Texas Instruments ISO15DWR

Overview

ISO15DWR from Texas Instruments is an isolated half-duplex RS-485 transceiver with 3.3-V logic-side operation, 2500 VRMS galvanic isolation, 1 Mbps signaling rate, ±7 V to +12 V common-mode bus voltage range, and fail-safe receiver for open/short/idle bus conditions. It enables robust industrial serial communication in factory automation and building control networks where ground-loop elimination is critical.

For engineers reviewing the ISO15DWR datasheet, ISO15DWR pinout, ISO15DWR application, or ISO15DWR equivalent, key selection criteria include its 16-pin SOIC (DW) package, 3.3-V logic compatibility with 5-V tolerant inputs, thermal shutdown protection, 50 kV/μs CMTI, and compliance with UL 1577, VDE 0884-17, and CSA 62368-1 safety standards.

Technical Context

The ISO15DWR implements a galvanically isolated half-duplex architecture with separate logic-side (GND1/VCC1) and bus-side (GND2/VCC2) power domains. Its driver and receiver share the same A/B differential bus terminals, controlled via DE (driver enable) and RE (receiver enable) logic inputs.

It features a fail-safe receiver that outputs logic-high when the bus is open, shorted, or idle; low bus capacitance (16 pF typical); and 1/8 unit load capability supporting up to 256 nodes on a single RS-485 bus. Transient immunity is rated at 50 kV/μs typical under common-mode step disturbances.

Key Specifications

Pinout & Package

ISO15DWR uses a 16-pin SOIC (DW) package with 10.30 mm × 7.50 mm body size and creepage/clearance ≥8 mm per safety standard requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISO15DR and ADM2483BRWZ, ISO15DWR delivers optimal balance of certified safety, compact SOIC-16 form factor, and cost efficiency for mainstream industrial RS-485 networks - avoiding unnecessary overhead from integrated power or excessive isolation margin.

Availability

ISO15DWR is available at Aetrix Electronics and suitable for factory automation, building HVAC networks, and industrial security systems requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for ISO15DWR 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 delivering analog, embedded processing, and connectivity solutions with emphasis on industrial, automotive, and power management applications.

The ISOx5 family-including ISO15DWR-is designed specifically for robust, safety-certified RS-485 communication in electrically harsh industrial environments where ground isolation, noise immunity, and regulatory compliance are non-negotiable.

FAQ

What is the isolation voltage rating of the ISO15DWR?

The ISO15DWR has a 2500 VRMS isolation rating per UL 1577 and CSA 62368-1, with 4000 VPK transient isolation voltage (VIOTM) and 560 VPK repetitive peak isolation voltage (VIORM) per VDE 0884-17. These ratings are verified through 100% production testing and qualify the device for reinforced insulation in industrial safety applications.

Does the ISO15DWR support full-duplex operation?

No, the ISO15DWR is a half-duplex isolated RS-485 transceiver. It shares the A and B bus terminals for both transmit and receive functions, controlled by separate DE (driver enable) and RE (receiver enable) inputs. For full-duplex operation, TI's ISO35DWR or ISO35DR would be required.

What is the maximum number of nodes supported on an RS-485 bus using ISO15DWR?

The ISO15DWR presents a 1/8 unit load, allowing up to 256 transceivers on a single RS-485 bus segment without exceeding the standard's 32-unit-load limit. This scalability is achieved through low input impedance and minimal bus capacitance (16 pF typical).

How does the fail-safe receiver in ISO15DWR behave during bus faults?

The ISO15DWR's fail-safe receiver outputs a logic-high state when the A/B bus lines are open-circuited, shorted together, or left idle. This prevents undefined UART framing and ensures microcontroller firmware receives valid stop bits - eliminating need for external bias resistors in most deployments.

Can ISO15DWR operate with 5-V logic inputs despite its 3.3-V supply?

Yes, the ISO15DWR's logic inputs (D, DE, RE) are 5-V tolerant while powered from a 3.3-V VCC1 supply. This allows direct interfacing with legacy 5-V MCUs or level-shifter-free integration into mixed-voltage systems without additional interface circuitry.