Integration
Cross-component rules — rule-rail-envelope, rule-tvs-clamp-vs-absmax, rule-u4-inverting-stress, rule-ldo-dropout-chain, rule-ab-interface-current, rule-q1-gate-drive-vs-contract, rule-inverting-startup-vs-pd-source, rule-pptc-vmax-vs-rail, rule-evidence-chain — with the records and facts each spans, its conditioned calculations, and what it refuses to conclude.
A component record answers questions about one part. These rules answer the ones that span several — whether a divider built from two resistors keeps a third part inside its own limit, whether a clamp event stays under everything downstream of it. Each rule is projected whole from stored evidence: its conditions, the exact facts it rests on, any conditioned arithmetic, and the exact wording of what it refuses to conclude.
How to read these rules
The refusal is the rule. — Every rule states, in its own words, what may NOT be concluded from the evidence above it. That sentence is the rule's real output; the verdict is shorthand for it.
A verdict belongs to the rule, not to a part. — A rule's verdict says how far the cross-component question has been settled. It is never a judgement about any of the parts the rule names, and the verdicts are never combined into one.
Calculations are conditioned, and the conditions are the point. — Each calculation publishes its expression, its inputs and the exact results that were recorded, together with the conditions under which the answer means anything. A result read without them is arithmetic mistaken for a measurement.
Numbers here were carried, not computed. — The expressions are published so a reader can redo the arithmetic. This page does not evaluate them — the results shown are the ones the evidence recorded.
An evidence chain does not flow downhill. — A stage being settled says nothing about any stage after it. A document confirming a limit is not a measurement of the assembled board.
Rules at a glance
| Rule | Domain | Records | Facts | Verdict |
|---|---|---|---|---|
rule-rail-envelope | rail-envelope | 7 | 15 | NEEDS BENCH |
rule-tvs-clamp-vs-absmax | tvs-clamp-vs-absmax | 7 | 16 | UNSOURCED |
rule-u4-inverting-stress | u4-inverting-stress | 3 | 13 | NEEDS BENCH |
rule-ldo-dropout-chain | ldo-dropout-chain | 3 | 19 | NEEDS BENCH |
rule-ab-interface-current | ab-interface-current | 3 | 7 | NEEDS BENCH |
rule-q1-gate-drive-vs-contract | q1-gate-drive-vs-contract | 4 | 7 | NEEDS BENCH |
rule-inverting-startup-vs-pd-source | inverting-startup-vs-pd-source | 2 | 5 | NEEDS BENCH |
rule-pptc-vmax-vs-rail | pptc-vmax-vs-rail | 6 | 16 | NEEDS BENCH |
rule-evidence-chain | source-to-bench-chain | 4 | 9 | NEEDS BENCH |
rule-rail-envelope
What this rule asks: 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.
Domain: rail-envelope
Verdict: NEEDS BENCH
This rule refuses to conclude: Do not declare any rail voltage correct from setpoint arithmetic; no v4 board has ever reached a negotiated 15 V contract, so every intermediate and output rail remains bench-unproven end to end.
Conditions: Trace the full envelope 15 V PD contract -> +13.5/+7.5/-13.5 V DC-DC intermediates -> +12/+5/-12 V LDO outputs, with the +15 V hop crossing the locked A-to-B J4/J5 interface. Every setpoint is nominal-resistor arithmetic at the 1.23 V typical reference; no v4 board ever completed PD negotiation, so no rail in this envelope has ever been energized from a negotiated contract, and load/line/thermal state remains separate per stage.
