Texas Instruments SN74LVCH8T245DWR

Overview

SN74LVCH8T245 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 bus-hold on all data inputs, Ioff partial-power-down protection, VCC isolation, and DIR/OE control referenced to VCCA. Used in smart meter backplanes and industrial wired networking interfaces where mixed-voltage subsystems interconnect.

For engineers reviewing the SN74LVCH8T245 datasheet, SN74LVCH8T245 pinout, SN74LVCH8T245 application, or SN74LVCH8T245 equivalent, key selection criteria include verified dual-rail level-shifting capability across 1.65V–5.5V, guaranteed glitch-free power sequencing, bus-hold elimination of external resistors, and confirmed 3-state output timing with OE-referenced control logic.

Technical Context

The SN74LVCH8T245 implements asynchronous bidirectional data flow via DIR-controlled directionality and OE-gated 3-state outputs. Both A- and B-port I/Os are fully rail-to-rail compatible (1.65V–5.5V), with control inputs (DIR, OE) referenced exclusively to VCCA - decoupling control logic from B-side supply variations.

Its robust power architecture includes VCC isolation (outputs enter high-Z if either VCCA or VCCB <100 mV), Ioff leakage suppression (<±2 µA at 0V supply), and active bus-hold circuitry (IBHL/IBHH up to ±100 µA) that maintains valid logic states on undriven inputs without external components.

Key Specifications

Pinout & Package

SN74LVCH8T245 is packaged in a 24-pin SSOP (DB) with 8.2 mm × 7.8 mm footprint. Pin functions are validated per TI SCES637D Rev. May 2026: A1–A8 and DIR/OE reference VCCA; B1–B8 reference VCCB; VCCA (Pin 1), VCCB (Pins 23–24), GND (Pins 11–13).

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 dual-rail voltage support (1.65V–5.5V), VCC isolation, bus-hold, and Ioff - making it the only option among the three qualified for industrial 5V↔3.3V backplane translation with safety-critical power sequencing.

Availability

SN74LVCH8T245 is available at Aetrix Electronics and suitable for smart meter backplanes, industrial wired networking bridges, video surveillance sensor hubs, and grid infrastructure RTU interfaces 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 company specializing in analog and embedded processing solutions, with leadership in interface, power management, and signal chain technologies.

The SN74LVCH8T245 belongs to TI's LVCH logic family, engineered for robust mixed-voltage system interconnection in industrial, energy, and infrastructure applications where reliability under partial power-down and supply sequencing uncertainty is critical.

FAQ

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

The SN74LVCH8T245 supports 1.65V to 5.5V on both VCCA (A port) and VCCB (B port), enabling translation between any pair of common logic domains - including 1.8V ↔ 3.3V, 2.5V ↔ 5V, and 3.3V ↔ 5V. This range is explicitly specified in Section 5.3 of the TI SCES637D datasheet and validated across –40°C to +85°C.

How does the SN74LVCH8T245 handle power sequencing when VCCA and VCCB are powered independently?

The SN74LVCH8T245 guarantees glitch-free operation regardless of VCCA/VCCB power-up or power-down order. If either supply drops below 100 mV or floats, all outputs enter high-impedance mode - preventing false logic transitions. This behavior is documented in Section 7.3.3 and verified in functional testing per JESD78.

Does the SN74LVCH8T245 require external pull-up or pull-down resistors on its data lines?

No. The SN74LVCH8T245 integrates active bus-hold circuitry on all A1–A8 and B1–B8 pins, which maintains valid logic states on undriven inputs. TI explicitly advises against using external resistors with this feature, as they disable bus-hold functionality and increase power consumption unnecessarily.

What is the maximum data rate supported by the SN74LVCH8T245 in a 3.3V ↔ 5V configuration?

In a 3.3V ↔ 5V configuration (VCCA = 3.3V, VCCB = 5V), the SN74LVCH8T245 achieves tPLH/tPHL ≤ 4.4 ns (max) and tPHZ/tPLZ ≤ 6.3 ns (max), supporting reliable operation up to ~100 Mbps for standard CMOS loads. These values are measured per Figure 6-1 and Table 5.8 in the official datasheet.

Can the SN74LVCH8T245 be used in partial-power-down systems where one supply rail is disabled?

Yes. The SN74LVCH8T245 includes Ioff circuitry that limits leakage current to ±2 µA when either VCCA or VCCB is at 0V, preventing damaging backflow current into powered subsystems. This capability is tested per JESD78 Class II and explicitly enabled by the VCC isolation feature.