SN74HC166DT

Shift Registers Overview

The SN74HC166DT is an 8-bit parallel-load shift register from the Texas Instruments HC logic family, housed in a 16-pin SOIC package. It operates on a supply voltage ranging from 2V to 6V and supports an operating temperature range of -55°C to 125°C. The device features synchronous loading, direct overriding clear, and outputs capable of driving up to 10 LSTTL loads with ±4mA drive at 5V. Typical propagation delay is 13ns, with maximum input current limited to 1μA.

Shift Registers Feature Summary

• Synchronous parallel load capability controlled by the SH/LD input
• Direct overriding asynchronous clear function for immediate reset
• TTL-compatible CMOS inputs allowing direct interface with TTL logic

Shift Registers Applications

• Increasing the number of inputs available to a microcontroller
• Parallel-to-serial data conversion
• Expanding I/O capabilities using simple GPIO pins without communication interfaces

Shift Registers Procurement Notes

Verify that the specific SN74HC166DT variant matches the required 16-pin SOIC package dimensions and thermal characteristics. Confirm the operating temperature range aligns with system requirements, as revisions may affect specifications. Ensure all unused inputs are terminated properly during implementation to prevent undefined states.

Shift Registers Selection Notes

Select this component when an 8-bit shift register with synchronous parallel loading is required within standard CMOS logic families. It is suitable for applications needing to expand microcontroller inputs without complex communication protocols. Consider the wide operating voltage range and high noise immunity provided by the HC series for robust digital signal processing.

Shift Registers Part Context

This device belongs to the SNx4HC166 family of 8-bit parallel-load shift registers manufactured by Texas Instruments. The family includes various packaging options such as SOIC, SSOP, PDIP, and TSSOP. The SN74HC166DT specifically denotes the industrial/commercial grade version in the SOIC-16 surface-mount package, designed for general-purpose digital logic applications.

Shift Registers Replacement Considerations

SN74HC166DRG4

Shift Registers FAQ

How does the SH/LD input control the device operation?

When the SH/LD input is low, parallel data from inputs A through H is loaded synchronously with the clock pulse. When high, the device shifts serial data from the SER input into the register on each rising edge of the clock.

What is the function of the CLR input?

The CLR (Clear) input provides a direct overriding asynchronous reset. When driven low, it resets all internal flip-flops to zero regardless of the clock or other input states.