Cantara/.claude/skills/manufacturers/littelfuse

Littelfuse Manufacturer Skill

Use this skill when working with Littelfuse circuit protection components - TVS diodes, fuses, varistors, and MOVs.

Overview

Littelfuse is a leading manufacturer of circuit protection components. The handler supports:

• TVS Diodes: Transient voltage suppressors for ESD and surge protection
• Fuses: SMD and through-hole fuses for overcurrent protection
• Varistors: Metal oxide varistors (MOVs) for voltage clamping

MPN Structure

TVS Diodes - SM Series (VR-Based Naming)

The SM series uses reverse standoff voltage (VR) in the part number:

SMXJ[Voltage][A/CA]

| Component | Description | |-----------|-------------| | SM | Surface Mount | | X | Package: A=SMA, B=SMB, C=SMC, D=SMD | | J | Series designator | | Voltage | Reverse standoff voltage (e.g., 5.0, 15, 33) | | A | Unidirectional | | CA | Bidirectional |

Power Ratings by Package: | Series | Package | Power (W) | DO Package | |--------|---------|-----------|------------| | SMAJ | SMA | 400 | DO-214AC | | SMBJ | SMB | 600 | DO-214AA | | SMCJ | SMC | 1500 | DO-214AB | | SMDJ | SMD | 3000 | - | | 5.0SMDJ | SMD | 5000 | - |

Examples:

• SMAJ5.0A - 400W, 5V standoff, unidirectional, SMA package
• SMBJ33CA - 600W, 33V standoff, bidirectional, SMB package

TVS Diodes - P Series (VBR-Based Naming)

The P series uses breakdown voltage (VBR) in the part number:

P[Power][Package][Voltage][A/CA]

| Series | Package | Power (W) | Package Type | |--------|---------|-----------|--------------| | P4KE | DO-41 | 400 | Axial | | P6KE | DO-15 | 600 | Axial | | P4SMA | SMA | 400 | SMD | | P6SMB | SMB | 600 | SMD | | 1.5KE | DO-15 | 1500 | Axial | | 1.5SMC | SMC | 1500 | SMD | | 3KP | P600 | 3000 | Axial |

Examples:

• P6KE6.8A - 600W, 6.8V breakdown, unidirectional, axial DO-15
• P6KE15CA - 600W, 15V breakdown, bidirectional, axial DO-15
• 1.5KE33CA - 1500W, 33V breakdown, bidirectional, axial

Fuses - NANO2 Series

[Series][Current].[Suffix]

| Series | Type | Size | |--------|------|------| | 0451 | Very Fast Acting | 6.1 x 2.69mm | | 0452 | Slow Blow (Slo-Blo) | 6.1 x 2.69mm | | 0453 | Very Fast Acting | 10.1 x 3.12mm | | 0454 | Slow Blow | 10.1 x 3.12mm | | 0448 | Nano2 SMF | Square SMD |

Suffixes:

• .MRL - Mini Reel (1,000 pcs tape & reel)
• .NRL - Full Reel (5,000 pcs tape & reel)

Examples:

• 0452005.MRL - Slow blow, 5A, mini reel
• 0451002.MRL - Very fast acting, 2A, mini reel
• 0448.125 - Nano2 SMF, 125mA

Varistors - V Series MOVs

Radial Lead MOVs:

V[Voltage][E/P][Size]

| Component | Description | |-----------|-------------| | V | Varistor prefix | | Voltage | Operating voltage (2-3 digits) | | E | Epoxy coating | | P | Phenolic coating | | Size | Disc diameter in mm |

Multilayer SMD Varistors (MLE Series):

V[Voltage]MLE[Package][Options]

Examples:

• V07E130P - 130V, 7mm disc, epoxy/phenolic
• V18MLE0603N - 18V, multilayer, 0603 package
• V26MLE0805N - 26V, multilayer, 0805 package

Supported ComponentTypes

• DIODE - Base type for all TVS diodes
• TVS_DIODE_LITTELFUSE - Specific TVS diode type
• FUSE_LITTELFUSE - Fuse type
• VARISTOR_LITTELFUSE - Varistor type

Handler Methods

Core Methods

// Pattern matching
boolean matches(String mpn, ComponentType type, PatternRegistry patterns)

// Extraction methods
String extractPackageCode(String mpn)  // Returns package (SMA, SMB, NANO2, etc.)
String extractSeries(String mpn)       // Returns series (SMAJ, P6KE, 0452, etc.)

