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Home > Products > Integrated Circuits (ICs) > Logic > Gates and Inverters

onsemi DM74S40N

Name: DM74S40N
Brand: onsemi
SKU: DM74S40N
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: DM74S40N

Manufacturer:: onsemi

Category:: Gates and Inverters

Package:: 14-DIP (0.300", 7.62mm)

Datasheet:: DM74S40N.pdf

Description:: IC GATE NAND 2CH 4-INP 14MDIP

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Product details

Overview

DM74S40N from Fairchild Semiconductor is a dual 4-input NAND buffer IC in a 14-lead PDIP package, operating at 4.75–5.25 V supply, with 2.7 V minimum VOH and 0.5 V maximum VOL at IOL = 60 mA, used for high-speed logic-level translation and fanout expansion in TTL-compatible digital control systems.

For engineers reviewing the DM74S40N datasheet, pinout, applications, or equivalent options, key selection considerations include guaranteed 60 mA sink current per output, sub-10 ns propagation delay (CL = 150 pF), TTL input compatibility (VIH ≥ 2 V, VIL ≤ 0.8 V), and operation across 0°C to +70°C industrial temperature range.

Technical Context

The DM74S40N implements two independent 4-input NAND gates using Schottky-clamped bipolar transistor logic (S-TTL), delivering higher speed and lower power-delay product than standard TTL. Each gate drives one output with complementary push-pull output stage capable of sourcing −3 mA and sinking 60 mA.

It operates strictly within 5 V ±5% supply tolerance and requires no external biasing or pull-ups. Input thresholds are fixed for TTL compatibility: VIH ≥ 2.0 V and VIL ≤ 0.8 V, ensuring robust noise margin in mixed-logic interfacing scenarios.

Key Specifications

Parameter	Value and Actual Design Meaning
VCC Range	4.75 V to 5.25 V - ensures stable operation under nominal 5 V rail with ±5% tolerance, compatible with standard TTL power distribution.
VOH (min)	2.7 V at IOH = −3 mA - guarantees HIGH-level logic compatibility with downstream TTL inputs requiring ≥2.0 V threshold.
VOL (max)	0.5 V at IOL = 60 mA - ensures reliable LOW-level assertion even under heavy capacitive or resistive loading.
tPLH / tPHL	2–9 ns (CL = 50–150 pF) - supports >100 MHz toggle rates in short-line applications with controlled load capacitance.
IOL (max)	60 mA per output - enables direct driving of multiple TTL inputs (fanout ≥ 20) or low-impedance loads without buffering.
Operating Temp	0°C to +70°C - certified for commercial/industrial ambient environments without derating.

Pinout & Package

DM74S40N is housed in a 14-lead plastic dual-in-line package (PDIP), JEDEC MS-001 compliant, 0.300-inch body width, through-hole mountable with 0.100-inch lead pitch.

Pin/Terminal	Circuit Role	Design Meaning
1	Input A1	First input of Gate 1 - all four inputs (A1–D1) must be HIGH to assert LOW on Y1.
2	Input B1	Second input of Gate 1 - contributes to NAND logic function Y1 = NOT(A1·B1·C1·D1).
3	Input C1	Third input of Gate 1 - required HIGH for Y1 to go LOW; any LOW forces Y1 HIGH.
4	Input D1	Fourth input of Gate 1 - completes 4-input NAND term for first gate.
5	Output Y1	Active-low output of Gate 1 - sinks up to 60 mA when LOW, sources −3 mA when HIGH.
6	Output Y2	Active-low output of Gate 2 - electrically isolated from Y1, identical drive capability.
7	GND	Ground reference - common return path for all inputs, outputs, and internal circuitry.
8	Input D2	Fourth input of Gate 2 - completes second independent 4-input NAND function.
9	Input C2	Third input of Gate 2 - same logic behavior as C1, independent of Gate 1.
10	Input B2	Second input of Gate 2 - no coupling or interaction with Gate 1 inputs.
11	Input A2	First input of Gate 2 - fully decoupled from A1–D1; enables dual independent logic paths.
12	VCC	+5 V supply - powers both gates; bypass capacitor recommended at pin for noise immunity.
13	N/C	No connection - internally unused; must remain unconnected and floating.
14	N/C	No connection - internally unused; must remain unconnected and floating.

