74LS165PC

Overview

The National Semiconductor 74LS165PC is an 8-bit parallel-load shift register belonging to the low-power Schottky (LS) logic family. It features asynchronous parallel loading capability, allowing data from eight inputs to be loaded simultaneously when the Parallel Load pin is asserted low. Serial shifting occurs on the rising edge of the clock signal, with new data entering via the serial data input. The device provides complementary outputs from the final stage and includes a two-input OR gate for the clock to combine sources or act as an active-low enable.

Feature Summary

• Asynchronous parallel load functionality for simultaneous data entry
• Serial shifting operation triggered by clock rising edges
• Complementary output configuration at the final stage
• Integrated two-input OR gate for flexible clock management

Applications

• Parallel-to-serial data conversion in digital systems
• Expansion of I/O ports in microcontroller-based designs
• Data acquisition interfaces requiring sequential processing

Procurement Notes

Verify that the specific suffix PC corresponds to the intended plastic DIP package variant. Confirm compatibility with standard LS logic voltage levels and timing requirements. Ensure the component meets RoHS directives if required for the target assembly process. Cross-reference datasheet revisions to confirm pinout consistency with existing schematics.

Selection Notes

Select this component when asynchronous parallel loading is required alongside serial output capabilities. The LS technology offers a balance of speed and power consumption suitable for general-purpose digital applications. Consider the complementary output availability if inverted signals are needed without additional gates. Evaluate board space constraints against the physical dimensions of the plastic DIP package.

Part Context

This part belongs to the widely used 74xx series of logic integrated circuits. The 74LS165 specifically addresses the need for converting parallel data streams into serial formats for transmission or storage. As an LS device, it utilizes Schottky diodes to prevent saturation, ensuring faster switching speeds compared to standard TTL while maintaining lower power dissipation than earlier families.

Replacement Considerations

• SN74LS165
• MM74LS165N