74AHCT164D,112

Shift Registers Overview

The 74AHCT164D,112 is an 8-bit serial-in/parallel-out shift register manufactured by Nexperia. It features two serial data inputs (DSA and DSB) and eight parallel outputs (Q0 to Q7). Data shifts on the LOW-to-HIGH clock transition. The master reset input clears the register when LOW. Inputs are overvoltage tolerant up to 5.5 V. Recommended operating voltage for the AHCT variant is 4.5 V to 5.5 V. It operates from -40 °C to +125 °C in a 14-lead SO plastic small outline package.

Shift Registers Feature Summary

• Features two serial data inputs where either can act as an active HIGH enable for the other.
• Includes a master reset input that forces all outputs LOW independently of other inputs.
• Inputs provide overvoltage tolerance up to 5.5 V for mixed voltage translation.
• All inputs incorporate Schmitt-trigger actions for high noise immunity.

Shift Registers Applications

• Serial-to-parallel data conversion
• Mixed voltage level translation
• Parallel output expansion

Shift Registers Procurement Notes

Verify the specific ordering suffix 'D,112' corresponds to the SO14 package (SOT108-1) and the -40 °C to +125 °C temperature range. Confirm the device is the AHCT version requiring 4.5 V to 5.5 V supply, distinct from the AHC version which supports lower voltages. Ensure compatibility with TTL input levels required by the CT logic family.

Shift Registers Selection Notes

Select this component when TTL-compatible input thresholds are necessary within a CMOS environment. The AHCT series ensures compatibility with standard TTL logic levels while offering CMOS performance characteristics. Verify that the application requires an 8-bit capacity and serial input configuration rather than parallel loading or bidirectional shifting capabilities found in other register families.

Shift Registers Part Context

This part belongs to the 74AHC/AHCT logic family, designed for high-speed CMOS applications. The 'AHCT' designation indicates compatibility with TTL input levels, bridging older logic standards with modern low-power CMOS technology. The 'D' suffix specifies the SO14 surface-mount package, suitable for automated assembly processes in compact electronic designs.

Shift Registers Replacement Considerations

Direct substitutes include the 74AHCT164PW (TSSOP14 package) and 74AHCT164BQ (DHVQFN14 package) from the same manufacturer. Cross-manufacturer equivalents must match the 8-bit serial-in/parallel-out architecture and AHCT voltage/input specifications.

Shift Registers FAQ

How do the two serial data inputs function?

Data enters through DSA or DSB. Either input acts as an active HIGH enable for data entry through the other input, allowing flexible control over data flow into the shift register.

What triggers the data shift operation?

Data is shifted into the register on the LOW-to-HIGH transitions of the clock (CP) input.

How does the master reset input operate?

A LOW signal on the master reset (MR) input clears the register and forces all outputs (Q0 to Q7) LOW, regardless of the state of the clock or data inputs.