74FST3245DTR2

Overview

The 74FST3245 is an 8-bit high-performance bus switch manufactured by onsemi. It operates within a supply voltage range of 4.0 V to 5.5 V and exhibits CMOS/TTL compatibility. The device provides bidirectional data transmission between Port A and Port B when the Output Enable (OE) pin is low, entering a high-impedance state when OE is high. Key electrical characteristics include a maximum propagation delay of 0.25 ns and a typical on-resistance (RON) of 4 Ω at 4.5 V. Quiescent supply current is typically 3 µA.

Feature Summary

• Provides bidirectional switching for 8-bit data buses with minimal signal distortion
• Features extremely low on-resistance and negligible propagation delay
• Control inputs are compatible with both TTL and CMOS logic levels
• Inherently adds no noise or ground bounce to the system during operation

Applications

• High-speed parallel data bus switching in computer systems
• Level translation between different voltage domains operating between 4.0 V and 5.5 V
• Buffering and driving high-capacitance loads on data lines

Procurement Notes

Verify the specific package suffix (DT for TSSOP-20, DW for SOIC-20, QS for QSOP-20) against the required footprint. Confirm that the application environment remains within the -40°C to +85°C operating temperature range. Ensure all control inputs are tied to valid logic levels rather than left open to prevent undefined states.

Selection Notes

Select this component for applications requiring fast switching speeds and low insertion loss. The device is suitable where space is constrained due to available compact packages like TSSOP-20. Verify that the load capacitance does not exceed the specified limits to maintain the guaranteed propagation delay performance.

Part Context

This part belongs to the FST (Fast Switching Technology) family of bus switches. It serves as a direct replacement for similar devices such as the QS3245, FST3245, and CBT3245, offering pin-for-pin compatibility while delivering high-speed performance characteristics suitable for modern digital interfaces.

Replacement Considerations

The datasheet explicitly lists pin-for-pin compatibility with the QS3245, FST3245, and CBT3245. These parts can be substituted directly without circuit redesign.