Nexperia USA Inc. 74HC123PW,118

Overview

74HC123PW,118 from Nexperia is a dual retriggerable monostable multivibrator in TSSOP16 package, operating from 2.0 V to 6.0 V supply, with Schmitt-trigger inputs (1A/1B/2A/2B), independent reset (1RD/2RD), and externally programmable pulse width via R_EXT/C_EXT networks. It delivers precise timing control for edge-sensitive pulse extension in digital logic systems, supporting applications such as debouncing, delay generation, and event synchronization.

For engineers reviewing the 74HC123PW,118 datasheet, 74HC123PW,118 pinout, 74HC123PW,118 application, or 74HC123PW,118 equivalent, this device offers verified retriggerable pulse extension up to 100% duty factor, direct asynchronous reset termination, and robust noise immunity across -40 °C to +125 °C industrial temperature range - critical for reliable timing in embedded control and instrumentation circuits.

Technical Context

The 74HC123PW,118 implements two independent monostable circuits, each with dual edge-triggered inputs (negative-edge on nA, positive-edge on nB) and a dedicated reset input (nRD) that terminates output pulses asynchronously on LOW-going transitions. Each monostable supports retriggering during an active output pulse, enabling indefinite pulse extension without external logic.

Timing is set by external R_EXT/C_EXT pairs connected to pins 15/14 (Channel 1) and 7/6 (Channel 2); typical pulse width at 5 V is 75 ns (REXT = 5 kΩ, CEXT = 0 pF) and scales to ~450 μs (REXT = 10 kΩ, CEXT = 100 nF). Schmitt-trigger action on all trigger inputs ensures tolerance to slow-rising/falling signals, while clamp diodes allow safe interfacing to voltages exceeding V_CC.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1), 16-pin, body width 4.4 mm, lead pitch 0.65 mm, exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HCT123PW,118, the 74HC123PW,118 offers superior noise immunity on trigger inputs but requires CMOS-level signals; versus SN74LV123APWR, it trades lower voltage flexibility for robust Schmitt-trigger operation and wider industrial temperature support.

Availability

74HC123PW,118 is available at Aetrix Electronics and suitable for switch debouncing, event synchronization, PWM gate control, and power-up sequencing requiring stable component supply across automotive, industrial, and test equipment design cycles.

Supply support for 74HC123PW,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 delivering high-performance, reliable logic, discrete, and MOSFET solutions with focus on efficiency, reliability, and sustainability.

The 74HC123 product line targets robust, low-power digital timing functions in industrial automation, automotive subsystems, and consumer electronics - emphasizing retriggerable flexibility, wide supply range, and extended temperature qualification.

FAQ

What is the minimum external timing capacitor value supported for stable operation?

The datasheet specifies stable operation down to C_EXT = 0 pF (with R_EXT = 5 kΩ), yielding a minimum pulse width of 75 ns at V_CC = 6.0 V. For C_EXT < 50 pF, a power-up reset pulse is recommended to avoid spurious outputs. Pins 6 and 14 (2CEXT/1CEXT) should be externally grounded to minimize noise coupling.

Can both monostable channels be triggered simultaneously without interference?

Yes - Channels 1 and 2 are fully independent. Triggering 1A and 2A simultaneously produces concurrent, non-interacting output pulses. Pin 15 (1REXT/CEXT) and pin 7 (2REXT/CEXT) are electrically isolated, and no shared internal nodes exist between channels, ensuring deterministic timing behavior under simultaneous operation.

How does the reset input (nRD) interact with an ongoing retriggered pulse?

A LOW-going edge on nRD terminates the current output pulse immediately, regardless of retrigger activity or remaining time. The monostable enters reset state (nQ = HIGH, nQ = LOW) and remains inactive until the next valid trigger edge occurs on nA or nB - no race conditions or metastability are observed per functional table.

Is the TSSOP16 package (SOT403-1) RoHS-compliant and lead-free?

Yes - the 74HC123PW,118 is manufactured in full compliance with RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. The TSSOP16 package uses lead-free matte tin terminal finish and halogen-free molding compound, certified per Nexperia's material declarations.