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

onsemi DM74AS244SJ

Name: DM74AS244SJ
Brand: onsemi
SKU: DM74AS244SJ
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: DM74AS244SJ

Manufacturer:: onsemi

Category:: Buffers, Drivers, Receivers, Transceivers

Package:: 20-SOIC (0.209", 5.30mm Width)

Datasheet:: DM74AS244SJ.pdf

Description:: IC BUFFER NON-INVERT 5.5V 20SOP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

DM74AS244SJ from Fairchild Semiconductor is an advanced Schottky TTL octal non-inverting 3-STATE bus driver with dual 4-bit enable control, operating at VCC = 4.5–5.5 V, delivering IOL = 64 mA sink and IOH = −15 mA source drive, and supporting propagation delays as low as 2 ns (tPLH/tPHL), used for unidirectional data buffering in microprocessor address/data buses.

For engineers reviewing the DM74AS244SJ datasheet, pinout, applications, or equivalent options, key selection criteria include 3-STATE output timing (tPZL ≤ 7.5 ns), CMOS-compatible VOH (VCC − 2 V), termination drive capability down to 133 Ω, and compatibility with 74LS/Schottky logic families in memory and communication interface designs.

Technical Context

The DM74AS244SJ implements two independent 4-bit non-inverting buffer groups, each controlled by a dedicated active-low 3-STATE enable (G1̅, G2̅), allowing selective bus isolation. Its oxide-isolated, ion-implanted Schottky TTL process enables faster switching than standard Schottky TTL while reducing power dissipation.

It is specified for operation across 0°C to +70°C with supply voltage 4.5–5.5 V, features input clamp voltage VIK = −1.2 V, and guarantees VOL ≤ 0.55 V at IOL = max and VOH ≥ 2.4 V at IOH = −3 mA - meeting TTL output thresholds and enabling reliable interfacing with both TTL and CMOS loads.

Key Specifications

Parameter	Value and Actual Design Meaning
VCC Range	4.5 V to 5.5 V - ensures stable operation across standard TTL supply tolerances.
IOL / IOH	64 mA sink / −15 mA source - drives terminated transmission lines down to 133 Ω without external buffers.
tPLH / tPHL	2 ns min / 6.2 ns max - supports high-speed bus cycles in microprocessor systems up to ~160 MHz effective toggle rate.
VOH / VOL	≥2.4 V / ≤0.55 V at rated load - meets TTL output specs and interfaces directly with CMOS inputs requiring VOH ≥ VCC − 2 V.
VIH / VIL	2.0 V / 0.8 V - compatible with standard TTL input thresholds for seamless integration into legacy logic systems.
ICC (3-STATE)	34–54 mA - lower quiescent current than DM74AS240 in 3-STATE mode, reducing system standby power.

Pinout & Package

DM74AS244SJ is supplied in a 20-lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" wide (Package Number N20A), with 2.54 mm lead pitch and through-hole mounting.

Pin/Terminal	Circuit Role	Design Meaning
1, 2, 3, 4, 5, 6, 7, 9	Input A1–A8	Non-inverting data inputs for eight buffer channels, grouped as A1–A4 (pins 1–4) and A5–A8 (pins 5–7,9).
11, 12, 13, 14, 15, 16, 17, 18	Output Y1–Y8	3-STATE outputs corresponding to A1–A8; high-impedance when respective enable is inactive.
10, 19	G1̅, G2̅	Active-low 3-STATE enables: G1̅ controls Y1–Y4; G2̅ controls Y5–Y8 - enables independent bus segment control.
20	VCC	Positive supply terminal (4.5–5.5 V); decoupling capacitor required near pin for noise immunity.
10	GND	Ground reference for all inputs, outputs, and internal circuitry; must be low-impedance connection.

Key Features

Feature	Design Value
Advanced Schottky TTL process	Oxide-isolated, ion-implanted fabrication delivers higher speed and lower power vs. standard Schottky TTL.
Dual independent 4-bit enables	G1̅ and G2̅ allow selective activation of upper/lower bus halves - critical for segmented memory or peripheral addressing.
CMOS-compatible VOH	Guaranteed VOH ≥ VCC − 2 V enables direct interfacing with 5 V CMOS without level-shifting circuitry.
Low-output-impedance drive	64 mA sink capability supports driving 50 Ω/133 Ω transmission lines - eliminates need for external line drivers in backplane designs.

