Skill/references/description_format.md

# Description format (Vecmocon Altium Library SOP)

This is the authoritative rule for the **Description** field the skill writes into a part's
workbook. It has two layers:

1. The **four formats the SOP defines outright** — Resistor, Capacitor, Zener, TVS — from
   *Engineering Data Management — SOP: Component Naming, Mandatory Parameters, and Design Item
   ID Format* (§6). Follow these parameter orders **strictly** (with one house tweak: the
   Zener/TVS prefix uses the generic diode code `ZEN`/`TVS`, not the SOP's `DIO-Z`/`DIO-T` — see
   the note under those two below).
2. A **house extension** that carries the *same basis* to every other type in the library
   (all 125 type-IDs / 18 classes), so no component is left without a Description convention.
   These are built on the SOP pattern and are the working standard; when a specific part
   doesn't fit cleanly, follow the pattern and confirm the token order with the engineer rather
   than inventing something off-pattern.

## The basis (applies to every component)

The Description is **not** a free-form sentence. It is a single string of `_`-joined tokens in
this shape:

```
PREFIX_param1_param2_..._Package_[AECQ-XXX]
```

- **PREFIX** — a short token (or two) naming the sub-family / technology, e.g. `CHIP_RES`,
  `ELE_CAP`, `SCH`, `NMOS`. The per-type prefix is listed for every type below.
- **params** — the part's defining ratings, in the **fixed order** given for that class. Read
  them off the datasheet. If the datasheet is silent on a required token, leave it out and flag
  it — an honest gap beats a guessed value.
- **Package** — the IPC/industry package or case code, near the end (`0402`, `SOD-323`,
  `SOIC-8`, `LQFP-48`, `SMD,D6.3xL5.8mm`, …).
- **AECQ-XXX** — only when the datasheet states automotive qualification (`AECQ-200`,
  `AECQ-101`, `AECQ-100`); it is always the **last** token. Omit entirely if not stated —
  never assume qualification.

Description ≠ Design Item ID ≠ Comment — three different fields that share notation but not
content: **Description** is the strict string here (SOP §6); **Design Item ID** (SOP §2) is a
shorter procurement id (`RES_36kΩ_±0.1%_0402`) — use it only as a guide to token vocabulary,
never put it in the Description column; **Comment** (SOP §4) is always the exact MPN.

## Notation conventions (from the SOP examples)

- **Value / unit** with SOP casing: `36kΩ`, `2.2uF`, `600Ω`, `48MHz`, `10uH`. Use `Ω` for ohms;
  `uF`/`nF`/`pF`, `uH`/`nH`/`mH`, `Hz`/`kHz`/`MHz`, `F` for farads (supercaps). A **range** uses
  `~` (`3.5V~28V`, `5.2V~5.6V`).
- **Power** `62.2mW`, `500mW`, `344W`; **voltage** `100v`, `25V`; **current** `0.25A`, `250mA`.
- **Tolerance** signed percent `±0.1%`, `±10%`.
- **Temperature coefficient** (ceramics) lower-case dielectric class: `x7r`, `c0g`, `x5r`.
- Keep tokens in the same style throughout so descriptions sort and read consistently.

---

# Layer 1 — the four SOP-defined formats (strict)

**Resistor**

```
Type_RES_Value_Wattage_Tolerance_Package_AECQ-XXX(optional)
```

Example: `CHIP_RES_36kΩ_62.2mW_±0.1%_0402`

**Capacitor**

```
Type_CAP_Value_Voltage_Tolerance_Package_TemperatureCoefficient_AECQ-XXX(optional)
```

Example: `CHIP_CAP_2.2uF_100v_±10%_1210_x7r`

**Zener diode**

```
ZEN_VoltageZener(Vz)_Power_Package_AECQ-XXX(optional)
```

**TVS diode**

```
TVS_VoltageBreakdown(Vbr)_VoltageClamping(Vc)_Current(Ip)_Package_AECQ-XXX(optional)
```

**House prefix note:** the SOP §6 wrote these two as `DIO-Z` / `DIO-T`, but Vecmocon
standardised on the **generic diode type code** (`ZEN`, `TVS`, and likewise `SCH`, `ESD`, …) as
the prefix for *all* diodes. So use `ZEN` / `TVS` here — the parameter order (Vz+Power for
Zener; Vbr+Vc+Ip for TVS) is still exactly the SOP's; only the prefix token differs.

