SN65LBC184, SN75LBC184 DIFFERENTIAL TRANSCEIVER WITH TRANSIENT VOLTAGE SUPPRESSION

SLLS236 - OCTOBER 1996

features

Transceiver with Integrated Transient Voltage Suppression
Protects Against Circuit Damage for Pulses of 400 W Peak (Typical)
Controlled Driver Output-Voltage Slew Rates Allows Longer Cable Stub Lengths
Designed to Transmit Data at 250-kbits/s in Electrically Noisy Environments
Open-Circuit Fail-Safe Receiver Design
1/2 Unit Load Allows for 64 Devices Connected on Bus
Thermal Shutdown Protection
Power-Up/-Down Glitch Protection
Each Transceiver Meets or Exceeds the Requirements of EIA RS-485 and ISO/IEC 8482:1993(E) Standards
Low Disabled Supply Current 300 uA Max
Pin Compatible with SN75176

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 CEI IEC 1000-4-5 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 us/50 us combination waveform is shown in Figure 1 and in the test description in Figure 9.

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 kbits/s. 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-half unit load allowing connection of up to 64 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.

Title: DIFFERENTIAL TRANSCEIVER WITH TRANSIENT VOLTAGE SUPPRESSION
Product Family: TRANSMITTERS AND RECEIVERS
Device Functionality: TRANSMITTERS/RECEIVERS
Orderable Devices: SN65LBC184D, SN65LBC184DR, SN65LBC184P, SN75LBC184D, SN75LBC184DR, SN75LBC184P

View the complete PDF datasheet: slls236.pdf (214 K Bytes) (Requires Acrobat Reader 3.x)

View more information about generic part numbers:SN65LBC184, SN75LBC184

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