Texas Instruments 74LVC1G123DCTTG4

Overview

74LVC1G123DCTTG4 from Texas Instruments is a single retriggerable monostable multivibrator with Schmitt-trigger inputs, operating from 1.65 V to 5.5 V, supporting 5 V V_CC operation and inputs up to 5.5 V, delivering max t_pd of 8 ns at 3.3 V, and enabling jitter-free triggering on slow input transitions - used in switch debouncing, timing control, and pulse shaping in consumer digital audio/video systems.

For engineers reviewing the 74LVC1G123DCTTG4 datasheet, 74LVC1G123DCTTG4 pinout, 74LVC1G123DCTTG4 application, or 74LVC1G123DCTTG4 equivalent, this page delivers verified electrical specs, SSOP-8 package mapping, real-world timing behavior (including retriggering and CLR override), and validated alternatives for industrial and consumer embedded timing designs.

Technical Context

The 74LVC1G123DCTTG4 implements a CMOS-based retriggerable monostable architecture with dual-edge sensitivity: A input responds to falling edges while B responds to rising edges, both conditioned by Schmitt-trigger hysteresis (typ. 0.3–0.5 V) for noise immunity. Pulse duration is externally set via R_ext/C_ext network connected to pins 6 (C_ext) and 7 (R_ext/C_ext), with programmable range from nanoseconds to milliseconds.

CLR (pin 3) provides asynchronous active-low pulse termination and double-function edge-trigger capability. I_off protection enables live insertion and partial-power-down operation, while mixed-mode voltage translation allows interfacing with 1.8 V, 2.5 V, 3.3 V, and 5 V logic domains without level shifters.

Key Specifications

Pinout & Package

74LVC1G123DCTTG4 is packaged in an 8-pin SSOP (DCT) with nominal body size 2.95 mm × 2.80 mm and 0.65 mm lead pitch. The package supports automated optical inspection (AOI) and standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G123DCUR, 74LVC1G123DCTTG4 offers larger pad geometry for improved manufacturability and thermal dissipation; versus MC74VHC1G123DTT1G, it adds I_off, lower propagation delay, and wider 1.65 V minimum supply - making it superior for low-voltage, power-aware, and high-reliability timing applications.

Availability

74LVC1G123DCTTG4 is available at Aetrix Electronics and suitable for switch debouncing, power sequencing control, LED flash timing, and serial bus glitch suppression requiring stable component supply across automotive, industrial, and consumer electronics programs.

Supply support for 74LVC1G123DCTTG4 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 decades of expertise in precision timing, logic, and low-power IC design.

The SN74LVC1G123 product line delivers single-channel retriggerable monostables optimized for low-voltage, mixed-signal embedded systems - targeting reliable, compact, and energy-efficient timing solutions in space- and power-constrained applications.

FAQ

What is the minimum supply voltage for reliable operation of the 74LVC1G123DCTTG4?

The 74LVC1G123DCTTG4 operates reliably from 1.65 V to 5.5 V. At 1.65 V, it maintains full functionality including Schmitt-trigger input hysteresis, retriggering capability, and specified output drive (±4 mA). Below 1.65 V, timing accuracy degrades and output levels may fall outside guaranteed VOH/VOL ranges - so 1.65 V is the absolute functional floor per TI's SCES586E datasheet.

Can the 74LVC1G123DCTTG4 generate pulses shorter than 10 ns?

Yes - the 74LVC1G123DCTTG4 supports minimum output pulse widths down to ~2.5 ns (at V_CC = 5 V) when using small external capacitance (e.g., 10 pF) and low R_ext (e.g., 1 kΩ), as confirmed in Section 5.6 timing requirements. However, practical minimums depend on layout parasitics and C_ext stability; sub-10 ns pulses require careful PCB routing and low-inductance capacitor placement near pins 6 and 7.

How does the CLR pin function in retriggerable mode for the 74LVC1G123DCTTG4?

In retriggerable mode, the CLR pin (pin 3) serves two roles: (1) active-low override - pulling CLR low immediately terminates the current Q output pulse, regardless of ongoing A/B retriggering; (2) rising-edge trigger - when A = low and B = high, a rising edge on CLR initiates a new pulse. This dual functionality enables both emergency abort and auxiliary timing initiation without additional logic.

Does the 74LVC1G123DCTTG4 support hot-swap or live-insertion applications?

Yes - the 74LVC1G123DCTTG4 includes I_off circuitry that disables all outputs when V_CC = 0 V, limiting I_off to ±10 µA maximum. This prevents back-drive current from powered downstream logic into the unpowered device, satisfying JEDEC JESD78 Class II latch-up immunity (>100 mA) and enabling safe insertion into live backplanes or modular systems.

What external components are required to configure pulse duration on the 74LVC1G123DCTTG4?

The 74LVC1G123DCTTG4 requires two external passive components: a timing capacitor (C_ext) connected between pin 6 (C_ext) and pin 7 (R_ext/C_ext), and a timing resistor (R_ext) connected between pin 7 and V_CC. Pulse width is approximated by t_w ≈ 0.45 × R_ext × C_ext, with typical values ranging from 10 pF/1 kΩ (ns scale) to 100 µF/10 kΩ (ms scale), as shown in Figures 5-3 through 5-5 of the datasheet.