S4020LTP Equivalent & Substitute Parts

Part Overview

The S4020LTP is a Silicon Controlled Rectifier (SCR) manufactured by Littelfuse Inc., rated for 400V off-state voltage with 20A on-state current capability in a TO-220AB-L isolated tab package. This thyristor is designed for standard recovery applications requiring through-hole mounting. The part is currently in active production status with 1310 units available in inventory. Alternative models become necessary when specific current ratings, package variants, or supply constraints require component substitution while maintaining circuit functionality within defined electrical parameters.

Substiute Parts

S4020LTP

Littelfuse Inc.In Stock: 1352S4020LTP Datasheet

Current PartRFQ

S4015LTP

Littelfuse Inc.In Stock: 3487S4015LTP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

The S4015LTP qualifies as a parametric equivalent to the S4020LTP based on the following substitution criteria:

Matching Parameters (Substitution Basis):

• Off-state voltage: 400V (identical)
• Gate trigger voltage (Vgt Max): 1.5V (identical)
• Gate trigger current (Igt Max): 30mA (identical)
• On-state voltage (Vtm Max): 1.6V (identical)
• Hold current (Ih Max): 40mA (identical)
• Off-state current: 10µA (identical)
• Operating temperature range: -40°C to 125°C (identical)
• Mounting type: Through Hole (identical)
• Package type: TO-220-3 Isolated Tab (identical)
• SCR type: Standard Recovery (identical)
• RoHS and REACH compliance: Identical

Differing Parameters (Current Rating):

• S4020LTP: 20A on-state current (It RMS Max)
• S4015LTP: 15A on-state current (It RMS Max)

The S4015LTP operates within a lower current envelope, making it suitable for applications where the 20A rating of the S4020LTP exceeds circuit requirements. Both parts share identical voltage, gate control, and thermal characteristics, differing only in maximum continuous current capacity.

Parameter Comparison

Engineering Selection Recommendations

S4020LTP Selection Criteria:

• Applications requiring continuous on-state current up to 20A RMS
• Circuits with non-repetitive surge current demands up to 300A (60Hz)
• Designs where maximum current capacity within the 400V voltage class is specified

S4015LTP Selection Criteria:

• Applications with on-state current requirements up to 15A RMS
• Circuits with non-repetitive surge current demands up to 225A (60Hz)
• Designs where lower current ratings are sufficient, enabling cost optimization
• Supply chain scenarios where S4015LTP inventory availability (3460 units) provides procurement advantage

Both parts maintain identical compliance certifications (ROHS3, REACH Unaffected, EAR99 ECCN classification) and thermal operating ranges. Selection between these parts depends solely on the maximum continuous and surge current requirements of the target application. The S4015LTP represents a downrated variant suitable for lower-current implementations within the same voltage and control parameter envelope.

Frequently Asked Questions (FAQ)

Q: Can S4015LTP replace S4020LTP in any application?

A: The S4015LTP can replace the S4020LTP only when the application's maximum on-state current requirement does not exceed 15A RMS. If the circuit design requires current capacity between 15A and 20A RMS, or surge currents exceeding 225A (60Hz), the S4020LTP is required.

Q: Are the gate trigger characteristics identical between these parts?

A: Yes. Both parts share identical gate trigger voltage (1.5V max) and gate trigger current (30mA max) specifications. Gate drive circuit design remains unchanged between the two parts.

Q: Do these parts use the same PCB footprint?

A: Yes. Both parts use the TO-220-3 Isolated Tab package with identical through-hole mounting configuration. PCB layout and thermal management design remain compatible.

Q: What is the primary difference between S4020LTP and S4015LTP?

A: The primary difference is the maximum on-state current rating: S4020LTP is rated for 20A RMS, while S4015LTP is rated for 15A RMS. All voltage, gate control, and thermal parameters are identical.

Q: Are there compliance or certification differences?

A: No. Both parts carry identical RoHS3 compliance, REACH Unaffected status, and EAR99 ECCN classification. Environmental and regulatory requirements do not differentiate these parts.

Q: Which part should be selected for new designs?

A: Select based on the actual current requirement of the application. If 15A RMS capacity is sufficient, either part is acceptable. If current demand may reach 20A RMS, specify the S4020LTP to ensure adequate margin and design flexibility.