Switching Regulator Efficiency Rechner

Berechnen Sie switching regulator input power und current draw aus output requirements und efficiency.

V
V
A
%

Input Power

7.33 W

Input Current0.611 A
Power Lost0.73 W

Input Power vs Input Voltage

Formel

## Switching Regulator Efficiency ### Formulas **P_in = P_out / Efficiency** **I_in = P_out / (Efficiency x V_in)** Switching regulators convert voltage using rapid switching and an inductor. They achieve 85-95% efficiency regardless of voltage ratio, far better than linear regulators for large step-downs.

Lösungsbeispiel

12 V to 3.3 V at 2 A with 90% efficiency.

  1. 01P_out = 3.3 x 2 = 6.6 W
  2. 02P_in = 6.6 / 0.9 = 7.33 W
  3. 03I_in = 7.33 / 12 = 0.611 A
  4. 04Power lost = 7.33 - 6.6 = 0.73 W

Häufig Gestellte Fragen

Buck vs boost vs buck-boost?

Buck steps voltage down, boost steps up, buck-boost can do either. Choose based on your input vs output voltage relationship.

What affects efficiency?

Switching frequency, inductor DCR, MOSFET Rds(on), diode losses, and controller quiescent current all reduce efficiency.

Why not always use switching regulators?

They generate switching noise (EMI). Linear regulators are preferred for noise-sensitive circuits like ADCs and audio.

Lernen

Ohm's Law Guide

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