Texas Instruments SN74LVTH245APW

Overview

SN74LVTH245APW 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 systems. It supports mixed-mode signal operation (5-V inputs/outputs with 3.3-V V_CC), delivers 64 mA sink current per output at 3 V, and features bus-hold circuitry eliminating external pullup/pulldown resistors - used in industrial backplane interfaces and legacy-to-modern voltage domain bridging.

For engineers reviewing the SN74LVTH245APW datasheet, SN74LVTH245APW pinout, SN74LVTH245APW application, or SN74LVTH245APW equivalent, key selection criteria include its 20-pin TSSOP package, I_off support for hot insertion, ±100 µA power-down leakage, 3.7 ns typical propagation delay (t_PLH/t_PHL), and guaranteed operation down to 2.7 V supply.

Technical Context

This device implements an active-high direction-control (DIR) input and active-low output-enable (OE) input to configure bidirectional data flow between A and B buses. Its ABT (Advanced BiCMOS Technology) architecture enables TTL-compatible input thresholds (V_IL = 0.8 V, V_VIH = 2 V) while operating from a 3.3-V supply, ensuring interoperability with 5-V logic without level shifters.

The integrated bus-hold circuitry maintains valid logic states on unused A/B inputs with ±750 µA dynamic hold current, and I_off protection limits reverse current to ±100 µA when V_CC = 0 V - critical for live-insertion systems. Power-up 3-state ensures high-impedance outputs during supply ramping, preventing bus contention.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.95 mm × 4.4 mm × 1.2 mm body, 0.65 mm pitch, exposed pad optional, RoHS-compliant NiPdAu lead 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 SN74LVC245APW and SN74AVC245PW, the SN74LVTH245APW uniquely combines 5-V tolerance, bus-hold, and I_off in a single TSSOP-20 package - making it the only drop-in solution for legacy voltage bridging with zero external components and full hot-swap compliance.

Availability

SN74LVTH245APW is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy system voltage translation, and modular rack I/O expansion requiring stable component supply across extended product lifecycles.

Supply support for SN74LVTH245APW 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 over 50 years of industrial-grade component development.

The SN74LVTH245A family targets mixed-voltage system integration, delivering robust 3.3-V ABT transceivers engineered for interoperability between legacy 5-V and modern low-voltage logic domains.

FAQ

What is the maximum operating temperature range for SN74LVTH245APW?

The SN74LVTH245APW is rated for operation from −40°C to +85°C ambient temperature. This industrial-grade range ensures reliable performance in factory automation, outdoor infrastructure, and transportation electronics where thermal cycling and extended temperature exposure occur. The device's thermal resistance (θ_JA = 83°C/W) and low ICC (0.19 mA in 3-state) support stable operation within this envelope without forced cooling.

Does SN74LVTH245APW require external pullup resistors on A/B bus lines?

No, SN74LVTH245APW does not require external pullup or pulldown resistors due to integrated bus-hold circuitry on all A and B data terminals. This feature actively maintains the last-valid logic state on floating inputs with ±750 µA hold current, eliminating BOM cost and PCB layout overhead. Using external resistors with bus-hold is explicitly discouraged in the datasheet.

Can SN74LVTH245APW safely interface a 5-V microcontroller with a 3.3-V FPGA?

Yes, SN74LVTH245APW safely bridges 5-V and 3.3-V domains: its inputs tolerate up to 5.5 V regardless of V_CC, and its outputs swing rail-to-rail (V_OH ≥ 2 V, V_OL ≤ 0.55 V at 3 V) compatible with 3.3-V FPGA I/O standards. No level-shifting components or voltage dividers are needed - the device operates natively at 3.3-V V_CC while accepting and driving 5-V logic levels.

What is the recommended power-up sequence for SN74LVTH245APW in hot-swap applications?

For hot-swap use, tie OE to V_CC through a pullup resistor (minimum value determined by driver sink capability) to ensure outputs remain in high-impedance until V_CC stabilizes. The built-in power-up 3-state circuitry automatically places outputs in high-Z during V_CC ramp-up, and I_off limits reverse current to ±100 µA if V_CC = 0 V while signals are present - protecting both SN74LVTH245APW and connected devices.

How does the bus-hold function behave when SN74LVTH245APW is powered down?

Bus-hold remains active only when V_CC is within specification (2.7–3.6 V); it is disabled when V_CC = 0 V. During power-down, I_off protection takes precedence, limiting leakage to ±100 µA and preventing current backflow. Unused inputs should still be terminated externally if the device is expected to float for extended periods without power, though bus-hold eliminates this need during normal powered operation.