Nexperia USA Inc. 74AHCT123APW,118

Overview

74AHCT123APW,118 from Nexperia is a dual retriggerable monostable multivibrator with independent reset inputs, TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V), 16-pin TSSOP package, and operating range of −40 °C to +125 °C. It generates programmable output pulses via external REXT/CEXT networks and supports pulse extension via edge-triggered retriggering on either A or B inputs - used in timing control for industrial PLC I/O modules, sensor signal conditioning, and digital debounce circuits.

For engineers reviewing the 74AHCT123APW,118 datasheet, 74AHCT123APW,118 pinout, 74AHCT123APW,118 application, or 74AHCT123APW,118 equivalent, key selection criteria include TTL-level input compatibility, dual independent monostable operation with direct reset, retriggerable pulse extension up to 100% duty cycle, and guaranteed operation across automotive-grade temperature extremes.

Technical Context

This device implements two independent monostable circuits, each with separate negative-edge (nA) and positive-edge (nB) trigger inputs, active-low direct reset (nRD), and complementary outputs (nQ, nQ). Pulse width t_W is set by external REXT and CEXT components per channel, with typical values ranging from 100 ns (CEXT = 28 pF, REXT = 2 kΩ) to 1.15 ms (CEXT = 0.1 μF, REXT = 10 kΩ) at VCC = 5.0 V.

Each monostable supports retriggering during an active output pulse to extend duration indefinitely, and immediate termination via LOW-going edge on nRD. Inputs feature Schmitt-trigger action and overvoltage tolerance up to 5.5 V, enabling mixed-voltage interfacing without level shifters.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1), 16 leads, body width 4.4 mm, 0.65 mm pitch, 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 74AHC123APW,118 and SN74LV123APWR, the 74AHCT123APW,118 uniquely balances TTL compatibility, automotive temperature range, and retriggerable flexibility - making it optimal for industrial control upgrades where legacy interface integrity and extended thermal reliability are mandatory.

Availability

74AHCT123APW,118 is available at Aetrix Electronics and suitable for industrial motor control, sensor interface timing, and digital signal debounce applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74AHCT123APW,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 logic, discrete, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74AHCT series targets robust, drop-in replacements for legacy TTL logic in industrial and automotive applications - emphasizing wide temperature operation, noise immunity, and interoperability with existing 5 V systems.

FAQ

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

The datasheet specifies no lower limit for CEXT, but stable operation requires ≥10 nF for predictable t_W = REXT × CEXT behavior. Values below 10 nF increase sensitivity to stray capacitance and reduce timing accuracy; 28 pF is used only for minimum-delay characterization (t_W ≈ 100 ns), not general design.

Can both monostable channels be triggered simultaneously without crosstalk?

Yes - channels are fully independent with separate timing networks, inputs, and outputs. No internal coupling exists between Channel 1 and Channel 2; simultaneous triggering produces concurrent, non-interfering output pulses with identical timing characteristics.

How does the Schmitt-trigger input affect switch debounce performance?

Schmitt-trigger inputs provide ≥0.5 V hysteresis, eliminating multiple transitions from slow-rising mechanical switch signals. This ensures a single, clean edge triggers the monostable - removing the need for external RC filtering or firmware-based debouncing algorithms.

Is the exposed thermal pad on the TSSOP16 package electrically connected?

No - the exposed pad on SOT403-1 (TSSOP16) is not electrically connected and has no internal bond. It may remain floating or be soldered to GND for thermal improvement, but no electrical function is assigned to it per Nexperia's package documentation.