INTERACTIVE MODEL · PWR-001-ANIMCOMPANION TO THE BUCK PRIMER

Synchronous Buck Converter — Switching States, Live

Duty D 0.40 Speed ×3 exaggerated dead time

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t_ON path: V_IN → Q_HS → L → load t_OFF path: GND → Q_LS → L → load dead time: LS body diode

LIVE WAVEFORMS — SCROLLING, SYNCHRONIZED TO SCHEMATIC

Watch for: the inductor current I_L never stops — it ramps up (slope (V_IN−V_OUT)/L) while Q_HS conducts and ramps down (slope −V_OUT/L) while Q_LS conducts. During dead time both gates are low and current freewheels through the LS body diode, dragging V_SW one diode drop below ground — the small negative notches on the V_SW trace. Move the duty slider: V_SW's average (= V_OUT) tracks D, and ripple peaks at D = 0.5 (ΔI_L ∝ D·(1−D)).