S4X8ES2AP Equivalent & Substitute Parts

Part Overview

The S4X8ES2AP is a 400 V, 800 mA sensitive gate SCR (silicon-controlled rectifier) manufactured by Littelfuse Inc. in a through-hole TO-92 package. This thyristor is designed for applications requiring controlled rectification and switching at moderate voltage and current levels. The part is currently in active production status with 662 units in stock.

Substitute parts become necessary when the original manufacturer part reaches end-of-life status, when alternative packaging formats are required for assembly optimization, or when supply chain availability necessitates qualified alternatives from other manufacturers. The STMicroelectronics P0102 and P0109 series provide functionally equivalent alternatives with compatible electrical and mechanical specifications.

Substiute Parts

S4X8ES2AP

Littelfuse Inc.In Stock: 728S4X8ES2AP Datasheet

Current PartRFQ

P0102DA 1AA3

STMicroelectronicsIn Stock: 4916P0102DA 1AA3 Datasheet

MFR RecommendedRFQ

P0102DA 2AL3

STMicroelectronicsIn Stock: 10177P0102DA 2AL3 Datasheet

MFR RecommendedRFQ

P0102DA 5AL3

STMicroelectronicsIn Stock: 35332P0102DA 5AL3 Datasheet

MFR RecommendedRFQ

P0109DA 5AL3

STMicroelectronicsIn Stock: 3609P0109DA 5AL3 Datasheet

MFR RecommendedRFQ

P0118DA 5AL3

STMicroelectronicsIn Stock: 2465P0118DA 5AL3 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the S4X8ES2AP is determined by strict equivalence across the following critical parameters:

• Voltage Rating (Off State): 400 V minimum
• Gate Trigger Voltage (Vgt): 800 mV maximum
• On-State Current (It RMS): 800 mA maximum
• Hold Current (Ih): 5 mA maximum
• Operating Temperature Range: -40°C to 125°C
• Package / Case: TO-92-3 (TO-226AA) through-hole configuration
• SCR Type: Sensitive Gate classification
• Compliance: ROHS3 Compliant, REACH Unaffected

All substitute parts listed below meet these electrical and mechanical requirements. Differences in gate trigger current (Igt), on-state voltage (Vtm), and packaging format (Bulk, Cut Tape) do not affect functional substitutability within the specified parameter envelope.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Active Status)

The P0102DA series from STMicroelectronics represents the preferred substitute group. All three variants—P0102DA 1AA3 (Bulk), P0102DA 2AL3 (Cut Tape), and P0102DA 5AL3 (Cut Tape)—are in active production with substantial inventory availability. These parts maintain identical electrical performance within the specified parameter envelope and are fully ROHS3 compliant and REACH unaffected.

Secondary Substitute (Active Status)

P0109DA 5AL3 is functionally equivalent and actively produced. This part offers an alternative base product number while maintaining all critical electrical and mechanical specifications.

Obsolete Alternative (Not Recommended for New Designs)

P0118DA 5AL3 carries obsolete product status and should not be selected for new circuit designs or long-term production commitments. This part is listed for reference only in legacy system maintenance scenarios. The gate trigger current specification (5 µA) differs significantly from other alternatives, which may affect circuit behavior in sensitive gate applications.

Packaging Considerations

Selection between Bulk, Cut Tape, and Tape & Box formats depends on assembly process requirements and volume. Cut Tape variants (P0102DA 2AL3, P0102DA 5AL3, P0109DA 5AL3) offer the highest inventory levels and are suitable for automated pick-and-place assembly. Bulk packaging (P0102DA 1AA3) is appropriate for manual assembly or lower-volume applications.

Frequently Asked Questions (FAQ)

Q: Can P0102DA series parts directly replace S4X8ES2AP in existing circuits?

A: Yes. All P0102DA variants meet the critical electrical parameters: 400 V off-state voltage, 800 mV gate trigger voltage, and 800 mA RMS on-state current. The TO-92-3 package and through-hole mounting are identical. No circuit redesign is required.

Q: What is the difference between P0102DA 1AA3, P0102DA 2AL3, and P0102DA 5AL3?

A: These parts are electrically identical. The differences are packaging format (Bulk vs. Cut Tape) and inventory availability. Selection depends on assembly process requirements. All three are in active production.

Q: Why does P0118DA 5AL3 have a different gate trigger current specification?

A: P0118DA 5AL3 is classified as obsolete and exhibits a gate trigger current (Igt) of 5 µA compared to 200 µA in the P0102DA series. This specification difference may affect circuit triggering behavior and makes it unsuitable for new designs. It is listed for legacy system reference only.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 compliance and REACH unaffected status, matching the original S4X8ES2AP specifications.

Q: What is the maximum operating temperature for these SCRs?

A: All parts, including the original and all substitutes, operate across the -40°C to 125°C temperature range.

Q: Can I use P0109DA 5AL3 instead of P0102DA 5AL3?

A: Yes. P0109DA 5AL3 is functionally equivalent with identical electrical specifications and active production status. The base product number differs, but electrical performance within the specified parameter envelope is equivalent.