Toshiba Semiconductor and Storage 74VHCT125AFT

Overview

74VHCT125AFT from Toshiba Electronic Devices & Storage Corporation is a quad non-inverting bus buffer with 3-state outputs, designed for bidirectional data bus isolation in 5 V digital systems. It features TTL-compatible inputs (VIH ≥ 2.0 V, VIL ≤ 0.8 V), 3.8 ns typical propagation delay at VCC = 5.0 V, ±8 mA output drive, and operates across -40 °C to +125 °C - enabling use in automotive body control modules requiring robust level translation between 3.3 V logic and 5 V buses.

For engineers reviewing the 74VHCT125AFT datasheet, 74VHCT125AFT pinout, 74VHCT125AFT application, or 74VHCT125AFT equivalent, key selection criteria include its active-high 3-state enable (G input high = high-impedance output), AEC-Q100 Rev. H qualification, TSSOP14B package, and guaranteed operation under 4.5–5.5 V supply with <4.0 µA quiescent current at 25 °C.

Technical Context

The 74VHCT125AFT implements four independent non-inverting buffers, each with a dedicated active-high 3-state control input (G). Its C2MOS silicon gate process delivers TTL-speed performance while maintaining CMOS-level static power consumption. Input protection circuitry allows 0–5.5 V input/output voltage tolerance regardless of VCC, supporting hot-insertion and battery-backup scenarios.

Propagation delays are balanced (tPLH ≈ tPHL), and output skew is limited to 8.8 ns max (at Ta = 25 °C, CL = 50 pF), ensuring deterministic timing in synchronous bus architectures. The device supports level conversion between 3.3 V and 5 V domains via TTL-compatible input thresholds and rail-to-rail output swing (VOH ≥ 4.4 V at VCC = 4.5 V, IOL = 8 mA).

Key Specifications

Pinout & Package

74VHCT125AFT is housed in a 14-pin Thin Shrink Small Outline Package (TSSOP14B), 4.4 mm × 5.0 mm footprint, 0.65 mm pitch, 0.054 g typical weight. Pin assignment follows JEDEC MS-012AC standard for 74-series logic.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74VHCT125AFT, 74VHCT125AM lacks automotive qualification and uses a larger SOIC package, while SN74HCT125PWR omits high-temperature operation - making 74VHCT125AFT the sole option meeting AEC-Q100 and -40 °C to +125 °C requirements in TSSOP14B.

Availability

74VHCT125AFT is available at Aetrix Electronics and suitable for automotive body control, industrial PLC backplanes, and medical diagnostic equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74VHCT125AFT 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

Toshiba Electronic Devices & Storage Corporation is a Japanese semiconductor manufacturer specializing in power devices, logic ICs, and storage solutions, with global design and manufacturing infrastructure.

The 74VHCT series targets high-reliability 5 V digital systems requiring TTL compatibility, low power, and automotive-grade robustness - specifically engineered for noise-immune bus buffering in harsh environments.

FAQ

What is the 3-state enable logic polarity for the 74VHCT125AFT?

The 74VHCT125AFT uses active-high 3-state control: when the G input is high, the corresponding Y output enters high-impedance state; when G is low, the buffer passes the A input to Y. This differs from the pin-compatible 74VHCT126AFT, which uses active-low enable. Confirm G signal polarity in your schematic to avoid unintended bus contention.

Does the 74VHCT125AFT support 3.3 V to 5 V level translation?

Yes, the 74VHCT125AFT supports bidirectional level translation: its TTL-compatible inputs (VIH ≥ 2.0 V, VIL ≤ 0.8 V) accept 3.3 V logic highs and lows, while its outputs swing rail-to-rail (VOH ≥ 4.4 V at VCC = 4.5 V) to drive 5 V loads. No external resistors or translators are needed for this interface.

Is the 74VHCT125AFT qualified for automotive applications?

Yes, the 74VHCT125AFT is AEC-Q100 Rev. H qualified and rated for operation from -40 °C to +125 °C, making it suitable for under-hood and chassis-mounted automotive ECUs. This qualification covers stress testing for temperature cycling, humidity, and ESD - critical for body control modules and lighting systems.

What is the maximum output current capability of the 74VHCT125AFT?

The 74VHCT125AFT delivers ±8 mA per output (IOL = 8 mA, IOH = -8 mA) at VCC = 4.5 V, enabling direct drive of standard TTL loads or termination of 50 Ω transmission lines. Exceeding this current risks violating VOH/VOL specifications or triggering thermal shutdown in sustained operation.

Can unused inputs on the 74VHCT125AFT be left floating?

No, unused inputs on the 74VHCT125AFT must be tied to either VCC or GND to prevent undefined logic states, increased power consumption, or oscillation. Floating inputs may cause excessive ICC due to internal MOSFET threshold uncertainty - especially critical in automotive applications where reliability is paramount.