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Home > Products > Integrated Circuits (ICs) > Logic > Buffers, Drivers, Receivers, Transceivers

STMicroelectronics 74LCX244TTR

Name: 74LCX244TTR
Brand: STMicroelectronics
SKU: 74LCX244TTR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 74LCX244TTR

Manufacturer:: STMicroelectronics

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 20-TSSOP (0.173", 4.40mm Width)

Datasheet:: 74LCX244TTR.pdf

Description:: IC BUF NON-INVERT 3.6V 20TSSOP

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Product details

Overview

74LCX244TTR from STMicroelectronics is a low-voltage CMOS octal non-inverting 3-state bus buffer with 5V-tolerant inputs and outputs, operating at 2.0–3.6 V supply, delivering 6.5 ns max propagation delay at 3.0 V, ±24 mA output drive, and symmetrical output impedance for PCI-bus-level interfacing in mixed-voltage systems.

For engineers reviewing the 74LCX244TTR datasheet, 74LCX244TTR pinout, 74LCX244TTR application, or 74LCX244TTR equivalent, key selection criteria include 3.3 V operation with 5 V signal compatibility, high-speed 3-state control timing (tPZL/tPLZ ≤ 8.0 ns), latch-up immunity (>500 mA), ESD robustness (HBM > 2 kV), and TSSOP-20 package suitability for space-constrained PCB layouts.

Technical Context

This device implements dual 4-bit non-inverting buffers with independent 3-state enable controls (1G and 2G), supporting bidirectional data flow isolation in memory address/data buses. All eight outputs feature high-impedance disable states with power-down protection and input/output clamping diodes.

It uses sub-micron C2MOS technology to achieve AC/ACT-family speed at 3.3 V while consuming significantly less power. Input thresholds are compatible with TTL and CMOS logic families across 1.5–3.6 V VCC, and output VOH/VOL remain specified under ±24 mA loads at 3.0–3.6 V.

Key Specifications

Parameter	Value and Actual Design Meaning
VCC Operating Range	2.0 V to 3.6 V - Enables direct integration into 3.3 V systems with 1.5 V data retention during standby
tPD (Max)	6.5 ns at VCC = 3.0 V - Matches 5 V AC/ACT speed for seamless voltage migration in high-throughput address/data paths
IOL / IOH (Min)	±24 mA at VCC = 3.0–3.6 V - Guarantees PCI-bus-compliant drive strength without external buffering
VI / VO Tolerance	0 V to 5.5 V - Allows safe connection to legacy 5 V logic without level shifters or clamping resistors
CIN / COUT	6 pF / 10 pF at VCC = 3.3 V - Minimizes capacitive loading on driving sources and improves signal integrity at 100+ MHz edge rates
ESD Rating (HBM)	>2000 V - Meets MIL-STD-883 Method 3015 for handling robustness in automated assembly and field service

Pinout & Package

TSSOP-20 package: 6.5 mm × 4.4 mm body, 0.65 mm pitch, 1.2 mm height, lead-free and RoHS compliant.

Pin/Terminal	Circuit Role	Design Meaning
1, 19	Output Enable (1G, 2G)	Active-low enables respective 4-bit buffer sections; both must be low for output assertion
2,4,6,8	Data Inputs (1A1–1A4)	Non-inverting inputs for first quad buffer; tolerate 0–5.5 V regardless of VCC
3,5,7,9	Data Outputs (1Y1–1Y4)	Corresponding non-inverting outputs; enter high-Z when 1G = high
11,13,15,17	Data Inputs (2A1–2A4)	Non-inverting inputs for second quad buffer; electrically isolated from first section
12,14,16,18	Data Outputs (2Y1–2Y4)	Corresponding outputs; independently controlled by 2G; share VCC/GND with first section
10	GND	Ground reference for all I/O and internal logic; decoupling capacitor required near pin
20	VCC	Primary supply for core logic and output drivers; requires local 100 nF ceramic bypass

Key Features

Feature	Design Value
5 V tolerant I/O	Supports direct interface to 5 V peripherals without level translation, reducing BOM count and layout area
Symmetrical output drive	\|IOH\| = IOL = 24 mA min ensures matched rise/fall times and reduced signal skew in parallel bus applications
Balanced propagation delays	tPLH ≅ tPHL minimizes duty cycle distortion in clocked or strobed data transfers
Power-down protection	Inputs and outputs remain high-impedance and clamped during VCC = 0 V, preventing back-driving of powered subsystems
Latch-up immunity	>500 mA per JESD17 ensures reliability in noisy industrial environments with transient ground shifts

Applications

PCI Bus Interface

Memory Address Buffering

Use Scenario: Interfacing 3.3 V microcontroller address/data bus to 5 V PCI slot peripherals.

IC Role / Device Role / Timing Role: Non-inverting 3-state buffer providing voltage-level bridging and bus isolation during DMA cycles.

Use Value: Eliminates need for discrete level shifters while maintaining <6.5 ns propagation delay and ±24 mA drive for PCI compliance.

Use Scenario: Driving 16-bit address lines from an FPGA to multiple SRAM chips sharing same bus.

IC Role / Device Role / Timing Role: Octal buffer with dual enable pins enabling selective activation of memory banks.

Use Value: Reduces address skew across channels and supports simultaneous enable/disable of two 4-bit segments for bank switching.

