THVD1550 - 5V RS-485 Transceiver, 50Mbps, ±18kV IEC ESD | TI
MPN: THVD1550 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.18 | $21.80 |
| 100 | $1.78 | $178.00 |
| 500 | $1.45 | $725.00 |
| 1,000 | $1.22 | $1,220.00 |
| 2,500 | $1.05 | $2,625.00 |
THVD1550 Overview
An RS-485 transceiver is a bus-interface IC that converts a single-ended UART/logic signal into a differential signal on a twisted-pair cable, enabling robust multi-drop communication over long distances. Within the broader hierarchy, RS-485 transceivers belong to physical-layer (PHY) interface ICs, which sit between a microcontroller's UART and the cable plant. The THVD1550 specifically targets half-duplex (1 driver + 1 receiver, shared bus) topologies per the TIA/EIA-485A standard, with an extended common-mode range that allows multipoint data acquisition networks over long cable runs.
Key features include a wide 3.0 V to 5.5 V supply range (note: 5 V nominal is required for full ESD and speed performance), 30 kV HBM ESD protection, 18 kV IEC 61000-4-2 contact discharge, 4 kV IEC 61000-4-4 fast transient burst (EFT) immunity, 1/8 unit-load support (up to 256 nodes on the bus), and thermal-shutdown protection. The low-power architecture typically draws ~3 mA of quiescent current in active mode and drops into a sub-µA shutdown via the EN pin.
Internally the THVD1550 uses a differential line driver with slew-rate control and a differential receiver with wide common-mode tolerance, satisfying TIA/EIA-485A. The 50-Mbps signaling rate makes it suitable for high-speed motor feedback, encoder interfaces, and multi-Mbps industrial backbones, while the THVD1510 sibling part drops to 500 kbps for EMI-sensitive sensor links.
Typical applications include factory-automation fieldbus nodes, building-automation BACnet/MS-TP segments, motor-drive position feedback, solar inverter string monitoring, and any point-to-multipoint industrial link where bus ESD and EFT events are routine.
When designing with this part, place 100 nF decoupling close to VCC, match the bus termination to the cable characteristic impedance (120 Ω), and provision 1 nF failsafe biasing resistors at the end nodes if no driver is active.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for THVD1550 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with THVD1550 (same form factor and footprint) — differing in Package, Product Type, Supply Voltage, Mounting Type, Common-Mode Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
THVD1450DRBR
✅ Drop-In✓ In Stock
$1.25 / Unit
View Datasheet →THVD1510DR
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →THVD1520DR
✅ Drop-In📋 Reference alternative (not in catalog)
SN65HVD3088EDR
✅ Drop-In📋 Reference alternative (not in catalog)
MAX13487EESA+T
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →ADM485JRZ
✅ Drop-In📋 Reference alternative (not in catalog)
THVD1550 Specifications
| Function | Transceiver |
| Protocol | RS-485 |
| Number of Drivers/Receivers | 1/1 |
| Duplex | Half |
| Data Rate (max) | 50 Mbps |
| Supply Voltage | 4.5 V to 5.5 V (5 V nominal) |
| Operating Temperature Range | -40 C to +125 C |
| IEC 61000-4-2 ESD (Contact) | ±18 kV |
| HBM ESD | ±30 kV |
| IEC 61000-4-4 EFT | ±4 kV |
| Common-Mode Range | -7 V to +12 V |
| Unit Load | 1/8 (up to 256 nodes) |
| Package | 8-pin SOIC (D) |
| Mounting Type | Surface Mount |
| Standards Compliance | TIA/EIA-485A |
| RoHS | Compliant |
THVD1550 Pin Configuration
| Pin 1 | RO — Receiver Output (logic-level, push-pull) |
| Pin 2 | RE# — Receiver Enable (active-low; logic low enables RO) |
| Pin 3 | DE — Driver Enable (logic high enables driver outputs A/B) |
| Pin 4 | DI — Driver Input (TTL/CMOS logic to differential bus) |
| Pin 5 | GND — Ground reference |
| Pin 6 | A — Bus Inverting (differential line) |
| Pin 7 | B — Bus Non-Inverting (differential line) |
| Pin 8 | VCC — 5V supply input |
Typical Applications
THVD1550 is suitable for 6 applications: Factory Automation Fieldbus Nodes, Motor Encoder and Servo Feedback, Solar Inverter String Monitoring, Building Automation and HVAC Networks, Industrial Process Instrumentation, Grid-Energy Storage and Battery Management.
