Texas Instruments SN74LVCH245APWT

Overview

SN74LVCH245APWT from Texas Instruments is an octal bus transceiver with tri-state outputs, designed for bidirectional data flow between 1.65-V to 3.6-V buses while accepting 5.5-V-tolerant inputs. It features direction control (DIR), active-low output enable (OE), bus-hold on all data I/Os, Ioff for live insertion, and a max propagation delay of 6.3 ns at 3.3 V. It enables voltage-level translation in mixed 3.3-V/5-V systems such as server memory interfaces.

For engineers reviewing the SN74LVCH245APWT datasheet, SN74LVCH245APWT pinout, SN74LVCH245APWT application, or SN74LVCH245APWT equivalent, key selection factors include its 20-pin TSSOP package, 1.65–3.6-V supply range, 5.5-V input tolerance, tri-state isolation timing (enable/disable <9 ns at 3.3 V), and bus-hold functionality eliminating external bias resistors.

Technical Context

This device implements asynchronous bidirectional data transfer via a single DIR signal that determines A→B or B→A flow, while OE independently places all outputs in high-impedance state. Its CMOS push-pull outputs deliver balanced sourcing/sinking capability up to ±24 mA at 3.0 V, with controlled edge rates (Δt/Δv ≤10 ns/V) to limit ringing.

The integrated bus-hold circuit maintains valid logic levels on floating A/B port inputs without external components, and Ioff protection limits reverse current during partial power-down-critical for hot-swap applications in telecom infrastructure and industrial backplanes.

Key Specifications

Pinout & Package

TSSOP-20 (PW package), 6.50 mm × 4.40 mm body, 0.65-mm lead pitch, exposed pad optional. Pin 1 marked by bevelled corner or dot; pin numbering counterclockwise from top-left.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245APW and 74AVC8T245PW, SN74LVCH245APWT uniquely combines bus-hold, Ioff, and 5.5-V tolerance in a single 20-pin TSSOP package-making it the only option for space-constrained, hot-pluggable, and floating-bus applications requiring zero external bias components.

Availability

SN74LVCH245APWT is available at Aetrix Electronics and suitable for server memory interconnect, industrial backplane interface, and wearable sensor hub applications requiring stable component supply across multi-year production cycles.

Supply support for SN74LVCH245APWT 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 solutions, with decades of expertise in logic interface ICs for industrial and computing markets.

SN74LVCH245APWT belongs to TI's LVCH logic family, engineered for robust mixed-voltage system interfacing-specifically targeting applications demanding bus-hold, Ioff, and wide-input-voltage tolerance without external components.

FAQ

What is the maximum operating temperature for SN74LVCH245APWT?

The SN74LVCH245APWT is rated for continuous operation from –40°C to +125°C ambient temperature. This extended range is validated per JEDEC JESD22-A108 and supports deployment in harsh environments such as base station RF modules and automotive engine-control units where thermal cycling exceeds standard commercial limits.

Does SN74LVCH245APWT require external pull-up or pull-down resistors on its data lines?

No. SN74LVCH245APWT integrates active bus-hold circuitry on all 16 A/B port pins, which maintains valid logic states on floating inputs without external resistors. This feature is always active-unaffected by OE or DIR-and eliminates BOM items and layout overhead in compact designs like SSD modules and IoT edge nodes.

Can SN74LVCH245APWT safely interface a 5-V microcontroller with a 1.8-V FPGA?

Yes. SN74LVCH245APWT accepts input voltages up to 5.5 V while operating from a 1.65–3.6-V VCC supply. When powered at 1.8 V, it translates 5-V logic highs to ~1.6 V outputs compatible with 1.8-V FPGA I/O thresholds, enabling direct connection without discrete level shifters in mixed-voltage control planes.

How does the Ioff feature protect SN74LVCH245APWT during live insertion?

The Ioff circuitry in SN74LVCH245APWT disables all outputs and isolates I/O paths when VCC = 0 V, limiting reverse current to ±20 µA. This prevents damaging back-drive current from powered subsystems into unpowered boards-critical for hot-plug PCIe expansion cards and modular telecom line cards where staggered power sequencing occurs.

What is the propagation delay variation across voltage and temperature for SN74LVCH245APWT?

At 3.3 V, SN74LVCH245APWT exhibits 6.3 ns max tpd at 25°C, rising to 6.7 ns at +125°C. At 1.8 V, tpd increases to 12.7 ns (–40°C to +85°C). These values are fully characterized per JEDEC JESD8-C and ensure timing predictability in both high-speed compute and low-power portable applications.