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.