SN74ALS563BNSR

Overview

The SN74ALS563BNSR is an octal D-type transparent latch from the Texas Instruments ALS logic family, housed in a 20-pin SOIC package. It features three-state outputs designed for driving bus lines directly. The device operates with a supply voltage range of 4.5 V to 5.5 V and supports a commercial temperature range of 0°C to 70°C. Propagation delays are specified between 3 ns and 29 ns depending on the signal path and load conditions.

Feature Summary

• Transparent latch operation allows Q outputs to follow complemented D inputs while latch-enable is high
• Three-state outputs provide high-impedance isolation without requiring external pullup components
• Buffered output-enable input controls normal logic states or high-impedance bus isolation independently of internal latching

Applications

• Implementing buffer registers in digital systems
• Serving as I/O ports for data interface
• Functioning as bidirectional bus drivers
• Acting as working registers within memory architectures

Procurement Notes

Verify the specific ordering suffix 'SR' corresponds to the SOP (NS) tape-and-reel packaging configuration. Confirm that the component meets RoHS standards and matches the required operating temperature range for the intended application environment before finalizing procurement.

Selection Notes

Select this component when designing systems requiring octal data storage with direct bus interfacing capabilities. The ALS series offers faster switching speeds compared to standard TTL equivalents. Ensure the design accommodates the specific setup and hold time requirements relative to the latch-enable signal transitions.

Part Context

This part belongs to the SN54/74ALS563B family of octal transparent latches. It is functionally similar to other ALS-series logic devices but specifically optimized for bus-driven applications. The device provides eight independent latches with complementary outputs and controlled three-state buffering.

Replacement Considerations

SN74ALS563BDW

FAQ

How does the latch-enable input affect the output state?

When the latch-enable input is high, the outputs follow the complements of the data inputs. When taken low, the outputs are latched at the inverse of the levels present at the data inputs.

What is the purpose of the buffered output-enable input?

The buffered output-enable input places the eight outputs into either a normal logic state or a high-impedance state, allowing the outputs to neither load nor drive bus lines significantly.