Texas Instruments SN74LVCH244APWT

Overview

SN74LVCH244APWT 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 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 buffering, bus isolation, and level-shifting applications in industrial control and embedded systems.

For engineers reviewing the SN74LVCH244APWT datasheet, SN74LVCH244APWT pinout, SN74LVCH244APWT application, or SN74LVCH244APWT equivalent, key selection criteria include its 20-pin TSSOP package, 5.9 ns max propagation delay at 3.3 V, ±24 mA output drive, bus-hold functionality eliminating external resistors, and I_off protection enabling safe hot-insertion in powered-backplane systems.

Technical Context

The SN74LVCH244APWT implements dual 4-bit noninverting buffers with independent 3-state enable controls (1OE and 2OE), allowing selective channel isolation. Its bus-hold circuitry actively maintains valid logic states on undriven inputs without external pullup/pulldown resistors-critical for stable operation in noisy or floating-bus environments.

It 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. The I_off feature disables outputs and blocks current flow when V_CC = 0 V, preventing backflow damage during partial power-down sequences.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 4.4 mm × 6.5 mm body, 0.65 mm pitch, 1.2 mm max height, RoHS-compliant NiPdAu lead finish, MSL Level-1 (unlimited floor life).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APW and 74ALVC244PW, the SN74LVCH244APWT uniquely combines bus-hold, I_off, and 5-V-tolerant inputs in a single 20-pin TSSOP package-making it optimal for robust, mixed-supply embedded designs requiring minimal external components and guaranteed signal stability.

Availability

SN74LVCH244APWT is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74LVCH244APWT 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 SN74LVCH244A product line delivers robust, low-voltage octal buffers optimized for mixed-signal interfacing, bus isolation, and power-aware system design in industrial, automotive, and communications applications.

FAQ

What is the maximum operating temperature range for the SN74LVCH244APWT?

The SN74LVCH244APWT is rated for operation from –40°C to +85°C ambient temperature. This industrial-grade temperature range ensures reliable performance in demanding environments such as factory automation controllers, automotive body modules, and outdoor instrumentation-without derating or thermal throttling under normal PCB layout conditions.

Does the SN74LVCH244APWT require external pullup or pulldown resistors on its inputs?

No, the SN74LVCH244APWT does not require external pullup or pulldown resistors on its inputs due to integrated bus-hold circuitry. This feature actively maintains the last-valid logic state on undriven or floating inputs, reducing component count and improving noise immunity-confirmed by TI's Electrical Characteristics table showing ±75 µA hold current at V_CC = 3.0 V.

Can the SN74LVCH244APWT safely interface a 5-V microcontroller with a 3.3-V FPGA?

Yes, the SN74LVCH244APWT can safely interface a 5-V microcontroller with a 3.3-V FPGA. Its inputs tolerate up to 5.5 V regardless of V_CC, and its outputs swing rail-to-rail within the 3.3-V domain. When V_CC = 3.3 V, VOH exceeds 2.2 V and VOL stays below 0.4 V-meeting LVTTL input thresholds for the FPGA while protecting its I/O cells from overvoltage.

What is the purpose of the I_off specification in the SN74LVCH244APWT datasheet?

The I_off specification (±10 µA maximum) defines the leakage current that flows through the SN74LVCH244APWT's I/O pins when V_CC = 0 V and inputs/outputs are biased to voltages up to 5.5 V. This parameter ensures safe hot-plug operation and prevents damaging back-current flow during partial power-down-critical for modular systems like programmable logic controllers and telecom line cards where boards may be inserted into live backplanes.

Is the SN74LVCH244APWT pin-compatible with other members of the SN74LVCH244A family?

Yes, the SN74LVCH244APWT is pin-compatible with all other SN74LVCH244A variants in the same 20-pin TSSOP (PW) package-including SN74LVCH244APW and SN74LVCH244APWR. Pin functions, electrical characteristics, and thermal behavior are identical across these orderable part numbers; only packaging format (tube vs. tape-and-reel) and reel quantity differ.