SN65LBC184 Status: ACTIVE

Product Information

Features

• Integrated Transient Voltage Suppression
• ESD Protection for Bus Terminals Exceeds:
  • ±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 of 400-W Peak (Typical) Per IEC 61000-4-5
• Controlled Driver Output-Voltage Slew Rates Allow Longer Cable Stub Lengths
• 250-kbps in Electrically Noisy Environments
• Open-Circuit Fail-Safe Receiver Design
• 1/4 Unit Load Allows for 128 Devices Connected on Bus
• Thermal Shutdown Protection
• Power-Up/-Down Glitch Protection
• Each Transceiver Meets or Exceeds the Requirements of TIA/EIA-485 (RS-485) and ISO/IEC 8482:1993(E) Standards
• Low Disabled Supply Current 300 µA Max
• Pin Compatible With SN75176
• Applications:
  • Industrial Networks
  • Utility Meters
  • Motor Control

Description

The SN75LBC184 and SN65LBC184 are differential data line transceivers in the trade-standard footprint of the SN75176 with built-in protection against high-energy noise transients. This feature provides a substantial increase in reliability for better immunity to noise transients coupled to the data cable over most existing devices. Use of these circuits provides a reliable low-cost direct-coupled (with no isolation transformer) data line interface without requiring any external components.

The SN75LBC184 and SN65LBC184 can withstand overvoltage transients of 400-W peak (typical). The conventional combination wave called out in IEC 61000-4-5 simulates the overvoltage transient and models a unidirectional surge caused by overvoltages from switching and secondary lightning transients.

A biexponential function defined by separate rise and fall times for voltage and current simulates the combination wave. The standard 1.2 µs/50 µs combination waveform is shown in Figure 1 and in the test description in Figure 15.

The device also includes additional desirable features for party-line data buses in electrically noisy environment applications including industrial process control. The differential-driver design incorporates slew-rate-controlled outputs sufficient to transmit data up to 250 kbps. Slew-rate control allows longer unterminated cable runs and longer stub lengths from the main backbone than possible with uncontrolled and faster voltage transitions. A unique receiver design provides a fail-safe output of a high level when the inputs are left floating (open circuit). The SN75LBC184 and SN65LBC184 receiver also includes a high input resistance equivalent to one-fourth unit load allowing connection of up to 128 similar devices on the bus.

The SN75LBC184 is characterized for operation from 0°C to 70°C. The SN65LBC184 is characterized from –40°C to 85°C.