SJ4020RTP Equivalent & Substitute Parts

Part Overview

The SJ4020RTP is a silicon-controlled rectifier (SCR) manufactured by Littelfuse Inc., classified as a standard recovery thyristor in the SJ series. This component operates at 600 V off-state voltage with a 20 A RMS on-state current rating and is packaged in a TO-220-3 through-hole configuration. The device is Active in product status and ROHS3 compliant. Substitute parts are identified when equivalent electrical and mechanical parameters allow direct replacement in circuit applications while maintaining the same functional performance and physical compatibility.

Substiute Parts

SJ4020RTP

Littelfuse Inc.In Stock: 1050SJ4020RTP Datasheet

Current PartRFQ

SJ6020RTP

Littelfuse Inc.In Stock: 1561SJ6020RTP Datasheet

Parametric EquivalentRFQ

SJ6025RTP

Littelfuse Inc.In Stock: 1445SJ6025RTP Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SJ4020RTP are identified based on the following critical parameters that determine functional equivalence:

Mandatory Matching Parameters:

• Voltage - Off State: 600 V
• SCR Type: Standard Recovery
• Package / Case: TO-220-3
• Mounting Type: Through Hole
• Voltage - Gate Trigger (Vgt) (Max): 1.5 V
• Current - Gate Trigger (Igt) (Max): 35 mA
• Voltage - On State (Vtm) (Max): 1.6 V
• Current - Hold (Ih) (Max): 75 mA
• Operating Temperature Range: -40°C to 150°C (TJ)

Allowable Variation Parameters:

• Current - On State (It (RMS)) (Max): Equal or greater than 20 A
• Current - Non Rep. Surge (Itsm): Equal or greater than specified values

The SJ6020RTP and SJ6025RTP meet these criteria. The SJ6020RTP provides identical current ratings, while the SJ6025RTP offers increased on-state current capacity (25 A RMS) and higher surge current ratings, making it suitable for applications requiring higher current handling without compromising voltage or gate control characteristics.

Parameter Comparison

Engineering Selection Recommendations

SJ6020RTP Selection Criteria: The SJ6020RTP provides direct parametric equivalence to the SJ4020RTP across all electrical and mechanical specifications. Both devices share identical voltage ratings, gate control characteristics, and current handling at 20 A RMS. This substitute is appropriate for applications where the original SJ4020RTP is specified and inventory or supply considerations necessitate an alternative. All compliance certifications (ROHS3, REACH Unaffected, EAR99) are maintained.

SJ6025RTP Selection Criteria: The SJ6025RTP is suitable as a substitute when the application circuit can accommodate increased on-state current capacity (25 A RMS versus 20 A RMS) and higher non-repetitive surge current ratings (300 A at 50 Hz, 350 A at 60 Hz versus 225 A and 300 A respectively). The SJ6025RTP maintains all critical voltage and gate control parameters identical to the SJ4020RTP. This part is appropriate for designs requiring higher current margin or for applications where the SJ4020RTP is at thermal or current limits. All compliance certifications remain equivalent.

Both substitute parts are Active in product status and manufactured by Littelfuse Inc. in the same SJ series, ensuring consistent quality and reliability standards.

Frequently Asked Questions (FAQ)

Q: Can the SJ6020RTP be used as a direct replacement for the SJ4020RTP?

A: Yes. The SJ6020RTP is a parametric equivalent with identical voltage ratings (600 V off-state), gate trigger specifications (1.5 V max, 35 mA max), on-state voltage (1.6 V max), hold current (75 mA max), and on-state current rating (20 A RMS max). Both devices use the TO-220-3 package with through-hole mounting and operate across the same temperature range (-40°C to 150°C TJ). No circuit modifications are required.

Q: What is the difference between the SJ4020RTP and SJ6025RTP?

A: The primary difference is on-state current capacity. The SJ6025RTP is rated for 25 A RMS on-state current compared to 20 A RMS for the SJ4020RTP. Additionally, the SJ6025RTP has higher non-repetitive surge current ratings (300 A at 50 Hz and 350 A at 60 Hz versus 225 A and 300 A). All voltage, gate control, and thermal specifications remain identical. The SJ6025RTP is suitable when higher current handling is required.

Q: Are all three parts (SJ4020RTP, SJ6020RTP, SJ6025RTP) physically compatible in the same PCB footprint?

A: Yes. All three devices use the TO-220-3 package with through-hole mounting configuration. Physical dimensions and pin assignments are identical, allowing direct PCB footprint compatibility without layout modifications.

Q: Do the substitute parts maintain the same compliance certifications?

A: Yes. Both SJ6020RTP and SJ6025RTP are ROHS3 compliant, REACH unaffected, and classified under ECCN EAR99, matching the compliance profile of the SJ4020RTP. Moisture sensitivity level (MSL 1 - Unlimited) is also identical across all three parts.

Q: Can the SJ6025RTP be used in an application designed for the SJ4020RTP?

A: Yes, provided the circuit design does not impose a maximum current limit below 25 A RMS. The SJ6025RTP's higher current rating makes it suitable for the same voltage and control specifications. However, if the application circuit is specifically designed to operate at or near 20 A RMS with thermal management calculated for that level, the SJ6025RTP may introduce thermal considerations that should be evaluated in the specific application context.

Q: What is the gate trigger specification common to all three parts?

A: All three devices share identical gate trigger specifications: maximum gate trigger voltage (Vgt) of 1.5 V and maximum gate trigger current (Igt) of 35 mA. This ensures consistent gate drive circuit requirements across all three parts.