FST34X245QSPX

Overview

The Fairchild FST34X245QSPX is a high-speed CMOS bus switch providing 32 bits of data transfer in a standard flow-through configuration. It operates within a supply voltage range of 4V to 5.5V and features TTL-compatible inputs. The device integrates four independent circuits, each configured as an 8-bit wide 1:1 switch, totaling 32 channels. Packaged in an 80-pin QVSOP (QSOP) surface-mount housing, it supports asynchronous operation with low on-resistance characteristics suitable for high-frequency signal routing.

Feature Summary

• Provides 32-bit high-speed CMOS bus switching capability
• Features TTL-compatible input logic levels
• Integrates four independent 8-bit 1:1 switching circuits
• Operates with a single power supply ranging from 4V to 5.5V

Applications

• High-speed data bus isolation and switching
• Signal routing in telecommunications equipment
• Data acquisition systems requiring bidirectional transfer
• Computer peripheral interface buffering

Procurement Notes

Verify the specific suffix 'QSPX' against the manufacturer's current datasheet to confirm package type and tape-and-reel specifications. Ensure compatibility with RoHS directives if required by your assembly process. Cross-reference the pinout diagram with your PCB layout to prevent orientation errors during surface-mount placement. Confirm that the operating temperature range meets your environmental design constraints.

Selection Notes

Select this component when a dense, high-channel-count bus switch is required for 32-bit parallel data paths. The 80-pin QSOP package offers a compact footprint for space-constrained designs. Ensure the system voltage remains within the 4V to 5.5V window to maintain signal integrity. Consider the propagation delay specifications if timing margins are critical for your synchronous or asynchronous interfaces.

Part Context

This device belongs to the Fairchild Switch family of high-speed CMOS bus switches. It is designed to replace older TTL-based switching solutions with lower power consumption and faster switching speeds. The part is manufactured by Fairchild Semiconductor, which has since become part of onsemi, ensuring continued support through updated documentation and manufacturing processes.

Replacement Considerations

Check for direct equivalents such as the FST34X245 without the 'QSPX' suffix if leaded versions are acceptable. Verify pin-to-pin compatibility with other 80-pin bus switches from manufacturers like NXP or Texas Instruments before substitution. Ensure that the replacement part maintains the same 4V-5.5V operating voltage range and 32-bit channel count.