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Texas Instruments SN74LS244DWR
- Part No.:
- SN74LS244DWR
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74LS244DWR.pdf
- Description:
- IC BUF NON-INVERT 5.25V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:9,703
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Product details
Overview
SN74LS244DWR from Texas Instruments is an octal non-inverting 3-state buffer/line driver in SOIC-20 package, designed for memory address and data bus driving. It features dual 4-bit channels with independent active-low output-enable (1G, 2G), 24 mA sink capability per output at VCC = 5 V, 18 ns maximum propagation delay, and hysteresis-enhanced noise immunity for reliable operation in noisy industrial bus environments.
For engineers reviewing the SN74LS244DWR datasheet, SN74LS244DWR pinout, SN74LS244DWR application, or SN74LS244DWR equivalent, key selection criteria include 3-state bus isolation capability, TTL-compatible input thresholds, PNP-input DC loading reduction, and compatibility with 5-V memory and I/O expansion systems requiring high fan-out and terminated-line drive down to 133 Ω.
Technical Context
The SN74LS244DWR implements two independent 4-bit non-inverting buffer sections, each controlled by a dedicated active-low output-enable input (1G and 2G). Its PNP input structure reduces DC loading on upstream drivers, while built-in input hysteresis provides 400-mV noise margin-critical for stable operation on long PCB traces or shared backplanes.
Each output supports true 3-state control with high-impedance disable, enabling bidirectional bus arbitration without external logic. The device operates within 4.75 V to 5.25 V supply range and is specified for 0°C to 70°C ambient temperature, targeting commercial-grade embedded control and memory interface applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 4.75 V to 5.25 V - ensures compatibility with regulated 5-V logic rails and tolerance to typical power supply ripple |
| IOH / IOL | –15 mA / 24 mA - sufficient to drive standard TTL loads and terminate lines down to 133 Ω |
| tPD (max) | 18 ns - enables reliable operation in 25-MHz bus systems with timing margin |
| VIH / VIL | 2.0 V / 0.8 V - compatible with both LS-TTL and mixed 3.3-V/5-V input sources |
| Input Hysteresis | 0.2–0.4 V - improves noise rejection on shared bus lines subject to EMI or crosstalk |
| ICC (active) | 27–46 mA - predictable power consumption during bus transmission phases |
| ESD Rating | 500 V HBM - meets standard handling requirements for automated assembly |
Pinout & Package
SN74LS244DWR uses a 20-pin SOIC (DW) package measuring 12.80 mm × 7.50 mm, optimized for surface-mount reliability and thermal dissipation in dense PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 19 | 1G, 2G | Active-low output-enable inputs - independently disable Channel 1 or Channel 2 outputs to high-impedance state |
| 2, 4, 6, 8, 11, 13, 15, 17 | 1A1–1A4, 2A1–2A4 | Buffer input terminals - accept TTL-level signals for non-inverting transfer to corresponding Y outputs |
| 3, 5, 7, 9, 12, 14, 16, 18 | 2Y4–2Y1, 1Y4–1Y1 | 3-state output terminals - drive bus lines when G is low; float when G is high for multi-driver arbitration |
| 10 | GND | Ground reference - common return path for all logic and output currents |
| 20 | VCC | Power supply - supplies internal logic and output stage; requires local 0.1-µF bypass capacitor |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent 4-bit channels | Enables simultaneous buffering of two separate data/address groups without cross-talk or shared enable constraints |
| PNP input structure | Reduces input DC loading to ≤0.2 mA per pin, minimizing burden on upstream drivers and improving fan-in |
| Hysteresis on all inputs | Provides 400-mV noise margin, preventing false triggering on slow-rising or noisy bus signals |
| 3-state outputs with common enable | Allows direct connection to shared buses; eliminates need for external bus transceivers in point-to-point or daisy-chain topologies |
| TTL-compatible voltage thresholds | Accepts 3.3-V or 5-V logic inputs, supporting mixed-voltage system interfacing without level shifters |
Applications
| Memory Address Buffering | LED Display Multiplexing |
|---|---|
Use Scenario: Driving 16-bit memory address bus between microcontroller and SRAM/ROM in embedded control systems. IC Role / Device Role / Timing Role: Non-inverting 3-state buffer isolating CPU address outputs from memory chip inputs; enables clean signal edge integrity over 10-cm PCB traces. Use Value: 24 mA sink current ensures full logic swing into capacitive bus loads; 18 ns tPD maintains setup/hold timing margins at 25 MHz clock rates. | Use Scenario: Row/column scanning control for 8×8 LED matrix displays in industrial HMIs. IC Role / Device Role / Timing Role: Output-enable-controlled line driver sequencing column anodes while sinking row cathode current via external transistors. Use Value: Independent 1G/2G pins allow precise interleaving of row/column activation; hysteresis prevents ghosting from EMI-induced glitches. |
| Network Switch Backplane Interface | I/O Expansion for PLC Modules |
