ISO124UE4

Overview

The ISO124UE4 is a precision isolation amplifier from Texas Instruments, housed in an 8-lead SOIC package. It features a rated continuous isolation voltage of 1500 Vrms and undergoes 100% testing for high-voltage breakdown at 2400 Vac. The device operates with a supply range of ±4.5 V to ±18 V and provides a signal bandwidth of 50 kHz. Key electrical characteristics include a maximum nonlinearity of 0.010%, an input offset voltage of 20 mV, and a common-mode rejection ratio of 140 dB at 60 Hz.

Feature Summary

• Utilizes duty-cycle modulation-demodulation technique for digital signal transmission across a capacitive barrier.
• Fixed unity gain configuration eliminates the need for external components for basic operation.
• High common-mode rejection ratio ensures excellent reliability and transient immunity across the isolation barrier.

Applications

• Industrial process control transducer isolators
• Isolation for thermocouples, RTDs, pressure bridges, and flow meters
• Ground loop elimination in measurement systems
• Motor and SCR control circuits
• PC-based data acquisition systems

Procurement Notes

Verify the specific suffix 'E4' corresponds to lead-free and RoHS compliance requirements for your assembly process. Confirm that the SOIC-28 package dimensions match your PCB footprint design. Ensure the operating temperature range of -25°C to +85°C aligns with your environmental specifications. Check for any recent product lifecycle notices regarding availability or obsolescence status before finalizing procurement plans.

Selection Notes

Select this component when a fixed unity gain isolation amplifier is required for precision analog signals. It is suitable for applications demanding high common-mode rejection and galvanic isolation up to 1500 Vrms. Consider the 50 kHz bandwidth limit when processing higher frequency signals. Evaluate power supply constraints as it requires dual supplies within the specified range for optimal performance.

Part Context

The ISO124 belongs to Texas Instruments' family of precision isolation amplifiers designed for industrial applications. It integrates both input and output sections on opposite ends of the package with embedded isolating capacitors. This architecture allows for robust signal transmission without external isolation components, distinguishing it from optocoupler-based solutions by offering superior linearity and stability.

Replacement Considerations

ISO124U/1K

FAQ

How does the ISO124 handle input frequencies above its Nyquist limit?

For input signals above 250 kHz, the device behaves like a sampling amplifier, generating aliasing effects where the output signal appears at a reduced magnitude below 250 kHz.

What is the purpose of the partial discharge test mentioned in the datasheet?

The 100% partial discharge test at 2400 Vac confirms transient overvoltage protection capability without damaging the device, ensuring barrier reliability beyond the rated 1500 Vrms.