FSTD3125MX

Overview

The FSTD3125MX is a 4-bit bus switch with level shifting capabilities manufactured by Fairchild Semiconductor. It features four high-speed CMOS TTL-compatible switches, each with separate output enable inputs. The device provides low on-resistance for minimal propagation delay and reduced ground bounce noise. It operates within an extended temperature range of -40°C to +85°C and is housed in a lead-free SSOP package.

Feature Summary

• Provides four independent one-bit switches with separate control inputs
• Enables level shifting between different voltage domains
• Ensures minimal propagation delay through the switch path
• Reduces ground bounce noise due to low on-resistance

Applications

• Connecting two ports with different logic voltage levels
• High-speed data bus switching applications
• System board signal routing and isolation

Procurement Notes

Verify the specific suffix 'MX' against official Fairchild documentation to confirm the exact packing method and reel specifications. Ensure the component matches the required RoHS compliance standards and lead-free JEDEC J-STD-020B requirements. Confirm the operating temperature range aligns with system design constraints before procurement.

Selection Notes

Select this component when bidirectional level shifting is required for four-bit wide buses. It is suitable for interfacing between TTL-compatible devices operating at different supply voltages. Consider the SSOP package dimensions and pin count for PCB layout compatibility. Verify that the low on-resistance meets the signal integrity requirements of the target application.

Part Context

This part belongs to the FST series of digital bus switches from Fairchild Semiconductor. It shares functional similarities with other members of the family but includes integrated level shifting capabilities. The device is designed to replace older discrete solutions for bus switching and voltage translation tasks in modern electronic systems.

Replacement Considerations

Check for direct substitutes such as the FSTD3125 or FSTD3125M. Verify pinout compatibility and electrical characteristics before substitution.