Nexperia USA Inc. 74HC161DB,118

Overview

74HC161DB,118 from Nexperia is a synchronous presettable 4-bit binary counter with asynchronous master reset (MR), internal look-ahead carry, dual count-enable inputs (CEP/CET), and parallel load capability via active-low PE. It operates from 2.0 V to 6.0 V, delivers TC output pulse synchronized to Q0, and supports cascaded n-bit counting in industrial timing and control logic circuits.

For engineers reviewing the 74HC161DB,118 datasheet, 74HC161DB,118 pinout, 74HC161DB,118 application, or 74HC161DB,118 equivalent, key selection criteria include CP-to-TC propagation delay (≤48 ns at VCC = 4.5 V), guaranteed operation from –40 °C to +125 °C, SO16 package compatibility, and precise set-up/hold timing for Dn/PE/CEP/CET inputs.

Technical Context

The 74HC161DB,118 implements four edge-triggered D-type flip-flops with synchronous clocking on the positive-going edge of CP. Its look-ahead carry architecture enables low-latency serial cascading: CET feeds forward to enable TC, which pulses HIGH only when CET = HIGH and Q0–Q3 = HHHH - duration ≈ Q0 HIGH time.

Asynchronous MR overrides all inputs to force Q0–Q3 = L regardless of CP, PE, CEP, or CET state. Parallel loading occurs on the next CP edge when PE = L, independent of CEP/CET levels. Counting requires both CEP and CET = H; hold mode activates when either enable is LOW.

Key Specifications

Pinout & Package

74HC161DB,118 is packaged in SO16 (SOT109-1), a plastic small outline package with 16 leads and 3.9 mm body width. Pin numbering follows standard JEDEC MS-012 orientation with pin 1 index marker.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC161DB,118, the 74HC163DB,118 trades asynchronous reset for synchronous controllability, while SN74HC161N offers identical logic in a through-hole package - choice depends on reset timing requirements and assembly process constraints.

Availability

74HC161DB,118 is available at Aetrix Electronics and suitable for industrial PLC timing modules, serial communication baud rate generators, automated test equipment pattern sequencers, and motor control index pulse counters requiring stable component supply across extended temperature ranges.

Supply support for 74HC161DB,118 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, reliable logic, analog, and discrete components optimized for efficiency and robustness in industrial, automotive, and consumer applications.

The 74HC161DB,118 belongs to Nexperia's 74HC high-speed CMOS logic family, designed specifically for low-power, noise-immune digital control and timing functions in harsh industrial environments.

FAQ

What is the maximum operating frequency of the 74HC161DB,118 at 5.0 V supply?

At VCC = 5.0 V with CL = 15 pF, the maximum clock frequency is 44 MHz per datasheet Table 7. This value reflects the highest guaranteed toggle rate under specified capacitive loading and voltage conditions, enabling use in high-speed digital control loops where minimal propagation delay is critical.

Can the 74HC161DB,118 be used with a 3.3 V microcontroller GPIO driving its clock input?

Yes - the 74HC161DB,118 accepts VIH ≥ 2.1 V and VIL ≤ 1.35 V at VCC = 4.5 V, and its CMOS input structure ensures compatibility with 3.3 V logic levels. A 3.3 V GPIO meets VIH margin (2.1 V) with >1.2 V noise immunity, eliminating need for level-shifting circuitry.

How does the TC output behave when CET is held LOW?

When CET = LOW, the TC output remains LOW regardless of counter state. TC only goes HIGH when both CET = HIGH and Q0–Q3 = HHHH. This behavior allows CET to act as a global enable for carry propagation in cascaded configurations, preventing spurious TC pulses during partial counting.

Is the SO16 package of 74HC161DB,118 RoHS compliant and lead-free?

Yes - the 74HC161DB,118 in SOT109-1 (SO16) package complies with RoHS Directive 2011/65/EU and is lead-free per Nexperia's product compliance documentation. The device uses matte tin termination and meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL1) for unlimited floor life at ≤30 °C/60% RH.