Texas Instruments SN74LVCZ245APWT

Overview

SN74LVCZ245APWT from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between 3.3-V and 5-V buses. It operates from 2.7 V to 3.6 V, accepts 5.5-V-tolerant inputs, delivers 6.3 ns max propagation delay at 3.3 V, and supports hot insertion via Ioff and power-up 3-state logic - used in mixed-voltage industrial backplane interfaces.

For engineers reviewing the SN74LVCZ245APWT datasheet, SN74LVCZ245APWT pinout, SN74LVCZ245APWT application, or SN74LVCZ245APWT equivalent, key selection criteria include 5-V input tolerance, 3.3-V VCC compatibility, tpd ≤6.3 ns, Ioff-enabled hot-swap capability, and TSSOP-20 package thermal performance (θJA = 83°C/W).

Technical Context

The SN74LVCZ245APWT implements dual-directional bus control using DIR (direction) and OE (output enable) inputs: DIR = L routes B→A; DIR = H routes A→B; OE = H forces all outputs into high-impedance isolation. Its Ioff circuitry disables outputs when VCC = 0, preventing backflow current during hot insertion.

It supports mixed-mode signaling: 5-V-tolerant inputs operate reliably with 3.3-V VCC, enabling level translation without external biasing. The device enters guaranteed high-impedance state when VCC is below 1.5 V, and maintains robust noise margins (VIH = 2.0 V min, VIL = 0.8 V max) across –40°C to 85°C.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), 6.95 mm × 4.4 mm × 1.2 mm max height, 0.65 mm lead pitch, exposed pad not present, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVCZ245APWT, SN74LVC245APWR offers lower unit cost but sacrifices ground-bounce control and hot-swap reliability, while 74ALVC16245PAG provides double width and dual-rail flexibility at the expense of single-supply simplicity and thermal efficiency in compact layouts.

Availability

SN74LVCZ245APWT is available at Aetrix Electronics and suitable for industrial automation interfaces, test equipment signal routing, and hot-swappable module adapters requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74LVCZ245APWT 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 50 years of innovation in industrial, automotive, and communications markets.

The SN74LVCZ245APWT belongs to TI's LVCZ logic family, engineered specifically for robust mixed-voltage system integration - emphasizing low-noise switching, hot-plug resilience, and seamless 3.3-V/5-V interoperability in mission-critical infrastructure.

FAQ

What is the maximum operating temperature range for the SN74LVCZ245APWT?

The SN74LVCZ245APWT is specified for operation from –40°C to +85°C ambient temperature. This industrial-grade range is validated across all electrical parameters including propagation delay, output drive, and input threshold stability - ensuring reliable performance in factory-floor PLCs, outdoor telecom gear, and motor-drive control cabinets where thermal cycling exceeds consumer-grade limits.

Does the SN74LVCZ245APWT require external pull-up resistors on OE or DIR pins?

No external pull-up resistors are required on OE or DIR for basic functionality, as both inputs are CMOS-compatible with rail-to-rail voltage recognition. However, TI recommends tying OE to VCC via a pull-up resistor (value determined by driver sink capability) to guarantee high-impedance state above 1.5 V during power-up - a design practice critical for preventing bus conflicts in systems with asymmetric power sequencing.

Can the SN74LVCZ245APWT safely interface a 5-V microcontroller with a 3.3-V FPGA?

Yes - the SN74LVCZ245APWT safely bridges those domains: its inputs tolerate 5.5 V regardless of VCC, and its outputs swing to 3.3-V logic levels when powered at 3.3 V. This eliminates level-shifter ICs or resistor dividers. The device maintains timing integrity (tpd ≤6.3 ns) and noise margins (VIH = 2.0 V min) across the full –40°C to 85°C range, making it ideal for FPGA co-processor interfaces in industrial edge nodes.

What is the thermal resistance (θJA) of the SN74LVCZ245APWT in its TSSOP-20 package?

The SN74LVCZ245APWT in TSSOP-20 (PW) package has a junction-to-ambient thermal resistance (θJA) of 83°C/W, measured under JEDEC-standard conditions (single-layer 1-in² copper pad). This value enables continuous operation at up to 100 mW dissipation in still-air environments - sufficient for typical 8-bit bus loads at 24 mA per pin and 10 MHz toggle rates without forced cooling.

How does the Ioff feature of the SN74LVCZ245APWT protect the system during hot insertion?

The Ioff feature in the SN74LVCZ245APWT disables all outputs when VCC = 0 V, blocking reverse current flow from live 5-V or 3.3-V buses into the unpowered device. This prevents latch-up, overheating, and corruption of upstream drivers - a requirement verified per JESD78 Class II (>100 mA) and essential for compliance with IEC 61000-3-2 harmonic emission standards in modular rack systems.