DSTF40120C Equivalent & Substitute Parts

Part Overview

The DSTF40120C is a Schottky diode array manufactured by Littelfuse Inc., configured as a 1 Pair Common Cathode rectifier with a maximum reverse voltage rating of 120 V and an average rectified current of 20 A per diode. The component is housed in a TO-220-3 Full Pack with isolated tab through-hole package and is classified as Active product status with ROHS3 compliance.

Equivalent and substitute parts are identified when design requirements permit operation at reduced current ratings or when component availability necessitates alternative sourcing while maintaining electrical and mechanical compatibility within the specified parameter envelope.

Substiute Parts

DSTF40120C

Littelfuse Inc.In Stock: 958DSTF40120C Datasheet

Current PartRFQ

SDT20120CTFP

Diodes IncorporatedIn Stock: 798SDT20120CTFP Datasheet

MFR RecommendedRFQ

SDT30120CTFP

Diodes IncorporatedIn Stock: 2012SDT30120CTFP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DSTF40120C is permissible with parts that maintain the following critical parameters:

Mandatory Matching Parameters:

• Diode Configuration: 1 Pair Common Cathode
• Technology: Schottky
• Voltage - DC Reverse (Vr) (Max): 120 V
• Mounting Type: Through Hole
• Package / Case: TO-220-3 Full Pack, Isolated Tab
• Operating Temperature - Junction: -55°C to 150°C
• Speed: Fast Recovery ≤ 500ns, > 200mA (Io)

Allowable Variation Parameters:

• Current - Average Rectified (Io) (per Diode): Equal to or greater than circuit requirement
• Voltage - Forward (Vf) (Max) @ If: Lower forward voltage drop is acceptable
• Current - Reverse Leakage @ Vr: Lower reverse leakage is acceptable

The identified substitute parts SDT20120CTFP and SDT30120CTFP satisfy all mandatory matching parameters. These parts are manufactured by Diodes Incorporated and maintain electrical and mechanical compatibility with the DSTF40120C within the specified parameter constraints.

Parameter Comparison

Engineering Selection Recommendations

DSTF40120C (Primary Component)

The DSTF40120C remains the primary selection for applications requiring 20 A average rectified current per diode. This component is Active product status with full ROHS3 compliance and REACH Unaffected designation. Current inventory of 919 pieces supports immediate procurement.

SDT30120CTFP (Preferred Substitute)

The SDT30120CTFP is the preferred substitute when the DSTF40120C is unavailable. This part maintains all mandatory electrical and mechanical parameters with a 15 A current rating. The 15 A rating accommodates applications designed for maximum 15 A operation. Forward voltage drop of 930 mV at 15 A and reverse leakage of 100 µA at 120 V are within acceptable operating margins. ROHS3 compliance and REACH Unaffected status are maintained. Inventory availability of 2000 pieces supports sustained supply.

SDT20120CTFP (Secondary Substitute)

The SDT20120CTFP is a secondary substitute for applications with maximum current requirements of 10 A or less. This part is suitable only when circuit design permits operation at reduced current capacity. Forward voltage drop of 880 mV at 10 A and reverse leakage of 80 µA at 120 V represent improved performance characteristics at the lower current rating. ROHS3 compliance and REACH Unaffected status are maintained. Inventory availability of 724 pieces supports procurement.

All substitute parts maintain Active product status and are suitable for direct PCB mounting in TO-220-3 through-hole applications with isolated tab configuration.

Frequently Asked Questions (FAQ)

Q: Can SDT20120CTFP be used as a direct replacement for DSTF40120C in all applications?

A: SDT20120CTFP is a direct mechanical and electrical substitute only for applications where the maximum average rectified current requirement does not exceed 10 A per diode. If the circuit design requires 20 A operation, SDT20120CTFP is not suitable. SDT30120CTFP is the appropriate substitute for applications requiring up to 15 A.

Q: What is the difference between the three parts in terms of forward voltage drop?

A: Forward voltage drop varies with current rating. DSTF40120C exhibits 970 mV at 20 A, SDT30120CTFP exhibits 930 mV at 15 A, and SDT20120CTFP exhibits 880 mV at 10 A. Lower forward voltage drop at reduced current ratings is characteristic of Schottky diode technology. Circuit designs must account for these differences in power dissipation calculations.

Q: Are all three parts compatible with the same PCB footprint?

A: Yes. All three parts use identical TO-220-3 Full Pack with isolated tab through-hole package configuration. PCB footprints, mounting hole spacing, and lead positions are identical. No PCB redesign is required for substitution.

Q: What is the significance of the isolated tab feature?

A: The isolated tab in the TO-220-3 Full Pack configuration electrically isolates the mounting tab from the diode circuit. This permits direct mounting to a heatsink without electrical isolation hardware. All three parts maintain this feature.

Q: Do the substitute parts meet the same compliance standards as the DSTF40120C?

A: Yes. Both SDT20120CTFP and SDT30120CTFP are ROHS3 Compliant and REACH Unaffected, matching the compliance status of DSTF40120C. Both parts carry EAR99 ECCN classification and 8541.10.0080 HTSUS code.

Q: What is the reverse leakage current difference between the parts?

A: DSTF40120C exhibits 500 µA reverse leakage at 120 V, SDT30120CTFP exhibits 100 µA, and SDT20120CTFP exhibits 80 µA. Lower reverse leakage in the substitute parts represents improved performance characteristics. Circuit designs sensitive to reverse leakage benefit from substitution.

Q: Can these parts be used interchangeably in high-temperature applications?

A: All three parts maintain identical operating temperature range of -55°C to 150°C junction temperature. Thermal management and heatsinking requirements depend on actual current loading and power dissipation, which varies with the selected part's current rating.