ISL3158AEMBZ-T

Overview

The ISL3158AEMBZ-T is a BiCMOS, half-duplex RS-485/RS-422 transceiver in an 8-lead SOIC package. It operates on a single 5V supply (4.5V to 5.5V) with a quiescent current of 600µA and a shutdown current of 70nA. The device supports data rates up to 10Mbps and features ±16.5kV IEC61000 ESD protection on bus pins. It delivers a minimum differential output voltage of 2.4V into a 54Ω load and presents a true 1/8 unit load, allowing up to 256 devices on the network. Operating temperature range is -55°C to +125°C.

Feature Summary

• High driver output voltage improves noise immunity and allows driving multiple terminations in non-standard topologies.
• Integrated full fail-safe receiver ensures logic high output when inputs are floating, shorted, or undriven.
• Hot plug circuitry maintains three-state outputs during power-up and power-down to prevent bus crashes.
• Advanced ESD structures protect RS-485 pins against severe electrostatic discharge events without external components.

Applications

• Utility meters and automated meter reading systems
• High node count fieldbus networks such as PROFIBUS
• Security camera networks
• Building lighting and environmental control systems

Procurement Notes

Verify the specific ordering suffix for tape and reel configuration, as the base part number requires a '-T' suffix for this packaging type. Confirm that the component meets RoHS compliance requirements for your assembly process. Check the manufacturer's lifecycle status, as this series may be classified as obsolete with potential substitute products available.

Selection Notes

Select this transceiver for applications requiring extended common mode voltage ranges from -7V to +12V. The low unit load specification is suitable for dense multipoint networks exceeding standard 32-device limits. Ensure the design accommodates the increased enable times required when waking from the ultra-low shutdown mode.

Part Context

This component belongs to the ISL3158AE family of high-performance RS-485 transceivers. It shares core electrical characteristics with variants like the ISL3158EIBZ-T but differs in package style and thermal rating. The datasheet identifies it as an obsolete product, suggesting evaluation of newer replacements for long-term production.

Replacement Considerations

Public confirmed substitutes include the ISL3158E and ISL3158AE series. Verify pinout compatibility and ensure the replacement matches the required operating temperature range and ESD protection levels.

FAQ

How does the device handle hot plug conditions?

The ISL3158A includes hot plug circuitry that keeps the transmitter and receiver outputs in a high impedance state until the VCC supply stabilizes above approximately 3.4V, preventing premature bus activation.

What is the maximum number of devices supported on the bus?

Due to its true 1/8 unit load characteristic, the transceiver allows up to 256 devices on a single RS-485 network without violating the standard's loading specifications.

Does the receiver have a fail-safe feature?

Yes, the receiver features a full fail-safe design that guarantees a logic high output if the inputs are open, shorted, or connected to a terminated but undriven bus.