Records this rule spans:
rec-stusb4500qtr— STUSB4500QTRrec-usb-type-c-009-c456012— USB-TYPE-C-009rec-lm2596s-adj-c347423— LM2596S-ADJrec-l7812cd2t-c13456— L7812CD2Trec-l7805abd2t-c86206— L7805ABD2Trec-cj7912-c94173— CJ7912rec-jst-b6b-xh-a— B6B-XH-A(LF)(SN)
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-usb-type-c-009-pd-contract-stresson USB-TYPE-C-009fact-stusb-supplieson STUSB4500QTRfact-jst-b6b-xh-a-locked-contracton B6B-XH-A(LF)(SN)fact-lm2596-project-placementson LM2596S-ADJfact-lm2596-vin-projecton LM2596S-ADJfact-lm2596-u2-vout-setpointon LM2596S-ADJfact-lm2596-u3-vout-setpointon LM2596S-ADJfact-lm2596-u4-vout-setpointon LM2596S-ADJfact-lm2596-u4-vout-targeton LM2596S-ADJfact-l7812cd2t-vin-railon L7812CD2Tfact-l7812cd2t-vout-25con L7812CD2Tfact-l7805abd2t-vin-railon L7805ABD2Tfact-l7805abd2t-vout-25con L7805ABD2Tfact-cj7912-rail-inputon CJ7912fact-cj7912-vout-nominalon CJ7912
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-rail-u2-setpoint-error
Expression:
fact_lm2596_u2_vout_setpoint - fact_l7812cd2t_vin_railResult:
error_v
Conditions: nominal U2 feedback-divider setpoint minus the documented +13.5 V rail target at the 1.23 V typical reference; reference tolerance band and load/line regulation excluded
Inputs:
fact-lm2596-u2-vout-setpointon LM2596S-ADJfact-l7812cd2t-vin-railon L7812CD2T
| error_v |
|---|
| 0.02999999999999936 |
calc-rail-u3-setpoint-error
Expression:
fact_lm2596_u3_vout_setpoint - fact_l7805abd2t_vin_railResult:
error_v
Conditions: nominal U3 feedback-divider setpoint minus the documented +7.5 V rail target at the 1.23 V typical reference; reference tolerance band and load/line regulation excluded
Inputs:
fact-lm2596-u3-vout-setpointon LM2596S-ADJfact-l7805abd2t-vin-railon L7805ABD2T
| error_v |
|---|
| 0.0029999999999992255 |
calc-rail-u4-setpoint-error
Expression:
fact_lm2596_u4_vout_setpoint + fact_lm2596_u4_vout_targetResult:
error_v
Conditions: signed nominal U4 inverting setpoint plus the 13.5 V magnitude target: negative result means the negative rail sits slightly deeper than -13.5 V at nominal resistors; reference tolerance band excluded
Inputs:
fact-lm2596-u4-vout-setpointon LM2596S-ADJfact-lm2596-u4-vout-targeton LM2596S-ADJ
| error_v |
|---|
| -0.02999999999999936 |
rule-tvs-clamp-vs-absmax
Domain: tvs-clamp-vs-absmax
Verdict: UNSOURCED
This rule refuses to conclude: Do not clear the TVS protection chain: the STUSB4500 absolute maxima are mirror-only, no installed clamp or surge waveform has been measured, and a clamp event arithmetically exceeds the Q1 VDS rating. TVS2's decision-a replacement (SMAJ6.5A/C87267) resolves the demoted SD05's zero-margin standoff BLOCKER, but the D5-side findings above remain open and the SMAJ6.5A 11.2 V clamp point cannot be cleared while no downstream +5 V absolute maximum is retained.
Conditions: Compare each TVS clamp/standoff against its downstream absolute maxima: D5 SMAJ20A on VBUS_IN clamps at the 32.4 V table point, 4.4 V above the mirror-only 28 V STUSB4500 VDD/VBUS-pin absolute maxima and 2.4 V past the Q1 -30 V VDS rating when the load switch is off with VBUS_OUT near 0 V, but 12.6 V under the LM2596 45 V input rating; D5's 20 V standoff leaves 5 V of margin at the 15 V contract and zero at a 20 V contract; SMAJ15A holds a 3 V / 25 percent standoff margin on the +/-12 V rails while the TVS3 orientation on -12 V is not yet locked; TVS2 (decision a replacement, Brightking SMAJ6.5A/C87267) holds a 1.5 V / 30 percent standoff margin over the +5 V rail, clears the L7805 5.2 V guaranteed upper output band by 1.3 V with its 7.22 V minimum breakdown 2.02 V above that band top, resolving the demoted SD05's zero-margin BLOCKER standoff fact; its 11.2 V maximum clamp at the 35.7 A 10/1000 us table point has no retained downstream +5 V absolute maximum to compare against (the L7805 bundle retains no output-pin absolute maximum, the coverage gap decision a records), so the TVS2 clamp exposure stays unverifiable rather than PASS. All clamp values are 10/1000 us table points, not the installed surge waveform.
