SMAJ20A

20 V TVS diode — High Diode — C571370 — board-p D5; board-l D10 — rec-high-diode-smaj20a

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: SMAJ20A

Identity

Record ID: rec-high-diode-smaj20a
Record kind: standalone
Manufacturer part number: SMAJ20A
Manufacturer: High Diode
Function: 20 V TVS diode
LCSC ID: C571370
Package: SMA_L4.2-W2.6-LS5.3-RD
Inventory line: line-c571370
Also known as: VBUS TVS
Owner skill: component-high-diode-smaj20a-c571370
Fit: Fitted
Identity state: VERIFIED
Source state: AVAILABLE
Coverage: 1 open of 6 published

Component references

Selected document

Datasheet PDF

High Diode SMAJ series transient voltage suppressors

Authority: MANUFACTURER_PRIMARY
Availability: AVAILABLE

Footprint preview

Package model

Shared footprint package: SMA_L4.2-W2.6-LS5.3-RD

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.

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-p	`D5`
board-l	`D10`

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.

manufacturer-and-MPN identity

Coverage ID: cov-high-identity
Status: COVERED

Reason: Official High Diode PDF contains the exact SMAJ20A row.

Facts in this domain:

fact-high-diode-smaj20a-manufacturer

exact C571370 distributor binding

Coverage ID: cov-high-orderable
Status: COVERED

Reason: Available stable distributor evidence confirms only the C571370-to-High-Diode-SMAJ20A orderable identity binding.

Facts in this domain:

fact-high-diode-smaj20a-identity

standoff/breakdown/clamp/leakage ratings

Coverage ID: cov-high-ratings
Status: COVERED

Reason: Official exact SMAJ20A row supplies conditioned VRWM, VBR, IR, IPP and VC limits.

Facts in this domain:

fact-high-diode-smaj20a-standoff
fact-high-diode-smaj20a-breakdown
fact-high-diode-smaj20a-clamp
fact-high-diode-smaj20a-leakage

pulse waveform/derating and thermal limits

Coverage ID: cov-high-pulse
Status: COVERED

Reason: Official PDF supplies atomic PPPM and temperature facts plus 10/1000 us waveform and derating context.

Facts in this domain:

fact-high-diode-smaj20a-thermal
fact-high-diode-smaj20a-temperature

polarity marking

Coverage ID: cov-high-polarity
Status: COVERED

Reason: Official PDF states that the device band marks cathode.

Facts in this domain:

fact-high-diode-smaj20a-polarity

project pad mapping and incoming continuity

Coverage ID: cov-high-project-map
Status: OPEN

Reason: Manufacturer marking does not prove numeric pad mapping or as-built D5/D10 orientation/continuity.

Facts in this domain: none are recorded against it.

Blocked by: no blocking fact is recorded. What is missing has not been reduced to a specific recorded fact, so the reason above is the whole of what is known.

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.

GUARANTEED_ELECTRICAL

A parameter the manufacturer guarantees over the stated conditions, usually with minimum, typical and maximum values.

Fact	Value	Unit	Conditions	Verdict	Provenance	Evidence
`fact-high-diode-smaj20a-leakage`	5	`uA`	maximum IR at VRWM 20 V, TA 25 C	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 2 exact SMAJ20A row IR and VRWM columns

TRANSIENT

Behaviour during a short event — startup, a switching edge, a fault or a surge.

Fact	Value	Unit	Conditions	Verdict	Provenance	Evidence
`fact-high-diode-smaj20a-thermal`	400	`W`	400 W peak pulse power at 10/1000 us waveform, TA=25 C, with the page 5 pulse-duration and ambient-temperature derating curves; not the catalog API PD_mW field	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 1 PPPM/temperature features and page 5 waveform/derating figures

THERMAL_SOA

Thermal and safe-operating-area behaviour: how much the part may dissipate, and under what mounting and ambient conditions.

Fact	Value	Unit	Conditions	Verdict	Provenance	Evidence
`fact-high-diode-smaj20a-temperature`	-55 to +150	`C`	operating junction and storage temperature range; pulse derating still applies	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 1 features section operating-junction/storage-temperature row

PROTECTION_STANDOFF

The voltage a protection device is expected to sit at without conducting.

Fact	Value	Unit	Conditions	Verdict	Provenance	Evidence
`fact-high-diode-smaj20a-standoff`	20	`V`	VRWM exact SMAJ20A row at TA 25 C	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 2 exact SMAJ20A row VRWM column

PROTECTION_BREAKDOWN

The voltage at which a protection device begins to conduct.

