onsemi MC74HC245ADWG

Overview

MC74HC245ADWG from onsemi is an octal 3-state noninverting bus transceiver in SOIC-20 wide package, operating from 2.0 V to 6.0 V, with 15 LSTTL load drive capability, propagation delay as low as 13 ns at 6.0 V, and bidirectional data flow controlled by Direction and active-low Output Enable pins - used for level-shifting and bus isolation in microcontroller peripheral expansion interfaces.

For engineers reviewing the MC74HC245ADWG datasheet, pinout, applications, or equivalent options, key selection criteria include supply voltage range (2.0–6.0 V), 3-state output timing (tPLZ/tPHZ ≤ 28 ns at 6.0 V), input compatibility with CMOS/LSTTL, and SOIC-20WB mechanical footprint compliance per case 751D.

Technical Context

The MC74HC245ADWG implements a dual-bus, bidirectional transceiver architecture with independent control of direction (DIR) and output enable (/OE). Its silicon-gate CMOS process ensures rail-to-rail logic swing and high noise immunity, meeting JEDEC Std No. 7A for interface compatibility.

It supports asynchronous 2-way communication between data buses A and B, where DIR determines signal path (A→B or B→A), and /OE places all I/Os into high-impedance state. Input leakage is ≤ ±1.0 µA at 6.0 V, and three-state leakage is ≤ ±10 µA over temperature.

Key Specifications

Pinout & Package

MC74HC245ADWG uses SOIC-20 Wide (Case 751D) package, 12.8 mm × 7.5 mm body, 1.27 mm pitch, with 20 leads and Pb-free (G-suffix) finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC245N and MC74HC245ADTR2G, the MC74HC245ADWG offers SOIC-20 wide mechanical stability for rework-friendly hand assembly, lower thermal resistance (96°C/W) than TSSOP, and direct drop-in replacement for legacy LS245 designs without layout changes.

Availability

MC74HC245ADWG is available at Aetrix Electronics and suitable for microcontroller bus expansion, industrial PLC backplane interfaces, and medical diagnostic data acquisition requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MC74HC245ADWG 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The MC74HC245ADWG belongs to onsemi's high-performance HC logic family, designed for robust, low-power bidirectional bus interfacing in harsh-temperature and noise-prone embedded systems.

FAQ

What is the maximum operating frequency supported by MC74HC245ADWG?

The MC74HC245ADWG does not specify a maximum clock frequency, but its propagation delay (tPLH/tPHL) is 13 ns at VCC = 6.0 V, enabling reliable operation up to approximately 30 MHz for toggling data on both A and B ports. System-level timing must account for board trace delays and loading effects, and actual usable frequency depends on the specific bus protocol and setup/hold requirements of connected devices. The MC74HC245ADWG is optimized for asynchronous bus bridging rather than synchronous clocked operation.

Can MC74HC245ADWG interface 3.3 V and 5 V logic domains?

Yes, the MC74HC245ADWG supports mixed-voltage operation: its 2.0–6.0 V supply range allows it to be powered from either 3.3 V or 5 V rails. When VCC = 3.3 V, outputs swing rail-to-rail (0 V to 3.3 V), compatible with 3.3 V CMOS inputs; when VCC = 5 V, outputs reach 5 V, driving standard TTL loads. Inputs are overvoltage-tolerant up to VCC + 0.5 V, permitting safe connection of 3.3 V signals to a 5 V-powered MC74HC245ADWG.

Is MC74HC245ADWG pin-compatible with SN74LS245?

Yes, the MC74HC245ADWG is explicitly designed as a pinout-identical replacement for SN74LS245, sharing identical SOIC-20 pin assignments, functional behavior, and logic diagram. It retains the same /OE and DIR control scheme and matches LS245's dual-bus transceiver functionality - making it a direct drop-in upgrade for power-sensitive, noise-immune, and wider supply voltage applications without PCB redesign.

What is the thermal resistance (θJA) of MC74HC245ADWG in SOIC-20WB package?

The MC74HC245ADWG in SOIC-20 Wide (Case 751D) package has a junction-to-ambient thermal resistance (θJA) of 96°C/W, measured under JEDEC JESD51-7 conditions (76 mm × 114 mm, 2-oz copper, no airflow). This value enables calculation of junction temperature rise (ΔTJ = θJA × PD) for thermal design validation, especially in enclosed industrial enclosures where ambient temperature may reach +70°C and power dissipation approaches 130 mW.

Does MC74HC245ADWG support hot-swap or live-insertion?

The MC74HC245ADWG itself does not include built-in hot-swap protection circuitry, but its 3-state outputs and high-impedance isolation during /OE assertion make it suitable for hot-swap-capable systems when combined with external current-limiting and sequencing controls. Its ±20 mA input clamp current rating and >2000 V HBM ESD rating provide baseline robustness, though full hot-swap compliance requires system-level implementation of slew-rate limiting and bus arbitration - which the MC74HC245ADWG supports via fast, predictable tPLZ/tPHZ timing (≤28 ns).