SN74LVC166APWR

Shift Registers Overview

The SN74LVC166APWR is an 8-bit parallel-load shift register from Texas Instruments, housed in a 16-pin TSSOP package. It operates within a supply voltage range of 1.1V to 3.6V and features over-voltage tolerant inputs supporting up to 5.5V independent of VCC. The device provides balanced push-pull outputs with drive strengths of ±24mA at 3.3V, ±8mA at 2.3V, and ±4mA at 1.65V. Maximum propagation delay is 11.2ns at 3.3V, with a maximum clock frequency of 104MHz.

Shift Registers Feature Summary

• Supports partial-power-down modes with back-drive protection via Ioff circuitry
• Includes asynchronous clear input that overrides all other control signals
• Features gated clock inputs allowing flexible clock enable or inhibit functionality

Shift Registers Applications

• Increasing the number of inputs on a microcontroller
• Reading board revision information
• Serial-to-parallel data conversion systems

Shift Registers Procurement Notes

Verify the specific ordering suffix 'PWR' corresponds to the TSSOP-16 package variant. Confirm RoHS compliance status and check for automotive qualification requirements if deploying in harsh environments. Ensure ESD handling protocols are followed during assembly due to CMOS sensitivity.

Shift Registers Selection Notes

Select this component when low-voltage operation below 1.8V is required alongside high-speed shifting capabilities. The over-voltage tolerant inputs simplify interfacing with 5V logic systems without additional level shifters. Consider thermal performance metrics if operating near maximum temperature limits.

Shift Registers Part Context

This part belongs to the SN74LVC166A family of 8-bit parallel-load shift registers. The 'PWR' suffix specifically denotes the Thin-Shrink Small Outline Package (TSSOP) with 16 pins. It shares functional compatibility with other LVC series devices but offers distinct voltage tolerance characteristics compared to standard LVC parts.

Shift Registers Replacement Considerations

SN74LVC166ADWR

Shift Registers FAQ

How does the SH/LD input control data loading?

When SH/LD is low, parallel data inputs A through H are loaded synchronously with the clock pulse. When high, serial data at SER is shifted into the register on each rising clock edge.

What happens to the outputs during partial power-down?

When the supply pin is held at 0V, the Ioff circuitry disables all outputs, preventing them from sourcing or sinking current regardless of applied input voltages.