Role of L1 in Buck Regulator

nico

nico

What is @L1 doing in this design?

flux

In this MP2162 buck regulator, L1 is the power inductor of the switching power stage.
What it does:
  • Stores energy when U1’s SW switch turns on, then releases that energy to the output when the switch turns off.
  • Together with the output capacitor C1, it filters the switching waveform at SW into a steady DC output on Net 4 (+1V2).
  • Sets the inductor ripple current and affects transient response and efficiency.
How it’s connected here:
  • L1.P1 is tied to U1 SW on Net 5 (the switching node).
  • L1.P2 goes to Net 4, which is the regulated output rail (+1V2), shared with U1 OUT, C1, and the sense network via R1/R2.
Notable property:
  • Inductance: 1 µH (as set on L1), which is typical for high-frequency, low-voltage buck converters like the MP2162 to balance ripple current and transient performance.
In short: L1 is the main energy storage/filter element that converts the SW node’s pulsed voltage into the smooth +1.2 V output.
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L1
Inductance
1uH
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MP2162 Reference Design

MP2162 Reference Design thumbnail
A power management circuit featuring the MP2162 from Monolithic Power Systems, incorporating inductors, capacitors, and resistors for regulation. #project #referenceDesign #powermanagement #template #reference-design #MP2162 #monolithicpower

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