STPS40M120CT Equivalent & Substitute Parts

Part Overview

The STPS40M120CT is a Schottky diode array manufactured by STMicroelectronics, configured as 1 pair common cathode with a maximum reverse voltage rating of 120 V and average rectified current of 20 A per diode. The device is packaged in TO-220-3 through-hole configuration and features fast recovery characteristics with switching speed ≤ 500 ns at currents > 200 mA.

This part is classified as obsolete. Identification of equivalent and substitute components is necessary to maintain design continuity and ensure procurement availability for new production runs and field replacements.

Substiute Parts

STPS40M120CT

STMicroelectronicsIn Stock: 3206STPS40M120CT Datasheet

Current PartRFQ

SDT30120CT

Diodes IncorporatedIn Stock: 1333SDT30120CT Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the STPS40M120CT is determined by the following critical parameters:

Mandatory Matching Parameters:

• Diode Configuration: 1 Pair Common Cathode
• Technology: Schottky
• Voltage - DC Reverse (Vr) (Max): 120 V
• Package / Case: TO-220-3
• Mounting Type: Through Hole
• Speed: Fast Recovery ≤ 500 ns, > 200 mA (Io)

Allowable Variation Parameters:

• Current - Average Rectified (Io) (per Diode): Equal or greater than 20 A
• Voltage - Forward (Vf) (Max) @ If: Within acceptable circuit operating margins
• Current - Reverse Leakage @ Vr: Within acceptable circuit operating margins
• Operating Temperature - Junction: Equal to or greater than 150°C maximum

The SDT30120CT from Diodes Incorporated meets the mandatory matching parameters. However, the current rating is 15 A per diode, which is lower than the 20 A specification of the main part. This substitute is suitable only for applications where the circuit design permits operation at the reduced current rating.

Parameter Comparison

Engineering Selection Recommendations

SDT30120CT Substitution Criteria:

The SDT30120CT is an active product from Diodes Incorporated and maintains full compliance with ROHS3 and REACH requirements, matching the regulatory status of the STPS40M120CT.

Electrical compatibility is established through matching reverse voltage rating (120 V), diode configuration (1 pair common cathode), technology (Schottky), and switching speed characteristics (fast recovery ≤ 500 ns).

The primary design consideration is the reduced current rating of 15 A per diode versus the 20 A specification of the main part. Selection of this substitute is appropriate for circuits designed to operate within the 15 A per diode current envelope. The forward voltage characteristic (930 mV @ 15 A) differs from the main part and must be evaluated within the specific circuit application to confirm acceptable voltage drop margins.

The SDT30120CT demonstrates superior reverse leakage performance (100 µA @ 120 V versus 370 µA @ 120 V) and extended operating temperature range (-55°C to 150°C versus 150°C maximum), both favorable characteristics for reliability.

Mechanical compatibility is confirmed through identical TO-220-3 through-hole packaging and mounting type.

Frequently Asked Questions (FAQ)

Q: Can the SDT30120CT directly replace the STPS40M120CT in all applications?

A: Direct replacement is limited by the reduced current rating. The SDT30120CT is rated for 15 A per diode versus 20 A for the STPS40M120CT. Substitution is valid only for applications where circuit design permits operation at 15 A per diode or lower. Circuit analysis must confirm that maximum operating current does not exceed the substitute part rating.

Q: Are the TO-220-3 packages physically identical?

A: Both parts use TO-220-3 through-hole packaging. Physical dimensions and pin configuration are compatible for PCB mounting. No mechanical redesign is required for package substitution.

Q: What is the impact of the different forward voltage specifications?

A: The SDT30120CT exhibits 930 mV forward voltage at 15 A compared to 790 mV at 20 A for the STPS40M120CT. Forward voltage characteristics are current-dependent and temperature-dependent. Circuit designers must evaluate voltage drop impact on power dissipation and circuit performance at the actual operating current of the application.

Q: Are both parts compliant with current regulatory requirements?

A: Both the STPS40M120CT and SDT30120CT are ROHS3 compliant and REACH unaffected. Regulatory compliance is equivalent between the main part and substitute.

Q: What is the significance of the reverse leakage current difference?

A: The SDT30120CT exhibits lower reverse leakage current (100 µA @ 120 V) compared to the STPS40M120CT (370 µA @ 120 V). Lower leakage current generally indicates superior device quality and reduced power loss in reverse bias conditions. This characteristic is favorable for circuit performance.

Q: Is the SDT30120CT suitable for high-temperature applications?

A: The SDT30120CT supports operating junction temperatures from -55°C to 150°C, matching the maximum junction temperature of the STPS40M120CT at 150°C. Both parts are suitable for equivalent thermal environments.