Texas Instruments SN74LVCH8T245DGVR

Overview

SN74LVCH8T245 from Texas Instruments is an 8-bit dual-supply noninverting bus transceiver enabling bidirectional voltage-level translation between 1.65V–5.5V domains (e.g., 1.8V ↔ 3.3V, 3.3V ↔ 5V). It features bus-hold on all data inputs, Ioff partial-power-down protection, VCC isolation, and DIR/OE control referenced to VCCA. Used in wired networking interfaces requiring robust level-shifting with no external biasing.

For engineers reviewing the SN74LVCH8T245 datasheet, SN74LVCH8T245 pinout, SN74LVCH8T245 application, or SN74LVCH8T245 equivalent, key selection criteria include dual-rail operating range (VCCA/VCCB = 1.65–5.5V), guaranteed 32mA output drive at 5V, bus-hold functionality eliminating pull resistors, glitch-free power sequencing, and 24-pin TVSOP (DGV) package compatibility with space-constrained industrial PCBs.

Technical Context

The SN74LVCH8T245 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 - enabling independent supply selection across 1.65V–5.5V. Its functional modes are defined by OE (output enable) and DIR (direction), with three states: A→B transmission (DIR=H, OE=L), B→A transmission (DIR=L, OE=L), or full 3-state isolation (OE=H).

Glitch-free power sequencing ensures safe operation during asymmetric rail ramp-up/down, and VCC isolation forces high-impedance outputs if either VCCA or VCCB falls below 100mV or floats. Bus-hold circuitry sustains valid logic levels on undriven A/B inputs without external components, and Ioff limits backflow current during partial power-down.

Key Specifications

Pinout & Package

SN74LVCH8T245 is packaged in a 24-pin TVSOP (DGV) measuring 5.0mm × 6.4mm, optimized for high-density routing and thermal performance (RθJA = 91.1°C/W). Pin functions are electrically isolated per supply domain: A-side pins reference VCCA; B-side pins reference VCCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVC8T245 and TXB0108, the SN74LVCH8T245 uniquely combines wide voltage support (1.65–5.5V), bus-hold, VCC isolation, and Ioff - making it the only option qualified for industrial infrastructure with mixed-rail hot-swap and partial-power-down requirements.

Availability

SN74LVCH8T245 is available at Aetrix Electronics and suitable for video surveillance systems, smart meter communication modules, and industrial wired networking equipment requiring stable component supply across extended temperature and mixed-voltage conditions.

Supply support for SN74LVCH8T245 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.

The SN74LVCH8T245 belongs to TI's LVCH logic family, engineered for robust voltage translation in infrastructure-grade systems where reliability under asymmetric power sequencing and partial power-down is mandatory.

FAQ

What voltage ranges does the SN74LVCH8T245 support on its A and B ports?

The SN74LVCH8T245 supports independent supply voltages from 1.65V to 5.5V on both VCCA (A port) and VCCB (B port). This allows translation between any common logic domains - including 1.8V ↔ 2.5V, 1.8V ↔ 3.3V, 3.3V ↔ 5V, and 2.5V ↔ 5V - without external components. The SN74LVCH8T245 maintains full functionality across this entire range, with specified timing and drive performance at each combination.

Does the SN74LVCH8T245 require external pullup or pulldown resistors?

No, the SN74LVCH8T245 integrates active bus-hold circuitry on all 16 data I/Os (A1–A8, B1–B8), which sustains valid logic states on undriven or floating inputs. Using external pull resistors disables the bus-hold feature and is explicitly discouraged in the datasheet. The SN74LVCH8T245 eliminates the need for those resistors, reducing BOM cost and PCB area.

How does the SN74LVCH8T245 behave during power-up or power-down sequencing?

The SN74LVCH8T245 features glitch-free power supply sequencing and VCC isolation. If either VCCA or VCCB drops below 100mV or floats, all outputs automatically enter a high-impedance state - preventing signal contention. Control inputs (DIR, OE) remain referenced to VCCA, ensuring deterministic behavior even during asymmetric rail transitions. This makes the SN74LVCH8T245 suitable for systems with staggered power domains.

Can the SN74LVCH8T245 drive heavy capacitive loads?

Yes - the SN74LVCH8T245 delivers ±32mA output drive at VCCO = 4.5–5.5V, enabling direct driving of >10 pF loads or multiple CMOS inputs. Its balanced push-pull outputs provide fast edge rates, though layout must minimize trace inductance to avoid ringing. For heavier loads, two outputs can be paralleled to double drive strength - provided total current stays within absolute maximum ratings.

Is the SN74LVCH8T245 compatible with partial-power-down systems?

Yes - the SN74LVCH8T245 includes Ioff circuitry that limits input/output leakage to ±2μA when either VCCA or VCCB is at 0V. This prevents damaging back-current flow from powered subsystems into unpowered sections, satisfying JEDEC JESD78 Class II latch-up requirements. The SN74LVCH8T245 is explicitly designed for partial-power-down node operation in modular industrial and medical systems.