Low-Power Industrial Controller

Mixed-Voltage Test Equipment

Use Scenario: Isolating sensor interface logic (3.3 V) from relay driver circuitry (5 V) in programmable logic controllers.

IC Role / Device Role / Timing Role: Voltage-tolerant buffer enabling safe signal routing between domains with independent power sequencing.

Use Value: Prevents latch-up during power-up/power-down sequences and withstands 2 kV HBM ESD common in factory-floor wiring.

Use Scenario: Signal conditioning stage in automated test equipment connecting 3.3 V pattern generator to 5 V DUT interfaces.

IC Role / Device Role / Timing Role: High-speed, low-skew buffer ensuring deterministic timing margins across multi-voltage stimulus paths.

Use Value: Delivers <1 ns output-to-output skew and 6.5 ns max tPD, critical for sub-10 ns setup/hold windows in high-speed digital testing.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
74LVC244APW,118 (Nexperia)	Lower ICC (max 10 µA vs 10 µA typical), identical 3.3 V specs, but only 5 V tolerant inputs (not outputs)	Not suitable for bidirectional 5 V bus termination where outputs drive 5 V loads	Select when only input-side 5 V tolerance is needed and cost sensitivity outweighs full I/O tolerance
SN74LVC244APWR (TI)	Same 5 V tolerant I/O, but tPD = 7.1 ns (max) at 3.3 V and lower IOL (±24 mA guaranteed only at VCC ≥ 3.0 V)	Marginally slower propagation and tighter VCC dependency may affect timing closure in high-frequency address latching	Prefer when TI's qualification pedigree or long-term availability in automotive-grade variants is required

Compared with 74LVC244APW and SN74LVC244APWR, the 74LCX244TTR uniquely guarantees 5 V tolerance on both inputs and outputs across its full 2.0–3.6 V VCC range while delivering the fastest max tPD (6.5 ns) and highest output drive symmetry-making it optimal for PCI-compliant, mixed-voltage bus isolation where timing margin and bidirectional voltage safety are critical.

Availability

74LCX244TTR is available at Aetrix Electronics and suitable for PCI bus interface design, memory address buffering, low-power industrial controller development, and mixed-voltage test equipment requiring stable component supply and long-term lifecycle support.

Supply support for 74LCX244TTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management ICs with broad analog, digital, and mixed-signal portfolios.

The 74LCX series was engineered specifically for low-voltage, high-speed 3.3 V system interfacing with legacy 5 V infrastructure-targeting PCI, memory expansion, and FPGA/CPU peripheral buffering applications.

FAQ

Can 74LCX244TTR operate at 2.5 V supply?

Yes. The device is fully specified from 2.0 V to 3.6 V, including VIH/VIL thresholds, propagation delay, and output drive. At 2.5 V, tPD increases to 7.5 ns (max), IOH/IOL drops to ±12 mA, and VOL rises to 0.4 V at 12 mA load-still sufficient for most 2.5 V logic families with appropriate noise margin analysis.

Is thermal pad required for TSSOP-20 package?

No. The 74LCX244TTR in TSSOP-20 (package code TTR) has no exposed thermal pad. Power dissipation remains below 200 mW under worst-case conditions (all outputs driving ±24 mA), and junction temperature stays within limits using standard PCB copper pour on GND/VCC pins without additional heatsinking.

What happens to outputs when VCC = 0 V?

Outputs enter high-impedance state with power-down protection active: input and output pins are clamped to GND and VCC rails via internal diodes, limiting leakage to ≤10 µA even if 5 V signals are applied-preventing back-powering or damage to unpowered upstream circuits.

Does 74LCX244TTR support hot insertion?

Yes. With 5 V tolerant I/O, power-down protection, and >500 mA latch-up immunity, the device meets essential requirements for hot-plug capable backplane interfaces. However, system-level current-limiting and sequencing must still be implemented externally to manage inrush and ensure controlled enable timing during insertion.

74LCX244TTR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: 74LCX

Package/Case:: 20-TSSOP (0.173", 4.40mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Logic Type:: Buffer, Non-Inverting

Number of Elements:: 2

Number of Bits per Element:: 4

Input Type:: -

Output Type:: 3-State

Current - Output High, Low:: 24mA, 24mA

Voltage - Supply:: 2V ~ 3.6V

Operating Temperature:: -55°C ~ 125°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-TSSOP

74LCX244TTR FAQ

1.How can I place an order for 74LCX244TTR through Aetrix?

Please submit a Request for Quotation (RFQ) for 74LCX244TTR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 74LCX244TTR reliable?

The price and inventory of 74LCX244TTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 74LCX244TTR is usually 5 days.

3.What payment methods are accepted for 74LCX244TTR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 74LCX244TTR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 74LCX244TTR?

74LCX244TTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 74LCX244TTR order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 74LCX244TTR?

For technical support, including 74LCX244TTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 74LCX244TTR requirements.

6.How does Aetrix verify that 74LCX244TTR is sourced from the original manufacturer or authorized distributors?

All 74LCX244TTR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 74LCX244TTR meets industry standards.

7.What is the process for return or replacement of 74LCX244TTR?

All 74LCX244TTR units undergo pre-shipment inspection (PSI). If there is an issue with 74LCX244TTR, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 74LCX244TTR part is unused and in its original packaging.

Return procedure for 74LCX244TTR:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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