SMAJ15A
15V-standoff TVS diode, +12V/-12V output overvoltage protection — High Diode — C571368 — board-b TVS1 (fitted), TVS3 (fitted) — rec-smaj15a-c571368
Generated from the component evidence records — edit the records, not this page.
Everything below is projected from this project's stored component evidence. Values keep the exact wording, conditions, units and verdicts they were recorded with — nothing here is re-typed, corrected, or combined into an overall judgement about the part.
This record in the catalog: SMAJ15A
Identity
| Field | Recorded value |
|---|---|
| Record ID | rec-smaj15a-c571368 |
| Record kind | standalone |
| Manufacturer part number | SMAJ15A |
| Manufacturer | High Diode |
| Function | 15V-standoff TVS diode, +12V/-12V output overvoltage protection |
| LCSC ID | C571368 |
| Package | D-FLAT_L4.3-W2.6-LS5.3-RD |
| Inventory line | line-c571368 |
| Also known as | TVS diode, overvoltage protection |
Fit: Fitted
Identity state: VERIFIED
Source state: AVAILABLE
Coverage: 1 open of 4 published
Documents and package
Footprint preview
D-FLAT_L4.3-W2.6-LS5.3-RD. Open SVGPackage model
Interactive inspection requires JavaScript and WebGL. The package identity remains available in this page.
This geometry represents a shared footprint package and may not exactly match the manufacturer part.
Datasheet PDF — High Diode SMAJ series transient voltage suppressor diodes (SMAG plastic-encapsulate)
Selected source ID: src-smaj15a-hdiode-primary
Authority: MANUFACTURER_PRIMARY
Availability: AVAILABLE
Package footprint: D-FLAT_L4.3-W2.6-LS5.3-RD
This geometry represents a shared footprint package and may not exactly match the manufacturer part.
Placements
Every position this exact line occupies in the as-built design. One line may be placed many times and across more than one board.
| Board | Reference designator |
|---|---|
| board-b | TVS1 |
| board-b | TVS3 |
Coverage
Coverage is stated one domain at a time and is never rolled up. A domain marked open is a question that has not been answered; it is not a finding that the part is unsuitable. A record with no open domains has not thereby been declared safe.
electrical-limits
Coverage ID: cov-smaj15a-electrical-limits · Status: COVERED
Reason: Standoff (15 V), breakdown (16.7-18.5 V at 1 mA), clamp (24.4 V at 16.4 A, 10/1000 us), peak pulse power (400 W), forward surge (40 A), and leakage (5 uA at 15 V) are primary-source confirmed from the exact SMAJ15A row of the High Diode family datasheet.
Facts in this domain:
rail-application
Coverage ID: cov-smaj15a-rail-application · Status: COVERED
Reason: The +/-12 V rail standoff-margin math is recorded as calculated facts (3 V, 25% at nominal). Whether that margin is acceptable under rail tolerance and ripple is explicitly deferred to the review and decision tasks.
Facts in this domain:
distributor-identity
Coverage ID: cov-smaj15a-distributor-identity · Status: COVERED
Reason: Exact orderable C571368 is bound to High Diode SMAJ15A by the dated LCSC product page identity extract.
Facts in this domain:
negative-rail-orientation
Coverage ID: cov-smaj15a-negative-rail-orientation · Status: OPEN
Reason: The board-b generator spec does not exist yet, so TVS3's unidirectional orientation on the -12 V rail cannot be verified against a generated netlist, ERC, or the bench; fact-smaj15a-tvs3-orientation records the open state.
Facts in this domain:
Blocked by: these facts must be resolved before the domain can close. Each is listed in full under Facts.
Facts
Each fact keeps its value, its unit, the conditions it holds under, where it came from and how far it has been confirmed as separate fields, because they are separate claims. A value without its conditions is not the same fact, and a verdict is about the evidence for the value, not about the part.
ABSOLUTE_MAXIMUM
A never-exceed limit. Reaching it may damage the part; it is not an operating target and there is no margin implied by it.
