Texas Instruments 74LVC1G123DCURG4

Overview

74LVC1G123DCURG4 from Texas Instruments is a single retriggerable monostable multivibrator with Schmitt-trigger inputs, designed for 1.65 V to 5.5 V operation. It delivers programmable output pulse durations (ns to ms range) via external R/C network, supports mixed-mode voltage translation, and features glitch-free power-up reset and I_off protection. It is used in switch debouncing, timing control, and edge-sensitive event capture in portable and embedded systems.

For engineers reviewing the 74LVC1G123DCURG4 datasheet, 74LVC1G123DCURG4 pinout, 74LVC1G123DCURG4 application, or 74LVC1G123DCURG4 equivalent, this page provides verified functional identity, validated VSSOP-8 package mapping, confirmed Schmitt-trigger input hysteresis, real-world timing behavior across 1.65–5.5 V, and two technically documented alternative parts with explicit functional and application-level differences.

Technical Context

The 74LVC1G123DCURG4 implements a retriggerable monostable architecture where output pulse width is externally set by R_ext and C_ext, with three distinct trigger modes (A↓/B↑, B↑/A↓, A↓/B↑/CLR↑). Its dual-edge-sensitive inputs (A active-low, B active-high) incorporate Schmitt-trigger circuitry with ≥0.3×V_CC hysteresis, enabling jitter-free response to slow-rising/falling signals.

It supports partial-power-down via I_off (≤±10 µA at 5.5 V), operates across –40°C to +125°C, and achieves t_pd ≤ 8 ns at 3.3 V with CL = 15 pF. The Rext/Cext terminal serves as a bidirectional node connecting both timing components, requiring no direct tie to V_CC or GND per design rules.

Key Specifications

Pinout & Package

74LVC1G123DCURG4 is packaged in an 8-pin VSSOP (DCU) with body size 2.30 mm × 2.00 mm, optimized for space-constrained PCB layouts while maintaining standard surface-mount assembly compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G123DBVR and MC74VHC1G123DTT1G, the 74LVC1G123DCURG4 uniquely combines VSSOP-8 packaging with full 8-pin timing interface, 8 ns propagation delay, –40°C to +125°C operation, and I_off-enabled live insertion-making it the only option meeting industrial and automotive timing integrity requirements without layout or thermal compromise.

Availability

74LVC1G123DCURG4 is available at Aetrix Electronics and suitable for switch debouncing, power sequencing, reset generation, and edge-sensitive event capture requiring stable component supply across industrial, automotive, and embedded computing programs.

Supply support for 74LVC1G123DCURG4 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 logic solutions, with decades of expertise in precision timing, low-power design, and automotive-grade qualification.

The SN74LVC1G123 series was developed to deliver compact, retriggerable timing functionality for space- and power-constrained systems-targeting portable electronics, industrial controls, and automotive infotainment where reliable, jitter-free pulse generation is critical.

FAQ

What is the maximum output pulse duration achievable with the 74LVC1G123DCURG4?

The 74LVC1G123DCURG4 supports output pulse durations from ~100 ns up to several milliseconds, depending on selected R_ext and C_ext values. With R_ext = 10 kΩ and C_ext = 0.1 µF, typical pulse width is 1 ms at 1.8 V; scaling to 100 kΩ and 1 µF extends duration beyond 10 ms. The device allows 100% duty cycle via continuous retriggering, making it suitable for sustained enable signals.

Does the 74LVC1G123DCURG4 support operation at 1.8 V supply voltage?

Yes, the 74LVC1G123DCURG4 is fully specified for 1.65 V to 5.5 V operation, including stable performance at 1.8 V. At this voltage, it delivers t_pd ≤ 18.5 ns (CL = 15 pF), maintains VIH/VIL thresholds compliant with 1.8 V logic families, and supports I_off protection-making it ideal for modern ultra-low-voltage microcontroller peripherals and battery-powered devices.

Can the 74LVC1G123DCURG4 be used to debounce a mechanical switch?

Yes, the 74LVC1G123DCURG4 is explicitly designed for switch debouncing. Its Schmitt-trigger inputs reject noise from contact bounce, and its retriggerable monostable mode ensures the output remains asserted throughout the entire bounce period. With R_ext = 10 kΩ and C_ext = 0.1 µF, it generates a clean 1 ms pulse-longer than typical switch bounce duration (<100 µs)-eliminating firmware-level debounce overhead.

What is the function of the Rext/Cext pin on the 74LVC1G123DCURG4?

The Rext/Cext pin on the 74LVC1G123DCURG4 is a bidirectional node that connects internally to both the timing capacitor (C_ext) and external resistor (R_ext). It forms the RC network that determines output pulse duration. Per TI design rules, this pin must never be tied directly to V_CC or GND; instead, R_ext connects between Rext/Cext and V_CC, while C_ext connects between Rext/Cext and the dedicated Cext pin.

Is the 74LVC1G123DCURG4 compatible with 5 V input signals while operating at 3.3 V VCC?

Yes, the 74LVC1G123DCURG4 accepts input voltages up to 5.5 V regardless of V_CC level-a feature called mixed-mode voltage translation. When V_CC = 3.3 V, A, B, and CLR inputs tolerate 5 V signals without damage or level-shifting circuitry. This allows direct interfacing with legacy 5 V peripherals while powering the device from a modern 3.3 V rail.