Texas Instruments SN74LVTH245APWE4

Overview

SN74LVTH245APWE4 from Texas Instruments is a 3.3-V ABT octal bus transceiver with 3-state outputs, designed for bidirectional asynchronous data transfer between 3.3-V and 5-V logic domains. It supports mixed-mode signal operation (5-V inputs/outputs with 3.3-V V_CC), delivers 64 mA sink current per output, features bus-hold on all data inputs, and operates across −40°C to 85°C - enabling use in industrial backplane interfaces and legacy system upgrades.

For engineers reviewing the SN74LVTH245APWE4 datasheet, SN74LVTH245APWE4 pinout, SN74LVTH245APWE4 application, or SN74LVTH245APWE4 equivalent, key selection criteria include its I_off support for hot insertion, 2.7-V minimum V_CC for battery-backed systems, ±100 µA I_off leakage, 3.5 ns typical propagation delay (t_PLH/t_PHL), and TSSOP-20 package compatibility with space-constrained PCB layouts.

Technical Context

This device implements an advanced BiCMOS ABT (Advanced Bus Transceiver) architecture optimized for low-voltage operation while maintaining TTL-compatible input thresholds and 5-V tolerant I/Os. Its dual-bus direction control (DIR) and output-enable (OE) logic enable flexible bidirectional data routing without external logic inversion.

The integrated bus-hold circuitry actively maintains valid logic states on floating A/B port inputs at ±750 µA hold current, eliminating external pullup/pulldown resistors. Power-up 3-state and I_off protection ensure safe hot-plug operation by disabling outputs during power transitions and blocking reverse current flow when V_CC = 0 V.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.5 mm × 4.4 mm × 1.2 mm body, 0.65 mm lead pitch, exposed thermal pad optional, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245A and SN74ALVC245, the SN74LVTH245APWE4 uniquely combines 5-V I/O tolerance, integrated bus-hold, and I_off-based hot-swap safety - making it the only option among the three qualified for mixed-voltage industrial backplanes requiring zero external bias components and live module replacement.

Availability

SN74LVTH245APWE4 is available at Aetrix Electronics and suitable for industrial automation, test equipment, and embedded computing applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant TSSOP packaging.

Supply support for SN74LVTH245APWE4 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 industrial-grade logic and interface solutions.

The SN74LVTH245A product line targets mixed-voltage system integration, delivering robust bidirectional bus interfacing for industrial control, instrumentation, and upgrade paths from legacy 5-V architectures to modern low-power platforms.

FAQ

What is the recommended power supply decoupling for SN74LVTH245APWE4?

Place a 0.1 µF ceramic capacitor between V_CC (Pin 20) and GND (Pin 10) within 10 mm of the package. For systems with high switching activity, add a 4.7 µF bulk capacitor nearby. This minimizes supply noise and ensures stable bus-hold operation and low ground bounce (<0.8 V) in the SN74LVTH245APWE4.

Can SN74LVTH245APWE4 interface directly with 5-V microcontrollers?

Yes - the SN74LVTH245APWE4 accepts 5-V inputs and drives 5-V loads while operating from a 3.3-V V_CC, making it ideal for bridging 5-V legacy MCUs to 3.3-V FPGAs or peripherals. Its 5.5-V absolute max input rating and 5-V tolerant I/Os eliminate external level-shifting components in the SN74LVTH245APWE4 design.

Does SN74LVTH245APWE4 require external pullup resistors on A/B ports?

No - the SN74LVTH245APWE4 integrates active bus-hold circuitry on all A1–A8 and B1–B8 pins, maintaining valid logic states on floating inputs with ±750 µA hold current. External pullups are unnecessary and discouraged, as they conflict with the internal bus-hold function of the SN74LVTH245APWE4.

How does SN74LVTH245APWE4 support hot insertion in modular systems?

The SN74LVTH245APWE4 uses I_off circuitry to disable outputs when V_CC = 0 V, preventing backdrive current into a powered-backplane. Combined with power-up 3-state, this ensures outputs remain high-impedance during power sequencing - a critical feature for safe live insertion of cards using the SN74LVTH245APWE4.

What is the thermal performance of SN74LVTH245APWE4 in TSSOP-20 package?

The SN74LVTH245APWE4 in TSSOP-20 (PW) has a θ_JA of 83°C/W. With typical I_CC ≤ 5 mA and 64 mA per output, junction temperature rise remains within limits up to ~70°C ambient at full load. No heatsink is required, but PCB copper pour under the exposed pad (if used) improves thermal dissipation for the SN74LVTH245APWE4.