Key Features

Feature	Design Value
High sink current (60 mA)	Enables direct interface to multiple TTL loads or moderate-current peripherals without external drivers.
Low propagation delay (≤9 ns)	Supports timing-critical combinational logic paths in control sequencers and address decoders.
TTL-compatible input thresholds	Guarantees interoperability with legacy 74-series and microcontroller GPIOs without level-shifting.
Dual independent gates	Reduces board space vs. two discrete 4-input NAND packages; eliminates inter-gate skew in synchronous logic.

Applications

Industrial Control Logic	Memory Address Decoding
Use Scenario: Decoding 4-bit enable signals in PLC I/O modules to activate relay banks or sensor interfaces. IC Role / Device Role / Timing Role: Dual NAND gate performing active-low enable generation with simultaneous evaluation of four status bits. Use Value: 60 mA sink capability directly drives electromechanical relay coils or optocoupler LEDs without added transistors.	Use Scenario: Generating chip-select signals for SRAM or EPROM in 8-bit microprocessor systems with limited address lines. IC Role / Device Role / Timing Role: Combinational logic element converting upper address bits into memory bank select strobes. Use Value: Sub-10 ns propagation ensures setup/hold timing margins are preserved across full memory access cycle.
Test Equipment Signal Gating	Digital Panel Interface Logic
Use Scenario: Enabling/disabling test signal paths in automated test fixtures based on multi-condition pass/fail criteria. IC Role / Device Role / Timing Role: Logic gate evaluating four independent test result flags before asserting PASS/FAIL latch enable. Use Value: Independent dual gates allow parallel evaluation of two separate test vectors within single package footprint.	Use Scenario: Interfacing pushbutton matrix rows/columns to microcontroller inputs in industrial HMI panels. IC Role / Device Role / Timing Role: Input conditioning and debounced logic combining for multi-button priority encoding. Use Value: TTL-compatible inputs accept direct switch-to-rail connections; 0.5 V VOL ensures clean LOW detection despite contact bounce.

Industrial Control Logic

Memory Address Decoding

Use Scenario: Decoding 4-bit enable signals in PLC I/O modules to activate relay banks or sensor interfaces.

IC Role / Device Role / Timing Role: Dual NAND gate performing active-low enable generation with simultaneous evaluation of four status bits.

Use Value: 60 mA sink capability directly drives electromechanical relay coils or optocoupler LEDs without added transistors.

Use Scenario: Generating chip-select signals for SRAM or EPROM in 8-bit microprocessor systems with limited address lines.

IC Role / Device Role / Timing Role: Combinational logic element converting upper address bits into memory bank select strobes.

Use Value: Sub-10 ns propagation ensures setup/hold timing margins are preserved across full memory access cycle.

Test Equipment Signal Gating

Digital Panel Interface Logic

Use Scenario: Enabling/disabling test signal paths in automated test fixtures based on multi-condition pass/fail criteria.

IC Role / Device Role / Timing Role: Logic gate evaluating four independent test result flags before asserting PASS/FAIL latch enable.

Use Value: Independent dual gates allow parallel evaluation of two separate test vectors within single package footprint.

Use Scenario: Interfacing pushbutton matrix rows/columns to microcontroller inputs in industrial HMI panels.

IC Role / Device Role / Timing Role: Input conditioning and debounced logic combining for multi-button priority encoding.

Use Value: TTL-compatible inputs accept direct switch-to-rail connections; 0.5 V VOL ensures clean LOW detection despite contact bounce.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NAND logic gate applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SN74S40N	Identical pinout, electrical specs, and package; manufactured by Texas Instruments under same S-series TTL family spec.	No functional or timing difference; suitable for drop-in replacement where TI-sourced parts are preferred.	Select SN74S40N when TI's quality documentation or long-term availability commitments are required.
DM74LS40N	Lower power (ICCL ≈ 12 mA vs. 44 mA), slower (tPLH/tPHL ≈ 15–25 ns), but same pinout and logic function.	Preferred in battery-powered or thermally constrained designs where speed < 20 MHz suffices.	Choose DM74LS40N only if reduced power consumption outweighs need for sub-10 ns timing performance.

Compared with SN74S40N, DM74S40N offers identical functionality and timing but differs in manufacturer qualification and traceability; versus DM74LS40N, it trades higher power for significantly faster switching-critical in high-throughput digital control loops.

Availability

DM74S40N is available at Aetrix Electronics and suitable for industrial control logic, memory address decoding, test equipment signal gating, and digital panel interface logic requiring stable component supply and long-lifecycle support.

