74AC161MTCX

Overview

The onsemi 74AC161MTCX is a high-speed synchronous modulo-16 binary counter housed in a 16-lead Thin Shrink Small Outline Package (TSSOP). It operates within a supply voltage range of 2.0V to 6.0V and supports an operating temperature from -40°C to +85°C. The device features D-type edge-triggered flip-flops with parallel data inputs (P0–P3) and outputs (Q0–Q3). Key electrical characteristics include a typical count rate of 125 MHz, output drive capability sourcing or sinking 24 mA, and reduced quiescent current. It includes asynchronous Master Reset and synchronous parallel load functions.

Feature Summary

• Synchronous presettable architecture allowing programmable division and multistage expansion via Terminal Count output.
• Asynchronous Master Reset input that overrides all other control signals to force outputs LOW.
• High-speed synchronous expansion capabilities utilizing dedicated Count Enable Parallel and Trickle inputs.

Applications

• Programmable frequency dividers
• Synchronous multistage counter systems
• Digital timing and sequencing circuits

Procurement Notes

Verify the TSSOP-16 package configuration and the 'X' suffix indicating tape and reel packaging. Confirm the AC logic family specifications against ACT requirements if TTL-compatible inputs are necessary for the target application. Ensure the design accounts for the asynchronous reset precedence over synchronous loading and counting modes.

Selection Notes

Select this component for applications requiring high-speed synchronous counting within a compact surface-mount footprint. The 74AC series offers lower power consumption compared to older technologies while maintaining high clock frequencies. Consider the specific setup and hold times relative to the clock pulse width when designing the control logic interface.

Part Context

This part belongs to the 74AC logic family, representing high-speed CMOS technology. The 'MTC' designation specifies the 16-lead TSSOP physical package, while the 'X' suffix denotes tape and reel shipping. It is functionally compatible with other 74AC161 variants differing only in package type or shipping method.

Replacement Considerations

CD74AC161E Texas Instruments

FAQ

How does the Master Reset input interact with other control signals?

The Asynchronous Master Reset (MR) input has the highest precedence. A LOW signal on MR overrides all other inputs, including Parallel Enable and Count Enables, forcing all outputs LOW immediately without waiting for a clock edge.

What is the function of the Terminal Count (TC) output?

The TC output goes HIGH when the counter reaches state 15 and CET is HIGH. It facilitates synchronous multistage counter designs by providing a carry signal that can trigger the next stage's counting enable inputs.