Records this rule spans:
rec-high-diode-smaj20a-c571370— SMAJ20Arec-smaj15a-c571368— SMAJ15Arec-cand-smaj6-5a-c87267— SMAJ6.5Arec-stusb4500qtr— STUSB4500QTRrec-lm2596s-adj-c347423— LM2596S-ADJrec-umw-ao3401a-c347476— AO3401Arec-l7805abd2t-c86206— L7805ABD2T
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-high-diode-smaj20a-standoffon SMAJ20Afact-high-diode-smaj20a-clampon SMAJ20Afact-smaj20a-d5-netson SMAJ20Afact-stusb-vdd-absolute-maxon STUSB4500QTRfact-stusb-vbus-pin-absolute-maxon STUSB4500QTRfact-lm2596-vin-absmaxon LM2596S-ADJfact-umw-ao3401a-vdson AO3401Afact-smaj15a-clampon SMAJ15Afact-smaj15a-margin-plus12on SMAJ15Afact-smaj15a-margin-percenton SMAJ15Afact-smaj15a-tvs3-orientationon SMAJ15Afact-cand-smaj6-5a-standoffon SMAJ6.5Afact-cand-smaj6-5a-breakdownon SMAJ6.5Afact-cand-smaj6-5a-clampon SMAJ6.5Afact-cand-smaj6-5a-plus5-marginon SMAJ6.5Afact-l7805abd2t-vout-bandon L7805ABD2T
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-tvs-d5-clamp-vs-stusb-vdd
Expression:
fact_high_diode_smaj20a_clamp - fact_stusb_vdd_absolute_maxResult:
overage_v
Conditions: conditioned subtraction of the mirror-only 28 V STUSB4500 VDD absolute maximum from the SMAJ20A 32.4 V clamp table point; UNSOURCED downstream limit and no claim about the real transient waveform
Inputs:
fact-high-diode-smaj20a-clampon SMAJ20Afact-stusb-vdd-absolute-maxon STUSB4500QTR
| overage_v |
|---|
| 4.399999999999999 |
calc-tvs-d5-clamp-vs-q1-vds
Expression:
fact_high_diode_smaj20a_clamp + fact_umw_ao3401a_vdsResult:
overage_v
Conditions: conditioned magnitude overage above the -30 V Q1 VDS absolute maximum at the 32.4 V clamp table point, for the off-state case where Q1's source rides VBUS_IN while VBUS_OUT sits near 0 V; actual polarity, waveform, and parasitics remain open
Inputs:
fact-high-diode-smaj20a-clampon SMAJ20Afact-umw-ao3401a-vdson AO3401A
| overage_v |
|---|
| 2.3999999999999986 |
calc-tvs-d5-clamp-vs-lm2596-vin-absmax
Expression:
fact_lm2596_vin_absmax - fact_high_diode_smaj20a_clampResult:
margin_v
Conditions: LM2596 45 V absolute-maximum input minus the SMAJ20A clamp table point; positive margin at the table point only, and the clamp event reaches board-b solely through the Q1 load switch and A-to-B interface
Inputs:
fact-lm2596-vin-absmaxon LM2596S-ADJfact-high-diode-smaj20a-clampon SMAJ20A
| margin_v |
|---|
| 12.600000000000001 |
calc-tvs-d5-standoff-vs-pdo
Expression:
fact_high_diode_smaj20a_standoff - vbus_vResult:
margin_v
Conditions: D5 20 V standoff minus the contract VBUS: 5 V of margin at the 15 V contract and zero at a 20 V contract, where the TVS sits at the very edge of its guaranteed non-conducting region with no tolerance for supply overshoot
Inputs:
fact-high-diode-smaj20a-standoffon SMAJ20A
| vbus_v | margin_v |
|---|---|
| 15 | 5 |
| 20 | 0 |
calc-tvs-smaj6-5a-standoff-vs-plus5
Expression:
fact_cand_smaj6_5a_standoff - rail_vResult:
margin_v
Conditions: TVS2 (decision a replacement, SMAJ6.5A/C87267) 6.5 V standoff minus the +5 V rail: 1.5 V margin at the 5.0 V nominal and 1.3 V at rail_v 5.2, the guaranteed upper output band from fact-l7805abd2t-vout-band -- both positive, resolving the demoted SD05's zero/negative margin; deterministic from primary-sourced values
Inputs:
fact-cand-smaj6-5a-standoffon SMAJ6.5Afact-l7805abd2t-vout-bandon L7805ABD2T
| rail_v | margin_v |
|---|---|
| 5 | 1.5 |
| 5.2 | 1.2999999999999998 |
rule-u4-inverting-stress
Domain: u4-inverting-stress
Verdict: NEEDS BENCH
This rule refuses to conclude: Do not treat the nominal 16.47 V absolute-maximum margin as proof: a VBUS clamp event arithmetically exceeds the U4 effective-input rating, and no ringing, startup, or surge waveform has been measured on the inverting stage.
Conditions: U4's GND pin rides at the -13.5 V output, so the device sees VIN plus the output magnitude: 28.53 V nominal against the 40 V operating and 45 V absolute-maximum input ratings. At the SMAJ20A 32.4 V clamp table point the same chain reaches 45.93 V, 0.93 V past the absolute maximum - a conditioned table-point subtraction, not a waveform claim. C9 bridges +15 V to the -13.5 V rail: 28.5 V of applied stress at nominal, leaving 21.5 V of margin to its 50 V rating. Switching-node ringing, startup overshoot, and any real clamp waveform at U4 are unmeasured.
