Q4004L4 TRIAC Equivalent & Substitute Parts

Part Overview

The Q4004L4 is a standard TRIAC manufactured by Littelfuse Inc., rated for 400V off-state voltage and 4A on-state current in a TO-220 isolated tab package. This component is discontinued at DiGi Electronics, making equivalent substitute parts necessary for ongoing design requirements and procurement. The part operates across a temperature range of -40°C to 125°C and is RoHS3 compliant with MSL 1 rating.

Substiute Parts

Q4004L4

Littelfuse Inc.In Stock: 5164Q4004L4 Datasheet

Current PartRFQ

BT137X-600F,127

WeEn SemiconductorsIn Stock: 896BT137X-600F,127 Datasheet

MFR RecommendedRFQ

BTA06-600CWRG

STMicroelectronicsIn Stock: 18740BTA06-600CWRG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the Q4004L4 are qualified based on the following electrical and mechanical criteria:

Mandatory Compatibility Parameters:

• Mounting Type: Through Hole (TO-220 package family)
• Configuration: Single
• Gate Trigger Voltage (Vgt) compatibility: Maximum 1.5V
• Gate Trigger Current (Igt) compatibility: Maximum 35mA
• Operating Temperature range: Minimum -40°C to 125°C support
• RoHS Compliance: ROHS3 or equivalent

Allowable Parameter Variations:

• Voltage - Off State: Equal to or greater than 400V (400V, 600V acceptable)
• Current - On State (It): Equal to or greater than 4A (4A, 6A, 8A acceptable)
• Current - Hold (Ih): Equal to or less than 30mA (20mA, 30mA, 35mA acceptable)

The two qualified substitutes meet these criteria while maintaining through-hole TO-220 package compatibility and active product status availability.

Parameter Comparison

Engineering Selection Recommendations

BT137X-600F,127 (WeEn Semiconductors)

This substitute provides higher voltage and current ratings (600V, 8A) compared to the Q4004L4 (400V, 4A), offering design margin for applications requiring increased headroom. The part maintains identical gate trigger current specification (25mA) and is RoHS compliant. Active product status ensures long-term availability. The TO-220F package is compatible with standard TO-220 footprints. Note that the operating temperature specification lists only the maximum junction temperature without explicit minimum temperature range in the provided data.

BTA06-600CWRG (STMicroelectronics)

This substitute is an Alternistor - Snubberless TRIAC with 600V and 6A ratings, providing voltage and current margin over the original part. It maintains the full operating temperature range (-40°C to 125°C) and is ROHS3 compliant with REACH unaffected status. The snubberless design may reduce external component requirements in certain applications. Active product status and high inventory availability (18,654 pcs) support procurement reliability. Gate trigger current is 35mA, which is within acceptable limits for the application class.

Frequently Asked Questions (FAQ)

Q: Can the BT137X-600F,127 directly replace the Q4004L4 in existing designs?

A: The BT137X-600F,127 is electrically compatible as a substitute. Both are standard TRIACs in TO-220 packages with compatible gate trigger specifications. The higher voltage (600V vs 400V) and current (8A vs 4A) ratings provide design margin. PCB footprint compatibility should be verified, as the TO-220F variant may have minor dimensional differences from the isolated tab version.

Q: What is the difference between the BT137X-600F,127 and BTA06-600CWRG?

A: Both are 600V TRIACs in TO-220 packages suitable for substitution. The BT137X-600F,127 is a standard TRIAC with 8A rating and 25mA gate trigger current. The BTA06-600CWRG is an Alternistor - Snubberless design with 6A rating and 35mA gate trigger current. The snubberless design may reduce external RC network requirements. The BTA06 maintains the full temperature range specification, while the BT137 specification shows only maximum temperature in the provided data.

Q: Are there package compatibility concerns when substituting these parts?

A: All three parts use TO-220 package variants suitable for through-hole mounting. The Q4004L4 uses TO-220-3 Isolated Tab, the BT137X-600F,127 uses TO-220-3 Full Pack with Isolated Tab, and the BTA06-600CWRG uses standard TO-220-3. These are mechanically compatible with standard TO-220 footprints, though isolated tab variants may have minor lead configuration differences. Verify PCB pad layout compatibility before assembly.

Q: Do these substitutes maintain RoHS compliance?

A: Yes. The Q4004L4 is ROHS3 compliant. The BT137X-600F,127 is RoHS compliant. The BTA06-600CWRG is ROHS3 compliant with REACH unaffected status. All three parts have MSL 1 (Unlimited) moisture sensitivity ratings, suitable for standard storage and handling conditions.

Q: Which substitute should be selected for new designs?

A: Selection depends on application requirements. For designs requiring snubberless operation and full temperature range specification, the BTA06-600CWRG is appropriate. For designs prioritizing higher current capacity, the BT137X-600F,127 offers 8A rating. Both are active products with established availability. Verify gate trigger circuit compatibility with the selected part's Vgt and Igt specifications.