Semiconductor buying guide

How to Read a Semiconductor Part Number Before Ordering

Do not decode an IC number with a universal formula. First identify the manufacturer and the complete orderable code. Then confirm the package, grade, qualification, packing format, lifecycle status, and any designator in the manufacturer’s current ordering information.

The safe ordering rule

Approve the full manufacturer part number or orderable part number—not a family name, package top mark, or distributor SKU. If the BOM, data sheet, package drawing, manufacturer status page, and supplier quote do not agree, stop and resolve the difference before issuing the purchase order.

01 / Identify what the code represents

One component can carry several different identifiers.

Before reading individual letters, decide whether the string came from the approved BOM, a manufacturer page, a package label, the top of the IC, or a distributor database. The same device can look different in each place.

Family or sales name

A product group

Describes a family or functional platform. It may cover several packages, grades, packing formats, or customer-specific versions.

Buyer action: do not order from this level alone.

MPN

Manufacturer part number

The manufacturer’s identifier for the device. In some product lines it is already the exact orderable code; in others, a longer OPN or suffix is still required.

Buyer action: verify it in the official ordering table.

OPN

Orderable part number

The order-specific code tied to attributes such as package, environmental status, packing, size, or a further designator.

Buyer action: quote and approve the complete string.

Top marking

Text printed on the IC

Often shortened because the package has limited space. It may omit parts of the orderable code and include a separate logo or trace code.

Buyer action: use the manufacturer’s marking lookup or data sheet.

Lot and date code

Production trace

Identifies production timing or manufacturing traceability. Its format is manufacturer- and product-specific.

Buyer action: review it as evidence, not as the MPN.

Distributor SKU

A seller’s database key

Useful for a seller’s inventory system, but it is not a substitute for the manufacturer’s exact code.

Buyer action: keep it separate from the approved BOM field.

Use this guide

02 / A repeatable method

Verify the code in four steps.

The goal is not to guess what every character means. The goal is to reach an exact, reviewable ordering identity that engineering, sourcing, quality, and the supplier all understand in the same way.

STEP 01

Identify the manufacturer

Use the logo, approved vendor data, or original design record. A familiar prefix can appear across different brands or acquired product lines.

STEP 02

Copy every character

Record spaces, dashes, slashes, suffixes, and revision characters exactly as shown. Do not normalize the BOM until the official format is known.

STEP 03

Open the official ordering data

Use the manufacturer product page, current data sheet, ordering table, package drawing, marking lookup, and lifecycle page.

STEP 04

Reconcile every document

Compare the approved BOM, supplier quotation, label photo, packing details, and purchase-order line. Escalate any mismatch.

No universal suffix legend exists.

A letter that means “tape and reel” for one manufacturer may mean a package, grade, revision, or nothing similar in another product line. Decode only within the exact manufacturer and device-family documentation.

03 / Order-critical attributes

What can change behind a suffix?

A similar-looking code can still change the physical fit, environmental rating, assembly process, or usable quantity. Treat each suffix as a pointer to official documentation, not as a shortcut.

Attribute What may differ Why the buyer cares Best place to verify
Device function Memory density, channel count, voltage, speed, accuracy, resistance, interface, or firmware option A near-match may power up but fail the required electrical or software behavior. Product data sheet and errata
Package Package family, pins or balls, dimensions, pitch, thermal pad, ball map, lead finish The component may not fit the PCB footprint, stencil, socket, or thermal design. Ordering table and package drawing
Temperature and grade Commercial, industrial, automotive, qualification level, reliability screen The device may not meet the operating environment or customer approval. Ordering table and qualification data
Material and compliance RoHS, halogen status, lead/ball finish, environmental version Assembly profile, compliance records, and customer declarations can change. Material-content or environmental page
Packing Tube, tray, cut tape, tape and reel, reel diameter, standard pack quantity, dry pack The parts may be electrically identical but incompatible with automation or receiving rules. Carrier-pack information and quotation
Designator or revision Customer-specific code, test version, ROM, wafer, temperature, bond-wire, or other change Different designators can be order-relevant even when the visible sales name is unchanged. Product page, PCN, manufacturer support

04 / Read structure, then verify

A code can combine the product name with order details.