---

# Layer 2 — house extension, every other type (same basis)

Each class below gives its **parameter order** (the tokens between prefix and package) and the
**per-type prefix**. Package is always the second-to-last token; optional `AECQ-XXX` is last.

## Resistor  (RES family) — `PREFIX_Value_Power_Tolerance_Package_[AECQ]`

| Type | Prefix | Notes |
|------|--------|-------|
| FIX Thick-film chip | `CHIP_RES` | SOP example; the strict format above |
| TFR Thin-film chip | `TFILM_RES` | precision/low-tempco; may append tempco (ppm) |
| MFR Metal-film | `MFILM_RES` | |
| CFR Carbon-film | `CFILM_RES` | |
| MOR Metal-oxide | `MOX_RES` | high-power leaded |
| WWR Wirewound | `WW_RES` | low-ohm/high-power |
| SHT Current-sense/shunt | `SHUNT_RES` | value in mΩ (e.g. `2mΩ`), power token is the sense power |
| ARR Array/network | `ARR_RES` | add element count/config, e.g. `4x`, before value |
| POT Potentiometer/trimmer | `POT` | `POT_Value_Taper_Power_Package` (taper `LIN`/`LOG`) |
| FSR Fusible/safety | `FUSE_RES` | |
| NTC thermistor | `NTC` | `NTC_R25_Beta_Tolerance_Package` (R25 e.g. `10kΩ`, Beta e.g. `B3950`) |
| PTC thermistor | `PTC` | `PTC_R25_Package` (or trip current/temp if that's the rated spec) |

Example: `SHUNT_RES_2mΩ_1W_±1%_2512` · `NTC_10kΩ_B3950_±1%_0402`

## Capacitor  (CAP family) — `PREFIX_Value_Voltage_Tolerance_Package_[Dielectric]_[AECQ]`

| Type | Prefix | Notes |
|------|--------|-------|
| CER Ceramic MLCC | `CHIP_CAP` | SOP; dielectric token (`x7r`/`c0g`…) required |
| ELE Aluminium electrolytic | `ELE_CAP` | tolerance often omitted; case like `SMD,D6.3xL5.8mm` |
| TAN Tantalum | `TANT_CAP` | |
| PLY Aluminium-polymer | `POLY_CAP` | low-ESR; ESR may follow voltage |
| FLM Film (MKT/MKP) | `FILM_CAP` | |
| SFY Safety Class-X/Y | `SAFETY_CAP` | add safety class token (`X2`/`Y1`) after value |
| SUP Supercapacitor/EDLC | `SUPERCAP` | value in farads, e.g. `1F`; add ESR if rated |

Example: `ELE_CAP_33uF_25V_SMD,D6.3xL5.8mm` · `SUPERCAP_1F_5.5V_RADIAL`

## Inductor / Magnetics — `PREFIX_Value_Current_[DCR]_Package_[AECQ]`

| Type | Prefix | Format detail |
|------|--------|---------------|
| PWR Power inductor | `PWR_IND` | `PWR_IND_L_Isat_DCR_Package` (L e.g. `10uH`, Isat `3A`) |
| FBD Ferrite bead | `FB` | `FB_Impedance@freq_Current_Package` (e.g. `FB_600Ω@100MHz_2A_0603`) |
| CMC Common-mode choke | `CMC` | `CMC_Impedance@freq_Current_Package` |
| RFI RFI choke | `RFI_CHK` | `RFI_CHK_L_Current_Package` |
| XFM Transformer | `XFMR` | `XFMR_Ratio_Power_Package` (ratio e.g. `1:1`) |
| CTX Current transformer | `CT` | `CT_Ratio_Package` (e.g. `1000:1`) |
| CPL Coupled inductor | `CPL_IND` | `CPL_IND_L_Current_Package` |