Fact	Value	Unit	Conditions	Verdict	Provenance	Evidence
`fact-high-diode-smaj20a-breakdown`	22.2 to 24.5	`V`	VBR minimum/maximum at 1 mA, TA 25 C	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 2 exact SMAJ20A row VBR and IT columns

PROTECTION_CLAMP

The voltage a protection device clamps to while conducting its rated surge current.

Fact	Value	Unit	Conditions	Verdict	Provenance	Evidence
`fact-high-diode-smaj20a-clamp`	32.4	`V`	maximum VC at IPP 12.3 A, 10/1000 us waveform, TA 25 C; not a universal rail ceiling	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 2 exact SMAJ20A row VC/IPP and page 5 pulse waveform

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	Value	Unit	Conditions	Verdict	Provenance	Evidence
`fact-high-diode-smaj20a-manufacturer`	High Diode	`NONE`	official High Diode SMAJ family document with exact SMAJ20A row	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 1 title/logo and page 2 SMAJ20A row
`fact-high-diode-smaj20a-identity`	`lcsc`=C571370; `manufacturer`=High Diode; `mpn`=SMAJ20A; `variant`=unidirectional SMA package	`NONE`	stable distributor identity binding to exact C571370; same-name cross-vendor substitution prohibited; supplies no electrical or thermal authority	CONFIRMED - distributor identity only	DISTRIBUTOR-IDENTITY	src-high-diode-c571370: title block and distributor orderable row C571370
`fact-high-diode-smaj20a-polarity`	device band marks cathode	`NONE`	manufacturer marking rule only; project numeric pad mapping and incoming continuity remain open	PASS - primary-source confirmed	PRIMARY-SPEC	src-high-diode-primary: page 1 polarity marking statement and page 6 package figure

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-high-diode-smaj20a

Symbol: SMAJ20A_C571370
Footprint: SMA_L4.2-W2.6-LS5.3-RD
Pins: 2

Pin assignments

Symbol pin	Name	Footprint pad	Function
`1`	`K`	`1`	project cathode/VBUS mapping
`2`	`A`	`2`	project anode/GND mapping

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-high-diode-netlist

Records involved: rec-high-diode-smaj20a (this record)
Conditions: Primary polarity/ratings are retained; assert and continuity-check that D5 and D10 numeric pads place the banded cathode on their VBUS rails and anode on GND before energization
Verdict: NEEDS BENCH

Facts this rests on:

fact-high-diode-smaj20a-polarity
fact-high-diode-smaj20a-standoff
fact-high-diode-smaj20a-clamp

int-high-diode-bench

Records involved: rec-high-diode-smaj20a (this record)
Conditions: Verify reel label/body marking, numeric pad orientation and continuity, leakage/heating, and both Board P and Board L surge waveforms with controlled fixtures; primary table limits do not prove the as-built response
Verdict: NEEDS BENCH

Facts this rests on:

fact-high-diode-smaj20a-identity
fact-high-diode-smaj20a-polarity
fact-high-diode-smaj20a-leakage
fact-high-diode-smaj20a-thermal

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-rail-envelope — rail-envelope — rule verdict: UNSOURCED — Whether every part on the input rail stays inside its own recorded limits across a legal power contract, a mis-contract, and a transient clamp event.

All cross-component rules

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.

LCSC exact C571370 High Diode SMAJ20A mirror

Source ID: src-high-diode-c571370
Document number: C571370
Revision: static mirror
Document date: not stated
Retrieved: 2026-08-02
Authority: DISTRIBUTOR_IDENTITY
Locator: Title block and productCode C571370 exact SMAJ20A row
Printed page: 1
Availability: AVAILABLE
Document URL: https://datasheet.lcsc.com/datasheet/pdf/491c1abda5fbc387430efce58160a2e0.pdf?productCode=C571370

High Diode SMAJ series transient voltage suppressors

Source ID: src-high-diode-primary
Document number: SMAJ series
Revision: 2025-06
Document date: 2025-06-10
Retrieved: 2026-08-02
Authority: MANUFACTURER_PRIMARY
Locator: Page 1 features/polarity and page 2 exact SMAJ20A electrical row; pages 5-6 waveform/package
Printed page: 2
Availability: AVAILABLE
Document URL: http://www.h-diode.com/upload/202506/10/202506100145085933.pdf

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.
`PASS - primary-source confirmed`	Confirmed against the manufacturer's own document for this exact part.

Provenance

Recorded term	What it means
`DISTRIBUTOR-IDENTITY`	Taken from a distributor listing. Identity information only.
`PRIMARY-SPEC`	Taken from the manufacturer's own specification document.

Fact class

Recorded term	What it means
`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.
`THERMAL_SOA`	Thermal and safe-operating-area behaviour: how much the part may dissipate, and under what mounting and ambient conditions.
`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.

Open the owning bundle component-high-diode-smaj20a-c571370