Records this rule spans:
rec-lm2596s-adj-c347423— LM2596S-ADJrec-c970687— RVT1H101M0810rec-high-diode-smaj20a-c571370— SMAJ20A
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-lm2596-u4-inverting-netson LM2596S-ADJfact-lm2596-inverting-topology-supporton LM2596S-ADJfact-lm2596-vin-projecton LM2596S-ADJfact-lm2596-u4-vout-setpoint-magnitudeon LM2596S-ADJfact-lm2596-u4-effective-inputon LM2596S-ADJfact-lm2596-u4-effective-input-setpointon LM2596S-ADJfact-lm2596-vin-absmaxon LM2596S-ADJfact-lm2596-vin-operating-maxon LM2596S-ADJfact-lm2596-u4-absmax-marginon LM2596S-ADJfact-lm2596-u4-operating-marginon LM2596S-ADJfact-c970687-voltageon RVT1H101M0810fact-c970687-topologyon RVT1H101M0810fact-high-diode-smaj20a-clampon SMAJ20A
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-u4-effective-input-envelope
Expression:
vbus_v + fact_lm2596_u4_vout_setpoint_magnitudeResult:
effective_v
Conditions: effective U4 input across the VBUS envelope: 15 V nominal contract, 20 V mis-contract, and the 32.4 V SMAJ20A clamp table point (fact-high-diode-smaj20a-clamp); ideal steady arithmetic on the nominal setpoint magnitude only
Inputs:
fact-lm2596-u4-vout-setpoint-magnitudeon LM2596S-ADJ
| vbus_v | effective_v |
|---|---|
| 15 | 28.53 |
| 20 | 33.53 |
| 32.4 | 45.93 |
calc-u4-absmax-margin-envelope
Expression:
fact_lm2596_vin_absmax - vbus_v - fact_lm2596_u4_vout_setpoint_magnitudeResult:
margin_v
Conditions: margin to the 45 V absolute maximum across the same VBUS envelope; the negative 32.4 V result is a conditioned table-point finding, not a measured transient, and the absolute maximum is not an operating target
Inputs:
fact-lm2596-vin-absmaxon LM2596S-ADJfact-lm2596-u4-vout-setpoint-magnitudeon LM2596S-ADJ
| vbus_v | margin_v |
|---|---|
| 15 | 16.47 |
| 20 | 11.47 |
| 32.4 | -0.9299999999999979 |
calc-u4-c9-bridge-margin
Expression:
fact_c970687_voltage - fact_lm2596_u4_effective_inputResult:
margin_v
Conditions: C9 50 V rating minus the 28.5 V nominal bridge stress between +15 V and the -13.5 V rail; ripple current at 150 kHz and clamp-event stress remain open
Inputs:
fact-c970687-voltageon RVT1H101M0810fact-lm2596-u4-effective-inputon LM2596S-ADJ
| margin_v |
|---|
| 21.5 |
rule-ldo-dropout-chain
Domain: ldo-dropout-chain
Verdict: NEEDS BENCH
This rule refuses to conclude: Do not claim any regulated output at rated load: the +12 V dropout at 1.2 A is unspecified, the +5 V margin is typical-only, and the -12 V regulator operates outside its guaranteed input band, so only bench measurement or a design change can close this chain.
Conditions: Evaluate each LDO's input headroom against its dropout evidence at the project load: L7812 has 1.5 V of headroom from +13.5 V, 0.5 V short of even the 2 V typical 1 A dropout, and DS0422 specifies no dropout at the 1.2 A project rating; L7805 clears its typical dropout by 0.5 V at the 5.0 V nominal output but only 0.3 V at the 5.2 V guaranteed upper band with no guaranteed-maximum dropout, leaving zero guaranteed input margin at 7.5 V; CJ7912's -13.5 V input sits 1.0 V outside its -14.5 to -27 V guaranteed operation band, so its 1.1 V typical dropout is the only evidence it can regulate at all. All three depend on unverified upstream DC-DC setpoints.
