1. Identify the Reference Topology Requirement
Locate the reference function in the released design and ask the circuit owner to identify its required topology. Keep the complete manufacturer code and the relevant schematic revision available. The purchase description should contain the accepted series or shunt identity where it affects the requirement. A short line headed precision reference can conceal a structural difference that a voltage-only search will not resolve.
Start with the existing approved circuit rather than designing connections from a category description. If the design record uses an internal material code, retain the reference connecting it to the manufacturer device. Where the topology is unclear, name that uncertainty and request the owner's confirmation. The component enquiry can then distinguish a missing identity field from a proposed change in how the reference function is implemented.
State whether the sourcing request allows a topology change. A search for the released device and a search for redesign candidates have different review needs. Preserve the accepted item while the owner considers proposals. This prevents an offer with an appealing reference-voltage description from becoming the purchase baseline before the circuit implications of its topology have been assessed.
2. Preserve Manufacturer Category Examples
TI places LM4040-N within shunt voltage references and describes its reverse-breakdown reference operation. Its REF50 product page belongs to the series-voltage-reference category. These official classifications provide two concrete examples of why topology should have its own field. Keep the examples linked to their named families; a classification is evidence of the category described, not approval for a customer's reference circuit.
For a proposed device, locate its own manufacturer category and applicable product documentation. Record the topology beside its full identity before comparing voltage or other characteristics. If a supplier offers another family under the same general reference heading, ask for the source that identifies its structure. This keeps the component description precise while allowing engineering to consider candidates on a consistent basis.
A category match is an early sorting decision. It tells the reviewer which type of reference has been proposed, while leaving exact operating limits and application conditions to the relevant device evidence. Keep those stages distinguishable. Neither the LM4040-N nor the REF50 classification should be copied into another product's record simply because its nominal reference output appears similar.
3. Retain Load and Supply Questions Separately
Ask the design owner to preserve the supply and load requirements for the existing reference stage. Keep their source, operating context and design revision identifiable. A topology field cannot supply those application inputs. The reviewer needs to know what the stage is required to do before it can determine which exact-device evidence supports the intended use of a proposed reference.
Retain current-direction and headroom questions separately where the owner identifies them as relevant. Record the established requirement and the source needed to assess it; leave an unresolved input open. This gives engineering a focused list without procurement choosing external components or deriving a load allowance from a product category. The source classification and the application requirement should remain clearly attributable to their respective owners.
Supply and load records also help identify what changed between product revisions. If the reference device stays the same while another connected circuit changes, preserve the new operating requirement alongside the old release reference. The engineer can see which assumptions need reconsideration. Matching the original ordering code is useful for identity, but it cannot document that every revised application condition has already been assessed.
4. Keep a Topology Change as an Exception
Treat a proposed change between series and shunt as a visible technical exception. Identify the original topology, candidate topology and the person responsible for reviewing the change. Keep any required circuit work within the engineering proposal rather than folding it into the existing purchase line. A supplier's general description should not replace the released design's documented reference structure.
Record the owner's decision against the exact candidate and applicable design revision. If further supply, load or connection evidence is required, list it with its next action. The topology review can be complete while another field remains unresolved, so avoid collapsing all of the reference questions into a single approval box. This makes the result understandable to both component engineering and purchasing.
For an ICULTRA sourcing enquiry, send the permitted full reference code, quantity and destination, with the accepted topology and any shareable requirement references. Label a topology-changing candidate as a proposal and retain its pending questions. Once the design owner accepts a revised selection, update the controlled requirement before obtaining quotations against it. That record gives subsequent supplier discussions a stable, clearly defined reference identity.
Sources and further reading
Manufacturer documents support the technical guidance above. They do not confirm our stock, authorisation or the condition of any offered lot.