Nexperia USA Inc. 74HC194DB,118

Overview

74HC194DB,118 from Nexperia is a 4-bit bidirectional universal shift register in SSOP16 package, supporting synchronous parallel load, left/right serial shift, and hold modes via S0/S1 control. It operates from 2.0 V to 6.0 V, features asynchronous master reset (MR), and delivers 25 ns typical propagation delay at 6.0 V - used in digital logic sequencing, data serialization for microcontroller peripherals, and LED pattern controllers.

For engineers reviewing the 74HC194DB,118 datasheet, 74HC194DB,118 pinout, 74HC194DB,118 application, or 74HC194DB,118 equivalent, key selection criteria include mode-select timing margins, CP-to-Q propagation at target VCC, MR pulse width compliance, and SSOP16 thermal derating above 91 °C.

Technical Context

The 74HC194DB,118 implements four edge-triggered D-type flip-flops with shared clock (CP) and mode-select logic governing data routing between DSL/DSR inputs and Q0–Q3 outputs. Its function table defines five distinct operations - reset, hold, shift-left, shift-right, and parallel load - all synchronized to the LOW-to-HIGH CP transition.

Inputs are CMOS-level compatible with VIH ≥ 3.15 V (at VCC = 4.5 V) and VIL ≤ 1.35 V; output drive capability is ±4.0 mA at VOH/VOL specifications, and internal clamp diodes allow safe interfacing to voltages beyond VCC using current-limiting resistors.

Key Specifications

Pinout & Package

74HC194DB,118 is housed in SOT338-1 (SSOP16): plastic shrink small outline package, 16 leads, 5.3 mm body width, 0.65 mm lead pitch, and 1.03 mm max height - optimized for high-density PCB layouts with improved thermal dissipation vs. SOIC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-bit bidirectional shift register applications.

Compared with SN74HC194N, the 74HC194DB,118 offers superior thermal performance and PCB density; versus 74HCT194DB,118, it provides tighter noise immunity and lower static power at the cost of TTL input compatibility.

Availability

74HC194DB,118 is available at Aetrix Electronics and suitable for industrial control panels, embedded sensor interfaces, and LED display drivers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HC194DB,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 focused on high-volume, high-reliability logic, discrete, and MOSFET solutions - serving automotive, industrial, and consumer markets with ISO/TS 16949-certified manufacturing.

The 74HC194 belongs to Nexperia's 74HC logic family, engineered for robustness in industrial automation and instrumentation where wide VCC tolerance, ESD resilience, and extended temperature operation are mandatory.

FAQ

What is the minimum clock pulse width required for reliable operation of 74HC194DB,118 at 6.0 V?

The minimum CP HIGH and LOW pulse width is 17 ns each at VCC = 6.0 V, per Table 7. This ensures sufficient time for internal logic evaluation and flip-flop state capture. Violating this spec risks metastability or skipped clock edges, especially under worst-case temperature and process corners.

Can 74HC194DB,118 operate with a 3.3 V supply while maintaining full functionality?

Yes - the device is fully specified from 2.0 V to 6.0 V. At 3.3 V, propagation delay increases to ≤44 ns (−40 °C to +125 °C), VIH is 2.31 V min, and VOL remains ≤0.33 V at 4.0 mA sink, ensuring compatibility with 3.3 V LVTTL and LVCMOS interfaces without level shifters.

How does the asynchronous master reset (MR) interact with ongoing shift operations?

MR overrides all other inputs immediately upon going LOW, forcing Q0–Q3 to LOW within tPHL ≤36 ns (VCC = 4.5 V). This occurs independently of CP, S0/S1, or data inputs - making it suitable for hard-reset scenarios like power-on initialization or fault recovery without waiting for clock alignment.

Is there any restriction on mixing serial and parallel operations within a single clock cycle?

Yes - mode selection (S0/S1) and data inputs (Dn, DSR, DSL) must be stable for ≥15 ns before the LOW-to-HIGH CP transition at VCC = 6.0 V. Attempting to change mode and inject new serial data in the same cycle violates setup timing and may result in undefined output states per the function table.