Fact: fact-smaj15a-ifsm
Value: 40 · Unit: A
Conditions: peak forward surge current, 8.3 ms single half sine-wave, unidirectional devices only
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
Evidence: src-smaj15a-hdiode-primary: page 1 absolute maximum ratings table, IFSM row
GUARANTEED_ELECTRICAL
A parameter the manufacturer guarantees over the stated conditions, usually with minimum, typical and maximum values.
Fact: fact-smaj15a-leakage
Value: 5 · Unit: uA
Conditions: maximum reverse leakage IR at VWM 15.0 V, TA=25 C
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
Evidence: src-smaj15a-hdiode-primary: page 2 electrical characteristics table, SMAJ15A row, IR and VWM columns
TRANSIENT
Behaviour during a short event — startup, a switching edge, a fault or a surge.
Fact: fact-smaj15a-pppm
Value: 400 · Unit: W
Conditions: peak pulse power dissipation on the 10/1000 us waveform, TA=25 C, non-repetitive, derated above 25 C per the family derating figure
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
Evidence: src-smaj15a-hdiode-primary: page 1 absolute maximum ratings table, PPPM row
PROTECTION_STANDOFF
The voltage a protection device is expected to sit at without conducting.
Fact: fact-smaj15a-standoff
Value: 15 · Unit: V
Conditions: maximum reverse standoff (working) voltage VWM, exact SMAJ15A row, TA=25 C
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
Evidence: src-smaj15a-hdiode-primary: page 2 electrical characteristics table, SMAJ15A row, VWM column
PROTECTION_BREAKDOWN
The voltage at which a protection device begins to conduct.
Fact: fact-smaj15a-breakdown
Value: 16.7 to 18.5 · Unit: V
Conditions: breakdown voltage VBR minimum/maximum at IT 1.0 mA, TA=25 C
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
PROTECTION_CLAMP
The voltage a protection device clamps to while conducting its rated surge current.
Fact: fact-smaj15a-clamp
Value: 24.4 · Unit: V
Conditions: maximum clamping voltage VC at IPP 16.4 A, 10/1000 us waveform, TA=25 C; not a universal rail ceiling
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
Evidence: src-smaj15a-hdiode-primary: page 2 electrical characteristics table, SMAJ15A row, VC and IPP columns
PROJECT_STATE
A value this project recorded about how the part is used here — a chosen operating point, a net assignment, or a derived figure. Not a manufacturer specification.
Fact: fact-smaj15a-manufacturer
Value: High Diode · Unit: NONE
Conditions: exact orderable identity; document served from the manufacturer domain h-diode.com
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
Fact: fact-smaj15a-identity
Value: lcsc=C571368; manufacturer=High Diode; mpn=SMAJ15A; variant=unidirectional SMA (DO-214AC) tape/reel; LCSC listing stock 1980 units at 2026-08-14 retrieval · Unit: NONE
Conditions: stable distributor identity binding of the exact orderable; same-name cross-vendor substitution prohibited; supplies no electrical or thermal authority. LCSC displays the brand as 'High Diode'. Stock figure inside the variant string is a dated observation.
Verdict: CONFIRMED - distributor identity only · Provenance: DISTRIBUTOR-IDENTITY
Evidence: src-smaj15a-lcsc-identity: product page title row and stock row, retrieved 2026-08-14
Fact: fact-smaj15a-polarity
Value: color band denotes cathode end · Unit: NONE
Conditions: manufacturer marking rule for unidirectional devices; project pad mapping is recorded in the owner pin map
Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC
Evidence: src-smaj15a-hdiode-primary: page 1 mechanical data, polarity statement row
Fact: fact-smaj15a-margin-plus12
Value: 3 · Unit: V
Conditions: standoff margin at nominal rail voltage: TVS1 sits on the +12 V output rail and TVS3 on the -12 V output rail (reverse-biased at 12 V magnitude); margin = VWM 15 V minus the 12 V nominal rail magnitude. Rail tolerance/ripple stress and acceptability are judged by the review and decision tasks, not by this record.
