Verified calculation capability

MOSFET total loss Calculation Capability

Compose MOSFET loss workspace: device dissipation (conduction + hard-switching + optional Coss/Eoss) plus optional gate-drive and Qrr commutation, with optional Tj = Ta + P_device·Rth. Omitted optional terms are not treated as 0 W. · Electrical · Mosfet

Capability ID electrical.mosfet.total_loss · version 1.1.2

Open calculator REST API MCP Evidence Evidence JSON CVP Manifest Review policy

Model

Device dissipation

Device dissipation: P_device = P_cond + P_sw + P_coss
Associated loss budget: P_total = P_device + P_gate + P_rr
Conduction: P_cond = I² × Rds_Tj × D (D only for on-interval RMS)
Switching: P_sw = ½ × Vds × Id × (tr + tf) × f_sw
Gate-drive: P_gate = Qg × Vdrive × f_sw (not in P_device / Tj)
Coss / Eoss: P_coss = ½ × Coss × Vds² × f_sw or Eoss × f_sw
Qrr commutation: P_rr = Qrr × Vds × f_sw (usually complementary switch)
Junction (optional): Tj_est = Ta + P_device × Rth_JA

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

Symbol	Quantity	Unit	Role
`I`	Conduction current (A). Meaning set by current_basis.	—	input / output
`Rds`	Rds(on) at Tref (Ω). Scale with temperature_model.	—	input / output
`D`	Duty cycle in (0, 1]. Used only for current_basis=on_interval_rms.	—	input / output
`current_basis`	How I is defined. Required. Same contract as electrical.mosfet.conduction_loss v1.2.1+.	—	input / output
`temperature_model`	Optional Rds(Tj). Same contract as electrical.mosfet.conduction_loss: omitted temperature_model infers ratio if rds_ratio is set (ratio wins even when Tj_C is also present), else linear if Tj_C or alpha_per_C is set.	—	input / output
`Tj`	Junction temperature for linear Rds(Tj) (°C).	°C	input
`Tref`	Rds reference temperature (°C). Default 25.	°C	input
`alpha_per`	Linear α (1/°C). Default 0.006 planning.	°C	input
`rds_ratio`	Datasheet Rds(Tj)/Rds(Tref).	—	input / output
`Vds`	Switched drain-source voltage (V).	—	input / output
`Id`	Switched current (A). Often equal to conduction I for rectangular PWM.	—	input / output
`tr`	Effective rise/overlap time (s).	—	input / output
`tf`	Effective fall/overlap time (s).	—	input / output
`f_sw`	Switching frequency (Hz).	—	input / output
`Qg`	Total gate charge (C). Requires Vdrive.	—	input / output
`Vdrive`	Gate-drive voltage (V). Requires Qg.	—	input / output
`coss_model`	Output-capacitance loss. none (default): omit. coss_eq: ½·Coss·Vds²·f. eoss: Eoss·f. Omitting infers eoss if Eoss set, else coss_eq if Coss set.	—	input / output
`Coss`	Equivalent Coss (F) for coss_eq.	—	input / output
`Eoss`	Output switching energy (J) at Vds for eoss.	—	input / output
`Qrr`	Body-diode reverse-recovery charge (C). P_rr = Qrr·Vds·f_sw is commutation loss, usually attributed to the complementary switch — not this MOSFET's junction.	—	input / output
`Ta`	Ambient temperature (°C) for optional Tj estimate.	°C	input / output
`Rth_JA`	Junction-to-ambient thermal resistance (°C/W).	—	input / output
`P_total`	Associated converter loss: P_device + P_gate + P_rr (W). Includes terms not dissipated in this MOSFET die.	W	output
`P_device`	MOSFET device dissipation: P_cond + P_sw + P_coss (W). Used for Tj_est. Excludes gate-drive and Qrr commutation.	W	output
`P_cond`	Conduction loss at Rds_Tj (W).	W	output
`P_sw`	Hard-switching overlap loss (W).	W	output
`P_gate`	Gate-drive power (W). 0 when Qg/Vdrive omitted — see terms_omitted; unknown ≠ 0.	W	output
`P_coss`	Output-capacitance / Eoss loss (W). 0 when omitted — see terms_omitted; unknown ≠ 0.	W	output
`P_rr`	Qrr-related commutation loss Qrr·Vds·f (W). Usually not this die. 0 when omitted — see terms_omitted.	W	output
`V_drop`	I·Rds_Tj at entered conduction current (V).	—	output
`Rds_Tj`	—	—	output
`Tj_est`	Ta + P_device·Rth_JA when both thermal inputs are set.	°C	output
`terms_applied`	Loss terms included in P_total_W.	—	output
`terms_omitted`	Optional terms not entered (unknown ≠ 0). Values remain 0 in P_*_W.	—	output
`terms_in_device`	Terms included in P_device_W / Tj_est.	—	output
`dominant_included`	Largest included term among terms_applied.	—	output
`included_count`	Count of terms_applied (2–5).	—	output

