# adom-fields 0.9.2

- **Decoupling optimiser (`decapPlan` on each PDN rail).**
  - **The search:** a beam search over sets of up to six new capacitors at the load pin, using MLCC values in 0402, 0603 and 0805 (each at its DC bias) and polymer parts.
  - **Results:** the cheapest set that meets the rail's target impedance, ranked by estimated part cost then board area, and up to five options. When no set can meet it, the set that gets lowest, with the note that the copper's inductance sets the floor.
  - **On a rail that already passes:** the existing capacitors it could lose. The converter's own input and output capacitors are never offered.
  - **Prices and footprints:** typical catalogue values, for ranking.
- **Conducted emissions (`review.conductedEmissions`, `conducted-emissions`).**
  - **The model:** a switching converter's input current pulses split between its input capacitors (at their bias, with ESR and ESL) and any input filter, and into a LISN (50 Ω ∥ 50 µH).
  - **The check:** the voltage per harmonic against CISPR 32 / FCC 15.107 class B quasi-peak (class A with `emcLimit` set to a class-A set), from 150 kHz to 30 MHz, with the spectrum in the report.
  - **The fix:** the input-filter inductor that gains the missing attenuation.
  - **On the TPS54202 buck with no input filter:** 89 dBµV at 500 kHz, 33 dB over class B. A worked hand check gives the same number.
  - **Scope:** differential mode only.