SN74ALS166DR

Shift Registers Overview

The SN74ALS166DR is a parallel-load 8-bit shift register from the ALS logic family, housed in a 16-pin SOIC package. It operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating temperature range of 0°C to 70°C. The device features a maximum clock frequency of 45 MHz, with propagation delays ranging from 2 ns to 14 ns depending on the signal path. It includes asynchronous clear, gated clock inputs, and input clamping diodes for transient suppression.

Shift Registers Feature Summary

• Supports parallel-to-serial conversion via synchronous loading or serial shifting modes controlled by the SH/LD input.
• Features a direct overriding clear (CLR) input that sets all flip-flops to zero regardless of other control signals.
• Incorporates buffered inputs with clamping diodes to minimize switching transients and reduce drive requirements.

Shift Registers Applications

• Parallel-to-serial data conversion systems
• Serial-in/parallel-out data routing
• Digital pulse generation circuits

Shift Registers Procurement Notes

Verify the specific ordering suffix 'DR' corresponds to the SOIC package and tape-and-reel quantity of 2500 units. Confirm RoHS compliance status and lead finish details against the latest Package Option Addendum. Ensure the component meets the specified commercial temperature range of 0°C to 70°C for your application environment.

Shift Registers Selection Notes

Select this component when designing with the ALS logic family for its speed and power characteristics. Ensure the system operates strictly within the 4.5 V to 5.5 V supply voltage limits. Verify that the required clock frequency does not exceed the 45 MHz maximum rating. Consider the 16-pin SOIC footprint constraints during PCB layout.

Shift Registers Part Context

This part belongs to the SN74ALS166 series of parallel-load 8-bit shift registers. It is compatible with most other TTL logic families. The 'DR' suffix specifically denotes the plastic small-outline (D) package configuration. It serves as a digital storage element for sequential logic applications requiring serial data handling.

Shift Registers Replacement Considerations

Compatible substitutes include SN74ALS166N (PDIP), SN74ALS166DBR (SSOP), and SN74ALS166NSR (SOP). These variants share identical electrical specifications and pinouts but differ in physical package dimensions and reel quantities.

Shift Registers FAQ

How is the shift/load mode determined?

The mode is established by the SH/LD input. When high, the device shifts serial data; when low, it synchronously loads parallel data on the next clock pulse.

What is the function of the CLK INH input?

The CLK INH input acts as a clock inhibit. Holding either clock input high inhibits clocking, while holding it low enables the other clock input.