NXP Semiconductors 74AHC245D,112

Overview

74AHC245D,112 from Nexperia is an 8-bit non-inverting bus transceiver with 3-state outputs, direction control (DIR), and active-low output enable (OE). It operates from 2.0 V to 5.5 V, supports bidirectional data flow between A- and B-buses, features overvoltage-tolerant inputs up to 5.5 V, and is rated for -40 °C to +125 °C operation in SO20 package. It enables voltage-level translation in mixed-supply systems such as FPGA-to-microcontroller I/O bridging.

For engineers reviewing the 74AHC245D,112 datasheet, 74AHC245D,112 pinout, 74AHC245D,112 application, or 74AHC245D,112 equivalent, key selection criteria include its CMOS input compatibility, 3.5 ns typical propagation delay at 5 V/50 pF, 8.0 mA output drive strength, Schmitt-trigger input hysteresis, and SO20 thermal derating profile above 109 °C.

Technical Context

The 74AHC245D,112 implements a dual-bus bidirectional interface using complementary MOS logic with independent DIR and OE controls. Its functional table defines three states: A→B pass-through (DIR = L, OE = L), B→A pass-through (DIR = H, OE = L), and high-impedance isolation (OE = H), enabling flexible data routing in shared-bus architectures.

All eight A-side and B-side I/Os are overvoltage tolerant to 5.5 V regardless of VCC, allowing safe interfacing between 3.3 V and 5 V domains without external level shifters. Inputs incorporate Schmitt-trigger action for noise immunity on slow or noisy signals, while static characteristics guarantee VIH ≥ 3.85 V and VOL ≤ 0.36 V at 8 mA load under 5.5 V supply.

Key Specifications

Pinout & Package

74AHC245D,112 is housed in a plastic small outline package (SO20, SOT163-1) with 20 leads and 7.5 mm body width. The package is RoHS-compliant, surface-mountable, and features gull-wing leads suitable for reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74AHCT245D,112, the 74AHC245D,112 offers lower static current and CMOS input thresholds ideal for mixed-signal SoC interfaces, while SN74LVC245APWR trades voltage flexibility for higher drive in compact 3.3 V applications - making the 74AHC245D,112 optimal for robust, wide-supply, mixed-voltage bus bridging.

Availability

74AHC245D,112 is available at Aetrix Electronics and suitable for industrial bus arbitration, FPGA I/O expansion, automotive body control modules, and test equipment signal routing requiring stable component supply across extended temperature ranges and mixed-voltage environments.

Supply support for 74AHC245D,112 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 74AHC245D,112 belongs to Nexperia's AHC logic family, designed specifically for low-power, high-speed bidirectional data transfer in mixed-voltage embedded systems where reliability, noise immunity, and thermal robustness are critical.

FAQ

Can 74AHC245D,112 operate with VCC = 2.5 V?

Yes. The device is fully specified from 2.0 V to 5.5 V. At VCC = 2.5 V, VIH is guaranteed ≥ 1.7 V and VOL ≤ 0.44 V at 4 mA load per output, supporting interoperability with 2.5 V logic families. Propagation delay increases to ~10.0 ns (max) at 2.5 V/50 pF, which remains suitable for ≤33 MHz bus operation.

What is the maximum capacitive load the outputs can drive reliably?

The outputs are characterized up to 50 pF load capacitance, with tpd and timing parameters guaranteed under that condition. Driving >50 pF may increase propagation delay and reduce edge rate but will not damage the device. For loads exceeding 50 pF, add series termination or buffer stages to maintain signal integrity and meet setup/hold timing.

Is the GND pin (pin 10) electrically connected to the exposed pad in SO20 package?

No. The SO20 package (SOT163-1) used for 74AHC245D,112 has no exposed thermal pad. Pin 10 is the sole ground connection, and the package body contains no internal thermal slug or auxiliary ground plane - proper PCB grounding relies entirely on the leadframe GND pin and surrounding copper pour.

Does DIR pin require pull-up or pull-down resistor when unused?

Yes. DIR is an active CMOS input with no internal bias; leaving it floating risks metastability and increased ICC. Tie DIR to VCC (for B→A default) or GND (for A→B default) via a 10 kΩ resistor. This ensures deterministic direction control during power-up and prevents unintended bus conflicts in unconfigured states.