Nexperia USA Inc. 74HC161PW-Q100J

Overview

74HC161PW-Q100 from Nexperia is an AEC-Q100 Grade 1 qualified, synchronous 4-bit binary counter with asynchronous master reset (MR), parallel load capability via active-low PE, dual count-enable inputs (CEP/CET), and look-ahead carry output (TC). It operates from 2.0 V to 6.0 V across –40 °C to +125 °C and delivers up to 48 MHz maximum clock frequency at VCC = 6.0 V. Used in automotive timing control, odometer logic, and gear-position encoding systems.

For engineers reviewing the 74HC161PW-Q100 datasheet, 74HC161PW-Q100 pinout, 74HC161PW-Q100 application, or 74HC161PW-Q100 equivalent, key selection considerations include its asynchronous clear behavior, TC pulse width matching Q0 high time, cascading support via CEP/CET, and automotive-grade thermal and ESD robustness (HBM >2000 V, CDM >1000 V).

Technical Context

This device implements four edge-triggered D-type flip-flops with synchronous counting, parallel loading, and asynchronous reset-ensuring deterministic state initialization independent of clock or enable states. Its look-ahead carry architecture enables low-latency serial cascading: TC asserts only when CET = HIGH and Q0–Q3 = HHHH, with propagation delay as low as 20 ns (VCC = 6.0 V).

The dual count-enable structure separates gating (CEP) from carry propagation (CET), allowing precise control over counting vs. terminal-count generation. Inputs feature CMOS-level thresholds (VIH ≥ 3.15 V @ VCC = 4.5 V) and integrated clamp diodes for overvoltage tolerance with current-limiting resistors.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1); 16-pin, 4.4 mm body width; lead pitch 0.65 mm; RoHS-compliant, halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC161PW-Q100, the 74HC163PW-Q100 trades asynchronous reset for synchronous control-critical in metastability-sensitive pipelines-while the SN74LV161APWRE4 offers speed and voltage flexibility at the cost of automotive qualification and different input threshold behavior.

Availability

74HC161PW-Q100 is available at Aetrix Electronics and suitable for automotive engine control units, instrument cluster electronics, transmission control modules, and ADAS camera synchronization circuits requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HC161PW-Q100 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 automotive, industrial, and mobile applications.

The 74HC161PW-Q100 belongs to Nexperia's automotive-qualified HC logic family, designed specifically for robust, low-power timing and sequencing functions in safety-critical vehicle subsystems.

FAQ

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

The TC output goes HIGH only when CET = HIGH and the counter reaches its maximum value (Q0–Q3 = HHHH). Its pulse width approximates the HIGH time of Q0, making it ideal for triggering the next stage in a cascaded counter chain without external timing components. TC does not assert during parallel load or reset operations.

Can 74HC161PW-Q100 operate at 3.3 V supply?

Yes. The device is fully specified from 2.0 V to 6.0 V, including 3.3 V. At VCC = 3.3 V, typical propagation delay is ~30 ns (CP to Qn), VIH is 2.31 V minimum, and VOL remains ≤0.26 V at 4 mA sink-ensuring reliable interfacing with 3.3 V microcontrollers and FPGAs.

How does the asynchronous MR differ from synchronous reset in similar counters?

MR forces Q0–Q3 = LLL immediately upon going LOW, irrespective of CP, PE, CEP, or CET states. This enables guaranteed power-on initialization or emergency stop without waiting for a clock edge-unlike synchronous reset variants (e.g., 74HC163) that require a clock transition to take effect.

Is external pull-up required on PE or MR pins?

No. Both PE and MR are active-LOW inputs with standard CMOS input structure; they must be driven actively to LOW for function activation. Leaving them unconnected results in indeterminate (floating) logic levels. Use pull-up resistors (e.g., 10 kΩ to VCC) only if default HIGH state is required in absence of driving logic.