Texas Instruments SN65HVD82DR

Overview

SN65HVD82DR from Texas Instruments is a half-duplex RS-485 transceiver designed for industrial wired communication. It operates from a single 4.5–5.5-V supply, delivers 250-kbps signaling rate, features ±12-kV IEC 61000-4-2 contact ESD protection on bus pins, and supports up to 256 nodes per bus in multi-point networks-ideal for electrical metering and building automation systems.

For engineers reviewing the SN65HVD82DR datasheet, SN65HVD82DR pinout, SN65HVD82DR application, or SN65HVD82DR equivalent, key selection criteria include its failsafe receiver (VIT+ = –20 mV typ., VHYS = 60 mV), low standby current (<400 nA), robust transient immunity (±4-kV IEC 61000-4-4), SOIC-8 package compatibility, and explicit support for long-cable, noise-prone RS-485 deployments.

Technical Context

The SN65HVD82DR integrates a differential driver and receiver sharing a common bus port (A/B), with independent DE (driver enable, active-high) and RE (receiver enable, active-low) control inputs. Its internal failsafe biasing ensures R outputs logic High during open/short/idle bus conditions by setting VIT+ at –20 mV and VIT– at –150 mV (typ.), yielding 60-mV hysteresis.

It implements low-power standby mode when DE = Low and RE = High, reducing ICC to <400 nA (typ.). Driver output swing exceeds 1.5 V into 54-Ω RS-485 load, while receiver input thresholds comply with RS-485 standard logic levels and tolerate ±7-V common-mode voltage.

Key Specifications

Pinout & Package

SN65HVD82DR is housed in an 8-pin SOIC (D) package measuring 4.90 mm × 3.91 mm, with gull-wing leads suitable for automated PCB assembly and industrial reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX13487EESA+ and THVD1550DR, the SN65HVD82DR offers the most balanced trade-off of failsafe certainty, 5-V compatibility, industrial ESD/EFT immunity, and node-count scalability - making it the preferred choice for retrofitting and high-reliability metering infrastructure.

Availability

SN65HVD82DR is available at Aetrix Electronics and suitable for electrical metering, building automation, industrial networks, and security electronics requiring stable component supply across multi-year production cycles.

Supply support for SN65HVD82DR 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 leader focused on analog, embedded processing, and connectivity technologies, serving industrial, automotive, and communications markets.

The SN65HVD82DR belongs to TI's robust RS-485 transceiver portfolio, engineered specifically for noise-immune, multi-node industrial communications in harsh electromagnetic environments.

FAQ

What is the maximum recommended cable length for SN65HVD82DR at 250 kbps?

The SN65HVD82DR supports up to 4000 ft (≈1200 m) at 250 kbps under conservative jitter conditions (≤5%). This assumes proper termination, AWG-24 twisted-pair cable, and adherence to stub-length limits (≤30.6 ft). Real-world length may vary based on noise, topology, and connector quality - always validate with eye-diagram testing in final system configuration. SN65HVD82DR's 60-mV hysteresis and ±12-kV ESD enhance margin in marginal installations.

Does SN65HVD82DR require external bias resistors for failsafe operation?

No, SN65HVD82DR does not require external bias resistors. Its internal failsafe design sets VIT+ at –20 mV (typ.) and VIT– at –150 mV (typ.), ensuring R outputs logic High during open, shorted, or idle bus conditions. This eliminates external components and board space while guaranteeing deterministic startup and fault recovery - a key differentiator versus basic RS-485 transceivers. SN65HVD82DR's 60-mV hysteresis further prevents chatter near threshold.

Can SN65HVD82DR operate with a 3.3-V microcontroller interface?

Yes, SN65HVD82DR supports 3.3-V MCU interfacing: its D, DE, and RE inputs accept 3.3-V logic levels directly (VIH min = 2 V), and its R output (5-V CMOS) can be level-shifted using a Schottky diode + 10-kΩ pull-up as documented in TI's application note. Do not connect R directly to 3.3-V inputs without translation. SN65HVD82DR's 4.5–5.5-V VCC requirement remains unchanged - separate 5-V rail or regulator needed.

What is the thermal performance of SN65HVD82DR in SOIC-8 package?

SN65HVD82DR in SOIC-8 (D package) has RθJA = 116.1°C/W, RθJB = 57.1°C/W, and ψJB = 56.5°C/W. At 900 µA quiescent current and 250-kbps operation, junction temperature rise remains well below 150°C derating limit even at 85°C ambient - provided standard 2-oz copper PCB with ≥1 in² thermal pad. No heatsink required for typical industrial use. SN65HVD82DR's low dynamic power (≤1 mA) minimizes thermal stress in enclosed enclosures.

How many SN65HVD82DR devices can share one RS-485 bus?

Up to 256 SN65HVD82DR transceivers can share a single RS-485 bus. This is enabled by its 1/8 unit load (UL) rating - each device draws only 1/8 the bus capacitance and leakage current of a standard UL device. The RS-485 standard allows 32 UL total, so 32 ÷ (1/8) = 256. SN65HVD82DR's low bus input current (75–125 µA at ±12 V) and high input impedance ensure signal integrity across full node count without repeaters.