Texas Instruments SN74LVCZ240APWRG4

Overview

SN74LVCZ240APWRG4 from Texas Instruments is an octal buffer with power-up 3-state outputs, configured as two independent banks of four non-inverting drivers each, operating from 2.7V to 3.6V supply. It supports mixed-mode signal operation (5.5V-tolerant inputs with 3.3V VCC), delivers 6.5ns max propagation delay at 3.3V, and enables hot insertion via Ioff and power-up 3-state functionality - used in bus interface and level-shifting applications within industrial control backplanes.

For engineers reviewing the SN74LVCZ240APWRG4 datasheet, SN74LVCZ240APWRG4 pinout, SN74LVCZ240APWRG4 application, or SN74LVCZ240APWRG4 equivalent, key selection criteria include its dual-bank output enable architecture, 5.5V input tolerance, ground bounce (VOLP < 0.8V) and undershoot (VOHV > 2V) performance at 3.3V, and TSSOP-20 packaging for high-density PCB layouts.

Technical Context

The SN74LVCZ240APWRG4 implements eight CMOS non-inverting buffers split into two functionally isolated banks (Bank 1: pins A1–A4/Y1–Y4; Bank 2: pins A5–A8/Y5–Y8), each controlled by a dedicated active-low output enable (OE1/OE2). Its balanced push-pull outputs drive high/low states symmetrically while entering true high-impedance when disabled - critical for bidirectional bus contention avoidance.

It features partial power-down (Ioff) protection that disables all outputs when VCC = 0V, and TTL-compatible inputs with VIH(min) = 2.0V and VIL(max) = 0.8V at 3.3V VCC. Input overvoltage tolerance up to 5.5V allows direct interfacing with 5V logic without external level shifters, while power-up 3-state ensures outputs remain high-Z during supply ramp-up.

Key Specifications

Pinout & Package

Packaged in a 20-pin TSSOP (PW), the SN74LVCZ240APWRG4 measures 6.5mm × 6.4mm with a 0.65mm lead pitch and exposed pad not present. The package supports fine-pitch surface-mount assembly and provides thermal resistance RθJA = 120.3°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC240APWR and 74LVC240ADB, the SN74LVCZ240APWRG4 uniquely combines 5.5V input tolerance, guaranteed power-up 3-state, and low-noise output characteristics in a compact TSSOP-20 package - making it optimal for space-constrained, mixed-voltage, and hot-swap-capable industrial designs.

Availability

SN74LVCZ240APWRG4 is available at Aetrix Electronics and suitable for industrial backplane interfaces, embedded microcontroller bus expansion, hot-swappable module control, and LED driver interfaces requiring stable component supply across extended temperature ranges (–40°C to +85°C) and long production lifecycles.

Supply support for SN74LVCZ240APWRG4 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 technologies, with leadership in logic, power management, and signal chain solutions for industrial, automotive, and communications markets.

The SN74LVCZ240APWRG4 belongs to TI's LVCZ advanced logic family, designed specifically for robust, mixed-voltage digital interfacing in harsh industrial environments where signal integrity, hot-swap reliability, and long-term supply stability are critical.

FAQ

What is the purpose of the dual output enable (OE1/OE2) pins on the SN74LVCZ240APWRG4?

The SN74LVCZ240APWRG4 uses two independent active-low output enables (OE1 on pin 1, OE2 on pin 19) to separately control its two banks of four buffers. When OE1 is low, Bank 1 outputs (Y1–Y4) are enabled; when high, they enter high-impedance. OE2 performs the same for Bank 2 (Y5–Y8). This allows selective bus gating, power domain isolation, or staggered signal activation - a key feature distinguishing SN74LVCZ240APWRG4 from single-OE octal buffers.

Does the SN74LVCZ240APWRG4 support 5V logic inputs while operating at 3.3V VCC?

Yes, the SN74LVCZ240APWRG4 explicitly supports 5.5V-tolerant inputs across its full operating range (2.7V–3.6V VCC). This means it can accept 5V logic signals directly on all A-input pins without damage or level-shifting circuitry - a core capability of the "Z" variant confirmed in TI's SCES273I datasheet Section 1 and Table 5.3. This makes SN74LVCZ240APWRG4 ideal for interfacing legacy 5V peripherals with modern 3.3V controllers.

How does the power-up 3-state feature work in the SN74LVCZ240APWRG4?

The SN74LVCZ240APWRG4 guarantees high-impedance outputs during power-up by design: when VCC ramps from 0V to operating voltage, internal circuitry holds all outputs in 3-state regardless of OE pin state until VCC exceeds ~1.5V and stabilizes. This behavior is verified in TI's functional description (Section 7.1) and eliminates bus contention risks during system boot - a critical differentiator from standard LVC240 variants that lack this guarantee.

What is the maximum capacitive load the SN74LVCZ240APWRG4 can drive while maintaining specified timing?

TI specifies that the SN74LVCZ240APWRG4 maintains full datasheet timing performance (including 6.5ns tpd) with total load capacitance ≤50pF, as stated in Section 8.2.1.1. Exceeding this value increases propagation delay and output transition time, potentially violating setup/hold margins in high-speed interfaces. For loads >50pF, series damping resistors or buffer replication should be used - guidance detailed in Figure 8-2 and Section 8.1 of the SN74LVCZ240APWRG4 datasheet.

Can unused inputs on the SN74LVCZ240APWRG4 be left floating?

No, unused inputs on the SN74LVCZ240APWRG4 must never be left floating. As a CMOS device with TTL-compatible inputs, floating pins cause excessive current draw, oscillation, and increased power consumption. TI mandates termination to VCC or GND (Section 7.3.3); a 10kΩ pull-up or pull-down resistor is recommended for unused inputs that may transition during system operation - a requirement explicitly called out in the SN74LVCZ240APWRG4 datasheet Section 7.3.3 and Application Note SCLA015.