STMicroelectronics (ST) Manufacturer Skill

Product Families

STMicroelectronics produces a wide range of components:

STM32 - 32-bit ARM Cortex-M microcontrollers
STM8 - 8-bit microcontrollers
ST MOSFETs - Power transistors (STF, STP, STD, STB, STW)
L78/L79 - Linear voltage regulators
Op-amps - Various analog ICs

STM32 Microcontroller Naming

MPN Structure

STM32 F 1 03 C 8 T 6
  │   │ │  │ │ │ │ │
  │   │ │  │ │ │ │ └── Temperature range (6 = -40 to 85°C)
  │   │ │  │ │ │ └── Package (T = LQFP)
  │   │ │  │ │ └── Flash size (8 = 64KB)
  │   │ │  │ └── Pin count (C = 48 pins)
  │   │ │  └── Line (03 = access line)
  │   │ └── Core (1 = Cortex-M3)
  │   └── Type (F = Mainstream)
  └── Family (STM32)

Type Letters (after STM32)

| Letter | Type | Description | |--------|------|-------------| | F | Mainstream | General purpose, good balance | | L | Low-power | Ultra-low-power modes | | H | High-performance | High clock speeds, more features | | G | General-purpose | Newer mainstream series | | W | Wireless | Integrated radio (BLE, LoRa) | | U | Ultra-low-power | Next-gen low-power |

Core Digit

| Digit | Core | Notes | |-------|------|-------| | 0 | Cortex-M0/M0+ | Entry level | | 1 | Cortex-M3 | Mainstream | | 2 | Cortex-M3 | Performance | | 3 | Cortex-M4 | DSP instructions | | 4 | Cortex-M4 | With FPU | | 7 | Cortex-M7 | High performance |

Pin Count Codes

| Code | Pins | Notes | |------|------|-------| | F | 20 | Smallest | | G | 28 | | | K | 32 | | | T | 36 | | | S | 44 | | | C | 48 | Common | | R | 64-66 | Popular | | V | 100 | | | Z | 144 | | | I | 176 | Largest |

Flash Size Codes

| Code | Size | Notes | |------|------|-------| | 4 | 16 KB | | | 6 | 32 KB | | | 8 | 64 KB | Common | | B | 128 KB | | | C | 256 KB | | | D | 384 KB | | | E | 512 KB | | | F | 768 KB | | | G | 1024 KB | | | H | 1536 KB | | | I | 2048 KB | Largest |

Package Codes

| Code | Package | Description | |------|---------|-------------| | T | LQFP | Low-profile Quad Flat Pack | | H | BGA | Ball Grid Array | | U | VFQFPN | Very thin Fine-pitch QFN | | Y | WLCSP | Wafer Level Chip Scale | | P | TSSOP | Thin Shrink SOP |

Temperature Range

| Code | Range | Application | |------|-------|-------------| | 6 | -40 to +85°C | Industrial | | 7 | -40 to +105°C | Extended |

Example Decoding

STM32F103C8T6
│     │  │││││
│     │  ││││└── 6 = -40 to +85°C
│     │  │││└── T = LQFP package
│     │  ││└── 8 = 64KB Flash
│     │  │└── C = 48 pins
│     │  └── 03 = Access line (medium density)
│     └── F1 = Mainstream Cortex-M3
└── STM32 family

Result: Mainstream M3 MCU, 48-pin LQFP, 64KB Flash, Industrial temp
Common Name: "Blue Pill" MCU

STM8 Microcontroller Naming

Structure

STM8 S 003 F 3 P 6
  │  │  │  │ │ │ │
  │  │  │  │ │ │ └── Temperature range
  │  │  │  │ │ └── Package
  │  │  │  │ └── Flash size
  │  │  │  └── Pin count
  │  │  └── Line
  │  └── Type (S=Standard, L=Low-power, A=Automotive)
  └── STM8 family

ST Power MOSFET Naming

Package Prefix

| Prefix | Package | Notes | |--------|---------|-------| | STF | TO-220FP | Isolated tab | | STP | TO-220 | Standard | | STD | DPAK (TO-252) | Surface mount | | STB | D²PAK (TO-263) | High power SMD | | STW | TO-247 | High power through-hole | | VN | Various | N-channel series | | VP | Various | P-channel series |

Naming Pattern

ST [Package] [Current] [Channel] [Voltage] [Suffix]
│     │         │         │         │         │
│     │         │         │         │         └── Technology (F, L, etc.)
│     │         │         │         └── Voltage class (20=200V, 25=250V)
│     │         │         └── Channel (N=N-ch, P=P-ch)
│     │         └── Current rating (amps)
│     └── Package code (F, P, D, B, W)
└── ST prefix

Example Decoding

STF5N52U
│││ │ ││
│││ │ │└── U = technology suffix
│││ │ └── 52 = 520V class
│││ └── N = N-channel
││└── 5 = ~5A rating
│└── F = TO-220FP package
└── ST prefix

L78/L79 Voltage Regulator Naming

Structure

L 78 [Voltage] [Grade] [Package]
│  │     │        │        │
│  │     │        │        └── Package suffix
│  │     │        └── Temperature grade (optional)
│  │     └── Output voltage (05=5V, 12=12V, etc.)
│  └── 78=Positive, 79=Negative
└── L prefix (ST designation)

