SN75LBC184M/TR

The SN75LBC184 and SN65LBC184 are differential data line transceivers in the industry-standard SN75176 footprint, with built-in protection against high-energy noise transients. This feature significantly improves reliability, offering better immunity to noise transients coupled onto data cables compared to most existing devices. These circuits provide a reliable, low-cost direct-coupled (no isolation transformer required) data line interface with no external components required. The SN75LBC184 and SN65LBC184 can withstand overvoltage transients of 400W peak (typical). The conventional combination wave specified in IEC 61000-4-5 simulates overvoltage transients and models unidirectional surges caused by overvoltages resulting from switching and secondary lightning strike transients. The combination wave is modeled by a double-exponential function defined by separate rise and fall times for voltage and current. The standard 1.2μs/50μs combination waveform is shown in Figure 1, and the test description is shown in Figure 15. The device also provides other desirable features for bus-type data buses in electrically noisy environments, including industrial process control applications. The differential driver design employs slew-rate-controlled outputs capable of transmitting data at up to 250 kbps. Slew rate control allows longer unterminated cable lengths and longer stub lengths extending from the main trunk compared to uncontrolled, faster voltage transitions. The unique receiver design provides a fail-safe high-level output when the input is floating (open circuit). The SN75LBC184 and SN65LBC184 receivers also feature high input impedance equivalent to one-quarter unit load, allowing up to 128 similar devices to be connected on the bus. The SN75LBC184 operates over a temperature range of 0°C to 70°C, and the SN65LBC184 operates over a temperature range of -40°C to 85°C.

Applications

• Industrial Networks
• Energy Meters
• Motor Control

Key features

• Integrated transient voltage suppression
• ESD protection on bus terminals exceeding: ±30 kV IEC 61000-4-2 contact discharge, ±15 kV IEC 61000-4-2 air-gap discharge, ±15 kV EIA/JEDEC human body model
• Circuit damage protection with 400 W peak (typical) per IEC 61000-4-5
• Controlled driver output slew rate allows longer cable stub lengths, up to 250 kbps in electrically noisy environments
• Open-circuit fail-safe receiver design
• Quarter-unit load allows up to 128 devices on the bus
• Thermal shutdown protection
• Power-on/power-off glitch protection
• Each transceiver meets or exceeds TIA/EIA-485 (RS-485) and ISO/IEC 8482:1993(E) requirements
• Low disabled supply current, 300 μA maximum
• Pin-compatible with SN75176