When a bipolar junction transistor is driven into hard saturation, excess charge carriers flood the base region. Storage time measures the interval required to clear these carriers once the input switches off, delaying the actual drop in collector current. Engineers must account for this lag in high-speed switching circuits to prevent timing errors or shoot-through currents.
We're getting too much shoot-through in the half-bridge because the storage time on these bipolars is dragging out past 200 nanoseconds.
Adding a speed-up capacitor across the base resistor provides a transient reverse current spike that actively sweeps out the stored charge, slashing storage time.
Related terms
Turn-off time
The duration required for a switching semiconductor to transition from fully conducting to fully blocking.
Fall time
The duration required for a digital signal to transition from a high state to a low state.
Propagation delay
The time it takes for a logic signal to travel through a gate and change its output state.