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

Hard-switching linear V/I overlap.
Conduction current_basis contract is identical to electrical.mosfet.conduction_loss.
Coss term is lumped or Eoss-at-Vds — not a Qoss(V) integral.
P_gate is drive-circuit power, not die dissipation.
P_rr is commutation loss, usually not this MOSFET.
Tj_est is steady-state RthJA of P_device only.

Example

One numerical check. The calculator page holds worked steps and FAQ.

I=10, Rds=0.05, current_basis=on_interval_rms, D=0.5, Vds=48, Id=10, tr=50ns, tf=40ns, f_sw=100kHz → P_device_W=4.66

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance. Computational verification is defined by CVP. Supplemental domain review (internal) and named expert review are defined by the Review policy and do not by themselves determine CVP conformance.

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· View Manifest · CVP overview · Specification
Assurance: Engineering
Declared partition coverage: PASS · 4/4 declared partitions (on_interval_rms, dc, with-optional-terms, invalid-domain)
Calculation version: 1.1.2
Verification: 39/39 calculation tests · 7/7 legacy golden · 22/22 legacy boundary · 8/8 legacy property
Production surface contract: 18/18
Versions: Calculation 1.1.2 · CVP protocol 1.0.0-proposed
CVP identity: 8/8 property · digest e1e9664a3ef4
Reference: O1 model · O2 expected_values · O2 numerical_behavior
Interfaces: PASS · UI (SSR) / REST / MCP
ui-ssr is query-result HTML, not a live browser session.
CVP suite: 3/3 golden · 22/22 CVP boundary · 19/19 invalid · 8/8 property · 1/1 cross-interface · 18/18 CVP contract
Supplemental domain review: Internal · Pass · electrical-engineer · CalculatorX electrical review (EE-001) · 2026-08-19
Named expert review: Not performed
Version lock: Supported (409 VERSION_MISMATCH)
Artifact consistency: Build verified · 1.1.2 (workspace artifacts agree)
Review-policy tier: Internally reviewed — catalog token internally_reviewed; supplemental; not CVP status

This calculator CURRENT · Public schema 1.1.2 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

Call this capability

Human page, REST, and MCP share the same engine and calculation_version. Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Reference Calculation Standard — Production surface contract 18/18.

Tool id: mosfet-total-loss
Engine: mosfet-total-loss
REST: POST /api/v1/calc/mosfet-total-loss
MCP: execute_calculation with capability_id: "electrical.mosfet.total_loss"
Agent input schema: Canonical (MCP / Agent)
Output schema: JSON Schema (latest)
Versioned input schema: Immutable pin (1.1.2)
Versioned output schema: Immutable pin (1.1.2)

References

Human-readable sources plus CVP reference evidence classes.

Sources

Infineon — OptiMOS device selection for synchronous rectification — Conduction losses P_cond = I_RMS² × RDS(on)
Texas Instruments SLYT664 — MOSFET power losses and how they affect power-supply efficiency — Conduction, switching, gate, and output capacitance
Texas Instruments SLUA618 — Fundamentals of MOSFET and IGBT Gate Driver Circuits — Gate-drive energy split among driver and gate resistance
Erickson & Maksimović — Fundamentals of Power Electronics — Semiconductor conduction and switching loss

Reference evidence classes: O1 model · O2 expected_values · O2 numerical_behavior

Try with an agent

Inspect this capability via same-origin MCP, then call execute_calculation.

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: inspect_capability' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"electrical.mosfet.total_loss"}}}'

Inspect the trust tier and required assurance level before execution. Pin calculation_version (1.1.2) when reproducibility matters. Full protocol notes: MCP docs.