Texas Instruments SN74AHC245MPWREP

Overview

SN74AHC245MPWREP from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between two 8-bit buses. It operates across 2 V to 5.5 V V_CC, supports –55°C to 125°C extended temperature range, features direction control (DIR) and output-enable (OE) inputs, and delivers propagation delays as low as 4 ns at 5 V - enabling use in high-reliability industrial backplane and legacy bus interface applications.

For engineers reviewing the SN74AHC245MPWREP datasheet, SN74AHC245MPWREP pinout, SN74AHC245MPWREP application, or SN74AHC245MPWREP equivalent, key selection considerations include its TSSOP-20 package, ±25 mA output drive, 3-state isolation behavior, latch-up immunity (>250 mA), and compatibility with 2.0–5.5 V logic systems requiring radiation-tolerant, extended-temperature bus bridging.

Technical Context

This device implements dual 8-bit bidirectional data paths controlled by a single DIR input and enabled/disabled via OE. Each transceiver channel operates independently with noninverting logic: when OE is low and DIR is high, data flows A→B; when OE is low and DIR is low, data flows B→A; when OE is high, both A and B ports enter high-impedance state regardless of DIR.

It uses advanced CMOS AHC logic with TTL-compatible input thresholds, supports mixed-voltage interfacing within its V_CC range, and incorporates robust ESD protection (>1000 V HBM, >100 V MM) and latch-up immunity per JESD17 - critical for deployment in harsh-environment avionics and defense subsystems where supply sequencing and signal integrity must be maintained during power-up/down transitions.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), 6.5 mm × 4.4 mm body, 0.65 mm pitch, exposed pad not present, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHC245MPWREP, the SOIC variant offers superior thermal performance but occupies 2.3× more PCB area, while the SN54AHC245 adds formal military qualification overhead and cost - making SN74AHC245MPWREP the optimal balance of size, reliability, and qualification scope for commercial-space and industrial-extended applications.

Availability

SN74AHC245MPWREP is available at Aetrix Electronics and suitable for industrial automation backplanes, avionics data concentrators, and secure test equipment requiring stable component supply across extended temperature and long product lifecycles.

Supply support for SN74AHC245MPWREP 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and aerospace markets since 1930.

The SN74AHC245-EP product line delivers enhanced-product (EP) versions of industry-standard logic devices, specifically engineered for high-reliability applications demanding extended temperature operation, controlled baseline manufacturing, and long-term supply assurance.

FAQ

What is the maximum operating voltage for SN74AHC245MPWREP?

The absolute maximum supply voltage for SN74AHC245MPWREP is 7 V, but the recommended operating range is strictly 2 V to 5.5 V. Operating above 5.5 V risks violating the recommended conditions and may degrade long-term reliability, especially under extended temperature stress. All DC and AC specifications in the datasheet are guaranteed only within the 2–5.5 V window.

Does SN74AHC245MPWREP support hot-swap operation?

SN74AHC245MPWREP supports controlled hot-swap behavior when OE is held HIGH during insertion: all A and B pins enter high-impedance state with leakage ≤±2.5 µA, minimizing bus disturbance. However, TI does not specify full hot-swap qualification - external current-limiting or sequencing circuitry is recommended for systems requiring IEC 61000-4-2 or MIL-STD-1399 compliance.

How is the direction-control logic implemented in SN74AHC245MPWREP?

In SN74AHC245MPWREP, the DIR input is sampled asynchronously: when OE is LOW, DIR = HIGH enables A→B data flow, and DIR = LOW enables B→A data flow. The transceiver does not latch direction; it responds immediately to DIR transitions, making it suitable for dynamic bus arbitration schemes where direction changes mid-transfer are required.

What is the thermal resistance (θ_JA) of SN74AHC245MPWREP in its TSSOP-20 package?

The published junction-to-ambient thermal resistance (θ_JA) for SN74AHC245MPWREP in the TSSOP-20 (PW) package is 83°C/W under standard JEDEC test conditions (JESD 51-7). This value assumes a 1-inch² copper pad with no internal planes; actual board-level θ_JA will improve with additional thermal vias and copper area, but derating is required for sustained >50 mW power dissipation.

Can SN74AHC245MPWREP interface directly between 3.3 V and 5 V buses?

Yes - SN74AHC245MPWREP operates natively across 2–5.5 V, and its inputs are 5 V tolerant regardless of V_CC. When V_CC = 3.3 V, it safely accepts 5 V signals on A/B and control pins, and outputs swing rail-to-rail (0 V to 3.3 V), enabling direct 3.3 V ↔ 5 V bus bridging without external level shifters or resistive dividers.