DM7403N NAND Gate IC Equivalent & Substitute Parts

Part Overview

The DM7403N is a 4-channel 2-input NAND gate IC manufactured by onsemi in 14-MDIP through-hole packaging. This logic component features open collector outputs and operates within the 4.75V to 5.25V supply voltage range, making it suitable for TTL-compatible digital logic applications. The DM7403N is classified as obsolete, necessitating identification of active substitute components that maintain functional and electrical equivalence for ongoing system support and new designs.

Key Parameters

Parameter	Value
Logic Type	NAND Gate
Number of Circuits	4
Number of Inputs	2
Features	Open Collector
Voltage - Supply	4.75V ~ 5.25V
Input Logic Level - Low	0.8V
Input Logic Level - High	2V
Operating Temperature	0°C ~ 70°C
Mounting Type	Through Hole
Package / Case	14-DIP (0.300", 7.62mm)
Series	7400
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution of the DM7403N is determined by strict equivalence across the following critical parameters:

Logic Type: NAND Gate (4 channels, 2 inputs per channel)
Output Configuration: Open Collector
Supply Voltage Range: 4.75V ~ 5.25V
Input Logic Thresholds: Low ≤ 0.8V, High ≥ 2V
Operating Temperature Range: 0°C ~ 70°C
Series Classification: 7400 family

The SN7438NSR from Texas Instruments satisfies all functional and electrical requirements for substitution. While the SN7438NSR utilizes surface-mount packaging (14-SOIC) rather than through-hole (14-DIP), the electrical characteristics and logic functionality remain equivalent. This substitution is valid for applications where PCB layout and assembly methods accommodate surface-mount components.

Parameter Comparison

Parameter	DM7403N (onsemi)	SN7438NSR (Texas Instruments)	Compatibility
Logic Type	NAND Gate	NAND Gate	Equivalent
Number of Circuits	4	4	Equivalent
Number of Inputs	2	2	Equivalent
Features	Open Collector	Open Collector	Equivalent
Voltage - Supply	4.75V ~ 5.25V	4.75V ~ 5.25V	Equivalent
Current - Output High, Low	-, 16mA	-, 48mA	Compatible (SN7438NSR higher capacity)
Input Logic Level - Low	0.8V	0.8V	Equivalent
Input Logic Level - High	2V	2V	Equivalent
Max Propagation Delay @ V, Max CL	45ns @ 5V, 15pF	22ns @ 5V, 45pF	Compatible (SN7438NSR faster)
Operating Temperature	0°C ~ 70°C	0°C ~ 70°C	Equivalent
Mounting Type	Through Hole	Surface Mount	Different (packaging only)
Package / Case	14-DIP (0.300", 7.62mm)	14-SOIC (0.209", 5.30mm Width)	Different (packaging only)
Series	7400	7400	Equivalent
Product Status	Obsolete	Active	Substitute is active
REACH Status	REACH Unaffected	REACH Unaffected	Equivalent

Engineering Selection Recommendations

The SN7438NSR is a functionally equivalent substitute for the obsolete DM7403N based on the following criteria:

Both components implement identical logic functionality (4-channel 2-input NAND gate with open collector outputs)
Electrical specifications are equivalent across supply voltage, input thresholds, and operating temperature ranges
The SN7438NSR demonstrates superior performance characteristics: higher output current capacity (48mA vs. 16mA) and faster propagation delay (22ns vs. 45ns)
The SN7438NSR maintains active product status with ongoing manufacturer support, whereas the DM7403N is obsolete
Both components comply with REACH regulations and carry equivalent environmental classifications
The primary distinction is packaging format: the SN7438NSR requires surface-mount assembly (14-SOIC) instead of through-hole (14-DIP)

Selection of the SN7438NSR is appropriate for new designs and legacy system updates where PCB assembly capabilities support surface-mount technology. Through-hole alternatives within the 7400 series should be evaluated if surface-mount implementation is not feasible.

Frequently Asked Questions (FAQ)

Q: Can the SN7438NSR directly replace the DM7403N in existing through-hole PCB designs?

A: Direct socket replacement is not possible due to different packaging formats. The DM7403N uses 14-DIP through-hole packaging, while the SN7438NSR uses 14-SOIC surface-mount packaging. PCB redesign or adapter solutions are required for physical integration.

Q: Are the logic functions identical between DM7403N and SN7438NSR?

A: Yes. Both components are 4-channel 2-input NAND gates with open collector outputs. Logic truth tables and functional behavior are identical.

Q: What are the key electrical differences between these parts?

A: The SN7438NSR provides higher output current capacity (48mA vs. 16mA) and faster propagation delay (22ns vs. 45ns). Both operate within the same supply voltage range (4.75V ~ 5.25V) and share identical input logic thresholds.

Q: Is the SN7438NSR suitable for applications requiring the DM7403N's electrical specifications?

A: Yes. The SN7438NSR meets or exceeds all electrical requirements of the DM7403N. The enhanced performance characteristics present no compatibility issues for applications designed around DM7403N specifications.

Q: What is the product status difference, and why does it matter?

A: The DM7403N is obsolete with no ongoing manufacturer support, while the SN7438NSR is active with current availability and technical support. For new designs and long-term system support, the active SN7438NSR is the appropriate choice.

Q: Are there compliance or regulatory differences between these components?

A: No. Both components carry identical REACH status (REACH Unaffected) and equivalent environmental classifications. Regulatory compliance is maintained with either component.

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