L4004F51 Equivalent & Substitute Parts

Part Overview

The L4004F51 is a Logic - Sensitive Gate TRIAC manufactured by Littelfuse Inc., rated for 400 V off-state voltage and 4 A on-state current in a Through Hole TO-202 package. This component is classified as Obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and procurement continuity. The sensitive gate configuration enables reliable triggering at low gate currents, suitable for applications requiring precise gate control in AC switching circuits.

Substiute Parts

L4004F51

Littelfuse Inc.In Stock: 776L4004F51 Datasheet

Current PartRFQ

BT136-600D,127

WeEn SemiconductorsIn Stock: 18546BT136-600D,127 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the L4004F51 is determined by the following critical parameters:

• Triac Type: Logic - Sensitive Gate configuration must be maintained
• Current Rating: On-state current of 4 A (RMS) maximum
• Gate Trigger Characteristics: Vgt (Max) and Igt (Max) must support low-level gate drive
• Configuration: Single TRIAC element
• Mounting Type: Through Hole technology
• Compliance: ROHS3 compliance required

The BT136-600D,127 qualifies as a substitute based on matching Triac Type, current rating, gate trigger parameters, configuration, mounting type, and RoHS compliance. The higher off-state voltage rating (600 V vs. 400 V) provides enhanced voltage margin and does not restrict application in circuits designed for 400 V operation.

Parameter Comparison

Engineering Selection Recommendations

The BT136-600D,127 is an active production substitute for the obsolete L4004F51. Both components meet ROHS3 compliance requirements and share identical gate trigger current and hold current specifications. The substitute provides enhanced electrical performance through higher off-state voltage rating and lower gate trigger voltage threshold, making it suitable for direct functional replacement in 400 V applications.

Package transition from TO-202 Long Tab to TO-220-3 requires PCB layout modification. The substitute's higher maximum junction temperature rating (125°C vs. 110°C) extends thermal operating margin. Availability of the BT136-600D,127 in active production status ensures long-term supply continuity compared to the obsolete L4004F51.

Frequently Asked Questions (FAQ)

Q: Can the BT136-600D,127 directly replace the L4004F51 without circuit modification?

A: Electrical parameters are compatible for direct functional substitution. Package differences (TO-202 Long Tab vs. TO-220-3) require PCB layout changes. Gate drive circuits designed for the L4004F51 will operate with the BT136-600D,127 due to matching gate trigger current specifications.

Q: Why is the substitute rated for 600 V when the original is 400 V?

A: Higher voltage rating provides additional safety margin and does not restrict operation in 400 V circuits. The component will function identically in applications designed for 400 V off-state voltage.

Q: What are the package implications of switching from TO-202 to TO-220?

A: TO-202 Long Tab and TO-220-3 have different pin configurations and footprints. PCB redesign is required to accommodate the TO-220-3 package. Thermal management characteristics may differ due to package geometry changes.

Q: Are both components RoHS compliant?

A: Yes. Both the L4004F51 and BT136-600D,127 are ROHS3 compliant.

Q: What is the significance of the lower gate trigger voltage in the substitute?

A: The BT136-600D,127 has a maximum gate trigger voltage of 1.5 V compared to 2 V for the L4004F51. This indicates improved gate sensitivity and may reduce gate drive circuit power requirements, but does not prevent compatibility with existing gate drive designs.