FST3125QSC

Overview

The FST3125QSC is a digital bus switch IC manufactured by Fairchild Semiconductor, which was acquired by ON Semiconductor. It contains four high-speed CMOS TTL-compatible bus switches organized as four one-bit switches with separate output enable inputs. The device provides low on-resistance connections between ports to minimize propagation delay and ground bounce noise.

Feature Summary

• Provides four independent high-speed CMOS bus switches compatible with TTL logic levels
• Features low on-resistance for minimal signal degradation and reduced ground bounce
• Includes separate output enable controls for each switch channel

Applications

• High-speed data bus switching applications
• Portable systems requiring low power consumption
• Consumer electronics utilizing TTL-compatible logic interfaces

Procurement Notes

Verify the manufacturer origin carefully, as the FST3125 series originates from Fairchild Semiconductor prior to its acquisition by ON Semiconductor. Ensure the specific suffix QSC matches the required SSOP-16 package and lead-free compliance specifications documented in the original Fairchild datasheet. Confirm that the component meets current RoHS standards as indicated in historical documentation.

Selection Notes

Select this component when designing circuits requiring isolated bidirectional switching between different voltage domains or buses. The TTL compatibility allows direct interfacing with standard logic families without additional level shifting. Consider the SSOP-16 package constraints for PCB layout and thermal management requirements during the design phase.

Part Context

This part belongs to the FST3125 family of digital bus switches derived from Fairchild's proven switch technology. The family includes variants such as FST3125M and FST3125MX, sharing similar functional characteristics but differing in package types and packing methods. The technology underpins related products like the FST3384 bus switch.

Replacement Considerations

Direct substitutes include other FST3125 variants such as FST3125M or FST3125MX if package differences are acceptable. Cross-reference with equivalent 4-bit bus switches from other manufacturers ensuring matching pinouts, voltage levels, and on-resistance specifications.