Texas Instruments 74LVC1G123DCTTE4

Overview

74LVC1G123DCTTE4 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 serves as a precision timing element in switch debounce, pulse stretching, and event synchronization circuits.

For engineers reviewing the 74LVC1G123DCTTE4 datasheet, 74LVC1G123DCTTE4 pinout, 74LVC1G123DCTTE4 application, or 74LVC1G123DCTTE4 equivalent, key selection criteria include its retriggerable architecture, 8 ns max t_pd at 3.3 V, ±50 mA output drive, Schmitt-trigger input hysteresis, and NanoFree™ SSOP-8 package compatibility with space-constrained embedded timing designs.

Technical Context

The 74LVC1G123DCTTE4 implements a CMOS-based retriggerable monostable circuit where output pulse width is determined by external R_ext and C_ext values connected to dedicated timing pins (Rext/Cext and Cext). Triggering occurs on edge transitions at A (falling) or B (rising), with independent active-low CLR override capability.

Schmitt-trigger inputs on A and B provide ≥0.3 V hysteresis at 3.3 V, enabling jitter-free response to slow-rising/falling signals. The device operates across –40°C to 125°C with I_off support for live insertion and partial-power-down modes, and meets JESD 78 Class II latch-up (>100 mA) and JESD 22 ESD ratings (2000 V HBM).

Key Specifications

Pinout & Package

74LVC1G123DCTTE4 is packaged in an 8-pin SSOP (DCT) with nominal body size 2.95 mm × 2.80 mm and 0.65 mm pitch. The NanoFree™ package uses the silicon die as the package substrate, minimizing footprint and thermal resistance (R_θJA = 220°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G123DCUR and MC74VHC1G123DTT1G, the 74LVC1G123DCTTE4 uniquely combines 1.65 V operation, I_off, and NanoFree™ SSOP packaging - making it optimal for battery-powered, hot-pluggable, and mixed-voltage embedded systems requiring guaranteed low-V_CC timing stability.

Availability

74LVC1G123DCTTE4 is available at Aetrix Electronics and suitable for switch debounce, pulse stretching, event synchronization, and power sequencing applications requiring stable component supply across automotive, industrial, and consumer electronics programs.

Supply support for 74LVC1G123DCTTE4 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 solutions, with over 90 years of innovation in power management, signal chain, and timing technologies.

The SN74LVC1G123 product line delivers compact, low-power monostable timing functions for space- and power-constrained embedded systems - targeting applications where software-based timing is unreliable or resource-intensive.

FAQ

What is the minimum V_CC required for reliable operation of the 74LVC1G123DCTTE4?

The 74LVC1G123DCTTE4 is fully specified down to 1.65 V V_CC, with guaranteed performance including t_pd, output drive, and Schmitt-trigger hysteresis across –40°C to 125°C. At 1.65 V, it delivers ±4 mA output drive and supports 100% retriggerable duty cycle. Operation below 1.65 V is not characterized and may result in undefined timing or logic states.

How does the 74LVC1G123DCTTE4 achieve retriggerable behavior, and what is the minimum retrigger interval?

The 74LVC123DCTTE4 achieves retriggerable behavior by allowing new A or B triggers to extend the active Q output pulse before its natural timeout. Minimum retrigger time depends on R_ext and C_ext: for R_ext = 1 kΩ and C_ext = 100 pF, it is 4.5 ns at 25°C; for C_ext = 100 µF, it is 1.4 µs. This ensures robust retriggering even with high-frequency input bursts.

Can the 74LVC1G123DCTTE4 be used with a 5 V microcontroller driving its inputs while operating at 3.3 V V_CC?

Yes - the 74LVC1G123DCTTE4 accepts input voltages up to 5.5 V regardless of V_CC, enabling direct connection to 5 V logic outputs while powered at 3.3 V. Its mixed-mode voltage translation capability eliminates external level shifters, and inputs remain overvoltage-tolerant with no current injection into V_CC.

What external components are mandatory for basic operation of the 74LVC1G123DCTTE4?

A 0.1 µF ceramic bypass capacitor between V_CC and GND is mandatory. For timing functionality, both an external resistor (R_ext) between Rext/Cext and V_CC, and an external capacitor (C_ext) between Cext and Rext/Cext are required. Omitting either disables pulse-width control; omitting the bypass capacitor risks erratic switching due to supply noise.

Does the 74LVC1G123DCTTE4 support hot-swap or partial-power-down operation?

Yes - the 74LVC1G123DCTTE4 incorporates I_off circuitry that disables outputs when V_CC = 0 V, preventing back-drive current from live signal lines into the unpowered device. This enables safe insertion/removal in powered backplanes and supports partial-power-down modes in multi-rail systems without external isolation components.