Nexperia USA Inc. 74LVC161DB,112

Overview

74LVC161DB,112 from Nexperia is a synchronous presettable 4-bit binary counter with asynchronous master reset (MR), internal look-ahead carry, and dual count-enable inputs (CEP/CET) for cascading. It operates from 1.2 V to 3.6 V, supports 3.3 V/5 V mixed-voltage interfacing via overvoltage-tolerant inputs (up to 5.5 V), and delivers terminal count (TC) pulse width ≈ Q0 HIGH duration. Used in digital timing control, address sequencing, and multi-stage counter chains in industrial logic systems.

For engineers reviewing the 74LVC161DB,112 datasheet, 74LVC161DB,112 pinout, 74LVC161DB,112 application, or 74LVC161DB,112 equivalent, this device serves as a JEDEC-compliant, temperature-stable (–40 °C to +125 °C) building block for synchronous counting, parallel loading, and ripple-free cascaded counting - critical for deterministic state machines and clock-domain bridging in embedded control.

Technical Context

The 74LVC161DB,112 implements four edge-triggered D-type flip-flops clocked synchronously on the positive-going edge of CP. Its parallel load function (enabled by active-low PE) overrides counting regardless of CEP/CET states, while MR forces Q0–Q3 LOW asynchronously - decoupling reset timing from clock domain constraints.

Look-ahead carry architecture enables deterministic TC generation: TC goes HIGH only when CET = HIGH and all outputs are HHHH (15_dec); TC pulse width matches Q0 HIGH time, allowing precise enable timing for next-stage counters without propagation delay accumulation across stages.

Key Specifications

Pinout & Package

74LVC161DB,112 is packaged in SO16 (SOT109-1), a plastic small outline package with 16 leads and 3.9 mm body width. Pin 1 is MR (asynchronous master reset), pin 2 is CP (positive-edge clock), pins 3–6 are D0–D3 (parallel data inputs), pin 7 is CEP (count enable parallel), pin 8 is GND, pin 9 is PE (parallel enable, active LOW), pin 10 is CET (count enable carry), pins 11–14 are Q3–Q0 (outputs, LSB Q0 at pin 14), pin 15 is TC (terminal count), and pin 16 is VCC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-bit synchronous counter applications.

Compared with 74LVC161DB,112, the 74LVC163DB,112 trades asynchronous reset for synchronous control - improving timing predictability but limiting emergency reset capability; the SN74LV161APW offers identical functionality in a smaller TSSOP package with marginally higher speed, easing layout density without altering system timing behavior.

Availability

74LVC161DB,112 is available at Aetrix Electronics and suitable for industrial PLC timing sequencers, embedded microcontroller address generators, multi-stage cascaded counters, and legacy system voltage translation interfaces requiring stable component supply across extended temperature ranges.

Supply support for 74LVC161DB,112 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global semiconductor expert delivering high-performance logic, analog, and MOSFET solutions optimized for efficiency, reliability, and miniaturization in industrial, automotive, and consumer applications.

The 74LVC161DB,112 belongs to Nexperia's LVC (Low-Voltage CMOS) logic family, designed specifically for robust, low-power, mixed-voltage digital interfacing in space- and energy-constrained embedded systems.

FAQ

What is the function of the TC (terminal count) output?

The TC output goes HIGH only when the counter reaches 15 (binary 1111) AND the CET input is HIGH. Its pulse width equals the HIGH time of Q0, providing a self-timed, glitch-free carry signal to enable the next cascaded counter stage without external logic or delay compensation.

Can 74LVC161DB,112 interface directly with 5 V logic inputs?

Yes - all inputs tolerate up to 5.5 V regardless of VCC (1.2–3.6 V), enabling direct connection to 5 V TTL or CMOS outputs. No level-shifting circuitry is required, simplifying mixed-voltage system design while maintaining signal integrity and timing accuracy.

How does the asynchronous MR differ from synchronous load behavior?

MR forces Q0–Q3 LOW immediately upon assertion, independent of CP, PE, CEP, or CET states - critical for fail-safe reset. In contrast, parallel load occurs only on the next CP↑ edge when PE = LOW, making it clock-synchronous and predictable within the system timing domain.

Is Schmitt-trigger input action enabled on all pins?

Yes - all inputs (MR, CP, D0–D3, PE, CEP, CET) feature Schmitt-trigger action, providing hysteresis that rejects noise and accommodates slow-rising signals (e.g., from mechanical switches or long PCB traces), eliminating external RC filtering in many applications.