Nexperia USA Inc. 74HC194D,652

Overview

74HC194D,652 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,652 datasheet, 74HC194D,652 pinout, 74HC194D,652 application, or 74HC194D,652 equivalent, key selection criteria include mode-select timing margins (tsu = 6 ns min at VCC = 4.5 V), bidirectional serial path isolation (DSR/DSL independent of parallel load), MR asynchronous assertion behavior, and SSOP16 thermal derating above 91 °C.

Technical Context

The 74HC194D,652 implements four synchronous flip-flops with shared clock (CP) and mode-select logic that routes DSR→Q0→Q1→Q2→Q3 (shift right), DSL→Q3→Q2→Q1→Q0 (shift left), or parallel D0–D3→Q0–Q3 (load). All mode and data inputs are edge-triggered on CP's LOW-to-HIGH transition.

Asynchronous MR forces Q0–Q3 LOW regardless of CP or mode state; input clamp diodes allow interfacing to voltages beyond VCC using current-limiting resistors. Operation is validated across -40 °C to +125 °C with static VIH/VIL thresholds defined at 2.0 V, 4.5 V, and 6.0 V supply levels.

Key Specifications

Pinout & Package

74HC194D,652 is housed in SSOP16 (SOT338-1): plastic shrink small outline package, 16 leads, 5.3 mm body width, 0.65 mm lead pitch, and 1.80 mm max height.

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,652 offers optimal thermal performance in surface-mount layouts and lowest static power draw-making it preferred for space-constrained industrial controllers where long-term reliability and self-heating are critical.

Availability

74HC194D,652 is available at Aetrix Electronics and suitable for industrial automation, test equipment, and embedded display subsystems requiring stable component supply, long-lifecycle support, and guaranteed SSOP16 packaging consistency.

Supply support for 74HC194D,652 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 specializing in high-performance logic, analog, and MOSFET solutions, with manufacturing rooted in process control and automotive-grade quality systems.

The 74HC logic family delivers robust CMOS performance across wide voltage and temperature ranges, designed specifically for industrial control, instrumentation, and reliable digital interfacing where noise immunity and timing predictability are essential.

FAQ

What is the minimum setup time required for S0/S1 inputs relative to the CP rising edge at 5 V supply?

At VCC = 5.0 V, the minimum setup time (tsu) for S0 and S1 is 15 ns prior to the LOW-to-HIGH CP transition, as specified in Table 7 of the datasheet. This ensures reliable mode capture before clocking; violating this margin risks metastability or incorrect functional mode execution.

Can DSR and DSL be driven simultaneously during a shift operation?

No-DSR and DSL are mutually exclusive inputs per shift cycle. The mode control (S0/S1) selects only one serial path: S0=1,S1=0 enables DSL→Q3 shift-left; S0=0,S1=1 enables DSR→Q0 shift-right. Driving both concurrently has no defined behavior and may cause bus contention or invalid output states.

Does the 74HC194D,652 support hot insertion or live-state configuration changes?

No. Mode inputs (S0/S1) and data inputs (Dn, DSR, DSL) must remain stable for the full tsu period before CP's rising edge. Changing S0/S1 mid-operation without observing setup/hold timing violates the functional table and may result in undefined output transitions or skipped states.

Is the MR pin 5 V tolerant when VCC = 3.3 V?

Yes. Input clamp diodes allow MR to accept voltages up to VCC + 0.5 V safely. With VCC = 3.3 V, MR tolerates up to 3.8 V. For 5 V logic driving MR, a series current-limiting resistor (e.g., 1 kΩ) is required to limit IIK to ±20 mA per Absolute Maximum Ratings (Table 4).