Use Scenario: Interfacing ASIC-based packet forwarding logic to shared control/status bus across multiple switch blades. IC Role / Device Role / Timing Role: Bidirectional bus buffer providing isolation and drive strength between FPGA and backplane control lines. Use Value: Dual-channel architecture allows separate enable control for status readback and command write paths; 133-Ω line drive supports impedance-matched routing. | Use Scenario: Expanding digital I/O count on programmable logic controller mainboards using parallel GPIO extension. IC Role / Device Role / Timing Role: Level-translating buffer between 3.3-V MCU GPIO and 5-V industrial sensor/actuator interfaces. Use Value: Input tolerance down to 2 V and VIH = 2.0 V ensure robust recognition of 3.3-V logic levels; PNP inputs reduce MCU port loading. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar octal 3-state buffer applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SN74LS240DWR | Inverting output logic (A→¬Y) vs. SN74LS244DWR's non-inverting (A→Y); identical pinout, timing, and drive specs | Required where bus polarity inversion is needed for signal alignment or legacy design compatibility | Select SN74LS240DWR only when inverting function is explicitly required; otherwise SN74LS244DWR preserves signal polarity end-to-end |
| SN74HC244N | CMOS technology: higher noise immunity (±2.5 V hysteresis), lower ICC (8 µA typ), but reduced drive (7.8 mA) and no PNP input loading benefit | Better suited for low-power, battery-operated systems; not recommended for driving terminated 133-Ω lines or legacy TTL loads | Choose SN74HC244N for new low-power designs with 3.3-V logic; retain SN74LS244DWR for 5-V TTL bus integrity and legacy interoperability |
Compared with SN74LS240DWR and SN74HC244N, SN74LS244DWR uniquely delivers non-inverting signal flow, PNP-input loading reduction, and 24 mA drive into heavy bus loads-making it the preferred choice for industrial memory addressing and noise-prone backplane interfaces where signal fidelity and legacy compatibility are critical.
Availability
SN74LS244DWR is available at Aetrix Electronics and suitable for memory address buffering, LED display multiplexing, network switch backplane interfaces, and PLC I/O expansion requiring stable component supply across extended production lifecycles.
Supply support for SN74LS244DWR 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 logic solutions for industrial, automotive, and communications markets.
SN74LS244DWR belongs to TI's legacy LS-TTL logic family, engineered specifically for high-reliability bus driving, memory address registration, and noise-immune signal conditioning in commercial-temperature embedded systems.
FAQ
What is the operating temperature range for SN74LS244DWR?
The SN74LS244DWR is rated for commercial operation from 0°C to 70°C ambient temperature. This range aligns with standard SOIC-packaged logic devices used in industrial control panels, networking equipment, and consumer electronics where airflow and thermal management are moderate. It does not support extended or military temperature grades.
Does SN74LS244DWR support 3.3-V input logic levels?
Yes, SN74LS244DWR accepts 3.3-V inputs reliably: its VIH threshold is 2.0 V minimum, and inputs tolerate down to 2 V while maintaining valid high-level recognition. This makes SN74LS244DWR suitable for mixed-voltage systems where 3.3-V microcontrollers interface with 5-V bus infrastructure.
How does the PNP input structure in SN74LS244DWR improve system design?
The PNP input structure in SN74LS244DWR reduces DC input loading to ≤0.2 mA per pin, significantly lowering the fan-out burden on upstream drivers. This allows more devices to be driven from a single source without signal degradation-especially valuable in memory address distribution networks where one CPU output may feed multiple buffer inputs.
Can SN74LS244DWR drive a 133-Ω terminated line?
Yes, SN74LS244DWR is explicitly characterized to drive terminated lines down to 133 Ω, as confirmed in the device description section of the datasheet. Its 24 mA sink capability at VOL ≤ 0.5 V ensures full logic-low voltage compliance under this load condition, supporting impedance-matched bus designs in telecom and industrial backplanes.
What is the maximum propagation delay for SN74LS244DWR at 5 V?
The maximum propagation delay (tPD) for SN74LS244DWR is 18 ns at VCC = 5 V and TA = 25°C, measured under RL = 667 Ω and CL = 45 pF conditions. This value applies to both tPLH and tPHL transitions and guarantees timing closure in 25-MHz synchronous bus applications with adequate setup/hold margin.
SN74LS244DWR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74LS
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 15mA, 24mA
- Voltage - Supply:
- 4.75V ~ 5.25V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SOIC
SN74LS244DWR FAQ
1.How can I place an order for SN74LS244DWR through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LS244DWR 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 SN74LS244DWR reliable?
The price and inventory of SN74LS244DWR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LS244DWR is usually 5 days.
3.What payment methods are accepted for SN74LS244DWR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LS244DWR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LS244DWR?
SN74LS244DWR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LS244DWR 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 SN74LS244DWR?
For technical support, including SN74LS244DWR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LS244DWR requirements.
6.How does Aetrix verify that SN74LS244DWR is sourced from the original manufacturer or authorized distributors?
All SN74LS244DWR 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 SN74LS244DWR meets industry standards.
7.What is the process for return or replacement of SN74LS244DWR?
All SN74LS244DWR units undergo pre-shipment inspection (PSI). If there is an issue with SN74LS244DWR, 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 SN74LS244DWR part is unused and in its original packaging.
Return procedure for SN74LS244DWR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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