Package Suffixes

| Suffix | Package | Description | |--------|---------|-------------| | CV | TO-220 | Standard through-hole | | V | TO-220 | Alternate | | CP | TO-220FP | Isolated tab | | P | TO-220FP | Alternate | | CD2T | D²PAK | High power SMD | | D2T | D²PAK | Alternate | | CDT | DPAK | SMD | | DT | DPAK | Alternate |

Grade Codes

| Grade | Temperature | Notes | |-------|-------------|-------| | (none) | 0 to +125°C | Standard | | C | 0 to +125°C | Commercial | | A | -40 to +125°C | Extended | | AB | -40 to +125°C | Extended | | AC | 0 to +125°C | Standard |

Example Decoding

L7805CV
│ ││ ││
│ ││ │└── V = through-hole variant
│ ││ └── C = Commercial grade
│ │└── 05 = 5V output
│ └── 78 = Positive regulator
└── L prefix

L7912ACD2T
│ ││ │ │ │
│ ││ │ │ └── T = tape packaging
│ ││ │ └── D2 = D²PAK
│ ││ └── AC = standard temp grade
│ │└── 12 = -12V output
│ └── 79 = Negative regulator
└── L prefix

Handler Implementation Notes

STM32 Package Extraction (CRITICAL BUG)

Current STHandler has a bug in extractPackageCode():

// WRONG - Tries to match last 2 chars as package+temp
String lastTwo = upperMpn.substring(upperMpn.length() - 2);
// For STM32F103C8T6: lastTwo = "T6"
// Then validates: "TUVRY".indexOf('T') >= 0 && isDigit('6')
// This passes but returns "T6" instead of just "T" (LQFP)

Correct approach:

// STM32F103C8T6 → Package is second-to-last char: "T"
if (upperMpn.startsWith("STM32") && upperMpn.length() >= 2) {
    char packageChar = upperMpn.charAt(upperMpn.length() - 2);
    return switch (packageChar) {
        case 'T' -> "LQFP";
        case 'H' -> "BGA";
        case 'U' -> "VFQFPN";
        case 'Y' -> "WLCSP";
        case 'P' -> "TSSOP";
        default -> String.valueOf(packageChar);
    };
}

MOSFET Package Extraction

// Extract from prefix: STF = TO-220FP, STP = TO-220, STD = DPAK
if (upperMpn.startsWith("STF")) return "TO-220FP";
if (upperMpn.startsWith("STP")) return "TO-220";
if (upperMpn.startsWith("STD")) return "DPAK";
if (upperMpn.startsWith("STB")) return "D2PAK";
if (upperMpn.startsWith("STW")) return "TO-247";

Series Extraction

// STM32F103C8T6 → Series: STM32F103 (or STM32F1)
// For STM32: Extract up to and including line number
if (upperMpn.startsWith("STM32")) {
    // STM32 + Type + Core + Line = STM32F103
    // Match pattern: STM32[A-Z][0-9]{1,3}
    Pattern p = Pattern.compile("^(STM32[A-Z][0-9]{1,3})");
    Matcher m = p.matcher(upperMpn);
    if (m.find()) return m.group(1);
}

Related Files

Handler: manufacturers/STHandler.java
Component types: MICROCONTROLLER_ST, MCU_ST, MOSFET_ST, VOLTAGE_REGULATOR_LINEAR_ST
Test: handlers/STHandlerTest.java (72 tests)

Handler Implementation Learnings (PR #81)

Fixed Issues

All issues discovered during analysis have been fixed:

~~HashSet in getSupportedTypes()~~ - Changed to Set.of()
~~Debug println statements~~ - Removed
~~Package extraction bug~~ - Now returns "LQFP" for STM32, "TO-220" for MOSFETs, etc.
~~Voltage regulator regex broken~~ - Fixed with proper prefix matching

Package Code Extraction (Fixed)

// STM32/STM8: Package is second-to-last character
if (upperMpn.startsWith("STM32") || upperMpn.startsWith("STM8")) {
    char packageChar = upperMpn.charAt(upperMpn.length() - 2);
    return switch (packageChar) {
        case 'T' -> "LQFP";
        case 'H' -> "BGA";
        case 'U' -> "VFQFPN";
        // ...
    };
}

// MOSFETs: Package is in prefix
if (upperMpn.startsWith("STF")) return "TO-220FP";
if (upperMpn.startsWith("STP")) return "TO-220";
// ...

// Voltage regulators: Strip prefix and grade, then match suffix
String suffix = upperMpn.replaceFirst("^[LM]C?7[89]\\d{2}", "")
                       .replaceFirst("^[A-C]{1,2}", "");
// CV → TO-220, D2T → D2PAK, etc.

Cross-Handler Pattern Matching Bug

When handler A's matches() falls through to patterns.matches(mpn, type), it can accidentally match patterns registered by handler B.

Fix in AtmelHandler: Don't fall through to pattern matching for base MICROCONTROLLER type - return false if prefix check fails. This prevents AtmelHandler from matching STM32 MPNs.

Learnings & Edge Cases

STM32 package code is NOT last 2 chars - It's the second-to-last char only
Temperature is the last digit - 6 or 7, not part of package
MOSFET package is in PREFIX - Unlike most components where it's suffix
L78/L79 have multiple suffix styles - CV, V, D2T, DT, etc.
STM32F4 naming differs slightly - Some devices don't follow standard pattern
Pattern registry is shared across handlers - Must use explicit prefix checks for base types to avoid cross-matching

Sources