Low cost passive input RS-485 isolated transceiver

The IL3185-3E low cost passive input RS-485 isolated transceiver from NVE is designed to galvanically isolate bidirectional data communication over balanced transmission lines. The IL3185 series delivers at least 1.5V into a 54Ω load for excellent data integrity over long cables, and is also compatible with 3V input supplies, allowing interfacing to standard microcontrollers without additional level shifting. A unique ceramic/polymer composite barrier provides excellent isolation and virtually unlimited barrier life. This particular device uses NVE’s patented IsoLoop spintronic Giant Magnetoresistance (GMR) technology and comes in a 0.15″ 16-pin SOIC package.

• Surface-mount low cost passive input RS-485 isolated transceiver
• Power supply V_DD1 3.3V to 5V, V_DD2 4.5V to 5.5V
• Data rate of 5Mbps
• Bus ESD protection of 15kV
• Isolation of 2,500 V_RMS (1 minute)
• Temperature range of −40°C to +85°C
• Typical common mode rejection 20kV/μs
• No carrier or clock for low EMI emissions and susceptibility
• Thermal shutdown protection
• Typical propagation delay of 90ns (5V)
• Coil input resistance of 85Ω typical
• UL 1577 recognised; IEC 60747-5-5 (VDE 0884) certified
• 0.15″ 16-pin SOIC package

The IL3185 has current limiting and thermal shutdown features to protect against output short circuits and bus contentions that may cause excessive power dissipation, and also incorporate a “fail-safe if open” design, ensuring a logic high on R if the bus lines are disconnected or “floating.”

Typical applications for the IL3185 series include:

• P.O.S. Systems
• Security networks
• Building environmental controls
• Industrial control networks
• Gaming systems
• Factory automation

The below table gives the recommended operating conditions for the NVE IL3185 high speed passive input RS-485 differential bus transceiver series including the IL3185-3E: