Overview
The ISO35DWR, produced by Texas Instruments, is an isolated full-duplex differential line driver and receiver designed for TIA/EIA 485/422 applications. This device is part of the ISOx5 family, which includes the ISO15 and ISO35 models. The ISO35DWR is specifically tailored for applications requiring full-duplex communication, allowing simultaneous transmission and reception of data.
It features galvanic isolation between the bus-line transceiver and the logic-level interface, providing a high level of protection against electrical noise and transients. This isolation is crucial for maintaining the integrity and reliability of the system, especially in harsh industrial environments.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC1 Supply Voltage, Side 1 | 3.15 | 3.3 | 3.6 | V |
| VCC2 Supply Voltage, Side 2 | 3.15 | 3.3 | 3.6 | V |
| Signaling Rate | - | - | 1 Mbps | - |
| Operating Ambient Temperature (ISO35) | -40 | 25 | 85 | °C |
| Operating Ambient Temperature (ISO35M) | -55 | 25 | 125 | °C |
| Isolation Voltage | - | - | 2500 VRMS | - |
| Differential Load Resistance | 54 | 60 | - | Ω |
| Driver Differential-Output Voltage Magnitude | 1.5 | 2 | - | V |
Key Features
- Meets or exceeds TIA/EIA RS-485 requirements.
- 1/8 unit load, allowing up to 256 nodes on a bus.
- Signaling rates up to 1 Mbps.
- Thermal shutdown protection.
- Low bus capacitance – 16 pF (typical).
- 50 kV/μs typical transient immunity.
- Fail-safe receiver for bus open, short, or idle conditions.
- 3.3-V inputs are 5-V tolerant.
- Galvanic isolation with 2500 VRMS isolation rating per UL 1577 and CSA 62368-1.
- Safety and regulatory approvals, including 4000-VPK VIOTM and 560-VPK VIORM per DIN EN IEC 60747-17 (VDE 0884-17).
Applications
- Security systems.
- Chemical production.
- Factory automation.
- Motor and motion control.
- HVAC and building automation networks.
- Networked security stations.
Q & A
- What is the primary function of the ISO35DWR?
The ISO35DWR is an isolated full-duplex differential line driver and receiver designed for TIA/EIA 485/422 applications.
- What are the operating supply voltage ranges for the ISO35DWR?
The operating supply voltage ranges are 3.15 V to 3.6 V for both VCC1 and VCC2.
- What is the maximum signaling rate of the ISO35DWR?
The maximum signaling rate is up to 1 Mbps.
- What is the isolation voltage rating of the ISO35DWR?
The isolation voltage rating is 2500 VRMS.
- What are the operating ambient temperature ranges for the ISO35 and ISO35M models?
The ISO35 operates from -40°C to 85°C, while the ISO35M operates from -55°C to 125°C.
- What safety and regulatory approvals does the ISO35DWR have?
The device has approvals including 4000-VPK VIOTM, 560-VPK VIORM per DIN EN IEC 60747-17 (VDE 0884-17), and 2500 VRMS isolation rating per UL 1577 and CSA 62368-1.
- What is the typical transient immunity of the ISO35DWR?
The typical transient immunity is 50 kV/μs.
- Is the ISO35DWR suitable for use in harsh industrial environments?
Yes, it is designed to provide high protection against electrical noise and transients, making it suitable for harsh industrial environments.
- What is the maximum number of nodes that can be connected on a bus using the ISO35DWR?
Up to 256 nodes can be connected on a bus due to its 1/8 unit load.
- Does the ISO35DWR have fail-safe receiver functionality?
Yes, the receiver is fail-safe for bus open, short, or idle conditions.
