Renesas 74HCT126TELL-E

Overview

74HCT126TELL-E from Renesas Electronics is a quad bus buffer gate with 3-state outputs and active-low output enable control, designed for bidirectional data bus isolation in digital systems. It operates at 4.5–5.5 V, delivers 12 ns typical propagation delay (CL = 50 pF), supports ±6 mA output drive, and features LSTTL-compatible input thresholds and CMOS-level outputs - used in microcontroller peripheral interfacing and memory address/data bus management.

For engineers reviewing the 74HCT126TELL-E datasheet, 74HCT126TELL-E pinout, 74HCT126TELL-E application, or 74HCT126TELL-E equivalent, key selection criteria include its active-low 3-state control logic, TSSOP-14 package footprint, guaranteed operation from –40°C to +85°C, and compatibility with both LSTTL and CMOS logic families in mixed-voltage system interconnects.

Technical Context

The 74HCT126TELL-E implements four independent non-inverting buffers, each with a dedicated active-low output enable (C) input that places the Y output in high-impedance state when asserted. Its HCT logic family ensures TTL-level input sensitivity (VIH = 2.0 V min, VIL = 0.8 V max) while delivering CMOS-level output swing (VOH ≥ 4.13 V, VOL ≤ 0.33 V at VCC = 4.5 V).

It uses standard CMOS silicon process with Schmitt-trigger-free inputs, supports fanout of 15 LSTTL loads, and maintains low static supply current (ICC ≤ 40 µA over temperature). All timing parameters - including tPLH/tPHL (25 ns max), tZL/tZH (38 ns max), and tLZ/tHZ (38 ns max) - are specified under industrial temperature and 50 pF load conditions.

Key Specifications

Pinout & Package

TSSOP-14 package (PTSP0014JA-B / TTP-14DV), 4.4 mm × 5.0 mm body, 0.65 mm pitch, Ni/Pd/Au plating, 0.05 g typical mass.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT126PW, the 74HCT126TELL-E offers identical timing and drive capability but differs in tape-and-reel packaging (ELL vs PW) and manufacturer qualification. Against 74VHC126FT, it provides guaranteed TTL input compatibility at the cost of narrower supply range - critical for legacy 5 V board upgrades.

Availability

74HCT126TELL-E is available at Aetrix Electronics and suitable for microcontroller bus expansion, memory address/data isolation, and legacy system logic interface requiring stable component supply, long-term industrial-grade availability, and RoHS-compliant TSSOP packaging.

Supply support for 74HCT126TELL-E 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

Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog and power devices, and logic ICs for industrial, automotive, and infrastructure applications.

The 74HCT126TELL-E belongs to Renesas' legacy HCT logic family, engineered for robust 5 V digital interfacing in industrial control, test equipment, and embedded systems where TTL compatibility and predictable timing are essential.

FAQ

What is the logic configuration of the 74HCT126TELL-E?

The 74HCT126TELL-E contains four independent non-inverting bus buffers, each with an active-low 3-state output enable (C) input. When C is low, the Y output follows the A input; when C is high, Y enters high-impedance state. This configuration enables bidirectional bus control in shared-data-path systems.

Does the 74HCT126TELL-E support 3.3 V operation?

No, the 74HCT126TELL-E is strictly a 5 V device with recommended supply range of 4.5–5.5 V. Its input thresholds (VIH = 2.0 V min, VIL = 0.8 V max) are optimized for TTL compatibility, and operation below 4.5 V violates the datasheet's recommended conditions. For 3.3 V systems, consider 74LVC126 or similar families.

What is the maximum capacitive load the 74HCT126TELL-E can drive reliably?

The 74HCT126TELL-E switching characteristics are characterized at CL = 50 pF, with tPLH/tPHL = 25 ns max over temperature. While it can drive higher capacitance, propagation delay increases linearly; for >100 pF loads, derate timing margins and verify setup/hold at target clock frequency using actual board layout parasitics.

Is the 74HCT126TELL-E pin-compatible with the 74HCT125TELL-E?

Yes - both share identical TSSOP-14 pinout and pin functions. The only functional difference is output enable polarity: 74HCT126TELL-E has active-low enable (C = L → Y enabled), while 74HCT125TELL-E has active-high enable (C = H → Y enabled). Swapping them requires inverting the enable signal in firmware or hardware.

What thermal considerations apply to the 74HCT126TELL-E in continuous operation?

The 74HCT126TELL-E has a maximum power dissipation of 500 mW and junction-to-ambient thermal resistance (θJA) of ~220°C/W in TSSOP-14. At full output drive (±6 mA per channel, all four active), total power is <15 mW - well within limits. No heatsinking is required, but ensure adequate PCB copper area and airflow for ambient temperatures approaching +85°C.