Nexperia USA Inc. 74HC423D,652

Overview

74HC423D,652 from Nexperia is a dual retriggerable monostable multivibrator IC in SO16 package, providing two independent timing channels with active-HIGH/LOW edge-triggered inputs (1A/1B, 2A/2B), direct active-LOW reset (1RD/2RD), and complementary outputs (1Q/1Q, 2Q/2Q). It supports external REXT–CEXT timing (2 kΩ–1000 kΩ / no capacitor limit), operates from 2.0 V to 6.0 V, and delivers pulse widths from 75 ns (REXT = 5 kΩ, CEXT = 0 pF) up to seconds (via retriggering), used in industrial control timing, debounce circuits, and programmable delay generators.

For engineers reviewing the 74HC423D,652 datasheet, 74HC423D,652 pinout, 74HC423D,652 application, or 74HC423D,652 equivalent, key selection considerations include retriggerable pulse extension capability, Schmitt-trigger input tolerance for slow edges, dual-channel independence, reset-controlled output termination, and SO16 package compatibility with legacy PCB layouts.

Technical Context

The 74HC423D implements two fully independent monostable multivibrators, each with two trigger inputs (nA: negative-edge, nB: positive-edge), one direct reset (nRD: active LOW), and complementary outputs (nQ/nQ). Pulse width is set by external REXT and CEXT on pins nREXT/CEXT and nCEXT, with timing governed by t_W = K × REXT × CEXT (K = 0.45 typ. at VCC = 5.0 V).

Retriggering extends the output pulse indefinitely-each new valid edge on nA or nB restarts the timing cycle before expiry-enabling 100 % duty factor operation. Schmitt-trigger inputs on nA/nB (but not nRD) provide hysteresis (ΔV ≈ 0.8 V at VCC = 4.5 V), ensuring noise immunity against slow-rising/falling signals.

Key Specifications

Pinout & Package

74HC423D,652 is housed in a plastic small outline package (SO16, SOT109-1) with 16 leads, 3.9 mm body width, and gull-wing leads suitable for wave and reflow soldering. The package includes internal clamp diodes on all inputs, enabling safe interfacing to voltages exceeding VCC using current-limiting resistors.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar monostable multivibrator applications.

Compared with 74HC123D,653 and SN74LVC1G123DBVR, the 74HC423D,652 uniquely combines dual-channel retriggerability, wide VCC range, and industrial temperature support in a single SO16 package-making it optimal for robust, multi-event timing in resource-constrained embedded systems.

Availability

74HC423D,652 is available at Aetrix Electronics and suitable for industrial motor control, pushbutton debounce circuits, programmable delay generation, and power sequencing supervision requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HC423D,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 delivering high-performance, reliable logic, discrete, and MOSFET solutions with leadership in efficiency, miniaturization, and quality assurance.

The 74HC423 belongs to Nexperia's 74HC logic family-designed specifically for robust, low-power, high-noise-immunity timing and signal conditioning in industrial, automotive, and consumer applications.

FAQ

What is the minimum external capacitor value required for stable operation?

The datasheet specifies that CEXT has no lower limit, but recommends initiating the device via a reset pulse at power-up when CEXT < 50 pF to prevent spurious output pulses. For reliable timing accuracy and reduced sensitivity to parasitic capacitance, use CEXT ≥ 100 pF with appropriate REXT scaling (e.g., REXT = 10 kΩ for ~0.45 μs nominal pulse width at VCC = 5.0 V).

Can the 74HC423D,652 be used with a 3.3 V supply?

Yes-the 74HC423D,652 is fully specified from 2.0 V to 6.0 V, including 3.3 V operation. At VCC = 3.3 V, VIH is guaranteed ≥ 2.1 V and VIL ≤ 1.35 V, ensuring compatibility with standard 3.3 V CMOS outputs. Propagation delay increases to ~35 ns (typ.), and output drive remains sufficient for most 3.3 V logic loads.

How does retriggering affect the output pulse width?

Retriggering resets the internal timing cycle: each valid edge on nA or nB (depending on edge type) restarts the full REXT–CEXT–determined pulse width from zero. This allows indefinite pulse extension-e.g., holding an enable signal active while a sensor remains asserted-achieving true 100 % duty factor operation unlike non-retriggerable monostables.

Is the SO16 package of 74HC423D,652 RoHS compliant and lead-free?

Yes-Nexperia confirms the 74HC423D,652 in SOT109-1 (SO16) package is RoHS-compliant and lead-free, meeting JEDEC J-STD-020 moisture sensitivity level (MSL) 1 and qualified per JESD22-A110 (thermal shock) and JESD22-A108 (temperature cycling) standards for industrial reliability.