Infineon describes its OPN as a sales name plus a five-character suffix. That suffix can describe environmental status, packing type, moisture-protection packing, packing size, and a two-character designator.

This is a useful example because it shows why the sales name alone may be incomplete. It is not a decoder for other manufacturers.

View Infineon’s OPN Guide ↗

SALES NAMEET SA1

Sales name

Identifies the base product or functional device.

Position 1

May encode RoHS, halogen, and lead-free status in this Infineon system.

Positions 2–3

May encode functional packing, moisture protection, and packing size.

Positions 4–5

Designator used to distinguish further order-relevant variants.

Illustrative structure only. Always translate the exact OPN with the current manufacturer table.

05 / Package evidence

A top marking is not always the orderable part number.

Small packages may not have enough space for a full MPN. A manufacturer can use an abbreviated device code plus separate lot, date, assembly-site, or trace symbols. The same short marking may also need the package and pin count to narrow the result.

Use a top marking safely

  • Photograph the entire package, including logo, orientation mark, and every text line.
  • Record package dimensions, pin or ball count, board reference, and application context.
  • Use the manufacturer’s official marking lookup where available.
  • Map the result to a full MPN or OPN, then verify its package drawing and ordering table.
  • Treat lot and date information as traceability evidence, not as the purchase identity.

For example, TI provides a part-marking lookup that can search by the actual package marking or by a TI part number. The result still needs to be checked against the correct package and orderable code.

06 / Release gate

Seven checks before you order an IC.

A decoded string is not the final decision. Close these checks against the actual design and the actual offered stock.

Manufacturer and full MPN/OPN

Confirm every character and the manufacturer’s official formatting. Keep customer part numbers and distributor SKUs in separate fields.

Evidence: approved BOM + official product page + quote

Function and electrical limits

Check the parameters that make the device usable in the circuit: voltage, speed, current, interface, memory, accuracy, power, or other application limits.

Evidence: current data sheet + engineering approval

Package and PCB fit

Verify package code, pin count, dimensions, pitch, exposed pad, ball map, orientation, and lead or ball finish.

Evidence: ordering table + package drawing + footprint

Temperature and qualification

Confirm the required temperature range, automotive or industrial qualification, reliability screen, and customer-program requirements.

Evidence: qualification summary + approved specification

Packing and usable quantity

State tape and reel, tray, tube, cut tape, dry pack, reel size, standard pack quantity, and whether partial packaging is acceptable.

Evidence: carrier-pack data + quotation + packing photo

Lifecycle and change status

Review active, NRND, obsolete, EOL, PCN, PDN, last-time-buy, and date-code requirements against the exact part.

Evidence: manufacturer status page + PCN/PDN record

Traceability and offered-stock evidence

Agree the labels, lot information, photos, documents, inspection scope, exceptions, and release authority that match the sourcing risk.

Evidence: supplier record + inspection report + approval

GO

Release only when the records agree

The BOM, manufacturer information, quote, purchase order, packing label, and receiving record should describe the same approved device.

Decision: release, approve an exception, or stop

07 / A common near-match

The electrical device can be right while the order is still wrong.

Suppose a buyer finds the correct base IC and electrical function, but the offered suffix maps to a different package or carrier format. The result may be unusable even if the silicon performs the same task.

Example scenario

Same family. Different delivery reality.

The approved BOM expects a 16-pin TSSOP supplied on a production reel. The offer describes the same logic function but maps to another package or a tube. It may not match the PCB footprint, pick-and-place feeder, stencil, thermal behavior, or planned production quantity.

Do not assume

That a shared base name guarantees package, grade, finish, or carrier equivalence.

Package drawing, pins, dimensions, lead finish, packing format, SPQ, and assembly process.

Escalate

Any proposed alternate to engineering, quality, and production before supplier confirmation.

