SN74ALS166DE4

Shift Registers Overview

The SN74ALS166DE4 is a parallel-load 8-bit shift register from the Texas Instruments ALS logic family. It operates within a supply voltage range of 4.5 V to 5.5 V and supports clock frequencies up to 45 MHz. The device features buffered inputs, input clamping diodes, and an overriding clear function. It is characterized for operation between 0°C and 70°C.

Shift Registers Feature Summary

• Supports synchronous parallel loading and serial shifting operations via dedicated control inputs.
• Features gated clock functionality allowing independent clock enable or inhibit control.
• Includes direct overriding clear to reset all flip-flops regardless of other active inputs.

Shift Registers Applications

• Parallel-to-serial data conversion circuits
• Serial-to-parallel data conversion systems
• Digital sequence generation applications

Shift Registers Procurement Notes

Verify the specific ordering suffix 'E4' against current manufacturer documentation to confirm environmental compliance status and material specifications. Confirm package availability as standard variants may have different lifecycle statuses. Ensure the component meets the required operating temperature range for the intended application environment.

Shift Registers Selection Notes

Select this component when designing with ALS logic families requiring buffered inputs and low drive requirements. Consider the asynchronous clear feature for system reset needs. Evaluate the maximum clock frequency limits against the system timing requirements to ensure reliable data shifting performance.

Shift Registers Part Context

This part belongs to the SN74ALS166 series of parallel-load 8-bit shift registers manufactured by Texas Instruments. The 'D' suffix indicates a Small-Outline (SOIC) package, while 'E4' denotes lead-free and RoHS-compliant materials. It is designed for compatibility with most other TTL logic families.

Shift Registers Replacement Considerations

Check for SN74ALS166DR or SN74ALS166DBR equivalents in tape-and-reel packaging if volume manufacturing is required. Verify that alternative packages maintain the same pinout and electrical characteristics for direct board replacement.

Shift Registers FAQ

How does the SH/LD input control the register mode?

When SH/LD is high, the register accepts serial data at the SER input. When SH/LD is low, parallel data on inputs A through H is loaded synchronously on the next clock pulse.

What is the function of the CLK INH input?

The CLK INH input works with the CLK input through a positive-NOR gate. Holding either input high inhibits clocking, while holding either low enables the other input to function as the clock source.