Factory Automation Fieldbus Nodes
The THVD1550 serves as the bus transceiver on PROFIBUS, Modbus RTU, and BACnet MS-TP fieldbus nodes where the bus is routinely exposed to ESD from cable handling and EFT from motor switching. Its integrated ±18-kV IEC contact discharge and ±4-kV EFT immunity remove the need for external TVS arrays on the bus, simplifying BOM. At 50 Mbps the part is comfortably headroom for 12 Mbps PROFIBUS DP and 500 kbps–10 Mbps Modbus TCP variants, and the 1/8-unit-load input supports dense multi-drop panels with up to 256 nodes per segment. Place 100 nF decoupling at VCC and 120 Ω termination at cable ends.
Recommended
Motor Encoder and Servo Feedback
Servo drives and brushless-DC motor controllers use the THVD1550 to communicate encoder position, torque, and temperature over long encoder cables that run parallel to power conductors. The wide -7 V to +12 V common-mode range tolerates ground-potential differences between the motor chassis and the controller, and the differential signaling rejects the common-mode noise injected by the PWM switching at 20 kHz+ frequencies. The 50-Mbps data rate captures 23-bit encoder counts at >1 MHz update rates without bus contention. Its low quiescent current (~3 mA typical) keeps heat low in enclosed motor housings.
Recommended
Solar Inverter String Monitoring
Solar combiner boxes and string-monitoring modules use the THVD1550 to relay per-string voltage and current telemetry back to the inverter's central controller over RS-485. The wide operating temperature range (-40 °C to +125 °C) handles rooftop enclosures in full sun, and the high HBM ESD withstand protects against installer-induced static discharge during commissioning. With 1/8-unit loading, a single THVD1550-equipped string monitor bus can aggregate more than 200 strings per inverter, supporting megawatt-scale arrays. Low power consumption keeps string-monitor standby current minimal, preserving solar yield.
Recommended
Building Automation and HVAC Networks
Building-automation controllers use the THVD1550 to communicate over BACnet MS-TP, Modbus RTU, or proprietary RS-485 trunks that span multiple floors and electrical panels. The ±18-kV IEC ESD rating tolerates service-installation events, while the 1/8-unit load supports 256-node BACnet segments without repeaters. The device's thermal protection and short-circuit-proof bus drivers allow indefinite bus contention during commissioning miswiring, reducing field-service time. Operating from a single 5-V rail simplifies power-tree design alongside Wi-Fi and BLE subsystems.
Recommended
Industrial Process Instrumentation
Process instruments such as flow meters, pH probes, and pressure transmitters use the THVD1550 to publish measurements over RS-485 to PLCs and SCADA systems. The wide common-mode range supports long cable runs in electrically noisy plant environments with significant ground-potential differences, and the 50-Mbps capability future-proofs instruments for high-speed protocols like EtherCAT-over-RS485 or proprietary high-rate telemetry. Robust IEC ESD and EFT protection reduces field returns from environmental transients.
Recommended
Grid-Energy Storage and Battery Management
Battery-management systems (BMS) for grid-scale energy storage use the THVD1550 to chain battery modules over RS-485 daisy-chains. Each module reports cell voltage, temperature, and SOC, with up to 256 modules on a single bus thanks to the 1/8-unit-load input. The 50-Mbps signaling rate aggregates many module updates per second without bus bottlenecking, while the -40 °C to +125 °C operating range covers outdoor cabinet installations. The fail-safe receiver ensures deterministic logic states during cable-fault events.
