Texas Instruments SN74LVCZ244APWT

Overview

SN74LVCZ244APWT from Texas Instruments is an octal 3-state buffer/driver IC configured as two independent 4-bit banks, each controlled by a dedicated active-low output enable pin. It operates from 2.7V to 3.6V, supports 5.5V-tolerant inputs, delivers ≤5.9ns propagation delay at 3.3V, and enables mixed-mode interfacing (e.g., 5V signals with 3.3V V_CC) in high-speed memory and bus interface applications.

For engineers reviewing the SN74LVCZ244APWT datasheet, SN74LVCZ244APWT pinout, SN74LVCZ244APWT application, or SN74LVCZ244APWT equivalent, key selection criteria include its dual-bank 3-state control architecture, I_off support for live insertion, ground bounce (VOLP) < 0.8V, and VOH undershoot (VOHV) > 2V - all critical for signal integrity in server backplanes and network switch data paths.

Technical Context

The SN74LVCZ244APWT implements two electrically isolated 4-bit buffer banks, each with independent OE control enabling precise bus segmentation. Its balanced CMOS 3-state outputs provide symmetrical sourcing/sinking capability up to ±24mA at 3V, while the I_off feature disables all outputs during partial power-down, limiting leakage to ±5μA when V_CC = 0V.

It supports mixed-voltage operation via 5.5V-tolerant inputs and rail-referenced outputs (0–V_CC), allowing direct connection to 5V logic without level shifters. The device meets JESD78 Class II latch-up immunity (>100mA), and its fast edge rates require careful PCB layout - including series damping resistors and controlled-impedance traces - to suppress ringing on traces >12cm.

Key Specifications

Pinout & Package

PW package: 20-pin TSSOP (6.5mm × 6.4mm body with pins), 0.65mm pitch, exposed thermal pad (optional GND connection).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with SN74LVC244APW and 74ALVC244PW, the SN74LVCZ244APWT uniquely combines 5.5V input tolerance, I_off, and <0.8V ground bounce - making it the only choice for industrial backplanes requiring both mixed-voltage interoperability and safe hot-plug operation.

Availability

SN74LVCZ244APWT is available at Aetrix Electronics and suitable for server backplanes, network switch data paths, and industrial memory subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVCZ244APWT 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 logic solutions, with decades of experience in high-reliability interface IC design.

The SN74LVCZ244APWT belongs to TI's LVCZ logic family, engineered specifically for robust mixed-voltage bus interfacing in enterprise infrastructure equipment where signal integrity, hot-swap safety, and wide temperature operation are non-negotiable.

FAQ

What is the maximum input voltage the SN74LVCZ244APWT can tolerate?

The SN74LVCZ244APWT accepts input voltages up to 5.5V regardless of V_CC level - a key Z-series feature enabling direct interfacing with 5V logic families while operating from a 3.3V supply. This tolerance is maintained across the full –40°C to +125°C temperature range and does not require external clamping circuitry, as internal diodes handle transient overvoltage conditions per the datasheet's absolute maximum ratings.

Does the SN74LVCZ244APWT support hot-plug or live insertion?

Yes, the SN74LVCZ244APWT supports live insertion via its I_off feature: when V_CC = 0V, all outputs enter high-impedance mode with leakage limited to ±5μA, preventing back-driving of powered systems. This behavior is explicitly characterized in the Electrical Characteristics table and validated per JESD78 Class II latch-up testing, making SN74LVCZ244APWT suitable for modular server and telecom chassis where field-replaceable units must be inserted into live backplanes.

What is the propagation delay of the SN74LVCZ244APWT at 3.3V?

The maximum propagation delay (t_pd) of the SN74LVCZ244APWT is 5.9ns at V_CC = 3.3V and T_A = –40°C to +85°C, as specified in Section 5.6 of the datasheet. At the extended temperature range (–40°C to +125°C), t_pd increases to 6.4ns under identical voltage conditions. These values are measured with 30pF load and reflect worst-case performance across process, voltage, and temperature corners - critical for timing closure in high-speed parallel bus designs.

How should the thermal pad on the SN74LVCZ244APWT PW package be handled?

The thermal pad on the SN74LVCZ244APWT PW (TSSOP) package may be connected to GND or left floating - it must not be tied to any signal or supply other than GND. TI's datasheet explicitly states this in the Pin Functions table (Section 4), and thermal characterization data (Section 5.4) assumes either configuration. For optimal thermal performance in high-power-density layouts, soldering the pad to a solid GND plane improves Ψ_JB by ~10°C/W, but electrical functionality is unaffected if left unconnected.

Can the SN74LVCZ244APWT drive 50Ω transmission lines directly?

No, the SN74LVCZ244APWT is not designed for direct 50Ω line driving; its output structure targets bus loading (typically 10–30pF), not impedance-matched RF signaling. Attempting to drive 50Ω loads causes excessive current draw beyond its ±24mA rating and induces severe signal reflections. For controlled-impedance traces >12cm, TI recommends source termination using a series damping resistor (e.g., 22–33Ω) placed near the SN74LVCZ244APWT output - as detailed in Figure 8-7 and Section 8.4.2 of the datasheet.