Records this rule spans:
rec-l7812cd2t-c13456— L7812CD2Trec-l7805abd2t-c86206— L7805ABD2Trec-cj7912-c94173— CJ7912
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-l7812cd2t-vin-railon L7812CD2Tfact-l7812cd2t-vout-25con L7812CD2Tfact-l7812cd2t-dropout-typ-1aon L7812CD2Tfact-l7812cd2t-dropout-1a2on L7812CD2Tfact-l7812cd2t-iout-ratingon L7812CD2Tfact-l7812cd2t-headroomon L7812CD2Tfact-l7805abd2t-vin-railon L7805ABD2Tfact-l7805abd2t-vout-25con L7805ABD2Tfact-l7805abd2t-vout-bandon L7805ABD2Tfact-l7805abd2t-dropout-typ-1aon L7805ABD2Tfact-l7805abd2t-dropout-05aon L7805ABD2Tfact-l7805abd2t-iout-ratingon L7805ABD2Tfact-l7805abd2t-headroomon L7805ABD2Tfact-cj7912-rail-inputon CJ7912fact-cj7912-vout-nominalon CJ7912fact-cj7912-vi-guarantee-bandon CJ7912fact-cj7912-dropout-typon CJ7912fact-cj7912-rail-headroomon CJ7912fact-cj7912-project-io-maxon CJ7912
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-ldo-7812-typ-dropout-deficit
Expression:
fact_l7812cd2t_vin_rail - fact_l7812cd2t_vout_25c - fact_l7812cd2t_dropout_typ_1aResult:
deficit_v
Conditions: headroom minus the 2 V typical dropout at 1 A: negative means the +13.5 V rail cannot support even typical dropout at the tabulated current, and the 1.2 A project-rated dropout is not specified at all
Inputs:
fact-l7812cd2t-vin-railon L7812CD2Tfact-l7812cd2t-vout-25con L7812CD2Tfact-l7812cd2t-dropout-typ-1aon L7812CD2T
| deficit_v |
|---|
| -0.5 |
calc-ldo-7805-typ-dropout-headroom
Expression:
fact_l7805abd2t_vin_rail - fact_l7805abd2t_vout_25c - fact_l7805abd2t_dropout_typ_1aResult:
headroom_v
Conditions: headroom above the 2 V typical 1 A dropout at the 5.0 V nominal output; shrinks to 0.3 V at the 5.2 V guaranteed upper output band and DS0422 gives no dropout maximum and no 0.5 A dropout row
Inputs:
fact-l7805abd2t-vin-railon L7805ABD2Tfact-l7805abd2t-vout-25con L7805ABD2Tfact-l7805abd2t-dropout-typ-1aon L7805ABD2T
| headroom_v |
|---|
| 0.5 |
calc-ldo-cj7912-guarantee-shortfall
Expression:
fact_cj7912_rail_input - band_min_vResult:
shortfall_v
Conditions: signed distance from the -13.5 V input to the shallow edge of the -14.5 to -27 V guaranteed VI band: a positive result is volts outside guaranteed operation; band_min_v is the shallow band edge from fact-cj7912-vi-guarantee-band
Inputs:
fact-cj7912-rail-inputon CJ7912fact-cj7912-vi-guarantee-bandon CJ7912
| band_min_v | shortfall_v |
|---|---|
| -14.5 | 1 |
rule-ab-interface-current
Domain: ab-interface-current
Verdict: NEEDS BENCH
This rule refuses to conclude: Do not promote the 1.6x derated nameplate margin to an installed-capacity PASS: the harness is unbuilt, the derating factor is assumed rather than measured, and the receptacle carries the same 3 A with zero margin.
Conditions: The locked A-to-B contract carries the full +15 V feed on J4/J5 pins 1-2 with a paired GND return on pins 5-6: two 3 A nameplate XH contacts at 80 percent continuous derating give 4.8 A against the 3.0 A PD-contract cap, a 1.6x derated margin (2.0x nameplate). The same 3.0 A cap is the receptacle's zero-margin mirror rating and flows through Q1 (-4.2 A continuous rating). The mating housing, crimp contacts, and wire gauge are unselected, so no installed harness capacity exists to measure.
Records this rule spans:
rec-jst-b6b-xh-a— B6B-XH-A(LF)(SN)rec-usb-type-c-009-c456012— USB-TYPE-C-009rec-umw-ao3401a-c347476— AO3401A
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-jst-b6b-xh-a-currenton B6B-XH-A(LF)(SN)fact-jst-b6b-xh-a-locked-contracton B6B-XH-A(LF)(SN)fact-jst-b6b-xh-a-current-derating-mathon B6B-XH-A(LF)(SN)fact-jst-b6b-xh-a-harnesson B6B-XH-A(LF)(SN)fact-usb-type-c-009-rating-currenton USB-TYPE-C-009fact-usb-type-c-009-pd-contract-stresson USB-TYPE-C-009fact-umw-ao3401a-currenton AO3401A
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-ab-derated-capacity
Expression:
2 * fact_jst_b6b_xh_a_current * deratingResult:
capacity_a
Conditions: two paired +15 V contacts at the locked 80 percent continuous derating; nameplate catalog rating with an unbuilt harness, not a measured capacity
Inputs:
fact-jst-b6b-xh-a-currenton B6B-XH-A(LF)(SN)
| derating | capacity_a |
|---|---|
| 0.8 | 4.800000000000001 |
calc-ab-derated-margin-ratio
Expression:
2 * fact_jst_b6b_xh_a_current * derating / fact_usb_type_c_009_rating_currentResult:
margin_ratio
Conditions: derated two-contact capacity over the 3.0 A PD-contract worst-case load (the receptacle's own mirror-rated maximum); matches the locked board-split contract arithmetic
Inputs:
fact-jst-b6b-xh-a-currenton B6B-XH-A(LF)(SN)fact-usb-type-c-009-rating-currenton USB-TYPE-C-009
| derating | margin_ratio |
|---|---|
| 0.8 | 1.6000000000000003 |
rule-q1-gate-drive-vs-contract
Domain: q1-gate-drive-vs-contract
Verdict: NEEDS BENCH
This rule refuses to conclude: Do not authorize any 20 V-capable PDO or NVM image while the present gate network arithmetically exceeds the Q1 VGS absolute maximum at 20 V, and do not certify 15 V-only operation without a measured gate waveform.
