Texas Instruments SN74LVCH245APWE4

Overview

SN74LVCH245APWE4 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 while accepting 5-V-tolerant inputs. It features 20-pin TSSOP packaging, 6.3 ns max propagation delay at 3.3 V, Ioff support for live insertion, and integrated bus-hold on all data inputs - enabling use in mixed-voltage server backplanes and industrial I/O modules without external resistors.

For engineers reviewing the SN74LVCH245APWE4 datasheet, SN74LVCH245APWE4 pinout, SN74LVCH245APWE4 application, or SN74LVCH245APWE4 equivalent, key selection criteria include voltage translation capability (1.65–3.6 V VCC with 5.5 V input tolerance), tri-state control timing (8.5 ns disable time at 3.3 V), bus-hold current specification (±75 µA at 3 V), and thermal performance (RθJA = 102.5°C/W in TSSOP).

Technical Context

This device implements a dual-bus, direction-controlled transceiver architecture with independent DIR and OE inputs: DIR selects data flow direction (A→B or B→A), while OE enables/disables all outputs into high-impedance state. Its Ioff circuitry actively isolates I/O terminals during partial power-down, preventing back-drive current when VCC = 0 V.

The integrated bus-hold latch maintains valid logic levels on floating A/B port inputs without external biasing, and its 5-V-tolerant inputs allow direct interfacing with legacy 5-V peripherals in modern 3.3-V or 1.8-V systems - a critical capability for upgrade paths in telecom infrastructure and embedded controllers.

Key Specifications

Pinout & Package

SN74LVCH245APWE4 is housed in a 20-pin TSSOP (PW) package measuring 6.50 mm × 4.40 mm, with 0.65-mm lead pitch and exposed pad for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVCH245APWE4, SN74LVC245A omits bus-hold and Ioff - increasing design complexity in floating-input or partial-power-down scenarios - while 74AVC8T245 trades industrial temperature rating and robustness for speed and lower-voltage compatibility.

Availability

SN74LVCH245APWE4 is available at Aetrix Electronics and suitable for server backplanes, industrial I/O modules, and telecom line cards requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVCH245APWE4 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 decades of experience in high-reliability logic and interface solutions.

The SN74LVCH245A product line delivers robust, voltage-flexible bus transceivers for mixed-signal system interconnect - specifically engineered for industrial automation, communications infrastructure, and automotive body electronics where voltage translation and power sequencing resilience are critical.

FAQ

What is the maximum operating temperature for SN74LVCH245APWE4?

The SN74LVCH245APWE4 is rated for operation from –40°C to +125°C ambient temperature. This extended range is validated per TI's characterization and testing protocols and makes SN74LVCH245APWE4 suitable for under-hood automotive applications, industrial motor drives, and telecom base station equipment where thermal margins are critical.

Does SN74LVCH245APWE4 support 5-V input signals when powered at 1.8 V?

Yes, SN74LVCH245APWE4 accepts input voltages up to 5.5 V regardless of VCC level (1.65–3.6 V). When powered at 1.8 V, its inputs remain 5-V tolerant - enabling direct interfacing with legacy 5-V peripherals without external level shifters, a key advantage confirmed in Section 6.3 of the official datasheet.

How does the bus-hold feature function on SN74LVCH245APWE4?

The bus-hold circuit in SN74LVCH245APWE4 actively maintains the last-valid logic state on each A/B port input when left floating, drawing ±75 µA at 3 V VCC. It operates independently of OE and DIR states and eliminates the need for external pull-up or pull-down resistors - reducing BOM cost and layout complexity in systems with unterminated data lines.

Is SN74LVCH245APWE4 pin-compatible with SN74LVC245A?

SN74LVCH245APWE4 and SN74LVC245A share identical 20-pin TSSOP (PW) packaging and pinout, including DIR, OE, A1–A8, B1–B8, VCC, and GND assignments. However, SN74LVCH245APWE4 adds bus-hold and Ioff functionality not present in SN74LVC245A - making it a functional superset but not a drop-in replacement where those features are unused or unsupported by firmware.

What is the typical power dissipation of SN74LVCH245APWE4 at 3.3 V with all outputs enabled?

At 3.3 V VCC and 25°C, SN74LVCH245APWE4 exhibits a typical power dissipation capacitance (Cpd) of 47 pF per transceiver when outputs are enabled and operating at 10 MHz. Combined with supply current (ICC ≤ 10 µA static), this yields sub-5-mW dynamic power consumption under typical bus activity - ideal for thermally constrained embedded designs.