SN74ABT646NT

Buffers, Drivers, Receivers, Transceivers Overview

The SN74ABT646NT is an octal bus transceiver and register with 3-state outputs, manufactured by Texas Instruments. It utilizes EPIC-IIB BiCMOS technology to reduce power dissipation while providing high-drive outputs capable of -32 mA IOH and 64 mA IOL. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports a maximum clock frequency of 125 MHz. It features independent control for data transfer between Bus A and Bus B, including storage capabilities via D-type flip-flops triggered on low-to-high clock transitions. The NT package is a plastic dual in-line configuration.

Buffers, Drivers, Receivers, Transceivers Feature Summary

• Integrates bus transceiver circuits with D-type flip-flops for multiplexed transmission of real-time or stored data.
• Provides high-drive outputs with significant current sourcing and sinking capabilities.
• Includes dedicated select-control inputs to multiplex between stored register data and transparent bus data.
• Features ESD protection exceeding 2000 V per MIL-STD-883C Method 3015.

Buffers, Drivers, Receivers, Transceivers Applications

• Multiplexed transmission of data directly from input buses or internal registers.
• Storage of data from either bus into internal registers during isolation modes.
• Controlled directional data transfer between two distinct 8-bit buses.

Buffers, Drivers, Receivers, Transceivers Procurement Notes

Verify the specific ordering suffix matches the required package type, as the NT designation indicates a plastic DIP package. Confirm that the selected variant aligns with the necessary operating temperature range, noting that the SN74 series is characterized for operation from -40°C to 85°C. Ensure compatibility with the 4.5 V to 5.5 V supply voltage requirements specified in the datasheet.

Buffers, Drivers, Receivers, Transceivers Selection Notes

Select this component when an octal bidirectional bus interface with internal storage is required. The ABT logic family offers a balance of speed and power consumption suitable for 5 V systems. Consider the NT package only if through-hole mounting is mandated by the mechanical design constraints. Verify that the drive strength meets the load requirements of the connected bus lines.

Buffers, Drivers, Receivers, Transceivers Part Context

This device belongs to the SN74ABT646 series of octal bus transceivers and registers. It shares functionality with other packages such as DB, DW, PW, and JT, differing primarily in physical form factor. The SN74ABT646 is part of the Advanced BiCMOS Technology (ABT) line, designed to replace older logic families with lower power and higher performance characteristics.

Buffers, Drivers, Receivers, Transceivers Replacement Considerations

SN74ABT646DB

Buffers, Drivers, Receivers, Transceivers FAQ

How does the device handle data storage during isolation?

When the output-enable (OE) input is high, the device enters isolation mode. In this state, data present at the A or B bus pins can still be stored in the respective internal registers upon the appropriate clock transition, even though the outputs are disabled.

What is the function of the SAB and SBA inputs?

The SAB and SBA inputs are select-control signals used to multiplex the data output. They determine whether the outputs reflect real-time data from the input bus or previously stored data from the internal registers.