SM4937A-TP Equivalent & Substitute Parts

Part Overview

The SM4937A-TP is a general-purpose rectifier diode manufactured by Micro Commercial Co, rated for 600 V DC reverse voltage and 1 A average rectified current in a surface mount DO-214AC (SMA) package. This component is classified as obsolete, which necessitates identification of active equivalent parts for ongoing design requirements and procurement needs. Substitute parts must maintain electrical performance within the specified parameter ranges while meeting current manufacturing and compliance standards.

Substiute Parts

SM4937A-TP

Micro Commercial CoIn Stock: 1249SM4937A-TP Datasheet

Current PartRFQ

FS1J-LTP

Micro Commercial CoIn Stock: 85139FS1J-LTP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete SM4937A-TP is determined by strict equivalence across the following critical parameters:

Mandatory Matching Parameters:

• Voltage - DC Reverse (Vr) (Max): 600 V
• Current - Average Rectified (Io): 1 A
• Package / Case: DO-214AC, SMA
• Mounting Type: Surface Mount
• Speed Classification: Fast Recovery ≤ 500ns, > 200mA (Io)
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)

The FS1J-LTP manufactured by Micro Commercial Co satisfies all mandatory parameters and is classified as an active product. This part maintains the same voltage and current ratings, identical package configuration, and equivalent fast recovery speed characteristics. The FS1J-LTP is available in high inventory quantities and carries current manufacturing status, making it suitable for direct substitution in applications previously designed for the SM4937A-TP.

Parameter Comparison

Engineering Selection Recommendations

The FS1J-LTP is the direct equivalent substitute for the obsolete SM4937A-TP. Both parts are manufactured by Micro Commercial Co and share identical electrical ratings for voltage, current, and package configuration. The FS1J-LTP carries active product status with substantial inventory availability (85,100 pieces), ensuring supply chain continuity for new designs and production requirements.

Both parts maintain ROHS3 compliance and MSL Level 1 (Unlimited) moisture sensitivity classification, satisfying environmental and handling requirements. The FS1J-LTP is supplied in Tape & Reel (TR) packaging, which is standard for high-volume surface mount assembly operations.

Minor parameter variations exist between the two parts: the FS1J-LTP exhibits a reverse recovery time of 250 ns compared to 200 ns for the SM4937A-TP, and capacitance at rated voltage is 50 pF versus 15 pF. These differences remain within the fast recovery speed classification and do not affect functional equivalence in standard rectification applications. The FS1J-LTP operating temperature range extends to -50°C minimum, compared to -55°C for the SM4937A-TP; this represents a 5°C reduction in the lower temperature limit.

Frequently Asked Questions (FAQ)

Q: Can the FS1J-LTP be used as a direct replacement for the SM4937A-TP in existing designs?

A: Yes. Both parts share identical voltage ratings (600 V), current ratings (1 A), package configuration (DO-214AC, SMA), and fast recovery speed classification. The FS1J-LTP is the designated substitute and carries active manufacturing status.

Q: What are the differences in reverse recovery time between these parts?

A: The SM4937A-TP specifies 200 ns reverse recovery time, while the FS1J-LTP specifies 250 ns. Both parts meet the fast recovery classification (≤ 500 ns for > 200 mA). The 50 ns difference does not affect functional equivalence in standard rectification circuits.

Q: Does the operating temperature range difference affect substitution?

A: The FS1J-LTP minimum junction temperature is -50°C, compared to -55°C for the SM4937A-TP. This represents a 5°C reduction in the lower temperature limit. Applications operating above -50°C encounter no thermal constraint. Applications requiring operation below -50°C require thermal analysis to confirm FS1J-LTP suitability.

Q: Are both parts RoHS compliant?

A: Yes. Both the SM4937A-TP and FS1J-LTP are ROHS3 compliant and carry MSL Level 1 (Unlimited) moisture sensitivity classification.

Q: What packaging formats are available?

A: The SM4937A-TP packaging format is not specified in the provided data. The FS1J-LTP is supplied in Tape & Reel (TR) packaging, which is standard for surface mount assembly operations.

Q: Why is the SM4937A-TP classified as obsolete?

A: The SM4937A-TP is no longer in active production. The FS1J-LTP serves as the active equivalent part for ongoing procurement and design requirements.

Q: Are there additional substitute options beyond FS1J-LTP?

A: The FS1J-LTP documentation references additional substitute parts (US1JHE3_A/H, RS1J, ES1J, FS1JE-TP, NRVA4005T3G). Verification of electrical and mechanical parameter equivalence is required for each alternative part before selection.