FSA1259K8X

Overview

The FSA1259K8X is a dual Single-Pole Single-Throw (SPST) analog switch fabricated with sub-micron CMOS technology. It operates within a supply voltage range of 1.65V to 5.50V and features an on-resistance of approximately 1Ω at 4.5V VCC. The device provides power-off isolation, ensuring low leakage when the supply is removed. Key electrical parameters include a maximum turn-on time of 7.5ns at 4.5V and a maximum turn-off time of 17ns for the standard variant. It supports continuous switch currents up to 200mA and peak currents of 400mA. The component is housed in an 8-Lead US8 package and functions across a temperature range of -40°C to +85°C.

Feature Summary

• Power-off isolation capability prevents signal leakage when the supply voltage is zero.
• Ultra-low on-resistance ensures minimal signal attenuation in the conductive state.
• Break-before-make enable circuitry prevents signal overlap during switching transitions.
• Space-saving surface mount packaging facilitates integration into compact electronic designs.

Applications

• Cellular phone signal routing
• Portable media player interface management
• Personal Digital Assistant (PDA) peripheral switching

Procurement Notes

Verify the specific ordering suffix K8X against current manufacturer documentation to confirm packing method and eco-status. Confirm that the standard FSA1259 variant meets input threshold requirements, as the FSA1259A offers reduced thresholds if necessary. Ensure compliance with RoHS directives by checking the official datasheet for environmental status definitions.

Selection Notes

Select the FSA1259K8X for applications requiring low-voltage operation and fast switching speeds. Consider the FSA1259AK8X variant if lower control input voltage thresholds are required for compatibility with specific logic families. Evaluate the 1Ω on-resistance against load conditions to ensure acceptable voltage drop. Verify that the US8 package dimensions fit the available PCB real estate constraints.

Part Context

This component belongs to the FSA1259 series of low-voltage analog switches originally developed by Fairchild Semiconductor, now part of onsemi. The series is designed for portable electronics where power efficiency and small form factors are critical. The K8X suffix specifically denotes the tape and reel packaging configuration for automated assembly processes.

Replacement Considerations

The FSA1259AK8X serves as a direct functional substitute within the same family, distinguished primarily by its select pin input voltage thresholds. Other generic replacements must be evaluated based on matching on-resistance, operating voltage ranges, and package compatibility.