Nexperia USA Inc. 74AHCT244BQ,115

Overview

74AHCT244BQ,115 from Nexperia is an octal 3-state buffer/line driver with TTL-compatible inputs and dual independent output enables (1OE, 2OE), operating from 4.5 V to 5.5 V supply. It provides eight bidirectional data paths split into two groups of four, supports mixed-voltage interfacing via overvoltage-tolerant inputs up to 5.5 V, and is rated for operation from −40 °C to +125 °C in the DHVQFN20 package.

For engineers reviewing the 74AHCT244BQ,115 datasheet, 74AHCT244BQ,115 pinout, 74AHCT244BQ,115 application, or 74AHCT244BQ,115 equivalent, this device serves as a level-translating bus interface in industrial control backplanes, microcontroller peripheral expansion, and legacy TTL-to-CMOS signal conditioning where low propagation delay (<7.4 ns at 5 V, CL = 15 pF), high noise immunity, and thermal-enhanced packaging are critical.

Technical Context

The 74AHCT244BQ,115 implements two independent 4-bit non-inverting buffer sections, each controlled by its own active-low output enable (1OE for Y0–Y3, 2OE for Y0'–Y3'). Its TTL-level input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5–5.5 V) ensure compatibility with legacy 5 V TTL logic families while driving CMOS loads.

Inputs tolerate voltages up to 5.5 V regardless of VCC, enabling safe interfacing between higher-voltage subsystems and the 4.5–5.5 V supply domain. The DHVQFN20 package features an exposed thermal pad and 0.85 mm profile, supporting high-density PCB layouts and improved thermal performance over SO20 or TSSOP20 variants.

Key Specifications

Pinout & Package

DHVQFN20 (SOT764-1) package: 2.5 mm × 4.5 mm × 0.85 mm body, no leads, 20-terminal quad flat layout with exposed thermal pad (non-soldered or floating per datasheet guidance).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74AHCT244PW,118 and SN74AHCT244PWR, the 74AHCT244BQ,115 offers superior thermal management in compact layouts and tighter typical supply current, making it optimal for high-density industrial modules requiring continuous operation at +125 °C.

Availability

74AHCT244BQ,115 is available at Aetrix Electronics and suitable for industrial PLC backplanes, microcontroller peripheral expansion, legacy system bus translation, and automated test equipment signal conditioning requiring stable component supply across extended temperature ranges.

Supply support for 74AHCT244BQ,115 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

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74AHCT244BQ,115 belongs to Nexperia's advanced logic family designed specifically for robust, low-power, mixed-voltage interfacing in harsh-environment embedded systems where reliability and thermal resilience are mandatory.

FAQ

What is the maximum input voltage the 74AHCT244BQ,115 can tolerate when VCC is unpowered?

The device supports overvoltage-tolerant inputs up to 5.5 V regardless of VCC state. When VCC = 0 V, inputs may safely remain at 5.5 V without damage or leakage exceeding ±2.0 μA, as verified in Section 9 static characteristics and Table 4 limiting values of the official Nexperia datasheet Rev. 7.

Can both output enable pins (1OE and 2OE) be tied together for single-control operation?

Yes - 1OE and 2OE may be paralleled to function as a unified 8-bit 3-state enable. This configuration is electrically valid and maintains full drive strength and timing, as confirmed by the functional diagram (Fig. 1) and truth table (Table 3), where each OE operates independently but shares identical logic behavior.

Does the exposed thermal pad on the DHVQFN20 package require soldering to PCB ground?

No - per Section 5.1 pinning description, the thermal pad has no electrical requirement to be soldered. If soldered, it must remain electrically floating or be connected to GND; intentional connection to other nets violates the datasheet specification and risks latch-up or thermal mismatch.

How does the 74AHCT244BQ,115 differ from the 74AHC244BQ variant?

The 74AHCT244BQ uses TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V), while the 74AHC244BQ uses CMOS thresholds (VIH = 3.85 V at VCC = 5.5 V). This makes the AHCT version interoperable with legacy 5 V TTL logic without pull-ups, whereas the AHC version requires compatible CMOS drivers.