SMD Code Lookup

Instantly decode SMD markings for resistors, capacitors, diodes, and small-signal transistors. Supports 3/4-digit resistor codes, EIA-96 system, common capacitor codes, and popular SOT-23 markings. Built for repair technicians, PCB reverse engineering, and electronics education.

Quick examples: 1AM 2F K72 VR 01Y 104 A7 R1
100% local decoding – no data uploaded.

Understanding SMD Marking Codes

Surface-mount devices (SMD) use abbreviated alphanumeric codes due to limited space. The SMD Code Lookup tool interprets these markings based on international standards (EIA-96, IEC 60062) and common manufacturer practices. Whether you're repairing a PCB or designing a circuit, rapid decoding of 3-digit, 4-digit, and letter-numeric codes saves hours of searching through datasheets.

Industry Relevance: Over 80% of passive SMD components use standardized marking systems. Our decoder covers resistor codes (E24/E96 series), ceramic capacitor codes (pF/nF/µF), and popular transistor codes used by NXP, ON Semi, and Rohm.

1. 3-Digit & 4-Digit Resistor Code

For resistors, a 3-digit code indicates two significant digits and a multiplier (power of 10). Example: 102 = 10 × 10² = 1000 Ω = 1 kΩ. A 4-digit code uses three significant digits: 1002 = 100 × 10² = 10 kΩ. Tolerance is usually indicated by an extra letter or by the number of digits (EIA-96).

2. EIA-96 High Precision Resistor Code

For 1% tolerance resistors, the EIA-96 system uses a two-digit number (01 to 96) followed by a letter multiplier. Example: 01Y → 01 = 100, Y = ×0.001 → 0.1 Ω. Our lookup table includes all EIA-96 base values and multiplier letters (X, A, B, C, D, E, F, G, H, Y, Z).

3. Capacitor Marking (pF/nF/µF)

Ceramic capacitors often use a 3-digit code in picofarads: 104 = 10 × 10⁴ pF = 100 nF. The third digit represents multiplier. Electrolytic caps may use numeric + voltage code, but our focus is on general-purpose MLCCs.

4. Transistor & Diode SMD Codes (SOT-23 / SOD-123)

Small-signal transistors use a two- or three-character alphanumeric marking (e.g., 1AM = MMBT3904 NPN transistor). Our built-in mapping includes common BJTs, MOSFETs, and diodes from major vendors.

How to Use This SMD Decoder – Step by Step

  1. Locate the marking on the component (may be 2 to 4 characters).
  2. Enter the code into the search box above (case-insensitive).
  3. Click "Lookup Component" or press Enter.
  4. The tool displays component type, value, tolerance, and reference notes.
  5. Use example pills to test and understand different encoding schemes.

Reference Table: Common SMD Code Families

Code Format Example Decoded Value Application
3-digit resistor 472 4.7 kΩ 5% resistors (E24)
4-digit resistor 6802 68 kΩ 1% resistors (E96)
EIA-96 (digit+letter) 68X 49.9 Ω 1% high precision
Capacitor pF code 224 220 nF Ceramic capacitor
Transistor (SOT-23) 2F BC817-25 NPN General purpose transistor
Diode marking W2 BAT54S Schottky Dual diode
Real-world Case Study: Decoding a Power Supply Board

During repair of a switching power supply, a technician finds a burnt SMD component marked "1AM". Using this lookup tool, the code resolves to MMBT3904 (NPN 40V 200mA transistor). Replacement with the correct component restores functionality. Another component marked "47C" decodes to 30.1 kΩ resistor (EIA-96 47C = 30.1 kΩ, 1% tolerance), preventing misreading of a 47 kΩ part.

Accuracy & Limitations – Important Notes

While this tool follows official EIA and IEC standards, some manufacturers use proprietary markings. Always verify against the specific component's datasheet when possible. For uncommon codes, the tool provides a "likely" interpretation based on the most widespread conventions. We continuously update the mapping database from leading brands: Vishay, Panasonic, Murata, Yageo, and Texas Instruments.

The EIA-96 Standard Explained (Expert Section)

The Electronic Industries Alliance (EIA) introduced the EIA-96 system for ±1% tolerance SMD resistors. It uses a two-digit number from 01 to 96 referencing a resistance value from the E96 series, and a multiplier letter: X=0.001, Y=0.01, A=0.1, B=1, C=10, D=100, E=1000, F=10000, G=100000, H=1000000. For example, 68X = 49.9 × 0.001 = 0.0499 Ω (current sense resistor). This encoding maximizes readability on 0603/0402 packages.

Our decoder contains the full E96 value table (01=100, 02=102, 03=105 … 96=976) and all multiplier letters, ensuring accurate decoding for any valid EIA-96 code.

Frequently Asked Questions

SMD means Surface Mount Device – electronic components soldered directly onto PCB surfaces. Their small size requires abbreviated marking codes.

We support most common resistor, capacitor, and popular transistor codes. For highly obscure or custom IC markings, refer to the manufacturer's datasheet. We provide fallback suggestions based on format.

First two digits are significant, third is multiplier (power of 10). Example: 103 = 10,000 Ω = 10 kΩ. For values below 10 Ω, 'R' indicates decimal (e.g., 4R7 = 4.7 Ω).

Typically yes for MLCC capacitors. The standard code yields pF, but we also convert to nF/µF for readability. Electrolytic capacitors often have direct value printing.

Different manufacturers may reuse the same marking for different components. We provide the most common match based on industry usage, and suggest checking the package outline.

Engineered for precision – This SMD Code Lookup tool is developed by getzenquery Tech team. Data sources include IPC-7351, EIA-96 official tables, and cross-referenced manufacturer datasheets (Murata, Yageo, Vishay, Rohm). Updated quarterly to include new standard codes. For corrections or additions, please contact our engineering team.

Last reviewed – April 2026.

References: Vishay SMD Resistor Marking • NXP SMD Code Handbook • IEC 60062