Supply support for DM74S40N 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 analog and discrete power products, acquired by ON Semiconductor in 2016; its legacy TTL logic portfolio remains widely deployed in industrial systems.

The DM74S40N belongs to the 74S (Schottky TTL) logic family, designed specifically for high-speed digital control applications where propagation delay and drive strength outweigh power efficiency concerns.

FAQ

What logic family does the DM74S40N belong to, and how does it differ from standard TTL?

The DM74S40N belongs to the 74S (Schottky TTL) family. It uses Schottky-clamped transistors to reduce saturation delay, achieving faster switching (≤9 ns) than standard 74-series TTL (e.g., 7400, ~10–22 ns). Unlike standard TTL, DM74S40N delivers 60 mA sink current and maintains tighter VOH/VOL specs across temperature, making it suitable for demanding fanout and timing-critical applications. DM74S40N retains full TTL voltage compatibility.

Can the DM74S40N drive multiple 74-series TTL inputs directly?

Yes, the DM74S40N can drive at least 20 standard 74-series TTL inputs per output due to its 60 mA sink current rating and −3 mA source capability. Its VOH ≥ 2.7 V and VOL ≤ 0.5 V meet or exceed TTL interface requirements across the full 0°C to +70°C range. This eliminates the need for additional buffer stages in most legacy digital systems where DM74S40N is deployed.

Is the DM74S40N still in production, and what is its obsolescence status?

The DM74S40N is discontinued by ON Semiconductor (which acquired Fairchild), but Aetrix Electronics maintains verified legacy stock with full traceability and extended availability support. No active second-source production exists; however, SN74S40N remains available from Texas Instruments as a functionally identical alternative. DM74S40N is supported for long-life industrial programs via Aetrix's continuity program.

What are the absolute maximum ratings for the DM74S40N, and why do they matter in design?

The DM74S40N has an absolute maximum supply voltage of 7 V, input voltage limit of 5.5 V, and operating temperature range of 0°C to +70°C. Exceeding these values-even briefly-risks permanent damage. These limits define safe design boundaries: for example, VCC must stay within 4.75–5.25 V during normal operation, and inputs must never be pulled above 5.5 V, even during power-up sequencing. Adhering to these ensures reliability of DM74S40N in field-deployed equipment.

Does the DM74S40N require external pull-up or pull-down resistors on its inputs or outputs?

No, the DM74S40N does not require external pull-up or pull-down resistors. Its TTL-compatible inputs have defined VIH (≥2.0 V) and VIL (≤0.8 V) thresholds with sufficient noise margin, and outputs are actively driven to valid HIGH or LOW states. Unused inputs should be tied HIGH or LOW to prevent floating; unused outputs may be left open. Proper VCC bypassing (e.g., 0.1 µF ceramic near pin 12) is essential for stable DM74S40N operation.

DM74S40N Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: 74S

Package/Case:: 14-DIP (0.300", 7.62mm)

Packaging:: Bulk

Product Status:: Obsolete

Logic Type:: NAND Gate

Number of Circuits:: 2

Number of Inputs:: 4

Features:: -

Voltage - Supply:: 4.75V ~ 5.25V

Current - Quiescent (Max):: -

Current - Output High, Low:: 3mA, 60mA

Input Logic Level - Low:: 0.8V

Input Logic Level - High:: 2V

Max Propagation Delay @ V, Max CL:: 9ns @ 5V, 150pF

Operating Temperature:: 0°C ~ 70°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: 14-MDIP

DM74S40N FAQ

1.How can I place an order for DM74S40N through Aetrix?

Please submit a Request for Quotation (RFQ) for DM74S40N 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 DM74S40N reliable?

The price and inventory of DM74S40N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DM74S40N is usually 5 days.

3.What payment methods are accepted for DM74S40N?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DM74S40N transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for DM74S40N?

DM74S40N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your DM74S40N 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 DM74S40N?

For technical support, including DM74S40N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DM74S40N requirements.

6.How does Aetrix verify that DM74S40N is sourced from the original manufacturer or authorized distributors?

All DM74S40N 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 DM74S40N meets industry standards.

7.What is the process for return or replacement of DM74S40N?

All DM74S40N units undergo pre-shipment inspection (PSI). If there is an issue with DM74S40N, 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 DM74S40N part is unused and in its original packaging.

Return procedure for DM74S40N:

1.Submit a request within 90 days.

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

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