74F161ASC

Overview

The Fairchild Semiconductor 74F161ASC is a high-speed synchronous modulo-16 binary counter belonging to the F/FAST logic series. It features a 4-bit up-counting architecture with synchronous preset capability, allowing data loading on the clock rising edge without overriding the count sequence. The device includes two Count Enable inputs and a Terminal Count output to facilitate synchronous multi-stage expansion. It operates within a supply voltage range of 4.5 V to 5.5 V and supports surface-mount packaging.

Feature Summary

• Synchronous counting and parallel loading mechanism
• High-speed synchronous expansion via terminal count output
• Asynchronous master reset input for immediate output clearing

Applications

• Programmable frequency dividers
• Synchronous multi-stage counter construction
• Digital timing and event sequencing circuits

Procurement Notes

Verify component authenticity through official manufacturer channels or authorized distributors. Confirm RoHS compliance status and specific suffix designations against current datasheets. Ensure storage conditions meet moisture sensitivity level requirements prior to assembly. Validate pin compatibility with target PCB footprint specifications.

Selection Notes

Select this component for applications requiring precise synchronous state transitions and high-speed operation within standard TTL voltage levels. Consider the asynchronous reset feature for immediate system initialization needs. Evaluate package availability constraints as surface-mount variants may have limited stock compared to through-hole equivalents in legacy designs.

Part Context

This integrated circuit belongs to the 74F logic family, characterized by bipolar technology for superior speed performance compared to standard 74-series counterparts. The 74F161 variant specifically provides synchronous preset functionality, distinguishing it from ripple counters. It serves as a foundational building block for complex digital systems requiring reliable binary counting operations.

Replacement Considerations

Equivalent parts include Texas Instruments SN74F161ANSR and onsemi MC74F161N. Verify pinout compatibility and electrical characteristics before substitution. Ensure replacement components match the required operating temperature range and supply voltage specifications.