## Diode — reverse-voltage / current ratings, then package

The prefix is the **generic diode type code (the typeid itself)** — `REC`, `FRD`, `SCH`, `SIC`,
`ZEN`, `TVS`, `ESD`, `SWI`, `BRG`, `LED` — not a `DIO-x` form.

| Type | Prefix | Format |
|------|--------|--------|
| REC Rectifier | `REC` | `REC_Vrrm_Io_Package` |
| FRD Fast-recovery | `FRD` | `FRD_Vrrm_Io_trr_Package` |
| SCH Schottky | `SCH` | `SCH_Vr_Io_Package` |
| SIC SiC Schottky | `SIC` | `SIC_Vr_Io_Package` |
| ZEN Zener | `ZEN` | `ZEN_Vz_Power_Package` |
| TVS TVS | `TVS` | `TVS_Vbr_Vc_Ip_Package` |
| ESD ESD protection | `ESD` | `ESD_Vrwm_Vc_Channels_Package` |
| SWI Switching/small-signal | `SWI` | `SWI_Vr_Io_trr_Package` |
| BRG Bridge rectifier | `BRG` | `BRG_Vrrm_Io_Package` |
| LED Indicator LED | `LED` | `LED_Color_Vf_If_Package` (color e.g. `RED`) |

Example (Schottky BAT46WJ, 100 V / 250 mA): `SCH_100V_0.25A_SOD-323F`

## Transistor — `PREFIX_Voltage_Current_[Rds(on)]_Package_[AECQ]`

The polarity/channel is **folded into the prefix** as a single token (matching the SOP's own
Design Item ID form, e.g. `NMOS_20V_SOT-23`), not carried as a separate `_NCH`/`_PCH` token.

| Type | Prefix | Format |
|------|--------|--------|
| BJT BJT | `BJT_NPN` / `BJT_PNP` | `BJT_NPN_Vceo_Ic_Package` |
| MOS MOSFET (Si) | `NMOS` / `PMOS` | `NMOS_Vds_Id_Rdson_Package` |
| SCM SiC MOSFET | `NSICFET` / `PSICFET` | `NSICFET_Vds_Id_Rdson_Package` |
| GAN GaN FET | `GANFET` | `GANFET_Vds_Id_Rdson_Package` |
| IGBT IGBT | `IGBT` | `IGBT_Vces_Ic_Package` |
| JFET JFET | `NJFET` / `PJFET` | `NJFET_Vds_Idss_Package` |
| DIG Digital/bias-R transistor | `DTR_NPN` / `DTR_PNP` | `DTR_NPN_Vceo_R1/R2_Package` |

Example: `NMOS_20V_6A_15mΩ_SOT-23` · `BJT_NPN_50V_0.1A_SOT-416FL`

## Integrated Circuit (IC) — one line per subtype; package always last (before AECQ)

| Type | Prefix | Format |
|------|--------|--------|
| MCU Microcontroller | `MCU` | `MCU_Core_Flash_Package` (e.g. `MCU_M0+_128Kb_LQFP-48`) |
| LDO LDO regulator | `LDO` | `LDO_Vout_Iout_Package` (`ADJ` if adjustable) |
| DCD DC-DC IC | `DCD` | `DCD_Topology_Vin_Iout_Package` (topology `BUCK`/`BOOST`/`BUCKBOOST`) |
| PMU PMIC | `PMIC` | `PMIC_Rails_Package` |
| BMS BMS AFE | `BMS` | `BMS_Cells_Package` (e.g. `16S`) |
| DRV Gate/motor driver | `DRV` | `DRV_Type_Voltage_Current_Package` (type `GATE`/`MOTOR`/`HB`) |
| AMP Amplifier/op-amp | `AMP` | `AMP_GBW_Channels_Package` |
| CMP Comparator | `CMP` | `CMP_Channels_Package` |
| VRF Voltage reference | `VREF` | `VREF_Voltage_Tolerance_Package` |
| ADC ADC | `ADC` | `ADC_Bits_Rate_Package` |
| DAC DAC | `DAC` | `DAC_Bits_Channels_Package` |
| ISO Isolator/optocoupler | `ISO` | `ISO_Channels_IsolationV_Package` |
| XCV Transceiver | `XCVR` | `XCVR_Bus_Speed_Package` (bus `CAN`/`RS485`; e.g. `XCVR_CAN_5Mbps_SOIC-8`) |
| AFE Analog front end | `AFE` | `AFE_Function_Package` |
| MEM Memory | `MEM` | `MEM_Type_Size_Interface_Package` (e.g. `MEM_FLASH_128Mb_SPI_SOIC-8`) |
| LOG Logic gate | `LOG` | `LOG_Function_Package` (e.g. `AND2`, `BUF`) |
| SEN Sensor IC | `SEN_IC` | `SEN_IC_Type_Package` |
| IFC Interface/expander | `IFC` | `IFC_Function_Package` |
| CLK Clock/RTC | `CLK` | `CLK_Freq_Package` (or `RTC_Package`) |
| SVR Supervisor/reset | `SVR` | `SVR_Threshold_Package` |
| MTR Energy metering | `METER` | `METER_Phases_Package` |

