SS34

40V/3A Schottky diode, DC-DC converter freewheeling/rectifier — MDD (Microdiode Semiconductor) — C8678 — board-b D2 (fitted) — rec-ss34-c8678

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: SS34

Identity

Field	Recorded value
Record ID	`rec-ss34-c8678`
Record kind	standalone
Manufacturer part number	`SS34`
Manufacturer	MDD (Microdiode Semiconductor)
Function	40V/3A Schottky diode, DC-DC converter freewheeling/rectifier
LCSC ID	`C8678`
Package	`SMA_L4.3-W2.6-LS5.2-RD`
Inventory line	`line-c8678`
Also known as	`Schottky diode`

Fit: Fitted

Identity state: VERIFIED

Source state: AVAILABLE

Coverage: 1 open of 3 published

Documents and package

Datasheet PDF

Surface Mount Schottky Barrier Rectifier — SS32 THRU SS3200

Authority: MANUFACTURER_PRIMARY
Availability: AVAILABLE

Footprint preview

Package model

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

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 — Surface Mount Schottky Barrier Rectifier — SS32 THRU SS3200

Selected source ID: src-ss34-datasheet

Authority: MANUFACTURER_PRIMARY

Availability: AVAILABLE

Package footprint: SMA_L4.3-W2.6-LS5.2-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	`D2`

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-ss34-electrical-limits · Status: COVERED

Reason: VRRM (40V), I(AV) (3.0A), VF at 3.0A/25C (0.55V max), and reverse leakage IR at 25C/125C (0.5mA/5mA max) are all primary-source confirmed from the MDD datasheet ratings table for the SS34 column.

Facts in this domain:

fact-ss34-vrrm
fact-ss34-if-avg
fact-ss34-vf
fact-ss34-ir-25c
fact-ss34-ir-125c

inverting-rail-application

Coverage ID: cov-ss34-inverting-rail-application · Status: COVERED

Reason: Historical pre-renewal calculation only: SS34 no longer occupies Board B D3; current D3 is SDT5A60SA-13, and current D2 retains SS34. D3's -13.5V inverting-rail reverse-voltage stress (Vin + |Vout| = 28.5V) leaves an 11.5V margin against the 40V VRRM rating, a smaller but still positive margin than D1/D2's non-inverting Vin-only stress (15V, 25V margin).

Facts in this domain:

fact-ss34-d3-reverse-margin

vf-temperature-derating

Coverage ID: cov-ss34-vf-temperature-derating · Status: OPEN

Reason: The datasheet gives only a single VF@3.0A/TA=25C maximum rating plus a qualitative per-family forward-characteristic curve; no numeric VF-vs-temperature coefficient is tabulated, so a temperature-derated VF value needs bench characterization or curve digitization.

Facts in this domain:

fact-ss34-vf-temp-note

Blocked by: these facts must be resolved before the domain can close. Each is listed in full under Facts.

fact-ss34-vf-temp-note

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-ss34-vrrm

Value: 40 · Unit: V

Conditions: maximum repetitive peak reverse voltage, TA=25C ambient unless otherwise specified

Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC

Evidence: src-ss34-datasheet — Page 1, Maximum Ratings And Electrical Characteristics table, row VRRM, MDD SS34 column

Fact: fact-ss34-if-avg

Value: 3 · Unit: A

Conditions: maximum average forward rectified current at TL (single phase half-wave 60Hz, resistive or inductive load), shared across the SS32-SS3200 family

Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC

Evidence: src-ss34-datasheet — Page 1, Maximum Ratings And Electrical Characteristics table, row I(AV), value spans all columns including MDD SS34

GUARANTEED_ELECTRICAL

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

Fact: fact-ss34-vf

Value: 0.55 · Unit: V

Conditions: maximum instantaneous forward voltage at 3.0A, TA=25C ambient unless otherwise specified

Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC

Evidence: src-ss34-datasheet — Page 1, Maximum Ratings And Electrical Characteristics table, row VF, merged MDD SS32/SS33/SS34 column group (verified against the table's vector gridlines, x=253.7-343.1pt, covering all three column headers)

Fact: fact-ss34-ir-25c

Value: 0.5 · Unit: mA

Conditions: maximum DC reverse leakage current at TA=25C, at rated DC blocking voltage (40V for SS34)

Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC

Evidence: src-ss34-datasheet — Page 1, Maximum Ratings And Electrical Characteristics table, row IR, TA=25C sub-row, merged MDD SS32/SS33/SS34/SS35/SS36 column group (x=253.7-409.1pt gridlines)

Fact: fact-ss34-ir-125c

Value: 5 · Unit: mA

Conditions: maximum DC reverse leakage current at TA=125C, at rated DC blocking voltage (40V for SS34)

Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC

Evidence: src-ss34-datasheet — Page 1, Maximum Ratings And Electrical Characteristics table, row IR, TA=125C sub-row, merged MDD SS32/SS33/SS34/SS35/SS36 column group (x=253.7-409.1pt gridlines)

TYPICAL_CURVE

A representative figure read from a characteristic curve. Typical values are not guaranteed and vary part to part.

