SN74CBT3245ADGVR

Overview

The SN74CBT3245ADGVR is an octal FET bus switch manufactured by Texas Instruments, housed in a 20-pin TVSOP (DGV) package. It operates within a supply voltage range of 4 V to 5.5 V and supports an operating temperature range from -40°C to +85°C. The device provides eight bits of high-speed TTL-compatible bus switching with a standard '245-type pinout. Key electrical characteristics include a maximum on-state resistance of 15 Ω at VCC = 5 V and VI = 2.4 V, and a typical propagation delay of 0.25 ns at VCC = 5 V.

Feature Summary

• Provides eight bits of high-speed bidirectional data transfer between two ports.
• Features low on-state resistance for minimal signal propagation delay.
• Maintains TTL-compatible input levels for broad logic interface compatibility.
• Ensures high-impedance state during power-up or power-down via OE control.

Applications

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

Procurement Notes

Verify the specific ordering suffix to confirm the package type and moisture sensitivity level. Confirm RoHS compliance status as indicated in the manufacturer's documentation. Ensure that unused control inputs are properly terminated to VCC or GND to maintain device reliability and prevent undefined states during operation.

Selection Notes

Select this component when an octal bus switch with standard '245 pinout is required. Consider the TVSOP package constraints for board space. Evaluate the 4 V to 5.5 V supply voltage range against system requirements. Assess the thermal impedance characteristics if operating near the upper temperature limits.

Part Context

This part belongs to the SN74CBT3245A family of octal FET bus switches. It shares functional similarities with other variants such as the SN74CBT3245ADBR and SN74CBT3245APW, differing primarily in packaging and manufacturing revisions. The device is designed for general-purpose digital bus switching tasks.

Replacement Considerations

The SN74CBT3245ADBR is listed as a recommended replacement offering identical functionality in an SSOP package. Verify pinout compatibility and package dimensions before substitution to ensure mechanical fit on the printed circuit board.

FAQ

How does the output-enable (OE) pin control the switch state?

When the OE input is low, the switch connects port A to port B. When OE is high, the switch disconnects the ports, resulting in a high-impedance state between them.

What is the purpose of tying OE to VCC through a pullup resistor?

Tying OE to VCC through a pullup resistor ensures the device enters a high-impedance state during power-up or power-down, preventing unintended data transmission while supply voltages are unstable.