Texas Instruments SN74LVCH244APWR

Overview

SN74LVCH244APWR from Texas Instruments is an octal noninverting buffer/driver with 3-state outputs, designed for 1.65-V to 3.6-V V_CC operation. It features two independent 4-bit channels, bus-hold circuitry on all data inputs, I_off support for partial-power-down mode, and mixed-mode signal translation (5-V input compatible with 3.3-V V_CC). It is used in address/data bus buffering and level translation in industrial control and embedded interface systems.

For engineers reviewing the SN74LVCH244APWR datasheet, SN74LVCH244APWR pinout, SN74LVCH244APWR application, or SN74LVCH244APWR equivalent, key selection criteria include 3-state output timing (t_pd = 5.9 ns at 3.3 V), bus-hold current (±75 µA at 3 V), I_off leakage (<±10 µA), and TSSOP-20 package compatibility with high-density PCB layouts.

Technical Context

This device implements dual 4-bit noninverting buffers with separate active-low output-enable (OE) controls per group. Each channel passes A-inputs to Y-outputs when its OE is low; outputs enter high-impedance state when OE is high. Bus-hold circuitry actively maintains valid logic levels on unused inputs without external resistors.

The SN74LVCH244APWR supports mixed-voltage interfacing: inputs tolerate up to 5.5 V regardless of V_CC, enabling direct connection to 5-V TTL or CMOS sources while operating at 1.65–3.6 V. Its I_off protection disables outputs during power-down to prevent back-current flow.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), 6.95 mm × 4.4 mm × 1.2 mm height, 0.65 mm pitch, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal buffer/level translation applications.

Compared with SN74LVC244APWR and 74ALVC244PW, the SN74LVCH244APWR uniquely combines bus-hold, I_off, and full 1.65–3.6-V operation-making it the only option for robust, low-voltage, floating-input industrial and automotive interfaces.

Availability

SN74LVCH244APWR is available at Aetrix Electronics and suitable for industrial PLC backplanes, embedded microcontroller bus expansion, automotive body control modules, and automated test equipment requiring stable component supply and long-term manufacturability.

Supply support for SN74LVCH244APWR 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 90 years of innovation in industrial, automotive, and communications markets.

The SN74LVCH244A belongs to TI's LVC/LVCH logic family, engineered for low-voltage, high-speed, mixed-signal interfacing in space-constrained and power-sensitive applications-from factory automation to portable instrumentation.

FAQ

What is the maximum input voltage rating for SN74LVCH244APWR?

The SN74LVCH244APWR supports input voltages up to 5.5 V across the full operating temperature range, regardless of V_CC level. This allows direct connection to 5-V logic families while operating at 1.65–3.6 V, making SN74LVCH244APWR ideal for mixed-voltage system interfacing without external level-shifting components.

Does SN74LVCH244APWR require external pullup resistors on its inputs?

No, SN74LVCH244APWR includes integrated bus-hold circuitry on all eight data inputs, which actively maintains the last-valid logic state when inputs are floating or undriven. Using external pullup or pulldown resistors with SN74LVCH244APWR is not recommended, as it may interfere with bus-hold functionality and increase power consumption unnecessarily.

What is the propagation delay of SN74LVCH244APWR at 3.3 V?

The maximum propagation delay (t_pd) of SN74LVCH244APWR is 5.9 ns when V_CC = 3.3 V and operating at 25°C. This value is measured from input transition to output transition under standard load conditions (30 pF, 500 Ω), confirming SN74LVCH244APWR's suitability for high-speed digital bus buffering in real-time embedded systems.

How does the I_off feature function in SN74LVCH244APWR?

The I_off circuitry in SN74LVCH244APWR disables all outputs when V_CC = 0 V, limiting leakage current to <±10 µA. This prevents damaging current backflow through the device during partial power-down or hot-swap events-ensuring system reliability in modular industrial and telecom infrastructure where power domains are sequenced independently.

Is SN74LVCH244APWR pin-compatible with other TSSOP-20 octal buffers?

Yes, SN74LVCH244APWR shares identical pinout and footprint with SN74LVC244APWR and SN74LVTH244APWR in the TSSOP-20 (PW) package. However, functional differences-including bus-hold presence, I_off support, and drive strength-must be verified against design requirements before substitution, as electrical behavior differs despite mechanical compatibility.