MC74HC165AF

Shift Registers Overview

The MC74HC165AF is an 8-bit serial or parallel-input/serial-output shift register manufactured by onsemi. It utilizes high-performance silicon-gate CMOS technology and features a pinout identical to the LS165. The device supports asynchronous parallel loading when the Serial Shift/Parallel Load input is low, and serial shifting on the rising edge of the Clock or Clock Inhibit inputs when that control signal is high. It operates within a voltage range of 2.0 V to 6.0 V for the HC variant.

Shift Registers Feature Summary

• Supports both asynchronous parallel data loading and serial shifting operations via dedicated control inputs.
• Features a dual-input NOR clock configuration allowing independent clock sources or clock inhibit functionality.
• Outputs are directly compatible with CMOS, NMOS, and TTL logic families without additional interface components.

Shift Registers Applications

• Interfacing parallel data buses to serial communication protocols
• Expanding digital input capacity in microcontroller systems
• Data acquisition systems requiring multiplexed input handling

Shift Registers Procurement Notes

Verify the specific suffix (e.g., -Q) against project requirements, as it indicates automotive qualification and unique site controls. Confirm package type availability matches design constraints. Ensure compliance with RoHS and lead-free standards if required. Cross-reference ordering information for tape and reel specifications to match assembly equipment capabilities.

Shift Registers Selection Notes

Select the HC variant for operation between 2.0 V and 6.0 V, or HCT for 4.5 V to 5.5 V applications. Consider the QFN-16 package for compact designs or SOIC/TSSOP for standard surface mount processes. Evaluate propagation delay and maximum clock frequency requirements against system timing constraints at the intended supply voltage.

Shift Registers Part Context

This component belongs to the 74HC series of high-speed CMOS logic devices. It serves as a direct replacement for legacy LS165 parts while offering improved power consumption and noise immunity characteristics typical of modern CMOS technology. The device is part of onsemi's standard product portfolio for general-purpose logic applications.

Shift Registers Replacement Considerations

MC74HC165A/D

Shift Registers FAQ

How does the Serial Shift/Parallel Load input control data entry?

When this input is low, data from the parallel inputs (A-H) is loaded asynchronously into the register. When high, data enters serially via the SA input on the rising edge of the clock.

Can the Clock and Clock Inhibit pins be used simultaneously?

Yes, they function identically as NOR inputs. They can combine two independent clock sources, or one can act as an inhibit signal, provided the inhibit goes high only while the clock is high to avoid double clocking.