net.switching

What it is ¶

net.switching(net) yields one row per net whose name reads as a regulator’s power-stage node, meaning a leaf name ending in _SW, _BOOT, _PHASE, or _LX. It is name-derived and is the twin of net.feedback, since both relations name a net that matches the rail vocabulary and is not a rail.

For hardware engineers ¶

The switch node is the point between a buck converter’s high-side and low-side transistors, before the inductor. It does not sit at the output voltage. It slams between ground and the input rail at the switching frequency, and that makes it the highest dV/dt net on most boards. _BOOT is the bootstrap capacitor’s node. It sits on top of the switch node and moves with it, so the high-side gate driver has a supply above the rail it is switching. _PHASE and _LX are the switch node under other vendors’ spellings.

All of them are conventionally named after the rail the converter produces, so a 12V converter’s switch node is 12V_SW and is never at 12V. A review cares about two consequences. Probing one is worse than useless, because a test point there loads the fastest edge in the design and couples it into whatever the probe is attached to. And any rule that reasons about a rail’s voltage will be wrong about this net by the whole input-to-output ratio.

During a review you query net.switching to list the power-stage nodes, and net.rail already leaves it out alongside net.feedback, so a probe-point or decoupling rule does not treat a switch node as ordinary distribution.

For software engineers ¶

A switch node’s name makes it look like a member of an object it does not belong to. 12V_SW reads as a member of the 12V rail, but it is a separate net with a different value. net.switching is a filtered projection over Nets() with the naming predicate, so rows are 1:1 with switching-named nets, and an empty result means no net name matched the power-stage lexicon.

Go projector ¶

switchingFacts in stdlib/relations/facts.go walks Model.Nets() and emits a row for each net carrying the switching role, falling back to Model.IsSwitchingName for a net that skipped the ingestion stamp. The role is stamped by classify.StampNetRoles from the active naming lexicon, so a project extends the patterns in its conventions: section rather than patching the engine. One row per switching-named net; empty when no net matches.

Datalog ¶

List every power-stage node:

net.switching(?n) => ?n

Every supply rail that is neither a sense node nor a power-stage node. A probe-point or pull-up rule may treat this set as ordinary distribution:

net.rail(?n), not net.feedback(?n), not net.switching(?n) => ?n

Note that net.rail already excludes a rail-NAMED net carrying either role, because Model.IsRailNet subtracts them before the rail role is granted. A net marked global or asserted-driven still answers net.rail whatever its name, since Model.IsPowerRail admits those before it consults the name. Write the form above anyway when the query sits beside one that does not go through the rail relation, such as a rule built from the name FFIs.