Conditions: With VBEN asserted low, the R11/R12 divider sets VGS = -VBUS x R11/(R11+R12): -9.62 V at the 15 V contract (2.38 V of margin to the +/-12 V absolute maximum) and -12.82 V at a 20 V contract, 0.82 V past the absolute maximum - the deterministic BLOCKER margin fact that feeds the wave-6 20 V-contract decision. Ideal steady divider only: MOSFET capacitance, the real VBEN waveform, and parasitics remain open, and the absolute maximum is not an operating target.
Records this rule spans:
rec-umw-ao3401a-c347476— AO3401Arec-stusb4500qtr— STUSB4500QTRrec-c25803— 0603WAF1003T5Erec-c23206— 0603WAF5602T5E
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-umw-ao3401a-vgson AO3401Afact-umw-ao3401a-vgs-pdo3-marginon AO3401Afact-umw-ao3401a-gate-networkon AO3401Afact-umw-ao3401a-gate-resistor-valueson AO3401Afact-stusb-gate-networkon STUSB4500QTRfact-c25803-resistanceon 0603WAF1003T5Efact-c23206-resistanceon 0603WAF5602T5E
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-q1-vgs-vben-low
Expression:
-(vbus_v * fact_c25803_resistance) / (fact_c25803_resistance + fact_c23206_resistance)Result:
vgs_v
Conditions: ideal steady gate-source voltage with VBEN held low through R12 56k against the R11 100k pull-up to VBUS; no device or waveform model
Inputs:
fact-c25803-resistanceon 0603WAF1003T5Efact-c23206-resistanceon 0603WAF5602T5E
| vbus_v | vgs_v |
|---|---|
| 15 | -9.615384615384615 |
| 20 | -12.820512820512821 |
calc-q1-vgs-margin-vben-low
Expression:
fact_umw_ao3401a_vgs - vbus_v * fact_c25803_resistance / (fact_c25803_resistance + fact_c23206_resistance)Result:
margin_v
Conditions: magnitude margin to the 12 V VGS absolute maximum; the negative 20 V result reproduces fact-umw-ao3401a-vgs-pdo3-margin and is an ideal-steady finding, not a measured transient
Inputs:
fact-umw-ao3401a-vgson AO3401Afact-c25803-resistanceon 0603WAF1003T5Efact-c23206-resistanceon 0603WAF5602T5E
| vbus_v | margin_v |
|---|---|
| 15 | 2.384615384615385 |
| 20 | -0.8205128205128212 |
rule-inverting-startup-vs-pd-source
Domain: inverting-startup-vs-pd-source
Verdict: NEEDS BENCH
This rule refuses to conclude: Do not assume the -13.5 V stage starts on a compliant 3 A PD source: the documented startup demand exceeds the contract by 1.5 A and only bench startup capture on a current-limited source can prove behavior.
Conditions: The manufacturer documents that U4's inverting startup can draw input current up to the ~4.5 A device current limit for 2 ms or more, 1.5 A beyond the 3.0 A PD-contract cap that the source, receptacle, and A-to-B interface share, and warns that current-limited sources may not start correctly. Whether a real adapter folds back, hard-resets the contract, or rides through on input capacitance is source-dependent; the datasheet's own mitigations (delayed startup, enlarged CIN) are not presently designed in.
Records this rule spans:
rec-lm2596s-adj-c347423— LM2596S-ADJrec-usb-type-c-009-c456012— USB-TYPE-C-009
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-lm2596-inverting-startup-currenton LM2596S-ADJfact-lm2596-current-limiton LM2596S-ADJfact-lm2596-project-placementson LM2596S-ADJfact-usb-type-c-009-rating-currenton USB-TYPE-C-009fact-usb-type-c-009-pd-contract-stresson USB-TYPE-C-009
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-inverting-startup-overdraw
Expression:
fact_lm2596_current_limit - fact_usb_type_c_009_rating_currentResult:
overdraw_a
Conditions: typical device current limit minus the 3.0 A PD-contract cap: the amount by which a >=2 ms inverting startup transient can exceed what the source guarantees; typical limit value, no waveform or source model
Inputs:
fact-lm2596-current-limiton LM2596S-ADJfact-usb-type-c-009-rating-currenton USB-TYPE-C-009
| overdraw_a |
|---|
| 1.5 |
rule-pptc-vmax-vs-rail
Domain: pptc-vmax-vs-rail
Verdict: NEEDS BENCH
This rule refuses to conclude: PTC1's decision-g replacement (SMD1210P150TF/16, C7529589) resolves the deterministic Vmax BLOCKER the demoted part carried, but do not treat this rail as bench-cleared: no 85 C hold-current figure is retained for the /16 variant, the family's derating curve estimates the 1.2 A rail budget could be crossed near ~48 C ambient (decisions.json dec-g-ptc1-replacement), and tripped-state behavior at the real fault waveform remains unmeasured for all three PPTCs.
