Nexperia USA Inc. 74HC194DB,112

Overview

74HC194DB,112 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 29 ns typical propagation delay at 4.5 V with CL = 50 pF - used in digital logic sequencing, data serialization for microcontroller peripherals, and LED display drivers.

For engineers reviewing the 74HC194DB,112 datasheet, 74HC194DB,112 pinout, 74HC194DB,112 application, or 74HC194DB,112 equivalent, key selection criteria include mode-select timing margins (tsu = 6 ns min at VCC = 4.5 V), guaranteed operation across -40 °C to +125 °C, CMOS-level input compatibility, and SSOP16 footprint compatibility with legacy 74HC194 variants.

Technical Context

The 74HC194DB,112 implements four edge-triggered D-type flip-flops with shared clock (CP) and mode-select logic governing data routing between DSL (shift-left serial input), DSR (shift-right serial input), D0–D3 (parallel inputs), and Q0–Q3 (parallel outputs). All mode and data inputs are sampled on the LOW-to-HIGH CP transition.

Its functional table defines five distinct operations: asynchronous reset (MR active LOW), hold (S0 = S1 = LOW), parallel load (S0 = S1 = HIGH), shift-left (S0 = HIGH, S1 = LOW), and shift-right (S0 = LOW, S1 = HIGH). Input clamping diodes enable safe interfacing to voltages exceeding VCC when current-limiting resistors are used.

Key Specifications

Pinout & Package

74HC194DB,112 uses the SOT338-1 (SSOP16) package: plastic shrink small outline, 16 leads, 5.3 mm body width, 0.65 mm lead pitch, and exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC194N and 74HCT194DB,112, the 74HC194DB,112 offers optimal thermal performance in space-constrained SMT designs and superior noise immunity for mixed-signal boards, while retaining full functional equivalence with standard HC logic families.

Availability

74HC194DB,112 is available at Aetrix Electronics and suitable for industrial control panels, LED signage controllers, and embedded communication gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HC194DB,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 focused on high-volume, high-reliability logic, discrete, and MOSFET solutions with leadership in automotive and industrial applications.

The 74HC194 belongs to Nexperia's HC logic family - designed for low-power, noise-immune digital interfacing in resource-constrained embedded systems where predictable timing and wide VCC tolerance are essential.

FAQ

What is the minimum setup time required for S0/S1 inputs before the CP rising edge?

At VCC = 4.5 V, the minimum setup time (tsu) for S0 and S1 is 6 ns prior to the LOW-to-HIGH CP transition, as specified in Table 7. This ensures correct mode latching; violating this margin may cause metastability or incorrect shift/load behavior. The value scales with supply voltage - 14 ns at VCC = 2.0 V and 5 ns at VCC = 6.0 V.

Can 74HC194DB,112 operate reliably at 3.3 V supply?

Yes - the device is fully specified from 2.0 V to 6.0 V, including VIH/VIL thresholds, propagation delay, and fmax at 3.3 V. At 3.3 V, typical tpd is 22 ns and fmax is ~65 MHz (interpolated from 2.0 V/4.5 V data), making it compatible with 3.3 V microcontrollers without level translation.

Is the MR (master reset) pin 5 V tolerant when VCC = 3.3 V?

No - MR is not 5 V tolerant. Absolute maximum rating for any input is VCC + 0.5 V, so at VCC = 3.3 V, MR must remain ≤3.8 V. Exceeding this risks latch-up or permanent damage. Use a series resistor or buffer if driven from 5 V logic.

Does 74HC194DB,112 support hot insertion or live swapping?

No - the device lacks hot-swap protection circuitry. Applying VCC or signals before GND stabilization, or inserting/removing while powered, may cause latch-up due to internal parasitic SCR activation. Always power-cycle with proper sequencing: GND first, then VCC, then signals.