256 nodes per bus and 20 Mbps data rates, enabling rapid polling of multiple peripherals from one master (per Analog Devices datasheet 285012fe). The 3.3V supply matches modern ARM-based POS controllers, while ±15 kV ESD safeguards against static discharge from frequent cable insertions by retail staff.
Recommended
Long-Distance RS422 Point-to-Point Links
For point-to-point RS422 connections such as industrial cameras, head-end displays, or test-instrumentation buses, the LTC2850HMS8#TRPBF provides differential signaling over cable runs exceeding 1200 m (per Analog Devices datasheet 285012fe). The 20 Mbps capability and 1/8 unit load simplify multi-drop extensions, and the H-grade ±15 kV ESD withstand protects the link against nearby coupling from switching power stages. Use a single 120 Ω termination at the receiver end and keep DE/RE tied together for simplex RS422 drive when only one-way traffic is needed.
Recommended
Motor Drive & Inverter Internal Communication
Inside motor drives and solar inverters, the LTC2850HMS8#TRPBF provides robust RS485 communication between the power-stage controller board and the user-interface panel across a noisy common-mode environment (per Analog Devices datasheet 285012fe). The H-grade ±15 kV ESD withstand, 256-node capability, and -40 °C to +125 °C automotive grade are well-matched to industrial cabinets with high dV/dt from switching IGBTs/MOSFETs. Use a low-capacitance digital isolator on the logic side to break ground loops and add a small common-mode choke on the bus for additional EMI immunity.
Recommended
Recommended Products Summary
Engineering reference data for LTC2850HMS8#TRPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2850IMS8#PBF | LTC2851HMS8#PBF | LTC2852HMS8#PBF | LTC2850CMS8#PBF | SN65HVD75E |
|---|---|---|---|---|---|---|
| Package | MSOP-8 | MSOP-8 - same | MSOP-8 - same | MSOP-8 - same | MSOP-8 - same | MSOP-8 - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments |
| Supply Voltage | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V |
| Data Rate | 20 Mbps | 20 Mbps | 20 Mbps | 20 Mbps | 20 Mbps | 20 Mbps |
| ESD (HBM, bus pins) | ±15 kV | ±15 kV (I-grade) | ±15 kV (H-grade) | ±15 kV (H-grade) | ±8 kV (C-grade) | ±16 kV |
| Duplex | Half | Half | Full | Half | Half | Half |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +85 °C | -40 °C to +125 °C | -40 °C to +125 °C | 0 °C to +70 °C | -40 °C to +85 °C |
| Unit Load | 1/8 (256 nodes) | 1/8 (256 nodes) | 1/8 (256 nodes) | 1/8 (256 nodes) | 1/8 (256 nodes) | 1/8 (256 nodes) |
Key Differentiators
- H-grade ±15 kV ESD on bus pins (vs LTC2850CMS8#PBF)
- Automotive temperature range -40 °C to +125 °C (vs LTC2850IMS8#PBF)
- Half-duplex pinout matches LTC2850 family (vs LTC2851HMS8#PBF)
Design Notes
Place a 100 nF ceramic decoupling capacitor (X7R, 16 V or higher) within 2 mm of the VCC pin (pin 8) of the LTC2850HMS8#TRPBF. A bulk 10 µF tantalum or ceramic capacitor on the same 3.3V rail helps absorb bus-induced transients when multiple transceivers switch simultaneously. Estimated: assuming 8 transceivers on a bus with 120 Ω termination, worst-case switching transient can demand > 50 mA in tens of nanoseconds, so a low-ESR bulk cap on the rail is required to keep VCC above 3.0 V during the event.
Route the differential A/B pair as a 100 Ω differential microstrip with matched lengths (≤ 5 mm mismatch) and keep the bus traces away from switching converter nodes. Place 120 Ω termination resistors only at the two cable ends; mid-cable stubs should be kept below 1/10 of the signal rise time in electrical length to prevent reflections. Add a small common-mode choke (e.g., 100 µH @ 100 MHz) in series with A/B at the cable entry for additional EMI immunity in industrial cabinets.
The LTC2850HMS8#TRPBF failsafe receiver guarantees a logic-high on floating inputs, but only when DE is de-asserted and there is sufficient bus bias (per the Analog Devices datasheet 285012fe). If your design ties DE and RE together for half-duplex auto-direction, ensure that there is a turn-around delay (≥ 1 bit time) before transmission to avoid bus contention. Avoid leaving DI floating when DE is high; tie DI to GND through a resistor if the MCU pin is high-impedance during reset.
Compliance Information
RoHS-compliant per the #PBF suffix in the MPN and the Analog Devices product page. AEC-Q100 not formally qualified (automotive-grade temperature range only).
