HT36BRP Equivalent & Substitute Parts

Part Overview

The HT36BRP is a Diac/Sidac thyristor manufactured by Littelfuse Inc., rated for 34–38V breakover voltage with 2A peak output current in a DO-35 axial package. This component is classified as obsolete, making equivalent substitutes necessary for new designs and ongoing production requirements. The HT36BRP operates across the industrial temperature range of -40°C to 125°C and complies with RoHS3 standards.

Substiute Parts

HT36BRP

Littelfuse Inc.In Stock: 920HT36BRP Datasheet

Current PartRFQ

DB3

Fairchild SemiconductorIn Stock: 770983DB3 Datasheet

MFR RecommendedRFQ

DB3TG

STMicroelectronicsIn Stock: 2484DB3TG Datasheet

MFR RecommendedRFQ

DB4

STMicroelectronicsIn Stock: 20892DB4 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the HT36BRP is determined by the following critical parameters:

• Voltage - Breakover Range: The HT36BRP operates at 34–38V. Substitute parts must have breakover voltage ranges that overlap or are compatible with this specification.
• Current - Peak Output: All qualified substitutes must support 2A peak output current.
• Package / Case: All substitutes must use the DO-35 axial package format (DO-204AH).
• Operating Temperature Range: All substitutes must support -40°C to 125°C operation.
• RoHS Compliance: All substitutes must maintain RoHS3 compliance for regulatory alignment.

Three substitute parts meet these criteria:

1. DB3 (Fairchild Semiconductor): Breakover voltage 28–36V, overlaps the lower end of HT36BRP range.
2. DB3TG (STMicroelectronics): Breakover voltage 30–34V, closely aligned with HT36BRP lower specification.
3. DB4 (STMicroelectronics): Breakover voltage 35–45V, overlaps the upper end of HT36BRP range.

Parameter Comparison

Engineering Selection Recommendations

DB3TG is the primary substitute for new designs. It maintains an active product status with STMicroelectronics, ensuring long-term availability and supply chain stability. The breakover voltage range of 30–34V provides the closest alignment to the HT36BRP specification within the lower tolerance band. Current-breakover characteristics match the original part at 15 µA. RoHS3 compliance and DO-35 packaging are maintained.

DB4 serves as an alternative for applications requiring higher breakover voltage tolerance. With a 35–45V range, it covers the upper specification band of the HT36BRP. This part is actively manufactured by STMicroelectronics and maintains full compliance with regulatory requirements.

DB3 (Fairchild Semiconductor) is available but carries obsolete product status, limiting its suitability for new production despite adequate electrical specifications.

Frequently Asked Questions (FAQ)

Q: Can DB3TG directly replace HT36BRP in existing designs? A: DB3TG is electrically compatible within the specified parameter ranges. Both parts share identical DO-35 packaging, 2A peak output current, and -40°C to 125°C operating temperature. The breakover voltage range of DB3TG (30–34V) overlaps the lower portion of HT36BRP (34–38V), making it suitable for applications where the trigger voltage tolerance permits this overlap.

Q: What is the difference between DB3 and DB3TG? A: Both parts are Diac/Sidac thyristors in DO-35 packages with 2A peak output. DB3 (Fairchild) has a breakover voltage of 28–36V and is obsolete. DB3TG (STMicroelectronics) has a breakover voltage of 30–34V and maintains active product status. DB3TG is preferred for new designs due to availability and supply continuity.

Q: When should DB4 be selected instead of DB3TG? A: DB4 is selected when the application circuit requires a higher breakover voltage threshold. With a 35–45V range, DB4 covers the upper specification band of the HT36BRP. Both DB4 and DB3TG are actively manufactured, so the choice depends on the specific voltage triggering requirements of the circuit.

Q: Are all substitutes RoHS3 compliant? A: Yes. HT36BRP, DB3, DB3TG, and DB4 all carry RoHS3 compliance certification, ensuring regulatory alignment for industrial and commercial applications.

Q: Does package format differ among these parts? A: No. All four parts use the DO-35 axial package format (DO-204AH), ensuring mechanical and electrical compatibility in existing PCB layouts and component mounting configurations.