Texas Instruments SN74LV123ARGYR

Overview

SN74LV123ARGYR from Texas Instruments is a dual retriggerable monostable multivibrator IC with Schmitt-trigger inputs, operating from 2 V to 5.5 V supply, delivering ≤11 ns propagation delay at 5 V, ±1% pulse-duration matching between channels, and programmable output pulse width up to 100% duty cycle via external R/C network - used for edge-sensitive timing control in digital interrupt conditioning and signal debouncing circuits.

For engineers reviewing the SN74LV123ARGYR datasheet, SN74LV123ARGYR pinout, SN74LV123ARGYR application, or SN74LV123ARGYR equivalent, key selection criteria include its retriggerable monostable behavior, Ioff partial-power-down support, mixed-mode voltage interface capability, and VQFN-16 (3.5 mm × 4.0 mm) package suitability for space-constrained embedded timing designs.

Technical Context

The SN74LV123ARGYR integrates two independent monostable multivibrators, each triggered by rising-edge (A=H, B=L), falling-edge (A=L, B=H), or gated logic (A=L, B=H, CLR↑). Pulse duration is set externally via Rext/Cext network with tw = K × RT × CT, where K ≈ 1.0 for CT ≥ 1000 pF. Retriggering occurs with minimum input interval tMIR = 0.30 × tw.

Each channel features separate Cext, Rext/Cext, A, B, and CLR terminals, with complementary Q and Q outputs. Schmitt-trigger inputs on A, B, and CLR tolerate slow transitions and noise; Ioff circuitry disables outputs during power-down to prevent backflow current.

Key Specifications

Pinout & Package

VQFN-16 (RGY) package, 3.5 mm × 4.0 mm body, 0.5 mm pitch, exposed thermal pad - optimized for thermal performance (RθJA = 39°C/W) and PCB area efficiency in compact timing modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G123DBVR and 74AHC123PW, SN74LV123ARGYR uniquely combines dual-channel integration, ±1% pulse matching, Ioff-enabled power-down safety, and VQFN thermal efficiency - making it optimal for space- and reliability-critical embedded timing.

Availability

SN74LV123ARGYR is available at Aetrix Electronics and suitable for AV receivers, desktop PCs or notebook PCs, digital video cameras (DVC), and network attached storage (NAS) requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74LV123ARGYR 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with over 90 years of innovation in precision timing, power management, and signal chain solutions.

The SN74LV123A product line is designed for robust, low-voltage monostable timing in consumer, computing, and industrial systems - emphasizing noise immunity, wide supply flexibility, and seamless integration into mixed-voltage architectures.

FAQ

What is the maximum output pulse duration achievable with SN74LV123ARGYR?

The SN74LV123ARGYR supports output pulse durations from approximately 100 ns up to several milliseconds, determined by external Rext and Cext values using tw = K × RT × CT. With CT = 0.1 µF and RT = 10 kΩ, tw reaches ~1 ms; larger values extend duration further, enabling 100% duty-cycle operation via retriggering. The VQFN package's low parasitic capacitance preserves timing accuracy at extremes.

Does SN74LV123ARGYR support true dual-edge triggering per channel?

Yes - each channel of SN74LV123ARGYR supports three distinct trigger methods: (1) falling edge on A with B held low, (2) rising edge on B with A held high, or (3) gated logic with A low, B high, and CLR rising. This enables flexible edge detection without external logic, and Schmitt-trigger inputs ensure jitter-free response even with slow or noisy signals.

How does the Ioff feature function in SN74LV123ARGYR during system power-down?

In SN74LV123ARGYR, the Ioff circuitry actively disables all outputs when VCC = 0 V, blocking current flow from powered I/O lines into the unpowered device. This prevents damaging back-current through input protection diodes - critical for hot-swap interfaces and multi-rail systems where logic domains power up/down asynchronously.

Can SN74LV123ARGYR be used with 1.8-V input signals while powered from 3.3 V?

Yes - SN74LV123ARGYR supports mixed-mode voltage operation: its Schmitt-trigger inputs accept 1.8-V signals (VIH min = 0.7 × VCC = 2.31 V at 3.3 V) and interpret them correctly, while outputs swing rail-to-rail at 3.3 V. This allows direct interfacing with 1.8-V FPGAs or sensors without level shifters, reducing design complexity and signal integrity risk.

What is the thermal performance advantage of the RGY (VQFN-16) package for SN74LV123ARGYR?

The SN74LV123ARGYR in VQFN-16 (RGY) package achieves RθJA = 39°C/W - significantly lower than SOIC (73°C/W) or TSSOP (64°C/W) variants. This enables higher sustained pulse rates or operation in thermally constrained enclosures without derating, and the exposed thermal pad improves heat transfer to the PCB ground plane for reliable long-term timing stability.