Applications

Microprocessor Address Bus Buffering	Memory Data Bus Interface
Use Scenario: Isolating and driving 8-bit address lines from a microprocessor to multiple memory chips on a shared bus. IC Role / Device Role / Timing Role: Non-inverting 3-STATE buffer with dual enable control, providing timing-matched signal amplification and bus contention prevention. Use Value: Enables clean address decoding with tPLH/tPHL ≤ 6.2 ns and prevents bus loading via high-impedance disable state.	Use Scenario: Interfacing an 8-bit data bus between a CPU and SRAM/ROM devices with varying access timing requirements. IC Role / Device Role / Timing Role: Unidirectional data driver that isolates memory devices during write cycles and reduces capacitive loading on the CPU data bus. Use Value: Delivers 64 mA drive strength to meet memory setup/hold timing under loaded conditions and supports fast turnaround via tPZL ≤ 7.5 ns.
Communications Backplane Driver	Legacy Industrial Control Bus
Use Scenario: Driving parallel control signals across a 133 Ω-terminated backplane in industrial PLC rack modules. IC Role / Device Role / Timing Role: High-speed, low-skew bus driver ensuring signal integrity over 10+ inch PCB traces with matched rise/fall propagation. Use Value: Low output impedance and tight delay matching (tPLH/tPHL variation ≤ 0.5 ns) minimize skew-induced timing errors.	Use Scenario: Replacing obsolete 74LS244 in retrofitted factory automation panels requiring drop-in reliability and extended temperature margin. IC Role / Device Role / Timing Role: Pin- and function-compatible TTL buffer offering improved speed/power trade-off over LS family parts. Use Value: Maintains existing PCB layout while improving system timing margin and reducing board-level power dissipation by ~25%.

Microprocessor Address Bus Buffering

Memory Data Bus Interface

Use Scenario: Isolating and driving 8-bit address lines from a microprocessor to multiple memory chips on a shared bus.

IC Role / Device Role / Timing Role: Non-inverting 3-STATE buffer with dual enable control, providing timing-matched signal amplification and bus contention prevention.

Use Value: Enables clean address decoding with tPLH/tPHL ≤ 6.2 ns and prevents bus loading via high-impedance disable state.

Use Scenario: Interfacing an 8-bit data bus between a CPU and SRAM/ROM devices with varying access timing requirements.

IC Role / Device Role / Timing Role: Unidirectional data driver that isolates memory devices during write cycles and reduces capacitive loading on the CPU data bus.

Use Value: Delivers 64 mA drive strength to meet memory setup/hold timing under loaded conditions and supports fast turnaround via tPZL ≤ 7.5 ns.

Communications Backplane Driver

Legacy Industrial Control Bus

Use Scenario: Driving parallel control signals across a 133 Ω-terminated backplane in industrial PLC rack modules.

IC Role / Device Role / Timing Role: High-speed, low-skew bus driver ensuring signal integrity over 10+ inch PCB traces with matched rise/fall propagation.

Use Value: Low output impedance and tight delay matching (tPLH/tPHL variation ≤ 0.5 ns) minimize skew-induced timing errors.

Use Scenario: Replacing obsolete 74LS244 in retrofitted factory automation panels requiring drop-in reliability and extended temperature margin.

IC Role / Device Role / Timing Role: Pin- and function-compatible TTL buffer offering improved speed/power trade-off over LS family parts.

Use Value: Maintains existing PCB layout while improving system timing margin and reducing board-level power dissipation by ~25%.

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal non-inverting 3-STATE bus driver applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74AS244N	Same pinout, identical electrical specs, TI-manufactured version with identical AC/DC characteristics and 0°C to +70°C rating.	No functional difference; validated for same microprocessor/memory interface roles.	Select when sourcing from TI-authorized channels or requiring TI-specific traceability.
74F244PC	Fast TTL variant: slightly faster tPLH/tPHL (1.5 ns min), but higher ICC (up to 85 mA in 3-STATE) and tighter VCC tolerance (4.75–5.25 V).	Better suited for ultra-high-speed timing-critical paths; less tolerant of supply variation.	Prefer for sub-5 ns timing budgets where supply regulation is robust and thermal management is available.

Compared with SN74AS244N, DM74AS244SJ offers identical functionality and interoperability; versus 74F244PC, it trades marginal speed gain for broader supply range and lower static power, making it more suitable for general-purpose industrial bus buffering.

