Texas Instruments SN74LVTZ244DBR

Overview

SN74LVTZ244DBR from Texas Instruments is an octal 3.3-V bus buffer/driver with two independent 4-bit channels, 3.3-V VCC operation, mixed-mode 5-V input tolerance, and bus-hold inputs eliminating external pullups. It supports unregulated battery operation down to 2.7 V and features high-impedance outputs during power-up/down for system-safe hot insertion in backplane and memory interface applications.

For engineers reviewing the SN74LVTZ244DBR datasheet, SN74LVTZ244DBR pinout, SN74LVTZ244DBR application, or SN74LVTZ244DBR equivalent, key selection criteria include its 20-pin SSOP (DB) package, ±64 mA output drive at 3.3 V, 2.5 ns typical propagation delay, bus-hold input retention, and compatibility with 5-V TTL signaling in 3.3-V systems.

Technical Context

This device implements Advanced BiCMOS Technology (ABT) to achieve low-static power dissipation while maintaining TTL-compatible switching performance. Its dual 4-bit architecture uses separate OE# inputs per channel, enabling independent control of output enable states without internal contention.

The bus-hold circuitry actively maintains valid logic levels on floating A-inputs at ±75 µA hold current, and the output stage supports 5-V-tolerant inputs with VIL = 0.8 V and VIH = 2 V under 3.3-V VCC - critical for mixed-voltage signal translation between legacy 5-V peripherals and modern 3.3-V controllers.

Key Specifications

Pinout & Package

SN74LVTZ244DBR is housed in a 20-pin Shrink Small-Outline Package (SSOP-DB), 7.4 mm × 5.0 mm footprint, 2.0 mm max height, 0.65 mm lead pitch, JEDEC MO-150 compliant. Pin 1 index located at top-left corner with notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and 74ALVC244MTCX, SN74LVTZ244DBR uniquely combines 5-V input tolerance, integrated bus-hold, and industrial temperature rating - making it the only choice for robust, drop-in replacement in legacy 5-V peripheral interfacing without redesign.

Availability

SN74LVTZ244DBR is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA I/O expansion, memory subsystem buffering, and hot-swap card edge applications requiring stable component supply across extended product lifecycles.

Supply support for SN74LVTZ244DBR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The SN74LVTZ244DBR belongs to TI's ABT-family of advanced BiCMOS logic devices, engineered specifically for reliable 3.3-V system interfacing with legacy 5-V components in space- and power-constrained industrial designs.

FAQ

What is the maximum operating voltage for SN74LVTZ244DBR?

The absolute maximum supply voltage (VCC) for SN74LVTZ244DBR is 4.6 V, but the recommended operating range is 2.7 V to 3.6 V. Exceeding 3.6 V may cause parametric degradation or reliability issues. The device tolerates 5-V input signals safely due to its 5-V-tolerant input structure - this does not extend to VCC itself. Always maintain VCC within 2.7–3.6 V for guaranteed functionality and lifetime reliability of SN74LVTZ244DBR.

Does SN74LVTZ244DBR require external pullup resistors on its inputs?

No, SN74LVTZ244DBR does not require external pullup resistors because it integrates active bus-hold circuitry on all eight A-inputs. This feature maintains the last-valid logic state with ±75 µA hold current, eliminating floating inputs and associated noise susceptibility. External pullups are unnecessary unless a specific logic default (e.g., forced HIGH during reset) is required beyond what bus-hold provides - a design choice, not a requirement, for SN74LVTZ244DBR.

Can SN74LVTZ244DBR interface directly between a 3.3-V microcontroller and 5-V peripherals?

Yes, SN74LVTZ244DBR supports direct interfacing between 3.3-V microcontrollers and 5-V peripherals. Its inputs tolerate up to 5.5 V regardless of VCC, and its outputs swing rail-to-rail within the 3.3-V domain. When driven by a 3.3-V MCU, SN74LVTZ244DBR translates logic levels to drive 5-V TTL-compatible inputs reliably - confirmed by VIH = 2 V and VIL = 0.8 V specs at VCC = 3.3 V. This capability is intrinsic to SN74LVTZ244DBR's ABT architecture.

What is the thermal performance of SN74LVTZ244DBR in its DB package?

SN74LVTZ244DBR in the SSOP-DB package has a maximum power dissipation of 0.6 W at TA = 55°C in still air, based on a junction temperature limit of 150°C. Its thermal resistance θJA is approximately 167°C/W (calculated from 150°C − 55°C ÷ 0.6 W). For continuous operation at full output load (64 mA per channel), ensure adequate PCB copper area and airflow; derate linearly above 55°C ambient. This thermal profile is validated for SN74LVTZ244DBR and documented in TI's SCBD002B thermal guidelines.

Is SN74LVTZ244DBR pin-compatible with other 20-pin octal buffers like SN74LVC244A?

No, SN74LVTZ244DBR is not pin-compatible with SN74LVC244A. Although both are 20-pin octal buffers, their pinouts differ: SN74LVTZ244DBR places 1OE at pin 1 and 2OE at pin 19, while SN74LVC244A assigns 1OE to pin 1 and 2OE to pin 19 *only in TSSOP*, but differs in SOIC. More critically, SN74LVTZ244DBR's DB package has 0.65 mm pitch versus 0.635 mm for many SOIC variants - mechanical incompatibility exists. Always verify physical and functional pin mapping before substitution; SN74LVTZ244DBR requires its own layout.