ISO7421ED

Overview

The ISO7421ED is a low-power, dual-channel digital isolator from Texas Instruments utilizing capacitive coupling technology. It provides bidirectional signal isolation with a unidirectional data flow configuration of one forward and one reverse channel. The device operates within a supply voltage range of 3V to 5.5V and supports data rates up to 50 Mbps. Key electrical specifications include an insulation voltage of 2500 Vrms, a common-mode transient immunity of 25 kV/µs, and a maximum propagation delay of 11 ns. It functions reliably across an extended temperature range from -40°C to +125°C and is housed in an 8-SOIC package.

Feature Summary

• Capacitive coupling architecture eliminates the need for isolated power supplies
• High common-mode transient immunity ensures reliable signal integrity in noisy environments
• Low quiescent current consumption supports energy-efficient system designs

Applications

• Industrial process control systems requiring galvanic isolation
• Medical equipment needing safe patient isolation barriers
• Power management circuits for monitoring and feedback loops

Procurement Notes

Verify the specific suffix designation against official Texas Instruments documentation to confirm exact performance characteristics and packaging options. Ensure that the selected variant matches the required thermal and electrical specifications for the target application environment. Cross-reference ordering information with authorized distributors to avoid counterfeit components.

Selection Notes

Select this component when high-speed digital isolation is required without the complexity of external isolated power supplies. The ISO7421ED is suitable for applications demanding robust noise immunity and wide operating temperature ranges. Compare its propagation delay and CMTI ratings against alternative isolators to ensure compatibility with system timing constraints.

Part Context

This part belongs to the ISO7421E series of digital isolators designed for general-purpose isolation tasks. It complements other devices in the family by offering a balance of speed, power efficiency, and reliability. The series is intended for use in various interface applications where electrical isolation between different voltage domains is necessary.

Replacement Considerations

Direct substitutes may include other Texas Instruments digital isolators with similar pinouts and specifications, such as variants within the ISO742x family. Verify functional equivalence regarding channel count, data rate, and insulation voltage before substitution.