Recommended
Recommended Products Summary
Engineering reference data for THVD1550 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | THVD1450DR | THVD1510DR | THVD1520DR | SN65HVD3088EDR | MAX13487EESA+T | ADM485JRZ |
|---|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Maxim Integrated | Analog Devices |
| Package | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 (D) | SOIC-8 | SOIC-8 |
| Data Rate (max) | 50 Mbps | 50 Mbps | 500 kbps | 10 Mbps | 20 Mbps | 16 Mbps | 5 Mbps |
| Supply Voltage | 4.5 V to 5.5 V | 3.0 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.75 V to 5.25 V | 4.75 V to 5.25 V |
| Unit Load | 1/8 | 1/8 | 1/8 | 1/8 | 1/8 | 1/8 | 1 (standard unit load) |
| Half/Full Duplex | Half | Half | Half | Half | Half | Half (auto-direction) | Half |
| Operating Temperature | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +125 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| Approx Unit Price (qty 1) | $2.45 | $2.20 | $2.10 | $2.30 | $1.95 | $3.20 | $1.80 |
Key Differentiators
- Highest integrated IEC contact ESD in 5V SOIC-8 RS-485 family (vs MAX13487EESA+T)
- 3.3V/5V dual-supply option in same footprint (vs SN65HVD3088EDR)
- 50-Mbps speed in THVD15xx family (vs THVD1510DR)
Design Notes
Place a 100 nF X7R decoupling capacitor within 3 mm of the THVD1550 VCC pin (pin 8) and a 10 µF bulk capacitor on the same 5-V rail. Keep the SOIC-8 ground lead (pin 5) tied to a continuous ground plane — do not place any signal traces between the IC and its decoupling pad. The bus-side differential pair (A at pin 6, B at pin 7) should be routed with 100-Ω differential impedance and a constant pair-to-pair spacing of 0.2 mm–0.5 mm to maintain field-cancellation performance. Estimated: at 50 Mbps, traces longer than ~50 mm require controlled impedance.
The bus pins of the THVD1550 are designed to survive ±18 kV IEC contact discharge without external protection, but a small TVS array (e.g. PESD5V0L4UG or SMAJ8.0CA) is still recommended on long outdoor cable runs where surge events exceed IEC ratings. Place 120 Ω termination resistors at the two physical ends of the bus segment — not at every node — to avoid parallel-loading the line. Fail-safe biasing resistors (typically 680 Ω pull-up on B, 680 Ω pull-down on A) are only required if no driver remains active on the bus at idle.
Do not exceed the 5.5 V absolute-maximum supply voltage on VCC (pin 8) — transients above this value can cause latch-up. The DE and RE# pins must not be left floating; if unused, tie RE# to GND and DE to GND to keep the driver in a high-impedance state. The receiver output (RO, pin 1) is a push-pull stage and should not be pulled above VCC or below GND. Finally, when connecting multiple THVD1550 nodes, verify that no two drivers enable simultaneously — the device does not have bus-collision protection beyond its internal thermal shutdown.
At 50 Mbps, the THVD1550 generates 1–2 ns edge rates that can radiate EMI if the bus cable is not properly terminated. Use twisted-pair cable (Cat 5e or shielded twin-axis) and 120 Ω termination at the physical ends to keep reflections below 10 %. Stub lengths from the bus backbone to each node should be kept under 10 cm; for backbones longer than 30 m, use repeaters rather than long stubs. Shield grounding should be single-point at the controller end to prevent ground loops through the cable shield.
Compliance Information
RoHS compliant per TI product page. Standard industrial-grade temperature range (-40 °C to +125 °C); not AEC-Q100 qualified — choose THVD1551-Q1 for automotive applications.