Logicic

Example Decoding

SN74HC595N
|  |  |  ||
|  |  |  |+-- N = DIP package
|  |  |  +-- 595 = 8-bit shift register function
|  |  +-- 74 = Commercial temperature range
|  +-- HC = High-speed CMOS family
+-- SN = Texas Instruments prefix

74LS04D
  |  ||
  |  |+-- D = SOIC package
  |  +-- 04 = Hex inverter function
  +-- LS = Low-power Schottky TTL family

CD4xxx Series

CD[FUNCTION][PACKAGE]
|     |         |
|     |         +-- Package suffix (BE, BM, UBE, etc.)
|     +-- Function number (4001, 4017, 4051, etc.)
+-- CD = CMOS Digital prefix

Example Decoding

CD4017BE
|  |   ||
|  |   |+-- E = Economy grade
|  |   +-- B = Buffered output
|  +-- 4017 = Decade counter/divider function
+-- CD = CMOS Digital prefix

CD4001UBE
|  |   |||
|  |   ||+-- E = Economy grade
|  |   |+-- B = Buffered
|  |   +-- U = Unbuffered variant
|  +-- 4001 = Quad 2-input NOR gate
+-- CD = CMOS Digital prefix

Technology Families (74xx Series)

Original TTL Technologies

CMOS Technologies (Modern)

Low-Voltage Technologies

Technology Selection Guide

Function Number Reference

Gates (2-digit)

Flip-Flops

Counters

Shift Registers

Decoders/Demultiplexers

Multiplexers

Buffers/Drivers

Package Codes

74xx Series Package Codes

CD4xxx Series Package Codes

Handler Implementation

Supported Component Types

ComponentType.IC         // Base type
ComponentType.LOGIC_IC   // Specific logic IC type

Pattern Recognition

// 74xx series pattern (includes 54xx military)
"^(?:74|54)[LSAHCTTF]{0,4}[0-9]{2,4}.*"

// CD4xxx series pattern
"^CD4[0-9]{3}.*"

Series Extraction Rules

The handler extracts the base series by:

1. 74xx: Extracts digits after technology code until non-digit

   • SN74HC595N -> 595
   • 74LS04D -> 04

2. CD4xxx: Extracts CD4 + 3-digit function

   • CD4017BE -> CD4017
   • CD4001UBE -> CD4001

Package Code Extraction Rules

CD4xxx:

• Check longest suffixes first: UBE, BE, BC
• Then shorter: B, E

74xx:

• Single letter suffix: N, D, P, M, T
• Pattern: .*?([NDPMT])$

Similarity Calculation

The LogicICSimilarityCalculator uses these rules:

Same Function, Compatible Technology = HIGH (0.9)

// These are highly similar (same function)
"74LS00" vs "74HC00"    // 0.9 - Same NAND function
"74LS04" vs "74ALS04"   // 0.9 - Same inverter function
"CD4001BE" vs "CD4001BM" // 0.9 - Same NOR gate, different package

Different Functions = LOW (0.3)

// These have low similarity (different functions)
"74LS00" vs "74LS04"    // 0.3 - NAND vs Inverter
"74HC595" vs "74HC138"  // 0.3 - Shift register vs Decoder
"CD4017" vs "CD4001"    // 0.3 - Counter vs NOR gate

Compatible Technology Groups

These 74xx families are considered compatible:

• LS, ALS, F, HC, HCT

Parts with the same function and compatible families score HIGH similarity.

Function Groups

Parts in the same function group may have increased similarity:

Example MPNs

Texas Instruments (SN prefix)

Nexperia (74 prefix without SN)

ON Semiconductor (MC74 prefix)

CD4000 Series (Multi-source)

Multi-Sourcing Guide

Logic ICs are second-sourced by many manufacturers. These are direct replacements:

Note: Nexperia uses HEF prefix for CD4000 series (e.g., HEF4001BT). STMicro uses HCF prefix (e.g., HCF4017BE). ON Semiconductor uses MC14 prefix (e.g., MC14001BCP).

Related Files

• Handler: manufacturers/LogicICHandler.java
• Similarity Calculator: componentsimilaritycalculators/LogicICSimilarityCalculator.java
• Component Types: ComponentType.LOGIC_IC, ComponentType.LOGIC_IC_NEXPERIA, ComponentType.LOGIC_IC_DIODES
• Similarity Skill: .claude/skills/similarity-logic/SKILL.md

Learnings & Quirks

Handler Patterns

• Pattern uses character class: [LSAHCTTF]{0,4} captures technology but has duplicates (TT). Works but could be cleaner.
• 54xx military parts: Pattern includes 54xx prefix for military temperature range variants. Same function as 74xx.
• No manufacturer prefix required: Pattern matches both SN74HC595 (TI) and 74HC595 (generic).

Series Extraction Gotcha

• The extractSeries() method uses regex replaceAll("([0-9]{2,4}).*$", "$1") which captures the function number.
• For 74LS04D, this extracts 04 (correct).
• For 74HC595N, this extracts 595 (correct).
• Note: Technology prefix (LS, HC) is NOT included in extracted series.

Package Code Order Matters

// CORRECT - Check longer suffixes first
if (mpn.endsWith("UBE")) return "UBE";  // 3 chars first
if (mpn.endsWith("BE")) return "BE";    // 2 chars second
if (mpn.endsWith("B")) return "B";      // 1 char last

// WRONG - Would never match UBE or BE
if (mpn.endsWith("E")) return "E";      // Matches first!

CD4000 Buffered vs Unbuffered

• B suffix: Buffered output (higher drive, lower speed)
• UB suffix: Unbuffered output (faster, lower drive)
• Most modern designs use buffered versions.

74xx vs CD4000 Comparison

Technology Selection for Mixed Voltage

Debug Statements in Calculator

The LogicICSimilarityCalculator contains System.out.println debug statements (lines 43, 47, 51, 59, 67, 78, 92, 113-123). These should be removed or replaced with SLF4J logging in production.

Cross-Handler Considerations

• LogicICHandler handles generic logic ICs (74xx, CD4xxx).
• Manufacturer-specific handlers (TI, Nexperia, etc.) may also match these parts.
• Handler ordering in ManufacturerHandlerFactory affects which handler processes the part first.