similarity-led

name	similarity-led
description	Use when working with LED similarity calculations - comparing LED MPNs, understanding color bins, brightness bins, families, or LED-specific similarity logic.

LED Similarity Calculator Skill

Guidance for working with LEDSimilarityCalculator in the lib-electronic-components library.

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For metadata-driven similarity architecture, see /similarity-metadata:

• SpecImportance levels (CRITICAL, HIGH, MEDIUM, LOW, OPTIONAL)
• ToleranceRule types (exactMatch, percentageTolerance, minimumRequired, etc.)
• SimilarityProfile contexts (DESIGN_PHASE, REPLACEMENT, COST_OPTIMIZATION, etc.)
• Calculator integration patterns and gotchas

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Overview

The LEDSimilarityCalculator compares LEDs based on:

• LED family - Same manufacturer series
• Bin codes - Brightness and color temperature bins
• Color temperature - Must match for high similarity

Applicable Types

ComponentType.LED
// Any type starting with "LED_"
// Uses getBaseType() == ComponentType.LED

Returns false for null type.

Similarity Thresholds

HIGH_SIMILARITY = 0.9;   // Same LED, same color temp
MEDIUM_SIMILARITY = 0.7; // Different families but valid LEDs
LOW_SIMILARITY = 0.3;    // Different color temperatures

LED Equivalent Groups

TI High-Power LED Series

Group	Members
TLHR5400 (Red)	TLHR5400, TLHR5401, TLHR5402, TLHR5403
TLHG5800 (Green)	TLHG5800, TLHG5801, TLHG5802, TLHG5803
TLHB5800 (Blue)	TLHB5800, TLHB5801, TLHB5802, TLHB5803

LG LED Series

Group	Members
LG R971 (Red)	LG R971, LG R971-KN, LG R971-PK
LG B971 (Blue)	LG B971, LG B971-KN, LG B971-PK
LG G971 (Green)	LG G971, LG G971-KN, LG G971-PK

Samsung LM Series

Group	Members
LM301B	LM301B, LM301B-K, LM301B-V2
LM281B	LM281B, LM281B-K, LM281B-V2

Nichia NCS Series

Group	Members
NCSW (White)	NCSW170, NCSW170T, NCSW170AT
NCSR (Red)	NCSR170, NCSR170T, NCSR170AT

Bin Code Handling

LEDs use bin codes for brightness and color sorting:

Brightness Bins (Typical)

• K, L, M, N - Brightness grades

Color Temperature Bins (Cree)

• FK* - One color temperature
• FC* - Different color temperature

// Same color temperature = HIGH
calculator.calculateSimilarity("XPERED-L1-FKA", "XPERED-L1-FKB", registry);
// Returns 0.9

// Different color temperatures = LOW
calculator.calculateSimilarity("XPERED-L1-FKA", "XPERED-L1-FCA", registry);
// Returns 0.3

Family Detection

Prefix	Manufacturer	Family
TLHR	TI	Red LED
TLHG	TI	Green LED
TLHB	TI	Blue LED
TLW	TI	White LED
LG R/B/G	LG	Color LEDs
LW, LR, LS	Osram	Standard LEDs
XP, XB, XQ	Cree	High-power LEDs
L130, L135	Lumileds	LUXEON series
LM	Samsung	LM series
NCS	Nichia	Standard series

Package Compatibility

Package Type	Compatible Packages
SMD	SMD, PLCC, 3528, 5050, 2835, 3030, 5630, 0603, 0805, 1206
Through-Hole	TH, DIP, 5MM, 3MM, 8MM, 10MM, T-1, T-1¾
High-Power	STAR, MCE, XPE, XPG, XML, LUXEON, REBEL

Test Examples

// Same LED
calculator.calculateSimilarity("TLHR5400", "TLHR5400", registry);
// Returns 0.9

// Same family, different bin
calculator.calculateSimilarity("TLHR5400", "TLHR5401", registry);
// Returns 0.9

// LG variants with suffix
calculator.calculateSimilarity("LG R971", "LG R971-KN", registry);
// Returns 0.9

// Different color temps
calculator.calculateSimilarity("XPERED-L1-FKA", "XPERED-L1-FCA", registry);
// Returns 0.3

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Metadata-Driven Implementation (January 2026)

Status: ✅ Converted (PR #118)

The LEDSimilarityCalculator now uses a metadata-driven approach with spec-based comparison.

Specs Compared

Spec	Importance	Tolerance Rule	Description
color	CRITICAL	exactMatch	Red, Green, Blue, White, etc.
family	HIGH	exactMatch	TLHR, LG R, LM301, XP-E, etc.
brightness	HIGH	exactMatch	Brightness bin code
package	LOW	exactMatch	0603, 0805, 5mm, SMD, etc.

Implementation Pattern

// Short-circuit check for CRITICAL incompatibility
if (!color1.isEmpty() && !color2.isEmpty() && !color1.equals(color2)) {
    return LOW_SIMILARITY;
}

// Weighted spec scoring
// color: CRITICAL (1.0 weight)
// family: HIGH (0.7 weight)
// brightness: HIGH (0.7 weight)
// package: LOW (0.2 weight)

// Family boost for known equivalent groups
if (areSameFamily(mpn1, mpn2)) {
    similarity = Math.max(similarity, HIGH_SIMILARITY);
}

Behavior Changes

Comparison	Legacy Result	Metadata Result	Notes
TLHR5400 vs TLHR5401	0.9	0.96	Same family, different bins
LG R971 vs LG R971-KN	0.9	1.0	Exact family + color match
TLHR5400 vs LCW E6SF	0.7	0.66	Different families, same color
XPERED-L1-FKA vs XPERED-L1-FCA	0.3	0.3	Short-circuit on color temp

Why more accurate: Metadata approach prioritizes color matching (CRITICAL) and separates family from brightness considerations.

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Learnings & Quirks

Color Temperature Codes

• Cree uses FK/FC in bin codes to indicate color temp
• Same base LED with different color temps are NOT equivalent

Brightness Bin Codes

• Adjacent brightness bins (K vs L) are usually interchangeable
• Large gaps in brightness bins may not be suitable substitutes

LG LED Format

• Format: LG R971-KN where -KN is the suffix variant
• All suffix variants of same base part are equivalent

Package Suffixes

• -RL, -RT = Tape and reel packaging
• -TUBE = Tube packaging
• These don't affect LED equivalence