Fact: fact-ss34-vf-temp-note

Value: No numeric VF-vs-temperature coefficient is tabulated; the datasheet gives only a single VF@3.0A/TA=25C maximum rating (fact-ss34-vf) plus a qualitative Fig.3 'Typical Forward Characteristic' curve grouped by part family (SS32~SS35 share one curve), not a per-temperature VF curve for SS34 alone. · Unit: NONE

Conditions: forward-voltage dependence on current and temperature beyond the single VF@3.0A/25C rating

Verdict: NEEDS BENCH · Provenance: PRIMARY-SPEC

Evidence: src-ss34-datasheet — Page 2, Fig.3 Typical Forward Characteristic curve (calculated: no digitized numeric value derivable without bench measurement or graph digitization)

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-ss34-manufacturer

Value: MDD (Microdiode Semiconductor) · Unit: NONE

Conditions: exact orderable identity

Verdict: PASS - primary-source confirmed · Provenance: PRIMARY-SPEC

Evidence: src-ss34-datasheet — Page 1, title block http://www.microdiode.com and ratings table column header 'MDD SS34'

Fact: fact-ss34-d3-reverse-margin

Value: 11.5 · Unit: V

Conditions: Historical pre-renewal calculation only: SS34 no longer occupies Board B D3; current D3 is SDT5A60SA-13, and current D2 retains SS34. D3 was the catch/freewheeling diode on the -13.5V LM2596S-ADJ inverting buck-boost rail (board-b dc-dc-conversion stage). Unlike D1/D2 on the non-inverting +13.5V/+7.5V buck rails, whose catch diode blocks only Vin during switch-off, D3's inverting topology reverses the blocking-voltage reference so it blocks Vin + |Vout| = 15V (project PD-negotiated input) + 13.5V (project intermediate rail target) = 28.5V during switch-off. Calculated margin = fact-ss34-vrrm (40V) minus 28.5V stress.

Verdict: PASS - primary-source confirmed · Provenance: CALCULATED

Evidence: src-ss34-datasheet — Calculated from fact-ss34-vrrm and the project's LM2596S-ADJ inverting buck-boost topology for the -13.5V rail (dc-dc-conversion.kicad_sch D3 placement; architecture per CLAUDE.md DC-DC Stage description: '+15V -> -13.5V (LM2596S-ADJ in inverting buck-boost configuration)')

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-ss34-d3-reverse-margin

Expression: fact_ss34_vrrm - (15 + 13.5)

Depends on:

fact-ss34-vrrm

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-ss34-c8678

Symbol: SS34_C8678
Footprint: SMA_L4.3-W2.6-LS5.2-RD
Pins: 2

Pin assignments

Symbol pin	Name	Footprint pad	Function
`1`	`K`	`1`	cathode
`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-ss34-d3-rail-reversal

Records involved: rec-ss34-c8678 (this record)
Conditions: Historical pre-renewal calculation only: SS34 no longer occupies Board B D3; current D3 is SDT5A60SA-13, and current D2 retains SS34. D3 as the -13.5V LM2596S-ADJ inverting buck-boost rail catch diode: reverse-voltage margin against the SS34 VRRM rating
Verdict: PASS - primary-source confirmed

Facts this rests on:

fact-ss34-d3-reverse-margin

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

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.

Surface Mount Schottky Barrier Rectifier — SS32 THRU SS3200

Source ID: src-ss34-datasheet · Authority: MANUFACTURER_PRIMARY

Field	Recorded value
Document number	SS32-SS3200
Revision	2024A5
Document date	2024-09-30
Retrieved	2026-08-14
Printed page	1

Locator: Page 1, title block http://www.microdiode.com Rev:2024A5, and Maximum Ratings And Electrical Characteristics table, MDD SS34 column

Availability: AVAILABLE

Document URL: https://datasheet.lcsc.com/datasheet/pdf/dfa1ff67dea875d0135103ba9ada713a.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
`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.
`PRIMARY-SPEC`	Taken from the manufacturer's own specification document.

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.
`TYPICAL_CURVE`	A representative figure read from a characteristic curve. Typical values are not guaranteed and vary part to part.

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
`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.