Conditions: A tripped PPTC absorbs its full rail voltage, so Vmax must cover the rail: PTC1 (decision g replacement, RUILON SMD1210P150TF/16 C7529589, demoting the SMD1210P200TF/C20808) rates 16 VDC on the +12 V rail, +4 V of margin; PTC2 (33 V on +5 V, +28 V) and PTC3 (16 V on -12 V, +4 V) also PASS on voltage. Hold-current margins of 0.3/0.6/0.7 A over the 1.2/0.5/0.8 A rail ratings PASS at 25 C but derate toward 85 C -- PTC1's thinner 0.3 A margin (vs the demoted part's 0.8 A) has no retained 85 C hold figure for the /16 variant, and tripped-state behavior at the real fault waveform is unmeasured for all three.
Records this rule spans:
rec-ptc-smd1210p150tf16-c7529589— SMD1210P150TF/16rec-ptc-msmd110-33v-c70119— mSMD110-33Vrec-ptc-bsmd1206-150-16v-c883133— BSMD1206-150-16Vrec-l7812cd2t-c13456— L7812CD2Trec-l7805abd2t-c86206— L7805ABD2Trec-cj7912-c94173— CJ7912
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-ptc1b-vmaxon SMD1210P150TF/16fact-ptc1b-vmax-marginon SMD1210P150TF/16fact-ptc1b-iholdon SMD1210P150TF/16fact-ptc1b-ihold-marginon SMD1210P150TF/16fact-ptc1b-hold-85con SMD1210P150TF/16fact-ptc2-vmaxon mSMD110-33Vfact-ptc2-vmax-marginon mSMD110-33Vfact-ptc2-iholdon mSMD110-33Vfact-ptc2-ihold-marginon mSMD110-33Vfact-ptc3-vmaxon BSMD1206-150-16Vfact-ptc3-vmax-marginon BSMD1206-150-16Vfact-ptc3-iholdon BSMD1206-150-16Vfact-ptc3-ihold-marginon BSMD1206-150-16Vfact-l7812cd2t-vout-25con L7812CD2Tfact-l7805abd2t-vout-25con L7805ABD2Tfact-cj7912-vout-nominalon CJ7912
Conditioned calculations
Arithmetic across the facts above. The expression and every input are published so the result can be recomputed rather than trusted, and each carries the conditions under which it means anything at all.
calc-pptc1-vmax-margin
Expression:
fact_ptc1b_vmax - fact_l7812cd2t_vout_25cResult:
margin_v
Conditions: PTC1 rated maximum voltage (decision g replacement, SMD1210P150TF/16 C7529589) minus the +12 V rail it protects: the positive result reproduces the bundle's PASS margin fact and holds whenever the fuse trips
Inputs:
fact-ptc1b-vmaxon SMD1210P150TF/16fact-l7812cd2t-vout-25con L7812CD2T
| margin_v |
|---|
| 4 |
calc-pptc2-vmax-margin
Expression:
fact_ptc2_vmax - fact_l7805abd2t_vout_25cResult:
margin_v
Conditions: PTC2 rated maximum voltage minus the +5 V rail; PASS-class margin on voltage only, interrupt rating and fault waveform unexamined here
Inputs:
fact-ptc2-vmaxon mSMD110-33Vfact-l7805abd2t-vout-25con L7805ABD2T
| margin_v |
|---|
| 28 |
calc-pptc3-vmax-margin
Expression:
fact_ptc3_vmax + fact_cj7912_vout_nominalResult:
margin_v
Conditions: PTC3 rated maximum voltage minus the 12 V magnitude of the -12 V rail (signed rail value added); PASS-class margin on voltage only
Inputs:
fact-ptc3-vmaxon BSMD1206-150-16Vfact-cj7912-vout-nominalon CJ7912
| margin_v |
|---|
| 4 |
rule-evidence-chain
What this rule asks: How far each claim has travelled from a manufacturer document towards a measurement on real hardware, stage by stage.
Domain: source-to-bench-chain
Verdict: NEEDS BENCH
This rule refuses to conclude: A completed upstream stage never implies a later as-built, programmed, or measured stage; every downstream stage stays open until the dead v4 boards confirm the diagnosed root cause on the bench.
