Texas Instruments 74LVC1G125DCKTE4

Overview

74LVC1G125DCKTE4 from Texas Instruments is a single 3-state bus buffer gate in SC-70 (DCK) package, supporting 1.65V–5.5V supply operation, 3.7ns max propagation delay at 3.3V, ±24mA output drive, and over-voltage tolerant inputs up to 5.5V - used for level translation and bidirectional bus isolation in compact embedded interfaces.

For engineers reviewing the 74LVC1G125DCKTE4 datasheet, 74LVC1G125DCKTE4 pinout, 74LVC1G125DCKTE4 application, or 74LVC1G125DCKTE4 equivalent, key selection criteria include 3-state control timing (ten/tdis), Ioff-enabled live insertion, thermal performance in SC-70 (RθJA = 371°C/W), and compatibility with mixed-voltage 3.3V/5V signal domains.

Technical Context

The 74LVC1G125DCKTE4 implements a noninverting buffer with active-low 3-state enable (OE), where Y follows A when OE is low and enters high-impedance when OE is high. Its CMOS input structure accepts TTL-compatible thresholds and supports down-translation from 5.5V inputs to VCC-level outputs.

It features Ioff circuitry that disables all outputs during partial power-down, preventing current backflow when VCC = 0V, and includes clamp diodes on inputs only - no positive clamping on outputs - requiring external protection for overvoltage on Y in powered-down systems.

Key Specifications

Pinout & Package

74LVC1G125DCKTE4 uses the SC-70-5 (DCK) package: 2.0mm × 2.1mm body, 0.65mm pitch, 5-pin surface-mount outline with exposed pad not present. Thermal resistance RθJA = 371°C/W enables operation up to 125°C ambient in properly routed PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus buffer applications.

Compared with SN74LVC1G125DBVR, the 74LVC1G125DCKTE4 saves 72% PCB area and improves thermal resistance marginally; versus 74AUP1G125GW, it delivers 71% faster propagation for real-time control loops at cost of 20× higher static current.

Availability

74LVC1G125DCKTE4 is available at Aetrix Electronics and suitable for industrial sensor interfaces, USB-C power delivery monitors, automotive body control modules, and medical imaging data links requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74LVC1G125DCKTE4 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 50 years of innovation in logic, power management, and signal chain technologies.

The SN74LVC1G125 belongs to TI's LVC (Low-Voltage CMOS) logic family, designed specifically for voltage-flexible, low-power, 3-state bus interfacing in space-constrained industrial and automotive systems.

FAQ

What is the recommended pull-up resistor value for OE on the 74LVC1G125DCKTE4?

The OE pin must be pulled up to VCC to ensure high-impedance output at power-up. TI specifies minimum pull-up resistance based on the driver's sink capability: for 3.3V operation, a 10kΩ resistor is standard and ensures reliable disable while limiting current to <330μA. Lower values (e.g., 4.7kΩ) improve noise immunity in electrically noisy environments but increase static current.

Can the 74LVC1G125DCKTE4 drive a 50Ω transmission line directly?

Yes - the 74LVC1G125DCKTE4 can drive a 50Ω load with ±24mA output capability at 3.3V, producing ~1.2V swing into 50Ω. However, for clean edges and minimal reflections, TI recommends series termination near the source (e.g., 22Ω resistor between Y and trace) when trace length exceeds 12cm or when operating above 25MHz. The device's inherent edge rate (10ns/V) helps suppress ringing without added components in short traces.

Does the 74LVC1G125DCKTE4 support hot-swap in a live 5V backplane?

Yes - the Ioff feature actively disables all I/Os when VCC = 0V, limiting leakage to ±10μA even with 5.5V applied to A or Y pins. This prevents back-driving powered rails and satisfies JEDEC JESD78 Class II latch-up immunity (>100mA). For full hot-swap compliance, pair with TVS diodes on A/Y lines and ensure OE is held high via backplane pull-up during insertion.

What is the maximum capacitive load the 74LVC1G125DCKTE4 can drive while meeting datasheet timing?

The 74LVC1G125DCKTE4 maintains guaranteed tpd ≤3.7ns and VOH/VOL specs up to CL = 15pF (per switching characteristics table). For CL = 30–50pF, timing degrades to ≤4.7ns (–40°C to 125°C), still usable in most 25MHz+ interfaces. Loads >50pF require series damping (e.g., 33Ω) to limit peak current and prevent overshoot - TI validates operation up to 100pF with proper layout.

How does the 74LVC1G125DCKTE4 handle input signals exceeding VCC?

The 74LVC1G125DCKTE4 features over-voltage tolerant inputs: A and OE accept –0.5V to 5.5V regardless of VCC (1.65–5.5V). This enables true 5V-to-3.3V up-translation without external components. Internally, input protection uses negative-only clamp diodes - no positive clamping - so 5.5V inputs are safely shunted to GND, not VCC, avoiding supply rail injection.