NXP Semiconductors 74HCT245DB,112

Overview

74HCT245DB,112 from Nexperia is an octal bus transceiver with 3-state outputs, designed for bidirectional data transmission between two 8-bit buses. It operates at 4.5–5.5 V, features ±4 mA output drive, 8 ns typical propagation delay at 5 V, and TTL-compatible inputs. Used in microcontroller peripheral interfacing and memory address/data bus isolation.

For engineers reviewing the 74HCT245DB,112 datasheet, 74HCT245DB,112 pinout, 74HCT245DB,112 application, or 74HCT245DB,112 equivalent, key selection criteria include voltage compatibility, bus direction control timing, 3-state output leakage, high-speed logic family behavior, and SO-20 package thermal performance.

Technical Context

This device implements dual-rail CMOS logic with TTL-level input thresholds and push-pull outputs capable of driving standard TTL loads. Direction control (DIR) and output enable (OE) pins operate independently to support asynchronous bus arbitration and hot-swap isolation.

Propagation delay is symmetric for A→B and B→A paths (t_PD = 8 ns max at V_CC = 5 V, T_A = 25 °C), and output transition times (t_r/t_f) are specified at 5 ns max under 15 pF load, ensuring clean signal integrity in synchronous digital systems.

Key Specifications

Pinout & Package

Supplied in a 20-pin SO (Small Outline) package with 0.65 mm pitch, JEDEC MS-013AC compliant, body width 7.5 mm, and thermal resistance R_θJA = 110 K/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT245N and 74LCX245MTCX, the 74HCT245DB,112 offers optimal thermal performance in compact SO-20 layout, full 5 V compatibility without level-shifting overhead, and proven reliability in industrial bus-isolation roles - making it preferred for space-constrained, high-reliability 5 V embedded systems.

Availability

74HCT245DB,112 is available at Aetrix Electronics and suitable for microcontroller bus expansion, memory address/data isolation, and industrial I/O module interface requiring stable component supply across production lifecycles.

Supply support for 74HCT245DB,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 high-volume, high-reliability logic, discrete, and MOSFET solutions for automotive, industrial, and consumer applications.

The 74HCT series delivers TTL-compatible CMOS logic optimized for 5 V systems with low power, high noise immunity, and robust ESD tolerance - targeting cost-sensitive, high-volume embedded control and interface applications.

FAQ

What is the maximum clock frequency supported by the 74HCT245DB,112 in a data bus application?

The 74HCT245DB,112 does not operate on a clock signal but functions asynchronously. Its 8 ns typical propagation delay allows reliable use in systems with bus cycle times ≥ 16 ns - supporting effective data rates up to approximately 50 MHz in synchronous bus architectures with proper setup/hold timing margins.

Can the 74HCT245DB,112 be used with 3.3 V logic inputs?

No. The 74HCT245DB,112 requires a 4.5–5.5 V supply and has TTL-compatible input thresholds (V_IH ≥ 2.0 V). While 3.3 V outputs may exceed V_IH, they fall below the recommended 2.4 V minimum for noise margin; level-shifting is required for guaranteed interoperability with 3.3 V CMOS drivers.

Is bus-hold functionality integrated into this device?

No. The 74HCT245DB,112 lacks internal bus-hold circuitry. Unused inputs must be externally terminated with pull-up or pull-down resistors to prevent floating states, oscillation, or excessive current draw due to undefined logic levels.

What is the recommended PCB layout practice for minimizing ground bounce?

Place a 100 nF ceramic decoupling capacitor between V_CC and GND within 5 mm of the SO-20 package, use solid ground plane beneath the device, and route GND pins directly to that plane with short, wide traces. Avoid daisy-chaining GND connections between multiple transceivers on the same bus.