Texas Instruments SN65HVD485EP

Overview

SN65HVD485EP from Texas Instruments is a half-duplex RS-485 transceiver designed for industrial bus networks. It operates from 4.5 V to 5.5 V, supports up to 10 Mbps data rate, draws ≤2 mA active supply current, features ±15 kV HBM ESD protection on bus pins, and enables up to 64 nodes per bus via 1/2-unit-load input impedance. It is used in motor control systems where noise immunity and robust bus termination are critical.

For engineers reviewing the SN65HVD485EP datasheet, SN65HVD485EP pinout, SN65HVD485EP application, or SN65HVD485EP equivalent, key selection criteria include failsafe receiver behavior under open/short/idle bus conditions, thermal shutdown protection, glitch-free power sequencing, industry-standard SN75176 footprint compatibility, and verified 10 Mbps operation over twisted-pair cabling up to 4000 ft at lower rates.

Technical Context

The SN65HVD485EP integrates driver and receiver functions with independent DE (driver enable, active-high) and RE (receiver enable, active-low) controls, enabling flexible half-duplex bus arbitration. Its receiver includes internal biasing for open-circuit, short-circuit, and idle-bus failsafe operation-outputting logic high when VID is indeterminate-and 30 mV hysteresis to suppress noise-induced output toggling.

Driver output delivers ≥1.5 V differential voltage into 54 Ω load, with propagation delays ≤30 ns (tPLH/tPHL), rise/fall times ≤25 ns, and pulse skew ≤5 ns. Thermal shutdown activates at 165°C junction temperature, and power-on reset holds outputs in high-impedance until VCC stabilizes.

Key Specifications

Pinout & Package

SN65HVD485EP is available in SOIC-8 (4.91 mm × 3.90 mm), VSSOP-8 (3.00 mm × 3.00 mm), and PDIP-8 (9.81 mm × 6.35 mm) packages. The pinout is identical across all variants and matches the industry-standard SN75176 footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RS-485 transceiver applications.

Compared with MAX485E and ST485E, the SN65HVD485EP delivers double the node density, quadruple the speed, and integrated thermal protection-making it the preferred choice for new industrial designs requiring future-proof scalability and reliability.

Availability

SN65HVD485EP is available at Aetrix Electronics and suitable for motor control, industrial process control, and building automation networks requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SN65HVD485EP includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The SN65HVD485EP belongs to TI's RS-485 transceiver product line, engineered specifically for rugged industrial networking-emphasizing ESD robustness, failsafe operation, thermal resilience, and interoperability with legacy bus architectures.

FAQ

What is the maximum data rate supported by the SN65HVD485EP?

The SN65HVD485EP supports a maximum data rate of 10 Mbps under recommended operating conditions with proper termination and cable layout. This performance is verified across the full –40°C to +85°C temperature range and into a 54 Ω differential load. At lower rates (e.g., 100 kbps), the SN65HVD485EP reliably operates over cable lengths up to 4000 ft, making it suitable for both high-speed and long-haul industrial applications.

Does the SN65HVD485EP require external failsafe biasing resistors?

No, the SN65HVD485EP does not require external failsafe biasing resistors. Its receiver incorporates internal biasing that guarantees a logic-high output during open-circuit, short-circuit, or idle-bus conditions. This built-in failsafe functionality eliminates design complexity and component count while ensuring deterministic MCU input states-critical for preventing UART framing errors or watchdog timeouts in safety-aware systems.

How does the SN65HVD485EP handle power-up sequencing?

The SN65HVD485EP includes an internal power-on reset (POR) circuit that holds the A, B, and R pins in high-impedance state until VCC reaches a valid operating level (≥4.5 V). This prevents bus contention, spurious transmissions, or receiver misreads during power ramp-up. The POR behavior is fully characterized and guaranteed across temperature and supply ramp rates, ensuring glitch-free initialization without external supervision circuitry.

Can the SN65HVD485EP be used in systems with ground potential differences between nodes?

Yes, the SN65HVD485EP supports a wide common-mode input voltage range of –7 V to +12 V, enabling reliable operation despite ground potential differences up to 19 V between nodes on the same RS-485 bus. This capability is essential in large-scale industrial installations where grounding practices vary across equipment cabinets or buildings-ensuring signal integrity without requiring complex isolation solutions in every node.

What thermal protection mechanisms are integrated into the SN65HVD485EP?

The SN65HVD485EP integrates a thermal shutdown circuit that disables the driver output when junction temperature exceeds 165°C. This protection activates independently of supply voltage or logic inputs and remains engaged until the die cools below the hysteresis threshold (~155°C). The feature safeguards against irreversible damage during sustained bus faults (e.g., shorted A/B lines) or inadequate heatsinking-providing fail-safe behavior required in mission-critical industrial deployments.