SN74CBT3245APW

Overview

The SN74CBT3245A is an octal FET bus switch manufactured by Texas Instruments. It provides eight bits of high-speed TTL-compatible bus switching in a standard '245-type pinout configuration. The device operates with a supply voltage range of 4 V to 5.5 V and supports continuous channel currents up to 128 mA. Key electrical characteristics include a typical on-state resistance of 5 Ω at VCC = 5 V, propagation delays as low as 0.25 ns, and input/output voltages compatible with TTL logic levels.

Feature Summary

• Provides bidirectional data transfer between Port A and Port B when the output-enable (OE) input is low.
• Features a low on-state resistance that minimizes signal path delay during active switching.
• Maintains a high-impedance state between ports when OE is high, effectively disconnecting the signal paths.

Applications

• High-speed digital bus switching applications requiring TTL compatibility.
• System architectures utilizing standard '245-type pinout configurations for port expansion.
• Circuit designs necessitating low-propagation-delay signal routing between logic blocks.

Procurement Notes

Verify the specific package variant against the datasheet ordering information, as the PW suffix denotes a TSSOP tube package which is listed as obsolete in recent addendums. Confirm current production status directly with Texas Instruments or authorized distributors before finalizing procurement plans due to potential lifecycle changes.

Selection Notes

Select this component for applications requiring an octal bus switch with a 4 V to 5.5 V operating range. Ensure the design accommodates the required 128 mA continuous channel current capability. Verify that the system's load capacitance aligns with the specified propagation delay parameters for optimal performance.

Part Context

This device belongs to the SN74CBT3245 family of octal FET bus switches. It shares functional similarities with other '245-type transceivers but utilizes FET technology for lower on-resistance and faster switching speeds compared to traditional bipolar implementations.

Replacement Considerations

Check the Package Option Addendum for current availability status. Obsolete parts like the DW and PW packages may require substitution with equivalent active devices from the same family or alternative manufacturers offering similar pinouts and electrical specifications.

FAQ

How does the Output-Enable (OE) pin control the switch?

When OE is low, Port A connects to Port B. When OE is high, the switch opens, creating a high-impedance state between the two ports.

What is the recommended handling for unused control inputs?

All unused control inputs must be held at VCC or GND to ensure proper device operation and prevent undefined states.