← Block library
⎓

Power Entry

@electrace/power-entry@1.0.0 · CC-BY-4.0
vin 9–18 Viout_max 2 A
The actual schematic inside this block — every part is explained below.

Power Entry

Takes a DC barrel-jack input (9–18 V) and protects everything downstream before handing off a clean VBUS rail and ground.

  • Q1 — a P-channel MOSFET for reverse-polarity protection. Unlike a series diode it drops almost no voltage, so you don't waste headroom or generate heat. The input goes to the drain: at power-up the body diode conducts, the source rises, and with the gate at ground the channel turns fully on (Vgs ≈ −Vin) — shorting out the diode drop. Plug the supply in backwards and both the body diode and the channel block.
  • D1 — a TVS diode that clamps input spikes (plug transients, inductive kicks) before they reach the regulator.
  • C1 — bulk capacitance to hold the rail up through fast current demands.

Exposes: vout (VBUS, 9–18 V, up to 2 A) and gnd.

⚠ The TVS clamps around 33 V — sustained input above ~30 V will cook it. Keep the supply within the rated range.

Exposed nets

●voutout · power · 9–18 V
●gndout · gnd

Inside this block

J1
barrel-2.1mm
DC input jack
Q1
p-fet
blocks reverse polarity without a diode drop
D1
tvs
clamps input voltage spikes
C1
100uF
bulk input hold-up

Limits & gotchas

⚠vin.max 30V — Input TVS clamps ~33 V; sustained input above 30 V will cook it.
Use this block in a real design
Drop it on a canvas, wire it up, and watch the live checks — free, no card.
Start designing →
✦This page is generated from the block's source — the same content powers the editor's explanations and live checks.