## Protection Device — `PREFIX_ratings_Package`

| Type | Prefix | Format |
|------|--------|--------|
| FUS Fuse | `FUSE` | `FUSE_Current_Voltage_Package` (speed `F`/`T` may precede current) |
| RSF Resettable/PPTC | `PPTC` | `PPTC_Ihold_Voltage_Package` |
| VAR Varistor/MOV | `MOV` | `MOV_Vrms_Energy_Package` |
| GDT Gas-discharge tube | `GDT` | `GDT_Vspark_Package` |
| CBK Circuit breaker | `BREAKER` | `BREAKER_Current_Poles_Package` |

## Power Conversion Module — `PREFIX_Vin_Vout_Power_Package`

| Type | Prefix | Notes |
|------|--------|-------|
| DCM DC-DC module | `DCM` | non-isolated PoL |
| IDC Isolated DC-DC | `IDCM` | isolated brick |
| INV Inverter (DC-AC) | `INV` | `INV_Power_Voltage_Package` |
| OBC On-board charger | `OBC` | `OBC_Power_Voltage_Package` |
| CHG Charger module | `CHG` | `CHG_Power_Voltage_Package` |
| PSU AC-DC SMPS | `PSU` | `PSU_Power_Vout_Package` |
| RCM Rectifier module | `RECT` | `RECT_Current_Voltage_Package` |

## Relay / Contactor — `PREFIX_CoilVoltage_ContactRating_Package`

| Type | Prefix | Notes |
|------|--------|-------|
| RLS Signal relay | `RLY_S` | contact rating e.g. `2A/30V` |
| RLP Power relay | `RLY_P` | |
| SSR Solid-state relay | `SSR` | `SSR_ControlV_LoadRating_Package` |
| RLR Reed relay | `RLY_REED` | |
| CTC Contactor | `CTC` | HV/HC contact rating |

## Switch / Button — `PREFIX_[Positions]_Rating_Package`

| Type | Prefix | Notes |
|------|--------|-------|
| SWT Tactile | `SW_TACT` | rating e.g. `50mA/12V` |
| PBT Push button | `SW_PB` | |
| DSW DIP/slide | `SW_DIP` | positions e.g. `4P` |
| RSW Rocker/toggle | `SW_ROCK` | |
| RSY Rotary | `SW_ROT` | positions e.g. `12POS` |

## Connector — `CON_TYPE_Positions_Pitch_Package`

| Type | Prefix | Notes |
|------|--------|-------|
| CWB Wire-to-board | `CON_W2B` | e.g. `CON_W2B_2x2_P2.0` |
| CBB Board-to-board | `CON_B2B` | |
| HDR Header/socket | `CON_HDR` | pitch e.g. `2.54mm` |
| FFC FFC/FPC | `CON_FFC` | |
| USB USB/data | `CON_USB` | add USB type (`C`, `MICRO`) |
| PWC Power/high-current | `CON_PWR` | add current rating |
| TBK Terminal block | `CON_TB` | |

