Texas Instruments SN74LV123ATPWRG4Q1

Overview

SN74LV123ATPWRG4Q1 from Texas Instruments is a dual retriggerable monostable multivibrator with Schmitt-trigger inputs, designed for automotive applications operating from 2 V to 5.5 V. It delivers programmable output pulse durations up to milliseconds via external R/C networks, supports mixed-mode voltage operation on all ports, and features glitch-free power-up reset and overriding clear functionality. Used in infotainment systems and ADAS for edge-triggered timing control.

For engineers reviewing the SN74LV123ATPWRG4Q1 datasheet, SN74LV123ATPWRG4Q1 pinout, SN74LV123ATPWRG4Q1 application, or SN74LV123ATPWRG4Q1 equivalent, key selection considerations include retriggerable pulse width control (up to 100% duty cycle), automotive-grade AEC-Q100 qualification (–40°C to +125°C), Schmitt-trigger input noise immunity, Ioff partial-power-down support, and dual-channel independent timing.

Technical Context

The SN74LV123ATPWRG4Q1 implements two independent positive-logic monostable multivibrators, each configurable for rising-edge (A=H, B=L, CLR↑), falling-edge (A↓, B=L), or gated-edge (A=L, B↑) triggering. Each channel uses external Rext and Cext components to set pulse duration (tw = K × Rext × Cext), with K varying by Cext value and supply voltage.

Schmitt-trigger inputs on A, B, and CLR provide hysteresis for robust operation with slow or noisy signals; Ioff circuitry disables outputs during power-down to prevent backflow current; propagation delay is ≤16 ns at 3.3 V and ≤11 ns at 5 V across temperature.

Key Specifications

Pinout & Package

TSSOP-16 package (5.00 mm × 4.40 mm), thermally optimized for automotive PCB layouts with exposed pad not present; RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV123ATPWRG4Q1, SN74LVC1G123DBVRQ1 saves board space but sacrifices channel density, while MC74VHC123ADR2G omits automotive qualification and Ioff - making SN74LV123ATPWRG4Q1 the sole choice for dual-channel, AEC-Q100-compliant, power-aware automotive timing.

Availability

SN74LV123ATPWRG4Q1 is available at Aetrix Electronics and suitable for automotive infotainment systems, advanced driver assistance systems (ADAS), and vehicle body electronics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LV123ATPWRG4Q1 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 company specializing in analog and embedded processing technologies, with leadership in automotive, industrial, and communications markets.

The SN74LV123A-Q1 belongs to TI's automotive-qualified logic portfolio, engineered specifically for timing-critical functions in harsh-temperature automotive subsystems including body control, lighting, and human-machine interface.

FAQ

What is the maximum output pulse duration achievable with SN74LV123ATPWRG4Q1?

The SN74LV123ATPWRG4Q1 supports output pulse durations up to several milliseconds - for example, 1.1 ms with Rext = 10 kΩ and Cext = 0.1 µF at 5 V. The theoretical upper limit depends on leakage and stability of external components, but practical designs reliably achieve ≥1 ms. Retriggering allows indefinite extension, enabling 100% duty cycle operation when needed for continuous enable signals.

Does SN74LV123ATPWRG4Q1 require external pull-up or pull-down resistors on unused inputs?

Yes - all unused inputs (A, B, CLR) of SN74LV123ATPWRG4Q1 must be held at VCC or GND to prevent floating states that cause excessive ICC, erratic triggering, or increased EMI. TI explicitly recommends this in the datasheet (SCLS467F, Section 6.2 Note 1) to ensure reliable operation across the full –40°C to +125°C automotive temperature range.

How does the Schmitt-trigger input on SN74LV123ATPWRG4Q1 improve noise immunity?

The Schmitt-trigger inputs on SN74LV123ATPWRG4Q1 provide built-in hysteresis (typically 0.3×VCC), allowing clean edge detection even with slow-rising/falling or noisy signals - such as those from mechanical switches or long PCB traces. This eliminates need for external RC filters or firmware debouncing, directly improving timing accuracy and system robustness in electrically noisy automotive environments.

Can SN74LV123ATPWRG4Q1 operate with different supply voltages on its inputs and outputs?

Yes - SN74LV123ATPWRG4Q1 supports mixed-mode voltage operation: inputs tolerate 0–5.5 V regardless of VCC level (2–5.5 V), enabling direct interface with higher-voltage sensors or legacy 5 V peripherals while powered from a 3.3 V rail. Outputs swing rail-to-rail (0 to VCC), maintaining compatibility with downstream logic at the same VCC.

What is the purpose of the Ioff feature in SN74LV123ATPWRG4Q1?

The Ioff feature in SN74LV123ATPWRG4Q1 disables output drivers when VCC = 0 V, placing them in high-impedance state. This prevents damaging current backflow from live system buses into the unpowered device - a critical requirement for automotive modules undergoing partial power-down during sleep modes or battery-disconnect scenarios.