onsemi 74LVT2244MTC

Overview

74LVT2244MTC from Fairchild Semiconductor is a low-voltage octal buffer/line driver with 3-STATE outputs and integrated 25Ω series output resistors, designed for memory address and clock distribution in 3.3V systems interfacing to 5V TTL buses. It delivers ±12mA drive strength, operates from 2.7V to 3.6V, and features live insertion/extraction support and power-up/down high-impedance behavior.

For engineers reviewing the 74LVT2244MTC datasheet, pinout, applications, or equivalent options, key selection criteria include its 20-pin TSSOP package, bushold-free input architecture, 3-STATE timing (tPZH ≤ 7.7ns), and 25Ω on-die series termination for signal integrity in high-speed bus driving.

Technical Context

The 74LVT2244MTC implements dual 4-bit non-inverting buffers with independent 3-STATE enable controls (OE1/OE2), each gating four outputs (O0–O3 and O4–O7). Its BiCMOS process enables ABT-class speed at 3.3V while maintaining low ICCZ (0.19mA) in disabled state.

Unlike the bushold-equipped LVTH variant, the 74LVT2244MTC omits bushold circuitry on inputs (I0–I7), requiring external pull-up/pull-down for unused pins. Output overshoot/undershoot suppression is achieved via monolithic 25Ω series resistors-no external termination needed.

Key Specifications

Pinout & Package

74LVT2244MTC uses a 20-lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 compliant, 4.4mm wide, with 0.65mm lead pitch and exposed pad not present. Pin 1 is marked by a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APWR and 74LVTH2244MTC, the 74LVT2244MTC uniquely balances 5V-tolerant interfacing, on-die 25Ω termination, and bushold-free flexibility - making it optimal for space-constrained 3.3V-to-5V bus bridging where trace-length variability demands intrinsic damping.

Availability

74LVT2244MTC is available at Aetrix Electronics and suitable for memory address buffering, clock distribution, backplane bus transceivers, and industrial I/O expansion requiring stable component supply and long-term industrial lifecycle support.

Supply support for 74LVT2244MTC 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and logic ICs before its acquisition by ON Semiconductor in 2016.

The 74LVT2244MTC belongs to Fairchild's LVT (Low-Voltage TTL) logic family, engineered for high-speed 3.3V bus interfacing with 5V systems - targeting dense PCB layouts in telecom infrastructure, industrial controllers, and legacy-compatible computing platforms.

FAQ

What is the function of the 74LVT2244MTC in a digital system?

The 74LVT2244MTC functions as an octal non-inverting buffer/line driver with 3-STATE outputs, enabling bidirectional bus isolation and signal amplification between 3.3V logic and 5V TTL systems. Its integrated 25Ω output resistors dampen signal reflections, and dual OE pins allow independent control of two 4-bit groups - critical for memory and clock distribution networks where timing skew and bus contention must be minimized. The 74LVT2244MTC is especially valuable in mixed-voltage backplanes and high-density PCBs.

Does the 74LVT2244MTC support 5V input signals while operating at 3.3V VCC?

Yes, the 74LVT2244MTC supports 5V-tolerant inputs: its VI rating extends to 5.5V under recommended operating conditions, allowing direct connection to 5V logic sources without level shifters. This capability is confirmed in the DC Electrical Characteristics table (VI max = 5.5V at VCC = 2.7–3.6V). The 74LVT2244MTC maintains full functionality - including proper HIGH/LOW recognition and 3-STATE control - when driven by 5V signals while powered from 3.3V, making it ideal for legacy interface bridging.

What is the purpose of the 25Ω series resistors on the outputs of the 74LVT2244MTC?

The 25Ω series resistors integrated into each output of the 74LVT2244MTC serve to reduce signal overshoot and undershoot by matching typical PCB trace impedances (40–70Ω) in source-series termination configurations. This on-die termination eliminates discrete resistors, saves board space, and improves signal integrity on unterminated or moderately loaded traces up to ~10cm. The value is fixed and process-trimmed - not user-adjustable - and directly contributes to the 74LVT2244MTC's suitability for high-speed bus driving without external components.

How does the 74LVT2244MTC differ from the 74LVTH2244MTC?

The 74LVT2244MTC lacks bushold circuitry on its inputs, whereas the 74LVTH2244MTC includes bushold to maintain last-valid logic state on floating inputs - eliminating external pull-up resistors. All other specifications - pinout, timing, drive strength, 25Ω outputs, and package - are identical. Therefore, the 74LVT2244MTC requires explicit biasing of unused inputs, while the 74LVTH2244MTC offers greater design flexibility in sparse-bus or configurable I/O applications. Both share the same 74LVT2244MTC footprint and thermal profile.

Is the 74LVT2244MTC compatible with live insertion and hot-swap operations?

Yes, the 74LVT2244MTC supports live insertion and extraction, as explicitly stated in its Features section and validated by its power-up/down high-impedance behavior and latch-up immunity (>500mA). During hot-swap, outputs remain in high-impedance until VCC stabilizes, preventing bus contention. This makes the 74LVT2244MTC suitable for modular systems like VMEbus or CompactPCI where field-replaceable units must be inserted or removed without system shutdown - a key reliability feature confirmed in Fairchild's original datasheet Rev. 1.5.0.