Document

The approved complete MPN/OPN and any allowed alternates on the PO and receiving record.

08 / Copyable review block

Send a part number that a supplier can verify.

Paste this block into an RFQ, quote clarification, or internal approval. Remove fields that do not apply, but do not leave order-critical assumptions hidden.

Manufacturer:
Approved manufacturer part number / OPN:
Customer part number (if used):
Required function or key electrical limits:
Package code, pin count, and footprint requirement:
Temperature range / qualification grade:
Required packing format and quantity per pack:
Required quantity and acceptable split:
Target delivery date and destination:
Lifecycle / PCN / date-code requirement:
Allowed alternates and approval authority:
Required labels, photos, traceability, or inspection evidence:
Any prohibited conditions or exceptions:

Before sending

Attach the approved BOM line or manufacturer ordering reference. If the source is only a top marking, attach clear photos and package measurements instead of guessing the full MPN.

09 / Avoidable ordering errors

Five shortcuts that create wrong-part risk.

Ordering from the family name

A family can contain several packages, grades, memory sizes, speeds, and orderable formats.

Dropping the suffix from the BOM

The missing characters may control the package, temperature, environmental condition, reel, or another variant.

Treating the top mark as a full MPN

Short markings often need the manufacturer logo, package, pin count, and official lookup to resolve correctly.

Assuming suffixes translate across brands

Part-number grammar is manufacturer- and product-line-specific. Similar letters do not promise equivalent meaning.

Ignoring carrier and SPQ

The same device in tube, tray, cut tape, or different reel sizes can change production usability and cost.

Approving an alternate without change control

Suffix differences may affect firmware, qualification, package, finish, or lifecycle. Use a documented engineering-equivalency review.

10 / Manufacturer context

Continue with the exact brand and product family.

Use the manufacturer’s current ordering information for the full code, then organize sourcing, evidence, and delivery around the actual offered stock.

Analog · power · embedded

Texas Instruments Solutions

MCU · power · sensing

STMicroelectronics Solutions

Power · automotive · security

Infineon Solutions

DRAM · flash · storage

Micron Solutions

Part number or top marking to review?

Send the exact code before committing the order.

Share the manufacturer, complete visible code, package photos, required quantity, target date, destination, and any qualification or evidence requirement. ICNETS can organize an order-specific sourcing and review response.

  • Full MPN or all visible marking lines
  • Package, pin count, and application context
  • Quantity, date, destination, and packing need
  • Required documents, photos, or inspection evidence

Semiconductor part-number questions

Q: Is there a universal way to decode semiconductor part numbers?

No. Manufacturers and even product families within one manufacturer can use different nomenclature. Identify the brand and exact product line, then use its current data sheet, ordering table, package information, and product page.

Q: Is the number printed on an IC the full MPN?

Not always. Small packages often use abbreviated top markings plus separate lot or date codes. Use the manufacturer’s marking lookup, the package and pin count, and the board context to map the marking to a complete orderable part number.

Q: Does a different suffix always mean a different chip?

A suffix can change the silicon function, but it can also change only the package, grade, environmental status, packing format, reel size, or another order-relevant designator. The exact meaning must be confirmed in official documentation.

Q: Can tape-and-reel and tray versions be substituted?

They may contain the same electrical device, but they are not automatically interchangeable for purchasing or production. Check package identity, orientation, standard pack quantity, moisture protection, feeder or handling needs, and the approved purchase specification.

Q: How do I verify an obsolete or hard-to-find part number?

Confirm the full code against archived manufacturer documentation, package drawings, lifecycle records, PCN or PDN information, and known-good design records. For offered stock, agree the lot, labels, photos, traceability, inspection evidence, and release authority before purchase.

Q: What should be written on the purchase order?

Use the approved full MPN or OPN and include any required manufacturer, package or packing condition, quantity, delivery, qualification, date-code, lifecycle, traceability, inspection, and exception terms. Keep distributor SKUs and internal customer part numbers in separate labeled fields.

Technical references and next steps

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