Littelfuse-Specific Methods

// TVS Diode specific
String extractVoltage(String mpn)      // Returns voltage rating
boolean isBidirectional(String mpn)    // True for CA suffix parts
int getPowerRating(String mpn)         // Returns power in watts

// Fuse specific
String extractCurrentRating(String mpn) // Returns current rating

Usage Examples

LittelfuseHandler handler = new LittelfuseHandler();
PatternRegistry registry = new PatternRegistry();
handler.initializePatterns(registry);

// TVS Diode detection
handler.matches("SMAJ15A", ComponentType.TVS_DIODE_LITTELFUSE, registry); // true
handler.extractPackageCode("SMAJ15A");  // "SMA"
handler.extractVoltage("SMAJ15A");      // "15"
handler.isBidirectional("SMAJ15CA");    // true
handler.getPowerRating("SMAJ15A");      // 400

// Fuse detection
handler.matches("0452005.MRL", ComponentType.FUSE_LITTELFUSE, registry); // true
handler.extractPackageCode("0452005.MRL");  // "NANO2"
handler.extractCurrentRating("0452005.MRL"); // "5"

// Varistor detection
handler.matches("V18MLE0603N", ComponentType.VARISTOR_LITTELFUSE, registry); // true
handler.extractPackageCode("V18MLE0603N");  // "0603"
handler.extractVoltage("V18MLE0603N");      // "18"

Common Selection Guide

TVS Diode Selection by Application

| Application | Recommended Series | Power | Package | |-------------|-------------------|-------|---------| | Low-power signal | SMAJ | 400W | SMA | | Medium-power | SMBJ | 600W | SMB | | High-power DC | SMCJ | 1500W | SMC | | Through-hole | P6KE | 600W | DO-15 | | Low capacitance | SAC | 500W | DO-15 |

Fuse Selection by Characteristics

| Characteristic | Recommended Series | |----------------|-------------------| | Fast acting, SMD | 0451 | | Slow blow, SMD | 0452 | | Fast acting, large | 0453 | | Slow blow, large | 0454 | | Ultra-small SMD | 0448 |

Learnings & Quirks

VR vs VBR Naming Systems

• VR-based (SMAJ, SMBJ, etc.): Part number shows standoff voltage
• VBR-based (P4KE, P6KE, etc.): Part number shows breakdown voltage
• Important: SMAJ10A and P4SMA10A have DIFFERENT voltage characteristics!
  • SMAJ10A has 10V standoff (VR), breakdown is higher
  • P4SMA10A has 10V breakdown (VBR), standoff is lower (~8.5V)

Bidirectional vs Unidirectional

• A suffix = Unidirectional (cathode band marking)
• CA suffix = Bidirectional (no polarity)
• Gotcha: CA parts have ~2x the capacitance of A parts

Fuse Current Ratings

• Current in 045x series is in the middle: 0452005 = 5A
• Leading zeros are significant for sub-1A ratings: 0452.250 = 250mA

Package Cross-Reference

| Littelfuse | DO Standard | Dimensions | |------------|-------------|------------| | SMA | DO-214AC | 4.5 x 2.5 x 2.3mm | | SMB | DO-214AA | 5.2 x 3.6 x 2.2mm | | SMC | DO-214AB | 7.1 x 6.2 x 2.3mm |

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Related Skills

• /semiconductor - General semiconductor handling
• /similarity-diode - TVS diode similarity calculations
• /component - Base component operations

Test Examples

// Test file: LittelfuseHandlerTest.java
// Location: src/test/java/no/cantara/electronic/component/lib/handlers/

@Test
void shouldDetectSMAJVariants() {
    assertTrue(handler.matches("SMAJ15A", ComponentType.TVS_DIODE_LITTELFUSE, registry));
    assertTrue(handler.matches("SMAJ33CA", ComponentType.TVS_DIODE_LITTELFUSE, registry));
}

@Test
void shouldExtractTVSInfo() {
    assertEquals("SMA", handler.extractPackageCode("SMAJ15A"));
    assertEquals("15", handler.extractVoltage("SMAJ15A"));
    assertEquals(400, handler.getPowerRating("SMAJ15A"));
}