P3500SB Equivalent & Substitute Parts

Part Overview

The P3500SB is a 320V off-state, 250A peak pulse TVS thyristor manufactured by Littelfuse Inc. in the SIDACtor® series, housed in a DO-214AA (SMB) surface mount package. This component is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and procurement continuity. The part's primary function is transient voltage suppression in electronic circuits requiring high current handling capability.

Substiute Parts

P3500SB

Littelfuse Inc.In Stock: 10228P3500SB Datasheet

Current PartRFQ

P3500SBLRP

Littelfuse Inc.In Stock: 55437P3500SBLRP Datasheet

DirectRFQ

SMP100LC-270

STMicroelectronicsIn Stock: 27501SMP100LC-270 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the P3500SB are identified based on the following critical parameters that determine functional equivalence:

Primary Substitution Criteria:

• Package compatibility: DO-214AA (SMB) surface mount form factor
• Voltage rating alignment: Off-state voltage within acceptable operating range
• Current handling capacity: Peak pulse current (8/20µs) sufficient for circuit protection
• Hold current: Minimum 150mA to maintain thyristor latching behavior
• Single element configuration for direct pin-compatible replacement

Substitution Categories:

Direct Equivalent (P3500SBLRP): Identical electrical specifications and packaging. Differs only in product status (active vs. obsolete) and packaging format (Cut Tape & Digi-Reel vs. standard packaging). RoHS3 compliance provides regulatory advantage over the non-compliant original part.

Manufacturer-Recommended Substitute (SMP100LC-270): STMicroelectronics TRISIL™ series part with modified voltage and current ratings. Off-state voltage reduced to 270V (lower than P3500SB), but peak pulse current increased to 400A (higher than P3500SB). Capacitance increased to 60pF. Suitable for applications where lower voltage suppression threshold and higher current capacity are acceptable or beneficial.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Preferred): P3500SBLRP is the optimal choice for applications requiring identical electrical performance to the P3500SB. This part maintains all original specifications while offering active product status and RoHS3 compliance. Procurement of P3500SBLRP eliminates obsolescence risk and provides regulatory compliance without circuit redesign.

For Alternative Suppression Strategy: SMP100LC-270 is suitable for designs where lower off-state voltage (270V vs. 320V) and higher peak pulse current capacity (400A vs. 250A) are compatible with system requirements. This substitution requires circuit analysis to confirm that the reduced voltage threshold does not cause premature triggering in the application. The increased capacitance (60pF vs. 40pF) may affect high-frequency circuit behavior and should be evaluated in context-specific applications.

Both substitute parts maintain the same package footprint (DO-214AA, SMB) and hold current specification (150mA), ensuring mechanical and functional compatibility at the board level.

Frequently Asked Questions (FAQ)

Q: Can P3500SBLRP be used as a direct drop-in replacement for P3500SB?

A: Yes. P3500SBLRP is electrically and mechanically identical to P3500SB. Both parts share the same voltage ratings (320V off-state, 400V breakover), current specifications (250A peak pulse at 8/20µs), and DO-214AA package. The primary differences are product status (active vs. obsolete) and RoHS3 compliance, which favor P3500SBLRP for new designs and ongoing production.

Q: What are the key differences between P3500SB and SMP100LC-270?

A: The primary differences are off-state voltage (320V vs. 270V) and peak pulse current (250A vs. 400A). SMP100LC-270 has a lower voltage threshold and higher current capacity. Capacitance also differs (40pF vs. 60pF). These differences require circuit validation to ensure the lower voltage suppression point does not cause unintended triggering in your specific application.

Q: Is SMP100LC-270 a pin-compatible replacement?

A: Yes, SMP100LC-270 is pin-compatible with P3500SB. Both parts use the DO-214AA (SMB) surface mount package with identical pinout. However, electrical compatibility must be verified based on your circuit's voltage and current requirements before implementation.

Q: Why is P3500SB marked as obsolete?

A: Product obsolescence is determined by the manufacturer based on market demand and product lifecycle decisions. P3500SBLRP is the active equivalent, ensuring continued availability and support for this specification.

Q: Does the increased capacitance of SMP100LC-270 affect circuit performance?

A: Capacitance differences (40pF vs. 60pF) may impact high-frequency circuit behavior, including signal integrity and EMI characteristics. Circuit-specific evaluation is necessary to determine if the 50% increase in capacitance is acceptable for your application.

Q: Are both substitute parts RoHS and REACH compliant?

A: Yes. Both P3500SBLRP and SMP100LC-270 are RoHS3 compliant and REACH unaffected. The original P3500SB is RoHS non-compliant, making either substitute preferable for regulatory compliance requirements.