Nexperia USA Inc. 74HC123DB,112

Overview

74HC123DB,112 from Nexperia is a dual retriggerable monostable multivibrator with independent reset inputs, operating across 2.0 V to 6.0 V supply. Each channel provides programmable pulse width via external R_EXT/C_EXT, supports edge-triggered retriggering (nA/nB), and features direct LOW-going reset (nRD). It delivers 75 ns minimum pulse width (REXT = 5 kΩ, CEXT = 0 pF) and operates from –40 °C to +125 °C in SO16 package - used in timing control, debounce, and pulse extension circuits.

For engineers reviewing the 74HC123DB,112 datasheet, 74HC123DB,112 pinout, 74HC123DB,112 application, or 74HC123DB,112 equivalent, this page provides verified functional behavior, validated SO16 pin mapping, confirmed retrigger timing (110 ns min), real-world power-up/power-down mitigation guidance, and cross-referenced alternatives for industrial timing designs.

Technical Context

The device implements two independent CMOS monostable circuits, each with Schmitt-trigger inputs on nA/nB (enabling tolerance to slow edges), clamped inputs for overvoltage interface, and separate active-LOW reset (nRD) that terminates output pulses asynchronously. Pulse width is determined by external R_EXT/C_EXT networks connected to pins 7/15 (2REXT/CEXT, 1REXT/CEXT) and 6/14 (2CEXT, 1CEXT).

Retriggering extends the output pulse period indefinitely - e.g., at VCC = 5.0 V with REXT = 5 kΩ and CEXT = 0 pF, t_W ≥ 75 ns and t_rtrig = 110 ns - while reset propagation delay is as low as 19 ns (VCC = 6.0 V). The SO16 package (SOT109-1) supports industrial thermal range (–40 °C to +125 °C) and meets JESD78 Class II Level B latch-up immunity (>100 mA).

Key Specifications

Pinout & Package

74HC123DB,112 is supplied in SO16 plastic small outline package (SOT109-1), 16-pin, 3.9 mm body width, with gull-wing leads and pin 1 index marker. Thermal resistance θ_JA = 80.6 K/W (JEDEC Std 22-A104); P_tot derates linearly at 12.4 mW/K above 110 °C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HCT123DB,112 and SN74LV123ADR, the 74HC123DB,112 uniquely combines wide supply range, Schmitt-trigger noise immunity, and industrial temperature rating - making it optimal for robust timing in mixed-voltage industrial controls.

Availability

74HC123DB,112 is available at Aetrix Electronics and suitable for industrial motor drives, automotive body controllers, and medical diagnostic equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HC123DB,112 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 discrete components - serving automotive, industrial, and consumer markets with ISO/TS 16949-certified manufacturing.

The 74HC123 belongs to Nexperia's High-Speed CMOS logic family, designed specifically for robust, low-power timing and waveform shaping in harsh-environment embedded systems.

FAQ

What is the minimum external capacitor value supported for stable pulse width generation?

The datasheet specifies stable operation down to CEXT = 0 pF (with REXT = 5 kΩ), yielding t_W ≥ 75 ns. For CEXT < 50 pF, a power-up reset pulse is mandatory per Section 11.2. Practical designs use ≥100 pF to ensure monotonic timing and reduce sensitivity to parasitic capacitance.

Can both monostable channels share the same REXT/CEXT network?

No - each channel requires dedicated REXT and CEXT components. Pins 7/15 (2REXT/CEXT, 1REXT/CEXT) and 6/14 (2CEXT, 1CEXT) are electrically isolated. Shared components would cause crosstalk and unpredictable pulse widths due to internal node coupling.

How does the reset input (nRD) interact with ongoing retriggering?

An active LOW on nRD immediately terminates the output pulse regardless of retrigger activity - nQ goes LOW and nQ goes HIGH within t_pd ≤ 19 ns (VCC = 6.0 V). Retrigger edges arriving during reset assertion are ignored until nRD returns HIGH.

Is the SO16 package (SOT109-1) RoHS-compliant and lead-free?

Yes - 74HC123DB,112 conforms to RoHS Directive 2011/65/EU and uses lead-free matte tin terminal finish. The SOT109-1 package is qualified per JEDEC J-STD-020 moisture sensitivity level 1 (unlimited floor life at ≤30 °C/85 % RH).