Diodes Incorporated 74LVC1G126FX4-7

Overview

74LVC1G126FX4-7 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-enabling safe use in hot-swap and battery-backed applications such as notebook I/O expansion and USB peripheral control.

For engineers reviewing the 74LVC1G126FX4-7 datasheet, 74LVC1G126FX4-7 pinout, 74LVC1G126FX4-7 application, or 74LVC1G126FX4-7 equivalent, key selection criteria include its 1.4mm × 0.9mm X2-DFN1409-6 package, 3.0ns typical propagation delay at 3.3V, 0.55V max VOL at 24mA, and guaranteed IOFF leakage <200μA during power-down-critical for low-power system architecture and signal integrity in space-constrained portable electronics.

Technical Context

This device implements a CMOS-based non-inverting buffer with active-high output enable (OE), where Y = A when OE = HIGH and Y = high-impedance when OE = LOW. Its IOFF functionality disables both output FETs when VCC = 0V, preventing back-current flow from live buses into unpowered logic sections.

The input structure supports 5.5V-tolerant operation regardless of VCC level (1.65–5.5V), enabling direct interfacing between 1.8V/2.5V/3.3V logic and 5V peripherals without external level shifters. Propagation delay is specified down to 0.5ns minimum across supply voltages, with tight timing control maintained over –40°C to +125°C ambient range.

Key Specifications

Pinout & Package

X2-DFN1409-6 is a 0.4mm-thick, 1.4mm × 0.9mm chip-scale package with six copper pads and no leads. It uses a bottom-side exposed thermal pad (not electrically connected) and requires controlled-impedance PCB layout per Diodes Inc. recommended footprint (C = 1.0mm, G = 0.2mm, X = 0.4mm, Y = 0.15mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G126DBVR, the 74LVC1G126FX4-7 saves >70% board area and improves thermal resistance margin in sealed modules; versus 74LVC1G125FX4-7, it preserves signal polarity critical for clock distribution and synchronous data paths.

Availability

74LVC1G126FX4-7 is available at Aetrix Electronics and suitable for USB peripheral isolation, mobile power sequencing, industrial PLC I/O expansion, and notebook embedded controller bus applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for 74LVC1G126FX4-7 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, energy-efficient components for computing, industrial, and consumer markets.

The 74LVC logic family targets low-voltage, mixed-supply digital interfacing-designed specifically for voltage translation, bus buffering, and power-aware signal isolation in space- and power-constrained systems.

FAQ

Can 74LVC1G126FX4-7 operate with VCC = 1.5V?

No. The absolute minimum recommended VCC is 1.65V per DS32203 Rev. 11–2. At 1.5V, output drive collapses below specification (IOH/IOL < ±1mA), propagation delay exceeds 10ns, and input threshold margins vanish-risking metastability and functional failure. Data retention is supported down to 1.5V, but not active operation.

Is the NC pin on 74LVC1G126FX4-7 electrically isolated?

Yes. Pin 5 (NC) is internally unconnected and must not be soldered to any net. Diodes Inc. recommends leaving it floating or connecting it to GND using a non-functional thermal relief pad to minimize solder wicking and ensure consistent reflow yield-no electrical function is assigned to this terminal.

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

At 3.3V supply and 24mA drive, the device maintains VOL ≤ 0.55V up to 30pF total load (including trace and input capacitance). Beyond 30pF, rise/fall times degrade and t_PD increases nonlinearly; for >50pF loads, add series termination or reduce edge rate via source-series resistor to prevent overshoot and ringing.

Does IOFF protect against reverse current when only OE is pulled HIGH while VCC = 0V?

Yes. IOFF activates whenever VCC is near 0V (≤0.2V), regardless of OE or input states. With VCC = 0V and OE = HIGH, both output FETs are fully disabled, limiting Y-to-GND or Y-to-A leakage to <200μA-even if Y is externally pulled to 5V. This behavior is verified in the datasheet's IOFF test conditions (VI or VO = 5.5V, VCC = 0V).