MMSD4148_G Equivalent & Substitute Parts

Part Overview

The MMSD4148_G is a general-purpose rectifier diode manufactured by onsemi, rated for 100 V DC reverse voltage and 200 mA average rectified current in a surface mount SOD-123 package. This component is classified as obsolete, necessitating identification of active equivalent alternatives for new designs and ongoing production requirements. Substitute parts must maintain electrical and mechanical compatibility across critical parameters including voltage rating, current capacity, forward voltage characteristics, and package form factor.

Key Parameters

Parameter	Value	Unit
Voltage - DC Reverse (Vr) (Max)	100	V
Current - Average Rectified (Io)	200	mA
Voltage - Forward (Vf) (Max) @ If	1 V @ 10 mA	V
Reverse Recovery Time (trr)	4	ns
Current - Reverse Leakage @ Vr	5 µA @ 75 V	µA
Capacitance @ Vr, F	4	pF @ 0V, 1MHz
Package / Case	SOD-123	—
Mounting Type	Surface Mount	—
Operating Temperature - Junction (Max)	150	°C
Technology	Standard	—
Speed Classification	Small Signal ≤ 200mA (Io), Any Speed	—

Substitute Part Grouping Explanation

Substitute parts for the MMSD4148_G are identified based on strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

Voltage - DC Reverse (Vr) (Max): 100 V
Current - Average Rectified (Io): 200 mA
Package / Case: SOD-123
Mounting Type: Surface Mount
Technology: Standard
Speed Classification: Small Signal ≤ 200mA (Io), Any Speed

Acceptable Variation Parameters:

Voltage - Forward (Vf) (Max) @ If: Variations permitted within small signal diode specifications
Reverse Recovery Time (trr): Consistent at 4 ns across all listed substitutes
Current - Reverse Leakage @ Vr: Consistent at 5 µA @ 75 V across all listed substitutes
Capacitance @ Vr, F: Minor variations acceptable (2–4 pF range)
Operating Temperature - Junction: Extended range acceptable for active parts

Two substitute parts meet these criteria: MMSD4148T1G (onsemi, direct manufacturer equivalent, active status) and MMSD4448 (Fairchild Semiconductor, parametric equivalent, active status).

Parameter Comparison

Parameter	MMSD4148_G	MMSD4148T1G	MMSD4448
Manufacturer	onsemi	onsemi	Fairchild Semiconductor
Product Status	Obsolete	Active	Active
Voltage - DC Reverse (Vr) (Max)	100 V	100 V	100 V
Current - Average Rectified (Io)	200 mA	200 mA	200 mA
Voltage - Forward (Vf) (Max) @ If	1 V @ 10 mA	1 V @ 10 mA	1 V @ 100 mA
Reverse Recovery Time (trr)	4 ns	4 ns	4 ns
Current - Reverse Leakage @ Vr	5 µA @ 75 V	5 µA @ 75 V	5 µA @ 75 V
Capacitance @ Vr, F	4 pF @ 0V, 1MHz	4 pF @ 0V, 1MHz	2 pF @ 0V, 1MHz
Package / Case	SOD-123	SOD-123	SOD-123
Mounting Type	Surface Mount	Surface Mount	Surface Mount
Operating Temperature - Junction	150°C (Max)	−55°C ~ 150°C	150°C (Max)
Technology	Standard	Standard	Standard
Speed Classification	Small Signal ≤ 200mA (Io), Any Speed	Small Signal ≤ 200mA (Io), Any Speed	Small Signal ≤ 200mA (Io), Any Speed

Engineering Selection Recommendations

MMSD4148T1G (onsemi) is the primary substitute for MMSD4148_G. This part is manufactured by the same original equipment manufacturer and maintains identical electrical specifications. The MMSD4148T1G carries active product status, ensuring ongoing availability and supply chain continuity. The part is RoHS3 compliant and carries REACH Unaffected certification. Operating temperature range is extended to −55°C ~ 150°C, providing broader environmental tolerance than the obsolete original. Packaging is available in Cut Tape (CT) and Digi-Reel® formats, supporting both manual and automated assembly workflows.

MMSD4448 (Fairchild Semiconductor) serves as a parametric equivalent substitute. This part maintains all critical electrical parameters including 100 V reverse voltage rating, 200 mA current capacity, 4 ns reverse recovery time, and SOD-123 surface mount package. The MMSD4448 exhibits lower junction capacitance (2 pF versus 4 pF), which may provide performance advantages in high-frequency applications. Forward voltage is specified at 100 mA rather than 10 mA, reflecting measurement at higher current levels. This part is active and available in bulk packaging. Compliance certifications are not provided in the available data.

For new designs and production transitions, MMSD4148T1G is the recommended primary selection due to manufacturer continuity, extended temperature range, and documented compliance certifications. MMSD4448 is suitable where Fairchild Semiconductor supply chain relationships are established or where lower capacitance characteristics provide circuit performance benefits.

Frequently Asked Questions (FAQ)

Q: Can MMSD4148T1G be used as a direct replacement for MMSD4148_G in existing designs?

A: Yes. MMSD4148T1G maintains identical electrical specifications for voltage rating (100 V), current capacity (200 mA), forward voltage (1 V @ 10 mA), reverse recovery time (4 ns), reverse leakage current (5 µA @ 75 V), and package form factor (SOD-123 surface mount). The extended operating temperature range (−55°C ~ 150°C) provides additional environmental margin compared to the original part specification.

Q: What is the difference between MMSD4148T1G and MMSD4448?

A: Both parts meet the core electrical requirements of 100 V reverse voltage and 200 mA current capacity in SOD-123 packages. MMSD4148T1G is manufactured by onsemi and maintains the original forward voltage specification (1 V @ 10 mA). MMSD4448 is manufactured by Fairchild Semiconductor and specifies forward voltage at 100 mA. MMSD4448 exhibits lower junction capacitance (2 pF versus 4 pF), which may reduce parasitic effects in high-frequency circuits. MMSD4148T1G carries documented RoHS3 compliance and extended temperature range.

Q: Are there packaging differences between the substitute parts?

A: MMSD4148T1G is available in Cut Tape (CT) and Digi-Reel® packaging, supporting both manual and automated assembly. MMSD4448 is supplied in bulk packaging. Both parts use the SOD-123 surface mount package with identical mechanical dimensions and land pattern requirements.

Q: Does the lower capacitance of MMSD4448 affect circuit performance?

A: The MMSD4448 capacitance specification of 2 pF (versus 4 pF for MMSD4148T1G) represents a reduction in junction capacitance. This characteristic may reduce parasitic capacitive effects in switching applications and high-frequency circuits. Circuit performance impact depends on specific application requirements and operating frequency. Both parts maintain identical reverse recovery time (4 ns) and reverse leakage current (5 µA @ 75 V).

Q: What compliance certifications apply to each substitute part?

A: MMSD4148T1G carries RoHS3 compliance and REACH Unaffected certification. MMSD4448 compliance certifications are not provided in the available technical data. Both parts are classified under ECCN EAR99 for export control purposes.

Q: Can MMSD4148_G inventory be used interchangeably with substitute parts in production?

A: MMSD4148_G is classified as obsolete. While electrical specifications are equivalent to MMSD4148T1G, the obsolete status indicates discontinued manufacturing and limited supply availability. New production should transition to MMSD4148T1G or MMSD4448 to ensure supply chain continuity and compliance with current manufacturing standards.

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