Texas Instruments SN74LVCH245ADWRG4

Overview

SN74LVCH245ADWRG4 from Texas Instruments is an octal bus transceiver with tri-state outputs, designed for bidirectional data translation between 1.65-V and 3.6-V logic domains. It supports mixed-mode operation (5-V-tolerant inputs with 3.3-V VCC), features Ioff for live insertion, bus-hold on all data inputs, and delivers 6.3 ns max propagation delay at 3.3 V - used in server memory interfaces and PC chipset interconnects.

For engineers reviewing the SN74LVCH245ADWRG4 datasheet, SN74LVCH245ADWRG4 pinout, SN74LVCH245ADWRG4 application, or SN74LVCH245ADWRG4 equivalent, key selection criteria include its 1.65–3.6-V supply range, 5.5-V input tolerance, tri-state control via active-low OE and DIR, bus-hold elimination of external resistors, and SOIC-20 package compatibility with legacy PCB layouts.

Technical Context

This device implements a dual-bus, direction-controlled transceiver architecture with independent A and B port I/Os. Its DIR input selects data flow direction (A→B or B→A), while OE enables/disables output drivers into high-impedance state - both inputs are CMOS-compatible and support 5-V signaling regardless of VCC.

The integrated bus-hold circuit maintains valid logic levels on floating A/B inputs without external components, and Ioff protection ensures no back-drive current flows when VCC = 0 V - critical for hot-swap and partial-power-down systems operating across –40°C to 125°C.

Key Specifications

Pinout & Package

SN74LVCH245ADWRG4 is housed in a 20-pin SOIC (DW) package measuring 12.80 mm × 7.50 mm, with standard 0.025-inch lead pitch and surface-mount gull-wing leads compatible with IPC-7351B footprint DW_20.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVCH245ADWRG4, SN74LVC245A trades bus-hold functionality for lower unit cost, while 74AVC8T245 extends voltage range downward but sacrifices Ioff and 5-V tolerance - making SN74LVCH245ADWRG4 optimal for industrial hot-swap and mixed-voltage robustness.

Availability

SN74LVCH245ADWRG4 is available at Aetrix Electronics and suitable for server backplanes, industrial PLCs, automotive domain controllers, and medical imaging subsystems requiring stable component supply across extended temperature and long-life production cycles.

Supply support for SN74LVCH245ADWRG4 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

SN74LVCH245ADWRG4 belongs to TI's LVCH logic family - engineered for robust mixed-voltage interoperability, live-insertion reliability, and bus-hold stability in mission-critical embedded control and data-path applications.

FAQ

What is the maximum input voltage rating for SN74LVCH245ADWRG4?

The SN74LVCH245ADWRG4 supports input voltages up to 5.5 V across all A and B port pins, regardless of VCC level - enabling direct connection to 5-V logic without external level-shifting circuitry. This specification is validated per Absolute Maximum Ratings and applies over the full –40°C to 125°C operating temperature range. The 5.5-V tolerance is maintained even when VCC is as low as 1.65 V, confirming true mixed-voltage translation capability for the SN74LVCH245ADWRG4.

Does SN74LVCH245ADWRG4 support hot-swap or live-insertion applications?

Yes, SN74LVCH245ADWRG4 supports live insertion via its Ioff feature, which limits power-off leakage current to ±10 µA when VCC = 0 V - preventing damaging back-current flow during board replacement in powered systems. This behavior is guaranteed across –40°C to 125°C and is explicitly tested per JEDEC JESD78. For reliable hot-swap operation, OE must be tied to VCC through a pullup resistor, and the SN74LVCH245ADWRG4 must be placed downstream of power sequencing controls.

How does the bus-hold function work on SN74LVCH245ADWRG4?

The SN74LVCH245ADWRG4 integrates active bus-hold circuitry on all A1–A8 and B1–B8 inputs, maintaining valid logic states (VI ≈ 0.7×VCC or VI ≈ 0.3×VCC) on floating pins without external resistors. It sources/sinks up to ±75 µA at VCC = 3.0 V to counteract noise-induced transitions. Bus-hold remains active regardless of OE or DIR state - meaning it functions even when outputs are disabled or direction is changed, ensuring deterministic behavior in undriven bus conditions for the SN74LVCH245ADWRG4.

What is the propagation delay performance of SN74LVCH245ADWRG4 at 1.8 V?

At VCC = 1.8 V and TA = 25°C, the SN74LVCH245ADWRG4 exhibits a maximum propagation delay (tpd) of 12.7 ns (–40°C to 85°C range) and 13.7 ns (–40°C to 125°C range), per Switching Characteristics tables in the official datasheet. These values apply to A↔B data path transitions under CL = 50 pF loading. The delay increases predictably with lower VCC due to reduced drive strength - a known trade-off confirmed in Figure 1 (TPD vs. VCC) of the SN74LVCH245ADWRG4 characterization data.

Is SN74LVCH245ADWRG4 pin-compatible with SN74LVC245A?

Yes, SN74LVCH245ADWRG4 is pin-compatible with SN74LVC245A in the SOIC-20 (DW) package - sharing identical pin assignments for DIR, OE, A1–A8, B1–B8, GND, and VCC. However, SN74LVCH245ADWRG4 adds bus-hold and enhanced Ioff functionality not present in SN74LVC245A, meaning it can directly replace SN74LVC245A in most layouts but may require minor firmware or timing validation due to differences in input hysteresis and leakage behavior.