Availability

DM74AS244SJ is available at Aetrix Electronics and suitable for microprocessor address buffering, memory data bus interfacing, and industrial communications backplane applications requiring stable component supply, long-lifecycle support, and legacy TTL compatibility.

Supply support for DM74AS244SJ 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 leading US-based analog and discrete semiconductor manufacturer, acquired by ON Semiconductor in 2016; known for high-performance TTL, MOS, and power management ICs.

The DM74AS244SJ belongs to Fairchild's Advanced Schottky TTL logic family, engineered specifically for high-speed, low-power bus interface applications in memory, microprocessor, and communication systems.

FAQ

What is the operating temperature range for DM74AS244SJ?

The DM74AS244SJ is rated for operation from 0°C to +70°C ambient temperature, consistent with commercial-grade TTL logic. This range supports use in standard industrial control panels, desktop computing peripherals, and non-automotive embedded systems. The device's thermal resistance (θJA = 57.0°C/W in PDIP) allows reliable operation within this envelope under typical PCB copper pour and airflow conditions. Always verify local junction temperature using actual power dissipation and board layout.

Is DM74AS244SJ pin-compatible with 74LS244?

Yes, DM74AS244SJ is functionally and pin-compatible with the 74LS244, sharing identical pin assignments, logic behavior, and package footprint (20-pin PDIP). It provides enhanced performance - faster propagation delays (6.2 ns vs. ~15 ns), higher output drive (64 mA vs. 24 mA), and lower power consumption - while maintaining full backward compatibility in existing 74LS244 layouts.

Does DM74AS244SJ support bidirectional data flow?

No, DM74AS244SJ is a unidirectional non-inverting buffer only. Unlike the DM74AS240 (which includes inverting capability), the DM74AS244SJ has fixed non-inverting inputs (A1–A8) and outputs (Y1–Y8). Bidirectional operation requires external direction control logic or use of transceiver parts such as the 74AS245; DM74AS244SJ is optimized for one-way bus driving tasks like address latching or memory read/write separation.

What is the maximum output current specification for DM74AS244SJ?

The DM74AS244SJ specifies IOL = 64 mA (low-level output sink current) and IOH = −15 mA (high-level output source current) under recommended operating conditions. These values are guaranteed across VCC = 4.5–5.5 V and TA = 0°C to +70°C. Exceeding these limits risks parametric shift or reliability degradation; sustained operation above 64 mA per output requires thermal derating and verification of junction temperature.

Can DM74AS244SJ interface directly with 5 V CMOS logic?

Yes, DM74AS244SJ can interface directly with 5 V CMOS inputs because its VOH is specified as ≥ VCC − 2 V (e.g., ≥3.0 V at VCC = 5.0 V), satisfying the minimum VIH requirement of most 5 V CMOS families. Its VOL ≤ 0.55 V also meets standard CMOS VIL thresholds. No level-shifting circuitry is needed, provided load capacitance remains within CL = 50 pF and trace lengths are controlled to avoid ringing.

DM74AS244SJ Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74AS

Package/Case:: 20-SOIC (0.209", 5.30mm Width)

Packaging:: Tube

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, 64mA

Voltage - Supply:: 4.5V ~ 5.5V

Operating Temperature:: 0°C ~ 70°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-SOP

DM74AS244SJ FAQ

1.How can I place an order for DM74AS244SJ through Aetrix?

Please submit a Request for Quotation (RFQ) for DM74AS244SJ 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 DM74AS244SJ reliable?

The price and inventory of DM74AS244SJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DM74AS244SJ is usually 5 days.

3.What payment methods are accepted for DM74AS244SJ?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DM74AS244SJ transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for DM74AS244SJ?

DM74AS244SJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your DM74AS244SJ 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 DM74AS244SJ?

For technical support, including DM74AS244SJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DM74AS244SJ requirements.

6.How does Aetrix verify that DM74AS244SJ is sourced from the original manufacturer or authorized distributors?

All DM74AS244SJ 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 DM74AS244SJ meets industry standards.

7.What is the process for return or replacement of DM74AS244SJ?

All DM74AS244SJ units undergo pre-shipment inspection (PSI). If there is an issue with DM74AS244SJ, 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 DM74AS244SJ part is unused and in its original packaging.

Return procedure for DM74AS244SJ:

1.Submit a request within 90 days.

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

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