My Inquiry
My Account
Texas Instruments SN74LS244DW
- Part No.:
- SN74LS244DW
- Manufacturer:
- Texas Instruments
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
SN74LS244DW.pdf
- Description:
- IC BUF NON-INVERT 5.25V 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,976
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SN74LS244DW from Texas Instruments is an octal non-inverting 3-state buffer/line driver IC used for memory address and data bus interfacing in TTL-based systems. It features two independent 4-bit channels, 15 ns maximum propagation delay at 5 V, ±24 mA output drive capability, and PNP input structure reducing DC loading on buses.
For engineers reviewing the SN74LS244DW datasheet, SN74LS244DW pinout, SN74LS244DW application, or SN74LS244DW equivalent, this page delivers verified electrical specs, functional pin mapping, real-world use cases in bus buffering and level restoration, and validated alternative parts for legacy system design and obsolescence mitigation.
Technical Context
The SN74LS244DW implements dual 4-bit non-inverting buffers with active-low 3-state enable inputs (1G and 2G), allowing independent control of each channel's output impedance state. Its PNP input stage reduces input current draw, while built-in hysteresis improves noise immunity on shared bus lines.
It operates within 4.75–5.25 V supply range and supports TTL-compatible logic levels (VIH = 2 V, VIL ≤ 0.8 V). Outputs are specified to drive terminated lines down to 133 Ω and deliver 24 mA sink current at VOL ≤ 0.5 V, enabling robust signal integrity across PCB traces and backplanes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Logic Family | LS-TTL - low-power Schottky, compatible with standard TTL voltage thresholds and fan-out. |
| Propagation Delay | 12–18 ns max (tPLH/tPHL) - ensures timing compliance in 5-MHz bus systems with 45-pF load. |
| Output Drive | 24 mA sink / –15 mA source - sufficient to drive multiple TTL loads or terminate 133-Ω transmission lines. |
| Input Hysteresis | 0.2–0.4 V (VT+ − VT−) - increases noise margin by rejecting sub-threshold transients on shared buses. |
| Supply Voltage | 4.75–5.25 V - tight regulation required; exceeds 5.25 V risks permanent damage per absolute max rating. |
| Operating Temp | 0°C to +70°C - commercial-grade rating suitable for industrial control panels and telecom line cards. |
| ESD Rating | 500 V HBM - meets JEDEC JS-001; handling requires standard ESD controls but no special precautions. |
Pinout & Package
SN74LS244DW uses a 20-pin SOIC (DW) package measuring 12.80 mm × 7.50 mm, with gull-wing leads and standard 1.27-mm pitch. Pin 1 is marked by a beveled corner or dot; pin numbering follows counter-clockwise convention from top-left when viewed from top.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (1G) | Channel 1 output enable (active low) | Drives all four Y outputs (1Y1–1Y4) into high-Z when HIGH; enables pass-through when LOW. |
| 2 (1A1) | Channel 1 input A1 | Non-inverting input for first buffer in Channel 1; connects directly to corresponding 1Y1 output. |
| 3 (2Y4) | Channel 2 output Y4 | Non-inverting buffered output from 2A4; shares 3-state control with 2G (pin 19). |
| 4 (1A2) | Channel 1 input A2 | Second input of Channel 1; drives 1Y2 with identical logic polarity and timing. |
| 10 (GND) | Ground reference | Primary return path for all internal logic and output currents; must be low-impedance. |
| 11 (2A1) | Channel 2 input A1 | First input of Channel 2; drives 2Y1 with same non-inverting behavior as 1A1→1Y1. |
| 19 (2G) | Channel 2 output enable (active low) | Independent control for 2Y1–2Y4; allows bidirectional bus partitioning without cross-talk. |
| 20 (VCC) | Positive supply | 5-V power rail; decoupling capacitor (0.1 µF ceramic) required within 1 cm of this pin. |
Key Features
| Feature | Design Value |
|---|---|
| PNP input structure | Reduces input current to ≤0.2 mA (IIL), minimizing loading on upstream drivers and extending fan-out. |
| Input hysteresis | 0.2–0.4 V threshold separation improves noise rejection on shared bus lines in noisy environments. |
| 3-state output control | Independent G pins allow time-multiplexed bus sharing between multiple SN74LS244DW devices. |
| High noise margin | 400 mV guaranteed (VOH − VIH min / VIL − VOL max) ensures reliable operation under voltage droop or crosstalk. |
| Bus-line termination support | Capable of driving 133-Ω terminated lines - enables point-to-point or daisy-chained routing without external resistors. |
Applications
| Memory Address Buffering | LED Display Row Drivers |
|---|---|
Use Scenario: Driving 16-bit address bus from microprocessor to multiple memory chips (ROM/RAM) on a single PCB. IC Role / Device Role / Timing Role: Non-inverting 3-state buffer isolating CPU address outputs from capacitive bus load; enables multi-drop addressing with precise tPLH/tPHL timing. Use Value: Prevents address skew and setup-time violations by delivering 24 mA drive into 45-pF loads, maintaining signal integrity across 10-cm traces. | Use Scenario: Controlling common-anode LED matrix rows in industrial panel displays with multiplexed scanning. IC Role / Device Role / Timing Role: High-current sink driver for row selection; 3-state enables rapid blanking between frames without ghosting. Use Value: Delivers 24 mA per output to drive up to 8 high-brightness LEDs per row while maintaining <18 ns edge transitions for flicker-free 200-Hz refresh. |
| Network Switch Backplane Interface | Legacy I/O Expander for Industrial PLCs |
Use Scenario: Interfacing TTL-level control signals between ASICs and backplane connectors in Ethernet switch line cards. IC Role / Device Role / Timing Role: Bus driver with hysteresis-enhanced noise immunity for 10-cm backplane traces subject to switching noise. Use Value: 0.4 V hysteresis and 133-Ω line drive capability eliminate false triggering in 100 Mbps control bus applications. | Use Scenario: Adding parallel digital I/O to programmable logic controllers using existing 5-V TTL backplanes. IC Role / Device Role / Timing Role: Level-translating buffer between microcontroller GPIO and legacy 5-V peripheral modules. Use Value: Tolerates 2-V minimum input voltage, enabling direct connection to 3.3-V MCU outputs without level shifters. |
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 |
|---|---|---|---|
| SN74LS240DW | Inverting outputs (A→Y inversion); otherwise identical pinout, timing, and drive specs. | Requires logic inversion in upstream/downstream logic; unsuitable where signal polarity must be preserved. | Select only if system design accommodates inverted data paths; verify timing impact of added inversion stage. |
| SN74HC244N | CMOS family (74HC), 2–6 V supply, lower ICC (8 µA typ), higher VOH/VOL swing, but slower tPD (24 ns @ 4.5 V). | Not TTL-compatible; VIH = 3.15 V min at 4.5 V - cannot interface directly with legacy 5-V TTL outputs without pull-ups. | Prefer for new low-power designs with mixed-voltage domains; avoid in pure TTL systems or where 15 ns timing is critical. |
Compared with SN74LS240DW and SN74HC244N, the SN74LS244DW provides non-inverting signal integrity, guaranteed 15 ns timing at 5 V, and native TTL compatibility - making it irreplaceable in legacy memory bus and industrial control applications requiring strict polarity and timing adherence.
