Texas Instruments CD74HCT126M96E4

Overview

CD74HCT126M96E4 from Texas Instruments is a quadruple non-inverting buffer with 3-state outputs, designed for bus interface and signal routing in digital systems. It operates across 2 V to 6 V supply voltage, supports –55°C to +125°C temperature range, delivers propagation delay as low as 17 ns at 6 V (CL = 50 pF), and drives up to 10 LSTTL loads - enabling reliable data enable control in industrial control backplanes.

For engineers reviewing the CD74HCT126M96E4 datasheet, CD74HCT126M96E4 pinout, CD74HCT126M96E4 application, or CD74HCT126M96E4 equivalent, key selection criteria include its 3-state output timing (enable/disable delays ≤32 ns at 6 V), wide temperature rating, SOIC-14 package compatibility, and HCT-level TTL-compatible input thresholds.

Technical Context

This device implements four independent positive-logic buffers (Y = A) with active-low 3-state enable inputs (OE). Each channel features balanced CMOS outputs capable of sourcing/sinking ≥6 mA at 4.5 V while maintaining VOH ≥3.98 V and VOL ≤0.33 V under load.

Input structure follows standard CMOS with VIH/VIL thresholds scaled to VCC (e.g., VIH = 3.15 V at VCC = 4.5 V), and includes clamp diodes for ±2000-V HBM ESD protection. Functional modes are defined by OE state: high enables Y = A; low places Y in high-impedance (IOZ ≤±10 µA).

Key Specifications

Pinout & Package

CD74HCT126M96E4 is packaged in a 14-pin SOIC (D package), 8.70 mm × 3.90 mm body size, with gull-wing leads and RoHS-compliant NiPdAu (NIPDAU) finish. Moisture sensitivity level is Level-1 (260°C peak reflow, unlimited floor life).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT125DR and CD74HC126M96, CD74HCT126M96E4 uniquely provides non-inverting logic with TTL-compatible inputs - making it the sole choice for direct replacement of legacy 74LS126 in upgrade paths requiring no PCB or firmware changes.

Availability

CD74HCT126M96E4 is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, automotive body control modules, and avionics data acquisition systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HCT126M96E4 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 delivering analog and embedded processing solutions, with over 90 years of innovation in logic, power management, and signal chain technologies.

CD74HCT126M96E4 belongs to TI's HCT logic family - engineered specifically for TTL-to-CMOS bridging in industrial and automotive systems where robustness, wide temperature operation, and pin-compatible upgrades from bipolar logic are required.

FAQ

What is the maximum capacitive load supported by CD74HCT126M96E4 while maintaining specified timing?

CD74HCT126M96E4 maintains guaranteed switching characteristics up to 50 pF load capacitance, as verified in Section 6.6 of the datasheet. At CL = 50 pF and VCC = 6 V, propagation delay is 17–36 ns and transition time is 10–15 ns. Loads exceeding 50 pF increase delay nonlinearly and may cause ringing; for >70 pF, TI recommends adding a series resistor to limit output current per Section 8.3.1.

Does CD74HCT126M96E4 support mixed-voltage operation between input and output sides?

No - CD74HCT126M96E4 uses a single-supply architecture (VCC only). All inputs and outputs reference the same VCC rail; there is no dual-supply or level-shifting capability. Input thresholds scale with VCC (e.g., VIH = 3.15 V at VCC = 4.5 V), and outputs swing between GND and VCC. Interfacing with different voltage domains requires external level translators.

How should unused inputs and outputs be terminated on CD74HCT126M96E4?

Unused inputs must be tied to VCC or GND - never left floating - to prevent undefined logic states and excessive current draw. A 10-kΩ pull-up/down resistor is recommended for flexibility. Unused outputs may be left unconnected (floating), as the 3-state architecture isolates them when OE is inactive; connecting outputs directly to VCC or GND violates absolute maximum ratings and risks damage.

What is the thermal resistance (RθJA) of CD74HCT126M96E4 in its SOIC package?

CD74HCT126M96E4 in the SOIC-14 (D) package has a junction-to-ambient thermal resistance (RθJA) of 133.6°C/W, as specified in Section 6.4 of the datasheet. This value assumes standard JEDEC 2-layer board conditions. For high-density layouts, RθJB = 89.5°C/W reflects improved heat conduction to the PCB, and ΨJB = 89.1°C/W provides a more accurate estimate of localized die temperature rise under typical operating power (≤10 mW).

Is CD74HCT126M96E4 pin-compatible with older 74LS126 devices?

Yes - CD74HCT126M96E4 is a direct pin-compatible and functionally equivalent replacement for 74LS126, sharing identical SOIC-14 pinout, non-inverting buffer + 3-state functionality, and TTL-compatible input thresholds. No PCB redesign is needed; however, verify that system-level timing margins accommodate HCT's faster propagation (17 ns vs. LS's ~25 ns) and lower power consumption.