similarity-diode

name	similarity-diode
description	Use when working with diode similarity calculations - comparing signal/rectifier/zener/Schottky diode MPNs, understanding equivalent groups like 1N4148/1N914, or diode-specific similarity logic.

Diode Similarity Calculator Skill

Guidance for working with DiodeSimilarityCalculator 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 DiodeSimilarityCalculator compares diodes based on:

• Diode type - Signal, rectifier, zener, Schottky
• Equivalent groups - Known interchangeable parts
• Voltage ratings - For rectifier and zener diodes

Applicable Types

ComponentType.DIODE
// Any type starting with "DIODE_"

Returns false for null type.

Similarity Thresholds

HIGH_SIMILARITY = 0.9;   // Equivalent parts
MEDIUM_SIMILARITY = 0.7; // Same family, compatible
LOW_SIMILARITY = 0.3;    // Same type, different specs

Signal Diode Equivalents

Group	Members	Notes
1N4148/1N914	1N4148, 1N914	Classic signal diodes, equivalent

calculator.calculateSimilarity("1N4148", "1N914", registry);
// Returns 0.9 (equivalent signal diodes)

Rectifier Diode Equivalents

1N400x Series (1A Rectifiers)

Part	Voltage	Equivalent
1N4001	50V	RL201
1N4002	100V	RL202
1N4003	200V	RL203
1N4004	400V	RL204
1N4005	600V	RL205
1N4006	800V	RL206
1N4007	1000V	RL207

// Same voltage equivalents
calculator.calculateSimilarity("1N4007", "RL207", registry);
// Returns 0.9 (both 1000V rectifiers)

// Same family, different voltage
calculator.calculateSimilarity("1N4001", "1N4007", registry);
// Returns 0.9 (same family, all rectifiers)

calculator.calculateSimilarity("1N4001", "1N4004", registry);
// Returns >= 0.7 (same family)

Zener Diode Rules

Zener diodes are compared by voltage rating:

Part	Voltage
1N4728	3.3V
1N4733	5.1V
1N4742	12V
1N4744	15V

// Same voltage zener
calculator.calculateSimilarity("1N4733", "1N4733", registry);
// Returns 0.9

// Different voltage zeners
calculator.calculateSimilarity("1N4733", "1N4742", registry);
// Returns 0.3 (5.1V vs 12V - not interchangeable)

Schottky Diode Equivalents

Group	Members
BAT54	BAT54, BAT54S (series dual)

calculator.calculateSimilarity("BAT54", "BAT54S", registry);
// Returns 0.9 (same Schottky, different configuration)

Test Examples

// Equivalent signal diodes
calculator.calculateSimilarity("1N4148", "1N914", registry);
// Returns 0.9

// Same rectifier diode
calculator.calculateSimilarity("1N4007", "1N4007", registry);
// Returns 0.9

// Cross-manufacturer rectifier
calculator.calculateSimilarity("1N4007", "RL207", registry);
// Returns 0.9

// Same zener voltage
calculator.calculateSimilarity("1N4733", "1N4733", registry);
// Returns 0.9

// Different zener voltage
calculator.calculateSimilarity("1N4733", "1N4742", registry);
// Returns 0.3

// Non-diode parts
calculator.calculateSimilarity("LM358", "LM324", registry);
// Returns 0.0

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Learnings & Quirks

1N400x Series Pattern

• 1N = JEDEC prefix
• 400x = 1A rectifier series
• x = voltage code (1=50V through 7=1000V)

Zener Voltage Codes

• 1N47xx series: xx roughly indicates voltage
• Need lookup table for exact voltage

Schottky Configurations

• BAT54 = Single diode
• BAT54S = Series dual (2 diodes in series)
• BAT54A = Common anode
• BAT54C = Common cathode
• These are same diode, different configurations

Signal vs Rectifier

• Signal diodes (1N4148): Fast switching, low current
• Rectifier diodes (1N4007): Higher current, slower