Nexperia USA Inc. 74HC166DB,118

Overview

74HC166DB,118 from Nexperia is an 8-bit parallel-in/serial-out CMOS shift register with synchronous parallel load, serial shift, and asynchronous master reset. It operates from 2.0 V to 6.0 V, features active-low parallel enable (PE), clock enable (CE), and master reset (MR), and delivers 14 ns propagation delay at 6.0 V - used in industrial I/O expansion, LED matrix controllers, and microcontroller GPIO extender circuits.

For engineers reviewing the 74HC166DB,118 datasheet, 74HC166DB,118 pinout, 74HC166DB,118 application, or 74HC166DB,118 equivalent, this device supports precise timing-critical serial data conversion, low-power synchronous control of multi-bit parallel data, and robust noise-immune operation across -40 °C to +125 °C ambient conditions.

Technical Context

The 74HC166DB,118 implements a synchronous 8-stage shift register with dual input modes: parallel load (triggered on CP rising edge when PE = LOW) and serial shift (enabled when PE = HIGH and CE = LOW). Its asynchronous MR input forces all outputs LOW independent of clock state.

Input clamping diodes allow safe interfacing to voltages exceeding VCC when used with current-limiting resistors. The device uses standard CMOS logic levels, achieves 68 MHz maximum clock frequency at 6.0 V, and maintains full functionality across its specified -40 °C to +125 °C temperature range.

Key Specifications

Pinout & Package

74HC166DB,118 is housed in a 16-pin SSOP (Shrink Small Outline Package) with 0.65 mm lead pitch, body width 4.4 mm, and JEDEC MO-153 compliant outline (SOT338-1). This compact surface-mount package supports high-density PCB layouts and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit parallel-in/serial-out shift register applications.

Compared with 74HC166DB,118, the 74HC165DB,118 omits MR and inverts Q7 - reducing fault tolerance but simplifying board layout; the SN74LV165APWR trades 2.0 V compatibility for superior 3.3 V noise margin and drive capability - making it optimal for modern low-voltage systems where voltage headroom is constrained.

Availability

74HC166DB,118 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, LED matrix row driving, microcontroller GPIO extension, and legacy parallel interface adaptation requiring stable component supply across extended temperature ranges.

Supply support for 74HC166DB,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, discrete, and MOSFET solutions with focus on efficiency, reliability, and miniaturization for industrial, automotive, and consumer markets.

The 74HC166DB,118 belongs to Nexperia's 74HC logic family - engineered for low-power, high-noise-immunity digital interfacing in space-constrained industrial control and embedded systems.

FAQ

What is the function of the MR (Master Reset) pin on the 74HC166DB,118?

The MR pin is an asynchronous active-LOW input that forces all internal flip-flops to reset, driving Q7 LOW immediately - independent of clock, enable, or parallel load states. It guarantees deterministic startup and error recovery in safety-critical sequences, with 17 ns typical propagation delay from MR assertion to Q7 transition at VCC = 4.5 V.

Can the 74HC166DB,118 operate reliably at 2.0 V supply voltage?

Yes - the 74HC166DB,118 is fully specified from 2.0 V to 6.0 V. At 2.0 V, it maintains functional operation with VIH = 1.5 V (min), VIL = 0.5 V (max), and tpd = 150 ns (max) from CP to Q7, enabling use in battery-powered sensors and ultra-low-voltage portable instrumentation.

How does the CE (Clock Enable) pin affect timing behavior?

When CE is HIGH, the CP input is disabled - preventing any register updates regardless of clock edges. When CE transitions LOW while CP is LOW, the next rising edge of CP will trigger shift or load action. This allows precise gating of clock events without introducing metastability risks.

Is the 74HC166DB,118 pin-compatible with other 74HC-series shift registers?

No - the 74HC166DB,118 uses a unique 16-pin SSOP (SOT338-1) footprint and functional pinout. While electrically similar to 74HC165 and 74HC595, it differs in MR placement (Pin 9), PE location (Pin 15), and absence of Q0–Q6 outputs - requiring dedicated PCB layout and firmware mapping.