Nexperia USA Inc. 74HC194D,653

Overview

74HC194D,653 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 alignment, and bus interface buffering.

For engineers reviewing the 74HC194D,653 datasheet, 74HC194D,653 pinout, 74HC194D,653 application, or 74HC194D,653 equivalent, key selection criteria include mode-select timing margins (tsu = 6 ns min at VCC = 4.5 V), MR pulse width (16 ns min), CP frequency capability (93 MHz typ), and dual-direction serial expansion compatibility with DSR/DSL isolation.

Technical Context

The 74HC194D,653 implements four edge-triggered D-type flip-flops with shared clock (CP) and mode-select logic governing data routing between parallel inputs (D0–D3), serial inputs (DSR, DSL), and outputs (Q0–Q3). Its function table defines five discrete operational states-reset, hold, parallel load, shift-left, and shift-right-each determined solely by S0/S1 levels prior to the LOW-to-HIGH CP transition.

All inputs are CMOS-level compatible with VIH ≥ 3.15 V and VIL ≤ 1.35 V at VCC = 4.5 V; outputs drive ±4.0 mA with VOH ≥ 3.98 V and VOL ≤ 0.26 V under same conditions. The device includes input clamp diodes enabling safe interfacing to voltages exceeding VCC when current-limiting resistors are used.

Key Specifications

Pinout & Package

74HC194D,653 is housed in a plastic shrink small outline package (SSOP16), SOT338-1, with 16 leads and 5.3 mm body width. Pin pitch is 0.65 mm; total package dimensions are 6.4 mm × 5.4 mm × 1.25 mm (L × W × H).

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 74HCT194D,653, the 74HC194D,653 provides optimal balance of surface-mount compactness, wide-voltage interoperability, and CMOS noise immunity - making it preferred for modern embedded designs requiring mixed-supply compatibility and thermal efficiency.

Availability

74HC194D,653 is available at Aetrix Electronics and suitable for industrial PLCs, microcontroller peripheral expansion, digital audio synchronization, and legacy bus interface buffering requiring stable component supply across extended temperature ranges.

Supply support for 74HC194D,653 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, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74HC194D,653 belongs to Nexperia's HC logic family, engineered for low-power, high-noise-immunity digital interfacing in space-constrained and thermally demanding applications.

FAQ

What is the minimum setup time (tsu) for mode inputs S0/S1 at 4.5 V supply?

The minimum setup time for S0 and S1 relative to the LOW-to-HIGH clock transition is 6 ns at VCC = 4.5 V, as specified in Table 7 of the datasheet. This value ensures reliable sampling of mode state before the clock edge and must be met in PCB layout routing and MCU GPIO timing configuration.

Can 74HC194D,653 operate reliably at 2.0 V supply?

Yes - the device is fully characterized down to 2.0 V, with propagation delay increasing to 145 ns (typ) and fmax dropping to 6.9 MHz (min) at that voltage. Input thresholds scale proportionally (VIH = 1.5 V min), preserving noise margin above 0.5 V in low-power battery systems.

Is the master reset (MR) pin truly asynchronous?

Yes - MR overrides all other inputs including CP, S0/S1, and data lines. When pulled LOW, it forces Q0–Q3 to LOW within 28 ns (typ) at VCC = 4.5 V, irrespective of clock phase or previous register state, satisfying strict functional safety requirements for deterministic reset behavior.

How does DSL differ from DSR in cascaded configurations?

DSL feeds data into Q3 for left-shift operations, while DSR feeds into Q0 for right-shift. In multistage chains, DSL of one device connects to Q0 of the next to extend leftward shift paths, and DSR of one connects to Q3 of the prior to extend rightward paths - enabling seamless bidirectional data flow without mode reconfiguration.