Texas Instruments SN74HC245PWRE4

Overview

SN74HC245PWRE4 from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between two 8-bit buses (A↔B). It operates from 2 V to 6 V, delivers ±6 mA output drive at 5 V, exhibits typical propagation delay of 12 ns (VCC = 6 V, CL = 50 pF), and draws ≤80 µA supply current - enabling low-power isolation in PC motherboard I/O expansion and embedded system bus bridging.

For engineers reviewing the SN74HC245PWRE4 datasheet, SN74HC245PWRE4 pinout, SN74HC245PWRE4 application, or SN74HC245PWRE4 equivalent, this page provides verified functional mode behavior, real-world timing under 50 pF/150 pF loads, thermal resistance values per TSSOP-20 package, and validated alternative parts for bus interface redesigns requiring voltage-level flexibility and high-impedance isolation.

Technical Context

The SN74HC245PWRE4 implements dual-control logic: DIR selects data direction (A→B or B→A), while OE enables/disables all outputs into high-impedance state. Its CMOS design ensures balanced rise/fall times and inherent noise immunity across its 2–6 V operating range.

It supports asynchronous operation without external clocks, minimizes bus contention risk via defined functional modes (DIR/L+OE/L → B→A; DIR/H+OE/L → A→B; OE/H → isolation), and features slow edge rates to suppress output ringing on light loads - critical for reliable signal integrity in mixed-voltage board interconnects.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.50 mm × 4.40 mm body, 0.65 mm lead pitch, surface-mount, RoHS-compliant NIPDAU finish, MSL Level-1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC245PWRE4, SN74LVC245APWR offers superior speed and drive in 3.3 V domains but sacrifices 5 V compatibility, while 74ACT245SCX delivers robust 5 V performance but eliminates low-voltage operation - making SN74HC245PWRE4 the optimal choice for flexible, dual-rail bus bridging.

Availability

SN74HC245PWRE4 is available at Aetrix Electronics and suitable for PC motherboard I/O expansion, industrial PLC backplane interfaces, and wearable health sensor hubs requiring stable component supply across extended production lifecycles.

Supply support for SN74HC245PWRE4 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 specializing in analog, embedded processing, and connectivity technologies, with decades of experience in logic IC design and high-volume manufacturing reliability.

The SN74HC245 family was engineered for robust, low-power bidirectional bus interfacing in computing, industrial automation, and communications infrastructure - emphasizing voltage flexibility, timing predictability, and long-term supply stability.

FAQ

What is the maximum operating temperature range for SN74HC245PWRE4?

The SN74HC245PWRE4 is rated for operation from –40°C to +85°C ambient temperature. This commercial-grade specification aligns with standard industrial board environments and ensures reliable performance in PC motherboards, network equipment, and embedded controllers without derating under typical airflow conditions.

Does SN74HC245PWRE4 support hot-swapping of connected buses?

Yes - the SN74HC245PWRE4 supports controlled hot-swap operation when OE is asserted high before insertion/removal. Its high-impedance outputs (IOZ ≤ ±5 µA) prevent bus contention, and the 2–6 V supply range accommodates gradual power ramp-up during module insertion, provided OE remains inactive until power stabilizes.

Can SN74HC245PWRE4 interface 3.3 V and 5 V logic domains without external components?

Yes - the SN74HC245PWRE4 operates natively from 2 V to 6 V and accepts input voltages compatible with both 3.3 V and 5 V logic families. When powered at 3.3 V, it drives outputs to ≥3.15 V (VIH), and at 5 V, it accepts inputs down to 1.35 V (VIL), enabling direct cross-voltage domain communication without level shifters.

What is the recommended bypass capacitor for SN74HC245PWRE4?

Texas Instruments recommends a 0.1 µF ceramic capacitor placed as close as possible to the VCC pin (Pin 20) of the SN74HC245PWRE4. This value mitigates high-frequency supply noise generated during output switching and ensures stable operation across the full 2–6 V range and temperature extremes.

How does the DIR pin affect data flow direction in SN74HC245PWRE4?

In SN74HC245PWRE4, a logic low on DIR routes data from Port B to Port A (B→A), while a logic high routes data from Port A to Port B (A→B). This directional control operates independently of OE - data flows only when OE is low, but direction is determined solely by DIR's state at that time.