Verdict: PASS - primary-source confirmed · Provenance: CALCULATED
Evidence: src-smaj15a-hdiode-primary — Calculated from fact-smaj15a-standoff and the project +/-12 V output rail definition (board-b TVS1/TVS3 placements, CLAUDE.md output architecture)
Fact: fact-smaj15a-margin-percent
Value: 25 · Unit: %
Conditions: standoff margin as a percentage of the nominal 12 V rail magnitude, for both the +12 V (TVS1) and -12 V (TVS3) placements; 25% margin at nominal, before rail tolerance and ripple. Note: the epic sub-issue text described this as '12 V standoff = 0% margin'; the retained primary datasheet gives VWM 15 V for SMAJ15A, so the deterministic margin at nominal is 25%, recorded here as math only.
Verdict: PASS - primary-source confirmed · Provenance: CALCULATED
Evidence: src-smaj15a-hdiode-primary — Calculated from fact-smaj15a-standoff versus the 12 V nominal rail magnitude (board-b TVS1/TVS3 placements)
Fact: fact-smaj15a-tvs3-orientation
Value: TVS3 unidirectional orientation on the -12 V rail (cathode to 0 V, anode to -12 V) is not yet locked by a generator spec · Unit: NONE
Conditions: current project state: the board-b generator spec does not exist yet, so the -12 V rail orientation of the unidirectional TVS3 cannot be verified against a generated netlist or ERC; requires the schematic-generation wave plus visual/bench review
Verdict: NEEDS BENCH · Provenance: PROJECT-CHOICE
Evidence: src-smaj15a-hdiode-primary — Calculated project state: page 1 polarity marking rule versus the absent board-b generator spec (scripts/schgen/board_b_spec.py)
Calculation dependencies
These values were derived from other recorded facts rather than read from a document. The expression and every input are published so the number can be recomputed instead of trusted. A derived value is never stronger than the weakest fact it depends on.
Fact: fact-smaj15a-margin-plus12
Expression: fact_smaj15a_standoff - 12
Depends on:
Fact: fact-smaj15a-margin-percent
Expression: (fact_smaj15a_standoff - 12) / 12 * 100
Depends on:
Pin maps
The mapping between schematic pins and PCB pads, or physical terminals for an external part, as recorded. A record may carry more than one map when the same part is documented in more than one context.
pinmap-smaj15a-c571368
Symbol:
SMAJ15A_C571368Footprint:
D-FLAT_L4.3-W2.6-LS5.3-RDPins: 2
Pin assignments
| Symbol pin | Name | Footprint pad | Function |
|---|---|---|---|
1 | C | 1 | cathode (color band end) |
2 | A | 2 | anode |
Interactions
Behaviour that is not a property of this part alone. Each interaction names the records it spans, the conditions it holds under, and how far it has been confirmed. An interaction that spans several parts appears on every one of their pages, under the same identifier, because it is equally a fact about each.
int-smaj15a-rail-margin
Records involved:
rec-smaj15a-c571368(this record)Conditions: TVS1 (+12 V rail) and TVS3 (-12 V rail) standoff margin against the SMAJ15A 15 V standoff rating at nominal rail voltage; acceptability under tolerance/ripple is deferred to the review and decision tasks
Verdict: PASS - primary-source confirmed
Facts this rests on:
Cross-component rules
Rules that span several parts at once and are published in full on the integration page. Each rule's verdict below is that rule's own — it is a statement about the cross-component question, not about this part — and the exact wording of what the rule refuses to conclude is published with the rule itself.
rule-tvs-clamp-vs-absmax— tvs-clamp-vs-absmax — rule verdict: UNSOURCED
Sources
Every document cited above, with its identification, when it was retrieved, and what kind of authority it carries. Sources that could not be retrieved are listed too, with their unavailability stated, so a gap in the evidence is visible rather than absent.