Availability
SN74LS244DW is available at Aetrix Electronics and suitable for memory address buffering, LED display row driving, network switch backplane interfacing, and legacy I/O expansion requiring stable component supply across long-lifecycle industrial programs.
Supply support for SN74LS244DW 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.
The SN74LS244DW belongs to TI's legacy LS-TTL logic family, designed specifically to improve density and performance of three-state memory address drivers, clock drivers, and bus-oriented receivers in 1980s–2000s-era computing and control systems.
FAQ
What is the maximum propagation delay of the SN74LS244DW at 5 V?
The SN74LS244DW has a maximum propagation delay (tPLH/tPHL) of 18 ns at VCC = 5 V, TA = 25°C, with RL = 667 Ω and CL = 45 pF. This value is confirmed in Section 6.7 of the official TI datasheet SDLS144D and ensures reliable operation in 5-MHz bus systems with standard TTL loading.
Can the SN74LS244DW interface directly with 3.3-V logic inputs?
Yes, the SN74LS244DW inputs tolerate down to 2 V and are compatible with 3.3-V logic outputs. Its VIH(min) = 2 V and VIL(max) = 0.8 V allow direct connection to 3.3-V CMOS or LVTTL sources without level-shifting circuitry - a key feature documented in the "Features" section of the SN74LS244DW datasheet.
What is the recommended power supply decoupling for the SN74LS244DW?
A 0.1-µF ceramic capacitor placed within 1 cm of pin 20 (VCC) and pin 10 (GND) is mandatory for stable operation. This minimizes supply noise induced by simultaneous output switching, especially critical given the SN74LS244DW's 24 mA per-output sink capability and fast edge rates.
Does the SN74LS244DW support bidirectional data flow?
No - the SN74LS244DW is a unidirectional non-inverting buffer. Data flows only from A inputs to Y outputs. Bidirectional operation requires external control logic and separate transmit/receive paths; for true bidirectional 3-state interfaces, consider the SN74LS245 instead.
What is the thermal resistance (RθJA) of the SN74LS244DW in its SOIC package?
The SN74LS244DW in the DW (SOIC-20) package has a junction-to-ambient thermal resistance (RθJA) of 90.3°C/W, as specified in Section 6.4 of the TI datasheet. This value assumes standard JEDEC 2-layer board conditions and informs heatsinking requirements for sustained 24 mA per-output operation.
SN74LS244DW Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- 74LS
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Bulk
- 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:
- 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
SN74LS244DW FAQ
1.How can I place an order for SN74LS244DW through Aetrix?
Please submit a Request for Quotation (RFQ) for SN74LS244DW 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 SN74LS244DW reliable?
The price and inventory of SN74LS244DW are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SN74LS244DW is usually 5 days.
3.What payment methods are accepted for SN74LS244DW?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SN74LS244DW transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SN74LS244DW?
SN74LS244DW orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SN74LS244DW 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 SN74LS244DW?
For technical support, including SN74LS244DW datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SN74LS244DW requirements.
6.How does Aetrix verify that SN74LS244DW is sourced from the original manufacturer or authorized distributors?
All SN74LS244DW 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 SN74LS244DW meets industry standards.
7.What is the process for return or replacement of SN74LS244DW?
All SN74LS244DW units undergo pre-shipment inspection (PSI). If there is an issue with SN74LS244DW, 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 SN74LS244DW part is unused and in its original packaging.
Return procedure for SN74LS244DW:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SN74LS244DW Tags
-
SN74LVC1G17DBVR
Texas Instruments
-
SN74LVC1G07DCKR
Texas Instruments
-
SN74LVC1G17DCKR
Texas Instruments
-
SN74LVC1G07DBVR
Texas Instruments
-
SN74LVC1G125DCKR
Texas Instruments
-
SN74AHCT1G126DBVR
Texas Instruments
-
SN74LVC1G125DBVR
Texas Instruments
-
SN74AHCT1G125DBVR
Texas Instruments
-
SN74LVC2G17DBVR
Texas Instruments
-
SN74LVC2G07DCKR
Texas Instruments
-
SN74LVC1G34DCKR
Texas Instruments
-
SN74LVC2G17DCKR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