Conditions: Trace every cross-component claim through official source, conditioned requirement, generated netlist, symbol/footprint, PCB orientation, BOM/CPL identity, as-built inspection, programmed NVM state, and bench evidence. The v4 root-cause diagnosis (CC termination) is netlist-stage evidence only; every stage from PCB orientation through bench is OPEN and the board-split respin is explicitly gated on bench-confirming the root cause on the dead v4 boards.
Records this rule spans:
rec-stusb4500qtr— STUSB4500QTRrec-usb-type-c-009-c456012— USB-TYPE-C-009rec-umw-ao3401a-c347476— AO3401Arec-lm2596s-adj-c347423— LM2596S-ADJ
Facts this rule rests on: each is published in full on the record page that owns it, at the anchor linked here.
fact-stusb-ds12499-primary-attempton STUSB4500QTRfact-umw-ao3401a-vgson AO3401Afact-usb-type-c-009-pd-contract-stresson USB-TYPE-C-009fact-lm2596-inverting-startup-currenton LM2596S-ADJfact-stusb-cc-terminationon STUSB4500QTRfact-umw-ao3401a-gate-networkon AO3401Afact-lm2596-u4-inverting-netson LM2596S-ADJfact-usb-type-c-009-pad-seton USB-TYPE-C-009fact-usb-type-c-009-cc-pinson USB-TYPE-C-009
Conditioned calculations: none are recorded for this rule.
Source-to-bench evidence chain
The stages a claim passes through, in order. A settled stage says nothing about any stage after it: a manufacturer document confirming a limit is not an inspection of the assembled board, and neither is a measurement. A stage with no facts against it is not one nobody got round to filling in: nothing has been established there yet, so the rule's conditions and its refusal above are the whole of what is known about it.
| Stage | Status | Facts at this stage |
|---|---|---|
| official-source | MIXED | fact-stusb-ds12499-primary-attempt on STUSB4500QTR, fact-umw-ao3401a-vgs on AO3401A |
| conditioned-requirement | MIXED | fact-usb-type-c-009-pd-contract-stress on USB-TYPE-C-009, fact-lm2596-inverting-startup-current on LM2596S-ADJ |
| generated-netlist | MIXED | fact-stusb-cc-termination on STUSB4500QTR, fact-umw-ao3401a-gate-network on AO3401A, fact-lm2596-u4-inverting-nets on LM2596S-ADJ |
| symbol-footprint | MIXED | fact-usb-type-c-009-pad-set on USB-TYPE-C-009, fact-usb-type-c-009-cc-pins on USB-TYPE-C-009 |
| pcb-orientation | OPEN | no fact is recorded at this stage |
| bom-cpl | OPEN | no fact is recorded at this stage |
| as-built | OPEN | no fact is recorded at this stage |
| programmed | OPEN | no fact is recorded at this stage |
| bench | OPEN | no fact is recorded at this stage |
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.
Rule 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. |
| UNSOURCED | No accepted source backs this value yet. Treat it as a claim, not a fact. |
Domain
| Recorded term | What it means |
|---|---|
| ab-interface-current | No plain-language description is recorded for this term yet. |
| inverting-startup-vs-pd-source | No plain-language description is recorded for this term yet. |
| ldo-dropout-chain | No plain-language description is recorded for this term yet. |
| pptc-vmax-vs-rail | No plain-language description is recorded for this term yet. |
| q1-gate-drive-vs-contract | No plain-language description is recorded for this term yet. |
| rail-envelope | 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. |
| source-to-bench-chain | How far each claim has travelled from a manufacturer document towards a measurement on real hardware, stage by stage. |
| tvs-clamp-vs-absmax | No plain-language description is recorded for this term yet. |
| u4-inverting-stress | No plain-language description is recorded for this term yet. |
Evidence stage
| Recorded term | What it means |
|---|---|
| as-built | The assembled board has been inspected and matches what was specified. |
| bench | The behaviour has been measured on powered hardware. |
| bom-cpl | The exact orderable part and its placement are confirmed in the assembly files. |
| conditioned-requirement | The claim has been restated as a requirement with the conditions it holds under. |
| generated-netlist | The requirement is reflected in the netlist the project generates. |
| official-source | The claim appears in a document the manufacturer published. |
| pcb-orientation | The part's orientation and pad mapping are confirmed on the board layout. |
| programmed | The device's stored configuration has been written and read back. |
| symbol-footprint | The schematic symbol's pins are mapped onto the footprint's pads. |
Evidence stage status
| Recorded term | What it means |
|---|---|
| MIXED | Some claims at this stage are settled and others are not. It is not a completed stage, and the facts listed against it are the ones that carry it. |
| OPEN | Nothing at this stage has been established yet. A completed earlier stage does not imply it. |
Raw agent resource
These rules are generated from a stored evidence bundle and do 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, so no reciprocal link can be given.