Industrial electronics
Explainer
The Buck Converter: Stepping DC Down Efficiently
How do you turn 24 V into 12 V without wasting half as heat?
Quick check · tap an answer to continue
Lesson notes
Key points
- A buck converter is a switch-mode circuit that steps a DC voltage down using a fast switch, a diode, an inductor and a capacitor.
- When the switch is on, the inductor stores energy from the source; when off, the diode freewheels its current into the load.
- In continuous conduction, the ideal output voltage equals the duty cycle multiplied by the input voltage.
- Compared with a linear regulator, which drops excess voltage as heat, the buck converter can reach much higher efficiency.
Definitions
- Buck converter
- A DC-DC switching converter whose output voltage is lower than its input, using a switch, diode, inductor and capacitor.
Takeaway: A buck converter steps DC down: Vout = D × Vin, with little heat.
Quick check: In a buck converter, what component carries load current while the switch is off?
- The input source
- The gate driver
- The diode
When the switch opens, the inductor's current freewheels through the diode to the load.
Buck converterTwo statesVout = D × VinEfficiency
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