Diodes Incorporated 74LVC1G125FS3-7

Overview

74LVC1G125FS3-7 from Diodes Incorporated is a single non-inverting 3-state buffer IC designed for voltage-level shifting and bus isolation in mixed-voltage digital systems. It operates from 1.65V to 5.5V, tolerates 5.5V inputs, delivers ±24mA output drive at 3.3V, and features IOFF circuitry for partial power-down protection. It is used in portable computing interfaces and signal routing in space-constrained PCBs.

For engineers reviewing the 74LVC1G125FS3-7 datasheet, 74LVC1G125FS3-7 pinout, 74LVC1G125FS3-7 application, or 74LVC1G125FS3-7 equivalent, key selection criteria include 3-state enable timing (tpd ≤ 4.5ns @ 3.3V), ultra-small X2-DFN0808-4 package (0.8mm × 0.8mm), input voltage tolerance, IOFF leakage (<200μA), and compatibility with TTL logic levels.

Technical Context

This device implements a CMOS-based non-inverting buffer with active-low 3-state output control (OE). Its IOFF functionality disables both output paths during power-down, preventing backflow current when VCC = 0V while inputs/outputs remain biased up to 5.5V.

The logic function follows a simple truth table: when OE = LOW, Y = A; when OE = HIGH, Y = high-impedance. Propagation delay (tpd) is 0.5–4.5ns across 1.8V–5.0V supply range, and enable/disable times (ten/tdis) are tightly matched to ensure clean bus release.

Key Specifications

Pinout & Package

X2-DFN0808-4 is a 0.8mm × 0.8mm, 0.35mm-thick, diamond-layout 4-terminal chip-scale package with exposed thermal pad (not electrically connected). Pin 1 (A) is marked by a diamond-shaped pad; orientation follows JEDEC MO-252 variant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-state buffer applications.

Compared with SN74LVC1G125DBVR and 74LVC1G125GW,125, the 74LVC1G125FS3-7 offers the smallest footprint and verified IOFF performance - making it optimal for miniaturized, multi-rail systems requiring guaranteed power-down isolation and minimal board area.

Availability

74LVC1G125FS3-7 is available at Aetrix Electronics and suitable for portable computing interfaces, industrial sensor hubs, wearable health monitors, and mobile display subsystems requiring stable component supply and long-term manufacturability.

Supply support for 74LVC1G125FS3-7 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

Diodes Incorporated is a global semiconductor manufacturer specializing in discrete, analog, and logic solutions for industrial, computing, consumer, and automotive markets.

The 74LVC logic family targets low-voltage, high-speed digital interfacing with emphasis on mixed-supply compatibility, power efficiency, and small-form-factor packaging - directly addressing design needs in portable and embedded electronics.

FAQ

What is the maximum capacitive load this buffer can drive reliably?

The 74LVC1G125FS3-7 is characterized for CL ≤ 50pF in switching tests, and its ±24mA drive strength supports typical PCB trace capacitance plus receiver input capacitance (e.g., 5–10pF per LVC input). For loads exceeding 50pF, propagation delay increases and edge rate degrades; layout optimization or fanout buffering is recommended.

Can OE be left floating in a system design?

No - OE must be actively driven HIGH or LOW. Floating OE may cause indeterminate output state, increased ICC, or oscillation due to noise coupling. Per datasheet Note 9, unused inputs including OE should be tied to VCC or GND via a pull-up/down resistor (typically 10kΩ) to ensure defined logic levels and prevent shoot-through current.

Does the X2-DFN0808-4 package require special PCB layout considerations?

Yes - the 0.5mm diamond pad pitch demands precise stencil aperture design and solder paste volume control. Diodes recommends using the manufacturer's suggested pad layout (0.32mm × 0.32mm pads, 0.106mm solder mask clearance) and a thermal relief-connected exposed pad (if used for mechanical anchoring). Reflow profile must avoid thermal shock to prevent pad lift.

How does IOFF behavior differ from standard high-impedance state?

Standard 3-state disables the output driver but leaves input circuitry active, allowing leakage paths. IOFF actively disables both input and output structures when VCC = 0V, blocking current flow from powered inputs to unpowered VCC/GND rails - a critical safety feature for systems with asynchronous power sequencing or hot-plug capability.