BOM Cross-Check: What to Send, What Comes Back, and Where Qualification Stops
A BOM cross-check returns a grade, the disclosed differences and the manufacturer evidence behind each line - not a price, a stock figure or a delivery date. Here are the inputs that make a line checkable, the format you get back, and the exact point where our research stops and your engineering validation starts.
A BOM cross-check takes each line of your bill of materials and returns what is provable about an alternative for that exact part number: a compatibility grade, the disclosed differences, and the manufacturer evidence behind it. What it does not return is a price, a stock figure or a delivery date - those are quote-only facts. This guide shows what to send, what comes back, and the exact point where our research stops and your engineering validation starts.
What "covered" means in this database
Three different things get called coverage, and they are not interchangeable:
- Parameter coverage - we hold the manufacturer's electrical and package data for the part.
- Document coverage - the manufacturer document itself is archived and can be cited back to you.
- Graded cross-reference coverage - a named target PN is mapped to a named alternative with a grade, disclosed differences and an evidence source.
Only the third one supports a compatibility statement. Every mapped alternative carries one of four grades:
| Grade | What it claims | Evidence it requires |
|---|---|---|
| P2P | Pin-to-pin mapping documented by the manufacturer | Manufacturer cross-reference or datasheet naming both parts |
| PIN | Pin-compatible, but the design may need porting | Manufacturer documentation plus a disclosed difference list |
| FUNC | Functionally equivalent; board or firmware changes expected | Documented parameter comparison |
| REF | Parameter-close only - a research lead, not a compatibility claim | Parameter data, with no compatibility claim attached |
For the longer version of how grades are assigned, /guides/how-to-qualify-chinese-mcu-alternative walks through the qualification sequence, and /guides/pin-compatible-vs-drop-in-compatible separates the two terms buyers most often confuse.
The six inputs that decide whether a line is checkable
A cross-check is only as precise as the line you send. These six fields decide whether an answer comes back specific or hedged:
| Input | Why it decides the answer | If it is missing |
|---|---|---|
| Full orderable PN | Suffix, package code and temperature grade change the pinout, the electrical limits and which documents apply | The line comes back flagged as needing the full PN instead of being guessed from the family |
| Package and footprint | Two parts can share a PN stem and differ by package; the footprint is what your board actually accepts | Any candidate comes back marked provisional |
| Quantity band | Compatibility does not depend on volume, but sourcing routes and commercial terms do | The engineering answer stands; the commercial part waits |
| Function on the board | Knowing what the part does (rail, interface, timing, protection) tells us which parameters are actually tight | The review defaults to a full datasheet comparison, which is slower |
| Flexibility on package | Some lines have a pin-compatible candidate only in a different package | Package-sensitive lines are held back rather than answered loosely |
| Destination, end user, end use | Screening applies before any commercial commitment; restricted destinations and military or dual-use end uses are refused | The line is paused for human review rather than quoted |
Worked example: the same part number from a second vendor
The easiest class of cross-reference to verify is one where two manufacturers publish the same generic part number. In the current live cross-reference set, the comparator LM2903 maps to a 3PEAK LM2903 at grade P2P, with no differences disclosed and the manufacturer datasheet as the cited evidence. LM211 and LM2901 are graded the same way. Both records are visible in the catalog at /products, and the datasheet behind the grade is archived as evidence.
That pattern is common in long-lived analog parts, where several vendors have produced the same number for decades. It is also the case most likely to be over-read. A matching part number is documentation, not a waiver: grade P2P still means we hand you the datasheet and the difference list, and you confirm suffix, package, pinout and electrical limits before anything goes into a build.
For MCU-class lines the alternative usually carries a different part number and the differences are structural - core, memory map, peripherals, firmware - which is a different review entirely. /guides/how-to-read-a-migration-guide-before-replacing-an-mcu covers that reading process; /guides/spi-nor-replacement-checklist covers the flash equivalent, where status registers and programmer support decide the outcome.
What comes back, line by line
Every line in your file gets the same output shape, whether or not a candidate exists:
| Field | What it contains |
|---|---|
| Target PN | The exact part number you supplied, unmodified |
| Candidate | Brand and part number from the live catalog |
| Grade | P2P, PIN, FUNC or REF |
| Disclosed differences | A list, or an explicit "none disclosed" |
| Evidence | Link to the manufacturer document the grade rests on |
| Data status | Whether the record is manufacturer-master or thinner |
| To verify before adoption | Suffix, package, pinout, electrical limits, firmware and peripherals |
Deliberately absent from that output: price, MOQ, stock, lead time, delivery date, sample terms and warranty. Those become facts only in a quotation for the exact part number and quantity, and they are never carried over from an article, a previous email or a standard list. /guides/how-procurement-should-document-approved-second-source shows how to file the engineering record and the commercial record as two separate documents.
Lines that come back empty - and why that is the useful answer
Some lines have no graded, evidence-backed cross-reference in the catalog. When that happens, the response says so and offers a BOM review instead of a name. Inventing a candidate from family similarity - "it is an STM32F1, so any Cortex-M part will do" - is the most expensive failure mode in this process, because the mistake surfaces in production rather than at quotation.
For one family you can inspect the underlying records yourself: the STM32F1 cross-reference dataset is published under CC BY 4.0 at github.com/Woolis182/senneon-stm32f1-xref. If a line you need is not covered there, that is a research request, not a rejection.
How to send one
- Export one row per unique orderable part number. Collapse duplicates, but keep the reference designators.
- Add package, quantity band, and destination.
- Mark lines you have already qualified or already rejected, so settled decisions are not reopened.
- Send it through /rfq. A plain list in the message body is fine - no template required.
- Expect triage first, then a graded line-by-line result, then commercial terms only for the lines you choose to pursue.
If your question is a single part number rather than a whole board, /contact with the full PN is enough to start.
Where our work stops
A grade is a research result, not an approval. Three limits apply to everything above:
- Independent supplier. Senneon is not an authorized distributor for any referenced manufacturer, and nothing in a cross-reference result implies affiliation or endorsement.
- Validation is yours. A grade narrows the review; it does not perform it. Final fitness is confirmed on your board, with your firmware, under your temperature and EMC conditions.
- Traceability is separate. Provenance, date codes, inspection documents and warranty terms belong to the specific order and its documents, not to the compatibility research. /guides/incoming-inspection-traceability-semiconductor-sourcing and /verification cover what can be evidenced and how it is checked.
What we hold, and the rules behind it, are listed at /products and /guides.
Frequently asked questions
Can you cross-check a BOM line if I only have the family name?
No. A family prefix cannot be mapped to a candidate. Give the full orderable part number including suffix, package code and temperature grade; without it the line comes back flagged as needing the full PN rather than being guessed from the family.
Does a BOM cross-check include pricing, MOQ or stock?
No. The cross-check returns a compatibility grade, the disclosed differences and the manufacturer evidence. Price, MOQ, stock, lead time, sample terms and warranty are confirmed only in a quotation for the exact part number and quantity.
What happens if there is no alternative for one of my lines?
The response says so explicitly and offers a BOM review or a targeted research request instead of a name. Naming a substitute from family similarity alone is not something we do, because that error surfaces in production rather than at quotation.