ISO7731DW

Overview

The ISO7731DW is a high-speed, robust EMC reinforced triple-channel digital isolator from Texas Instruments. It features two unidirectional channels in the forward direction and one reverse channel. The device provides enhanced insulation ratings of 5000 Vrms per UL 1577 standard for the DW package. It supports data rates up to 100 Mbps with a typical propagation delay of 11 ns at 5 V supply. The operating supply voltage range is 2.25 V to 5.5 V. It operates within a temperature range of -55°C to +125°C and offers a typical common-mode transient immunity (CMTI) of ±100 kV/µs.

Feature Summary

• Enhanced isolation barrier providing 5000 Vrms rating compliant with UL 1577 standards
• Robust electromagnetic compatibility (EMC) performance reducing system-level compliance requirements
• Configurable default output states for input power or signal loss scenarios
• Enable pins allow outputs to be placed in high-impedance state for multi-master applications

Applications

• Isolating CMOS or LVCMOS digital I/O interfaces
• Preventing noise current entry into local ground in sensitive circuits
• Multi-master driving applications requiring configurable output states
• Systems requiring high common-mode transient immunity

Procurement Notes

Verify the specific suffix indicates the standard non-F variant which defaults outputs high upon signal loss, unless an F suffix is explicitly required for low-default behavior. Confirm the DW package designation corresponds to the 16-pin wide SOIC form factor. Ensure the procurement order matches the exact part number including all relevant qualification and packaging codes to avoid functional mismatches regarding default output states or thermal ranges.

Selection Notes

Select this component when enhanced isolation voltage of 5000 Vrms is required alongside high-speed data transmission up to 100 Mbps. It is suitable for designs needing robust EMC performance to minimize external filtering. Consider the enable pin functionality if multi-master bus architectures are employed. Verify that the 2.25 V to 5.5 V supply range aligns with the system's logic levels and that the -55°C to +125°C temperature range meets environmental specifications.

Part Context

This device belongs to the ISO773x family of triple-channel digital isolators. The ISO7731 variant specifically distinguishes itself by offering a mixed direction configuration with two forward and one reverse channel, unlike the ISO7730 which has all three channels in the same direction. The DW package variant provides the highest insulation rating within the series.

Replacement Considerations

Direct replacements within the same family include ISO7730DW for identical channel directions or ISO7732DW for different direction configurations. Cross-family alternatives may exist but require verification of isolation ratings and CMTI specifications.