Texas Instruments SN74HCT245PWRE4

Overview

SN74HCT245PWRE4 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 at 4.5 V to 5.5 V, delivers ±6 mA output drive at 5 V, exhibits typical propagation delay of 14 ns (CL = 50 pF), and supports TTL-compatible inputs - commonly used in industrial backplane and ribbon-cable interconnects where signal integrity and bus isolation are critical.

For engineers reviewing the SN74HCT245PWRE4 datasheet, SN74HCT245PWRE4 pinout, SN74HCT245PWRE4 application, or SN74HCT245PWRE4 equivalent, key selection criteria include its 3-state bidirectional control architecture, 20-pin SOIC (DW) package, guaranteed operation from –40°C to +85°C, low 80-µA max ICC, and compatibility with LSTTL load driving (up to 15 loads).

Technical Context

The SN74HCT245PWRE4 implements a dual-rail CMOS logic interface with active-low output enable (OE) and direction control (DIR) pins that determine data flow direction (A→B or B→A). Its 3-state outputs provide high-impedance isolation when OE is high, enabling bus sharing without contention.

It uses standard HCT logic family design with TTL-voltage-compatible inputs, balanced rise/fall times (typ. 8–11 ns at 5.5 V), and robust ESD protection (±1500 V HBM). The device features center-aligned VCC and GND pins to minimize switching noise in high-speed digital systems.

Key Specifications

Pinout & Package

SN74HCT245PWRE4 is packaged in a 20-pin SOIC (DW) with body size 12.80 mm × 7.50 mm, RoHS-compliant NiPdAu lead finish, and moisture sensitivity level (MSL) 1 (unlimited floor life at ≤30°C/60% RH).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT245DWR and 74ACT245SCX, SN74HCT245PWRE4 provides optimal balance of proven LSTTL drive strength, industrial temperature range, and ultra-low static power - making it the preferred choice for cost-sensitive, noise-immune, and long-lifecycle embedded designs.

Availability

SN74HCT245PWRE4 is available at Aetrix Electronics and suitable for factory automation interfaces, telecom backplane interconnects, and multi-function printer engine control requiring stable component supply across extended production lifecycles.

Supply support for SN74HCT245PWRE4 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 logic solutions for industrial, automotive, and communications markets.

The SN74HCT245 product line delivers robust, pin-compatible bus interface ICs optimized for noise-immune 5-V system integration - particularly targeting legacy equipment upgrades and industrial control applications demanding reliability and long-term availability.

FAQ

What is the maximum operating temperature for SN74HCT245PWRE4?

The SN74HCT245PWRE4 is rated for operation from –40°C to +85°C. This industrial temperature range ensures reliable performance in factory automation, telecom infrastructure, and motor drive environments where ambient temperatures may exceed commercial-grade limits. The SOIC (DW) package's thermal resistance (RθJA = 70.4°C/W) supports this rating under standard PCB layout conditions with adequate copper pour.

Does SN74HCT245PWRE4 require external pull-up resistors on DIR or OE pins?

No, SN74HCT245PWRE4 does not require external pull-up resistors on DIR or OE. Its CMOS inputs draw only ±100 nA (max) at 5.5 V, allowing direct connection to microcontroller GPIOs or logic gates. However, unused inputs must be tied to VCC or GND to prevent floating states - TI recommends 10-kΩ biasing for unused channels per Application Report SCBA004.

Can SN74HCT245PWRE4 drive 15 LSTTL loads reliably at 5 V?

Yes, SN74HCT245PWRE4 guarantees ±6 mA output drive at 5 V, which meets the 1.6 mA per LSTTL input requirement for 15 loads (24 mA total). Electrical Characteristics tables confirm VOL ≤ 0.33 V and VOH ≥ 3.84 V under 6-mA loading, ensuring valid logic levels across the full temperature range and voltage tolerance (4.5–5.5 V).

What is the propagation delay variation between channels in SN74HCT245PWRE4?

SN74HCT245PWRE4 exhibits matched propagation delay across all eight channels, with typical tpd = 14 ns and max 25 ns (CL = 50 pF, VCC = 5.5 V). TI's characterization shows channel-to-channel skew <1 ns under identical load and temperature conditions - critical for parallel bus timing integrity in printer engines and backplane systems.

Is SN74HCT245PWRE4 pin-compatible with older SN74LS245 devices?

No, SN74HCT245PWRE4 is not pin-compatible with SN74LS245. While both are 20-pin octal transceivers with identical pin numbering, SN74LS245 uses bipolar TTL technology with different DC characteristics (e.g., higher ICC, asymmetric drive), and lacks HCT's TTL-compatible input thresholds and 3-state leakage specs. Direct replacement requires validation of VIH/VIL margins and bus loading behavior.