Due to the nature of the switching controller with a pulsating input current, a low ESR input capacitor is required for best input-voltage filtering and also for minimizing the interference with other circuits caused by high input-voltage spikes. For the controller, a typical 2.2-µF capacitor can be used for the DRV5V_x_x pin to handle the transients on the driver. For the FET input, 10 µF of input capacitance (after derating) is recommended for most applications. To achieve the low ESR requirement, a ceramic capacitor is recommended. However, the voltage rating and DC-bias characteristic of ceramic capacitors must be considered. For better input-voltage filtering, the input capacitor can be increased without any limit.

TI recommends placing a ceramic capacitor as close as possible to the FET across the respective VSYS and PGND pins of the FETs. The preferred capacitors for the controllers are two Murata GRM21BR61E226ME44: 22-µF, 0805, 25-V, ±20%, or similar capacitors.