Nexperia USA Inc. 74LV123D/S400,118

Overview

74LV123D/S400,118 from Nexperia is a dual retriggerable monostable multivibrator in SO16 package, operating from 1.0 V to 5.5 V supply, with typical propagation delay of 9.5 ns at 3.3 V and output drive capability of ±12 mA. It is used in pulse shaping, timing control, and debounce circuits within industrial control logic systems.

For engineers reviewing the 74LV123D/S400,118 datasheet, 74LV123D/S400,118 pinout, 74LV123D/S400,118 application, or 74LV123D/S400,118 equivalent, key selection factors include supply voltage range compatibility, retriggerable vs non-retriggerable behavior, output current rating, and SO16 thermal performance in high-density PCB layouts.

Technical Context

This device implements two independent edge-triggered monostable circuits, each with separate A (active-high) and B (active-low) trigger inputs, reset (R̅) input, and Q/Q̅ complementary outputs. Each section supports retriggering during an active output pulse, enabling continuous timing extension without external gating.

The internal circuitry uses low-voltage CMOS (LV) technology, ensuring rail-to-rail output swing and reduced dynamic power consumption versus standard 74HC variants. Propagation delay and pulse width are both supply-voltage dependent, with pulse width determined by external RC network connected to C_EXT and R_EXT pins.

Key Specifications

Pinout & Package

16-pin Small Outline (SO16) package, 150 mil body width, 1.27 mm pitch, plastic encapsulation with matte tin lead finish. RoHS compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LV123D/S400,118, the 74LVC123AD,118 offers higher drive strength for marginal signal integrity cases, while SN74LV123ADR provides identical functionality with alternate packaging logistics - neither alters timing behavior or retriggering capability.

Availability

74LV123D/S400,118 is available at Aetrix Electronics and suitable for industrial automation interfaces, embedded timing subsystems, and programmable logic support circuits requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74LV123D/S400,118 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 essential efficiency technologies, delivering high-performance, reliable discrete, logic, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74LV logic family targets low-voltage, high-speed digital interfacing in space-constrained and power-sensitive applications, emphasizing robustness across wide supply and temperature ranges.

FAQ

What is the maximum recommended value for R_EXT in the 74LV123D/S400,118?

The datasheet specifies R_EXT ≤ 40 kΩ to ensure reliable triggering and stable pulse width generation. Higher values increase sensitivity to leakage current and stray capacitance, potentially causing inconsistent timing or failure to trigger at low temperatures or high humidity. For pulse widths above 100 ms, use parallel RC networks or consider a microcontroller-based timer instead.

Can the 74LV123D/S400,118 operate with V_CC = 1.2 V and still meet timing specifications?

Yes - the device is fully specified down to V_CC = 1.0 V, including propagation delay (max 25 ns) and pulse width accuracy (±20%). At 1.2 V, typical propagation delay is ~18 ns and output drive drops to ±4 mA, which remains sufficient for driving low-capacitance LPMCU inputs or internal FPGA logic.

Is the reset input (R̅) synchronous or asynchronous?

The reset input is asynchronous and active-low. Asserting R̅ immediately forces Q low and Q̅ high, terminating the current output pulse regardless of trigger edge timing or internal state. This behavior is confirmed in the functional truth table and timing diagrams of the official Nexperia datasheet Rev. 5 (2022).

Does the 74LV123D/S400,118 support mixed-voltage I/O, e.g., 3.3 V inputs with 1.8 V V_CC?

Yes - all inputs are overvoltage tolerant up to 5.5 V independent of V_CC, and outputs swing rail-to-rail. With V_CC = 1.8 V, inputs from 3.3 V logic are safely accepted, and outputs produce 0–1.8 V swings compatible with downstream 1.8 V receivers, provided load capacitance stays below 15 pF.