## Antenna / RF — `PREFIX_Band_Package`

| Type | Prefix | Notes |
|------|--------|-------|
| ANC Chip antenna | `ANT_CHIP` | band e.g. `2.4GHz` |
| ANP PCB/trace antenna | `ANT_PCB` | |
| ANE External/whip | `ANT_EXT` | add connector token |
| SAW SAW filter | `SAW` | `SAW_Freq_Package` |
| RFM RF/wireless module | `RFMOD` | protocol e.g. `BLE`, `WIFI`, `LTE` |

## Crystal / Oscillator / Timing — `PREFIX_Freq_[Load]_Package`

| Type | Prefix | Notes |
|------|--------|-------|
| XTL Crystal | `XTAL` | `XTAL_Freq_LoadCap_Package` (e.g. `XTAL_48MHz_18pF_SMD2016-4P`) |
| OSC Crystal oscillator | `OSC` | `OSC_Freq_Package` |
| MMO MEMS oscillator | `MEMS_OSC` | |
| RSN Ceramic resonator | `RESON` | `RESON_Freq_Package` |

## Battery / Cell — `PREFIX_Capacity_Voltage_Format`

| Type | Prefix | Notes |
|------|--------|-------|
| CLI Li-ion cell | `CELL_LI` | format e.g. `18650`; capacity `2600mAh` |
| CLF LiFePO4 cell | `CELL_LFP` | |
| CCO Coin/button | `CELL_COIN` | add chemistry (`CR`/`LIR`) + size (`2032`) |
| CNI NiMH | `CELL_NIMH` | |
| BPK Battery pack | `PACK` | `PACK_Voltage_Capacity` (e.g. `48V_20Ah`) |
| CHL Cell holder | `HOLDER` | `HOLDER_CellType_Package` |

## Audible / Indicator

| Type | Prefix | Format |
|------|--------|--------|
| BUZ Magnetic buzzer | `BUZ_MAG` | `BUZ_MAG_Voltage_Freq_Package` |
| PBZ Piezo buzzer | `BUZ_PIEZO` | `BUZ_PIEZO_Voltage_Freq_Package` |
| SPK Speaker | `SPK` | `SPK_Power_Impedance_Package` |
| IND Indicator lamp | `IND` | `IND_Color_Voltage_Package` |

## Display / HMI — `PREFIX_Resolution/Digits_Size_Interface`

| Type | Prefix | Notes |
|------|--------|-------|
| DSG 7-segment | `DISP_7SEG` | `DISP_7SEG_Digits_Color_Package` |
| OLE OLED | `DISP_OLED` | resolution e.g. `128x64`, size `0.96in` |
| LCD LCD | `DISP_LCD` | char (`16x2`) or graphic resolution |
| TFT TFT | `DISP_TFT` | resolution + size + interface (`SPI`/`RGB`) |

## Sensor (discrete / module) — `SEN_TYPE_Range_[Interface]_Package`

| Type | Prefix | Notes |
|------|--------|-------|
| STE Temperature | `SEN_TEMP` | range + interface (`I2C`/`ANALOG`) |
| SCU Current (Hall) | `SEN_CURR` | range e.g. `±50A` |
| SVO Voltage/isolated | `SEN_VOLT` | |
| SHA Hall/position | `SEN_HALL` | type (`LATCH`/`LINEAR`) |
| SIM IMU/accel | `SEN_IMU` | axes (`6AXIS`) + interface |
| SPR Pressure | `SEN_PRES` | range + interface |

## Thermal / Cooling

| Type | Prefix | Format |
|------|--------|--------|
| FAN Fan | `FAN` | `FAN_Size_Voltage_Airflow` (size e.g. `40x40mm`) |
| HSK Heatsink | `HSK` | `HSK_Dimensions_ThermalResistance` |
| TPD Thermal pad/TIM | `TIM` | `TIM_Conductivity_Thickness` |

---

## When a part doesn't fit

The Layer-2 formats are the working house standard, but real datasheets vary. If a part is
missing a token the format asks for, leave it out and flag it. If it has a defining rating the
format doesn't capture, add it in the sensible position and **tell the engineer** what you
added so the convention can be updated deliberately. Never silently bend a format — an
inconsistent Description is worse than one confirmed question. The Layer-1 (SOP) formats are
fixed and are not up for reinterpretation.