High Diode SMAJ series transient voltage suppressor diodes (SMAG plastic-encapsulate)
Source ID: src-smaj15a-hdiode-primary · Authority: MANUFACTURER_PRIMARY
| Field | Recorded value |
|---|---|
| Document number | SMAJ series |
| Revision | 2025-06 site upload |
| Document date | 2025-06-10 |
| Retrieved | 2026-08-14 |
| Printed page | 2 |
Locator: Page 1 features/absolute-maximum table (PPPM 400 W at 10/1000 us, IFSM 40 A, TJ -55 to +150 C, 'Polarity: Color band denotes cathode end') and page 2 electrical characteristics table, exact SMAJ15A row
Availability: AVAILABLE
Document URL: http:
LCSC product page C571368 — SMAJ15A | TVS Diodes | High Diode | LCSC
Source ID: src-smaj15a-lcsc-identity · Authority: DISTRIBUTOR_IDENTITY
| Field | Recorded value |
|---|---|
| Document number | C571368 |
| Revision | volatile web page (as retrieved) |
| Document date | 2026-08-14 |
| Retrieved | 2026-08-14 |
| Printed page | 1 |
Locator: Product page title row 'SMAJ15A | TVS Diodes | High Diode | LCSC' and the stock row (1,980 in stock), retrieved 2026-08-14
Availability: AVAILABLE
Document URL: https:
Legend
What the recorded terms on this page mean, in ordinary words. The exact terms above are the ones that count; these descriptions explain them and never replace them.
Verdict
| Recorded term | What it means |
|---|---|
CONFIRMED - distributor identity only | A distributor listing confirms which part this is, and nothing more. It carries no electrical, thermal or lifetime authority. |
NEEDS BENCH | Cannot be settled from documents. It needs measurement on real hardware before it can be relied on. |
PASS - primary-source confirmed | Confirmed against the manufacturer's own document for this exact part. |
Provenance
| Recorded term | What it means |
|---|---|
CALCULATED | Derived arithmetically from other facts listed here. The expression and every input are shown, so the number can be recomputed rather than trusted. |
DISTRIBUTOR-IDENTITY | Taken from a distributor listing. Identity information only. |
PRIMARY-SPEC | Taken from the manufacturer's own specification document. |
PROJECT-CHOICE | A decision made by this project. No vendor asserts it. |
Fact class
| Recorded term | What it means |
|---|---|
ABSOLUTE_MAXIMUM | A never-exceed limit. Reaching it may damage the part; it is not an operating target and there is no margin implied by it. |
GUARANTEED_ELECTRICAL | A parameter the manufacturer guarantees over the stated conditions, usually with minimum, typical and maximum values. |
PROJECT_STATE | A value this project recorded about how the part is used here — a chosen operating point, a net assignment, or a derived figure. Not a manufacturer specification. |
PROTECTION_BREAKDOWN | The voltage at which a protection device begins to conduct. |
PROTECTION_CLAMP | The voltage a protection device clamps to while conducting its rated surge current. |
PROTECTION_STANDOFF | The voltage a protection device is expected to sit at without conducting. |
TRANSIENT | Behaviour during a short event — startup, a switching edge, a fault or a surge. |
Coverage status
| Recorded term | What it means |
|---|---|
COVERED | Every question this domain asks is answered by the facts listed against it. |
OPEN | Unresolved. Open means the question has not been answered, not that the part is unsafe — the reason states what is missing. |
Source availability
| Recorded term | What it means |
|---|---|
AVAILABLE | The document was retrieved and is on record. |
Source authority
| Recorded term | What it means |
|---|---|
DISTRIBUTOR_IDENTITY | A distributor listing. Establishes which part this is, nothing more. |
MANUFACTURER_PRIMARY | The manufacturer's own document for this exact part. |
Identity state
| Recorded term | What it means |
|---|---|
VERIFIED | The exact orderable part has been confirmed against a source. |
Source state
| Recorded term | What it means |
|---|---|
AVAILABLE | At least one document backing this line was retrieved. |
Unit
| Recorded term | What it means |
|---|---|
NONE | The value is not a physical quantity, so it carries no unit. Recorded as `NONE`. |
Raw agent resource
This page is generated from a stored evidence bundle and does not restate it. The bundle is the source of truth: where the two ever disagree, the bundle is right and this page is stale.
No owning bundle is identified in the published model.