Texas Instruments SN74LVCH8T245RHLR

Overview

SN74LVCH8T245RHLR from Texas Instruments is an 8-bit dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.65V–5.5V domains (e.g., 1.8V ↔ 3.3V, 3.3V ↔ 5V). It features configurable level-shifting, 3-state outputs, bus-hold on all data inputs, and VCCA-referenced DIR/OE control. Used in smart meter data interfaces requiring robust supply sequencing and Ioff partial-power-down protection.

For engineers reviewing the SN74LVCH8T245RHLR datasheet, SN74LVCH8T245RHLR pinout, SN74LVCH8T245RHLR application, or SN74LVCH8T245RHLR equivalent, key selection criteria include dual-rail voltage flexibility (VCCA/VCCB = 1.65–5.5V), guaranteed glitch-free power-up/down behavior, bus-hold elimination of external resistors, and VQFN-24 (5.5mm × 3.5mm) thermal performance (RθJB = 15.2°C/W).

Technical Context

The SN74LVCH8T245RHLR implements a fully configurable dual-rail architecture where A-port I/Os and control inputs (DIR, OE) are referenced to VCCA, while B-port I/Os track VCCB - both independently adjustable from 1.65V to 5.5V. This enables asynchronous bidirectional translation without direction-control timing constraints.

Its functional modes are defined by DIR (data flow direction) and OE (output enable): DIR = H + OE = L enables A→B transmission; DIR = L + OE = L enables B→A; OE = H forces both ports into high-impedance isolation. Bus-hold circuitry actively maintains valid logic states on undriven A/B inputs, and Ioff limits leakage to ±2μA when either VCCA or VCCB is at 0V.

Key Specifications

Pinout & Package

RHL package is a 24-pin VQFN (5.5mm × 3.5mm) with exposed thermal pad, optimized for low-inductance routing and efficient heat dissipation (RθJB = 15.2°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVCH8T245RHLR and TXB0108RKL, SN74LVCH8T245RHLR delivers optimal balance of voltage flexibility (1.65–5.5V), robustness (glitch-free sequencing, bus-hold, Ioff), and thermal efficiency (RθJB = 15.2°C/W) for industrial and infrastructure applications where reliability outweighs marginal speed gains.

Availability

SN74LVCH8T245RHLR is available at Aetrix Electronics and suitable for smart meter data interfaces, industrial PLC backplanes, video surveillance SoC bridges, and grid infrastructure RTUs requiring stable component supply across extended temperature and voltage ranges.

Supply support for SN74LVCH8T245RHLR 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 90 years of innovation in industrial, automotive, and communications markets.

The SN74LVCH8T245RHLR belongs to TI's LVCH logic family, designed specifically for robust, low-power bidirectional voltage translation in mixed-supply systems where supply sequencing, partial-power-down, and bus stability are critical.

FAQ

What voltage ranges does the SN74LVCH8T245RHLR support on VCCA and VCCB?

The SN74LVCH8T245RHLR supports independent supply voltages from 1.65V to 5.5V on both VCCA and VCCB. This allows translation between common logic families including 1.8V ↔ 2.5V, 1.8V ↔ 3.3V, 3.3V ↔ 5V, and others - all within a single device. The control inputs DIR and OE are referenced to VCCA, not VCCB.

Does the SN74LVCH8T245RHLR require external pullup or pulldown resistors?

No, the SN74LVCH8T245RHLR includes active bus-hold circuitry on all A1–A8 and B1–B8 inputs, which maintains valid logic states on undriven or floating lines. Using external resistors with bus-hold is not recommended, as it disables the feature and may cause contention or increased power draw.

How does the SN74LVCH8T245RHLR behave during power-up or power-down sequencing?

The SN74LVCH8T245RHLR guarantees glitch-free operation: either VCCA or VCCB may be powered on or off in any order without causing spurious output transitions. If either supply drops below 100mV or floats, all I/Os automatically enter high-impedance state - preventing false signaling to connected peripherals during brownout or hot-swap events.

What is the maximum output drive capability of the SN74LVCH8T245RHLR?

The SN74LVCH8T245RHLR delivers up to ±32mA per output at VCCO = 4.5–5.5V, with lower drive (±4mA to ±24mA) scaling down for 1.65–3.6V operation. Its balanced push-pull outputs ensure consistent rise/fall times, and two outputs can be paralleled for 2× drive strength - provided thermal limits (RθJB = 15.2°C/W) and absolute max ratings are observed.

Is the SN74LVCH8T245RHLR suitable for partial-power-down applications?

Yes - the SN74LVCH8T245RHLR incorporates Ioff circuitry that limits input/output leakage to ±2μA when either VCCA or VCCB is at 0V. This prevents damaging back-current flow into powered subsystems, making it ideal for applications like smart meters or PLCs where individual functional blocks are powered down to conserve energy.