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[Sample] Building a Discrete DC-DC Buck Converter

·electronics·1 min read·Challenge·Week 1·building
#power#analog
Goal

Design, calculate, and assemble a 12V to 5V step-down DC-DC buck converter capable of delivering 2A continuous output.

What I'm learning

[Placeholder] This section explores the fundamental dynamics of LC filter design, duty cycle regulation, and switching losses across varying load profiles.

[Placeholder] Understanding gate drive circuits and how parasitic inductance induces ringing on high-frequency switching nodes.

Build plan

[Placeholder] Phase 1 consists of SPICE simulations to verify inductor ripple currents and capacitor ESR requirements.

[Placeholder] Phase 2 transitions from breadboard prototyping to a dedicated copper perfboard layout with minimized loop area.

Parts list

  • [Placeholder] Power MOSFETs (N-channel logic level)
  • [Placeholder] 47µH shielded power inductor rated for 3A saturation
  • [Placeholder] Low-ESR electrolytic and ceramic decoupling capacitors
  • [Placeholder] Fast recovery Schottky freewheeling diode

Results

[Placeholder] Preliminary breadboard testing shows clean 5V output under a 500mA dummy load with approximately 45mV peak-to-peak ripple.

[Placeholder] Thermal testing and high-current efficiency measurements are ongoing as full load testing progresses.

What I'd change

[Placeholder] Future iterations will incorporate an integrated synchronous rectifier IC rather than discrete drive stages to maximize power conversion efficiency.

[Placeholder] A double-sided custom PCB with continuous ground plane will be designed to curb EMI emissions.